Preliminary comparison of sertraline levels in postbariatric surgery patients versus matched nonsurgical cohort

Medication and supplement pharmacokinetic changes following bariatric surgery: A systematic review and meta-analysis

OBJECTIVES

To evaluate the impact of bariatric surgery on the pharmacokinetic (PK) parameters of orally administered medications and supplements.

METHODS

Systematic searches of bibliographic databases were conducted to identify studies. Pooled effect estimates from different surgical procedures were calculated using a random-effects model.

RESULTS

Quantitative data were synthesized from 58 studies including a total of 1985 participants. Whilst 40 medications and 6 supplements were evaluated across these studies, heterogeneity and missing information reduced the scope of the meta-analysis to the following medications and supplements: atorvastatin, paracetamol, omeprazole, midazolam, vitamin D, calcium, zinc, and iron supplements. There were no significant differences in PK parameters post-surgery for the drugs atorvastatin and omeprazole, and supplements calcium, ferritin, and zinc supplements. Paracetamol showed reduced clearance (mean difference [MD] = -15.56 L/hr, p = 0.0002, I2 = 67%), increased maximal concentration (MD = 6.90 μg/ml, p = 0.006, I2 = 92%) and increased terminal elimination half-life (MD = 0.49 hr, p < 0.0001, I2 = 3%) post-surgery. The remaining 36 medications and 2 supplements were included in a systematic review. Overall, 18 of the 53 drugs and supplements showed post-operative changes in PK parameters.

CONCLUSION

This study demonstrates heterogeneity in practice and could not reach conclusive findings for most PK parameters. Prospective studies are needed to inform best practice and enhance patient healthcare and safety following bariatric surgery.

Changes in Serum Concentration of Antidepressants After Bariatric Surgery and Recommendations for Postbariatric Surgery Antidepressant Therapy

BACKGROUND

Bariatric surgery affects the absorption of medications including antidepressants, but data regarding these effects are limited.

OBJECTIVES

Our objectives were to review publicly available data regarding changes in antidepressant serum concentration following bariatric surgery in order to develop medication dosing recommendations in this patient population.

METHODS

A comprehensive literature review was performed utilizing key search terms in Pubmed. Additional data were retrieved from the Food and Drug Administration and DrugBank Online resources.

RESULTS

A total of twelve published articles were included in addition to the publicly available data from the Food and Drug Administration and DrugBank. The serum concentration of antidepressants following bariatric surgery demonstrated considerable variability between and within drug classes due to unique pharmacokinetic features, drug preparation, and formulation. Recommendations were developed from published data regarding changes in serum concentration and drug-specific pharmacokinetic data.

CONCLUSIONS

To our knowledge, this is the first study to propose medication dose-adjustment recommendations for patients on antidepressants undergoing bariatric surgery. We were limited by the relatively small amount of data available and recommend monitoring patients and use of clinical judgment along with this guidance.

The Effects of Bariatric Surgery on Pharmacokinetics of Drugs: a Review of Current Evidence

PURPOSE OF REVIEW

Obesity constitutes a major public health concern and has been recognized as an epidemic. To date, bariatric surgery remains the most effective way for substantial long-lasting weight loss in severe obesity. The purpose of this review is to summarize how the pharmacokinetics of drugs are affected by the most common types of bariatric surgery, i.e., Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG).

RECENT FINDINGS

Limited data are available regarding the changes in pharmacokinetics of drugs after bariatric surgery. The lack of existing guidelines may lead patients to experience drug toxicity or therapeutic undertreatment. Pharmacokinetic parameters that need to be taken into consideration postoperatively include gastric motility, gastric volume, pH, surface area, bile secretions, carrier proteins, and first-pass metabolism. For drugs with a narrow therapeutic index, other factors need to be monitored closely, including plasma drug levels, patients' clinical outcomes, and laboratory markers. Patients should be followed up frequently and treated in accordance with their response to the drug therapy. Bariatric surgery may affect the pharmacokinetics of various drugs, due to the resultant anatomical changes and the substantial weight loss. Therefore, there is a need to identify those potential changes and adjust patients' medication doses in order to achieve higher efficacy and avoid toxicity.

Suicide attempts after bariatric surgery: comparison to a nonsurgical cohort of individuals with severe obesity

BACKGROUND

The rate of suicide is higher among individuals following bariatric surgery compared with the general population; however, it is not clear whether risk is associated with bariatric surgery beyond having severe obesity.

OBJECTIVE

To compare the risk of a suicide attempt among those who had bariatric surgery versus a nonsurgical cohort with severe obesity.

SETTING

Aggregate count data were collected from 5 healthcare systems.

METHODS

Individuals were identified in the surgical cohort if they underwent bariatric surgery between 2009 and 2017 (n = 35,522) and then were compared with a cohort of individuals with severe obesity who never had bariatric surgery (n = 691,752). Suicide attempts were identified after study enrollment date using International Classification of Diseases, Ninth and Tenth Editions (ICD-9 and ICD-10) diagnosis codes from 2009 to 2021.

RESULTS

The relative risk of a suicide attempt was 64% higher in the cohort with bariatric surgery than that of the nonsurgical cohort (2.2% versus 1.3%; relative risk = 1.64; 95% CI, 1.53-1.76). Within the cohort with bariatric surgery, suicide attempts were more common among the 18- to 39-year age group (P < .001), women (P = .002), Hawaiian-Pacific Islanders (P < .001), those with Medicaid insurance (P < .001), and those with a documented mental health condition at baseline (in the previous 2 years; P < .001).

CONCLUSIONS

The relative risk of suicide attempts was higher among those who underwent bariatric surgery compared with a nonsurgical cohort, though absolute risk remained low. Providers should be aware of this increased risk. Screening for suicide risk after bariatric surgery may be useful to identify high-risk individuals.

Incidence of adverse mental health outcomes after sleeve gastrectomy compared with gastric bypass and restrictive bariatric procedures: a retrospective cohort study

OBJECTIVE

This study examined rates of suicide and hospitalization with psychiatric diagnoses after sleeve gastrectomy compared with gastric bypass and restrictive procedures (gastric banding/gastroplasty).

METHODS

This was a longitudinal retrospective cohort study comprising all patients who underwent primary bariatric surgery in New South Wales or Queensland, Australia, between July 2001 and December 2020. Hospital admission records, death registration, and cause of death records (if applicable) within these dates were extracted and linked. Primary outcome was death by suicide. Secondary outcomes were admissions with self-harm; substance-use disorder, schizophrenia, mood, anxiety, behavioral, and personality disorders; any of these; and psychiatric inpatient admission.

RESULTS

A total of 121,203 patients were included, with median follow-up of 4.5 years per patient. There were 77 suicides, with no evidence of difference in rates by surgery type (rates [95% CI] per 100,000 person years: 9.6 [5.0-18.4] restrictive, 10.8 [8.4-13.9] sleeve gastrectomy, 20.4 [9.7-42.8] gastric bypass; p = 0.18). Rates of admission with self-harm declined after restrictive and sleeve procedures. Admission with anxiety disorders, any psychiatric diagnosis, and as a psychiatric inpatient increased after sleeve gastrectomy and gastric bypass, but not restrictive procedures. Admissions with substance-use disorder increased after all surgery types.

CONCLUSIONS

Variable associations between bariatric surgeries and hospitalization with psychiatric diagnoses might indicate distinct vulnerabilities among patient cohorts or that differing anatomical and/or functional changes may contribute to effects on mental health.

Plasma concentrations of SSRI/SNRI after bariatric surgery and the effects on depressive symptoms

Background

Depression and treatment with antidepressants SSRI/SNRI are common in people with morbid obesity who are candidates for bariatric surgery. There is few and inconsistent data about the postoperative plasma concentrations of SSRI/SNRI. The aims of our study were to provide comprehensive data about the postoperative bioavailability of SSRI/SNRI, and the clinical effects on depressive symptoms.

Methods

Prospective multicenter study including 63 patients with morbid obesity and therapy with fixed doses of SSRI/SNRI: participants filled the Beck Depression Inventory (BDI) questionnaire, and plasma levels of SSRI/SNRI were measured by HPLC, preoperatively (T0), and 4 weeks (T1) and 6 months (T2) postoperatively.

Results

The plasma concentrations of SSRI/SNRI dropped significantly in the bariatric surgery group from T0 to T2 by 24.7% (95% confidence interval [CI], -36.8 to -16.6, p = 0.0027): from T0 to T1 by 10.5% (95% 17 CI, -22.7 to -2.3; p = 0.016), and from T1 to T2 by 12.8% (95% CI, -29.3 to 3.5, p = 0.123), respectively.There was no significant change in the BDI score during follow-up (-2.9, 95% CI, -7.4 to 1.0; p = 0.13).The clinical outcome with respect to SSRI/SNRI plasma concentrations, weight change, and change of BDI score were similar in the subgroups undergoing gastric bypass surgery and sleeve gastrectomy, respectively. In the conservative group the plasma concentrations of SSRI/SNRI remained unchanged throughout the 6 months follow-up (-14.7, 95% CI, -32.6 to 1.7; p = 0.076).

Conclusion

In patients undergoing bariatric surgery plasma concentrations of SSRI/SNRI decrease significantly by about 25% mainly during the first 4 weeks postoperatively with wide individual variation, but without correlation to the severity of depression or weight loss.

The Influence of a Roux-en-Y Gastric Bypass on Plasma Concentrations of Antidepressants

PURPOSE

Roux-en-Y gastric bypass (RYGB) involves alterations of the gastrointestinal tract resulting in altered absorption. Patients with obesity have a higher prevalence of depression, and antidepressants are often prescribed. Alterations caused by RYGB could modify drug bioavailability and cause potential subtherapeutic plasma concentrations, increasing the risk of depressive relapse. The aim of this study was to describe the evolution of trough drug dose-normalized antidepressant plasma concentrations before and after RYGB.

MATERIALS AND METHODS

This naturalistic prospective case series considers patients with trough plasma concentrations in a 1-year timeframe before and after RYGB. Only antidepressants prescribed to at least three patients were included in the present study.

RESULTS

Thirteen patients (n = 12 females, median age 44 years, median BMI before intervention = 41.3 kg/m²) were included. Two patients were treated concurrently with fluoxetine and trazodone; the remaining patients were all treated with antidepressant monotherapy. Therapeutic drug monitoring (TDM) values for duloxetine (n = 3), escitalopram (n = 4), fluoxetine (n = 4), and trazodone (n = 4) before (median 4.7 weeks) and after (median 21.3 weeks) RYGB intervention were analyzed. Compared to preintervention, median [interquartile range] decreases in dose-normalized trough plasma concentrations for duloxetine (33% [- 47; - 23]), escitalopram (43% [- 51; - 31]), fluoxetine (9% [- 20; 0.2]), and trazodone (16% [- 29; 0.3]) were observed.

CONCLUSION

This study shows a decrease in plasma antidepressant concentrations following RYGB. TDM before and after RYGB, in addition to close monitoring of psychiatric symptomatology, may help optimize antidepressant treatment after bariatric surgery. These results also highlight the need for prospective studies assessing the clinical evidence available through TDM in these patients.

Consultation-Liaison Case Conference: Psychiatric Care of Patients Who Undergo Bariatric Surgery

We present the case of a 42-year-old female with major depressive disorder who received a Roux-en-Y gastric bypass and subsequently decompensated in her depression symptoms and began newly engaging in problematic alcohol use. Top experts in the consultation-liaison field, specifically bariatric surgery psychiatry, provide guidance for this commonly encountered clinical case based on their experience and a review of the available literature. Key teaching points include the presurgical psychosocial assessment, pertinent perioperative psychopharmacology, and problematic alcohol use after bariatric surgery.

Drug absorption in bariatric surgery patients: A narrative review

Background

Despite the increase in the number of bariatric surgeries performed, little is known about the impact of the surgery on drug absorption. Unpredictability is assumed with drugs, given the anatomical changes after surgery.

Objective

To evaluate the impact of bariatric surgery on drug absorption based on the type of procedure performed.

Methods

We conducted a comprehensive literature review searching PubMed/Medline for published studies (from inception to December 2017) that evaluate the use of drugs and the assessment of drug absorption after bariatric surgery. Pharmacokinetic/pharmacodynamic studies, case reports, and observational studies were included in our review.

Results

We found 60 studies addressing drug use after bariatric surgery. Twenty‐eight studies reported a decrease in drug absorption after bariatric surgery while only four studies showed an increase in drug absorption. Unchanged absorption of drugs was seen in 23 studies after the surgery.

Conclusion

The available information shows variations in drug absorption after bariatric surgery. The unpredictability may result from factors related to the patient, drug, and/or type of surgery. Therefore, pharmacists' involvement and close monitoring of patients after bariatric surgery could be effective to avoid sub‐/supratherapeutic responses.

Psychotropic Medications in Metabolic and Bariatric Surgery: Research Updates and Clinical Considerations

PURPOSE OF REVIEW

We review evidence for assessing and monitoring psychotropic medications in metabolic and bariatric surgery (MBS) patients. We describe weight gain side effects, potential perioperative risks, pharmacokinetic changes that occur after MBS, and conclude with clinical recommendations.

RECENT FINDINGS

Research on psychiatric medication use and post-MBS weight outcomes is lacking and inconsistent; however, there is consistent evidence that, though variable, psychiatric medication use is associated with weight gain. Several meta-analyses and reviews provide guidance on lowering risk when appropriate. Perioperative lithium toxicity and SSRI discontinuation syndrome also warrant consideration, as do potential post-operative pharmacokinetic changes. In the absence of data for each psychiatric drug classification, close symptom monitoring and, where appropriate, serum concentration monitoring are recommended. MBS patients are a psychiatrically vulnerable population, and many are on psychiatric medications. Given potential weight/metabolic side effects, perioperative complications, and post-operative pharmacokinetic changes that occur with psychotropic medication use, providers should stay well informed on psychiatric medication management considerations.

The Effects of Bariatric Surgery and Gastrectomy on the Absorption of Drugs, Vitamins, and Mineral Elements

Bariatric surgery, which is an effective treatment for obesity, and gastrectomy, which is the primary treatment method for gastric cancer, alter the anatomy and physiology of the digestive system. Weight loss and changes in the gastrointestinal tract may affect the pharmacokinetic parameters of oral medications. Both bariatric and cancer patients use drugs chronically or temporarily. It is important to know how surgery affects their pharmacokinetics to ensure an effective and safe therapy. The Cochrane, PubMed, and Scopus databases were searched independently by two authors. The search strategy included controlled vocabulary and keywords. Studies show that bariatric surgery and gastrectomy most often reduce the time to maximum plasma concentration (t_max) and decrease the maximum plasma concentration (C_max) in comparison with the values of these parameters measured in healthy volunteers. Vitamin and mineral deficiencies are also observed. The effect depends on the type of surgery and the properties of the drug. It is recommended to use the drugs that have been tested on these groups of patients as it is possible to monitor them.

Serum concentrations of antidepressants, antipsychotics, and antiepileptics over the bariatric surgery procedure

Purpose

As a substantial proportion of bariatric surgery patients use psychotropic/antiepileptic drugs, we investigated the impact of this procedure on serum concentrations.

Methods

In a naturalistic, longitudinal, prospective case series, we compared dose-adjusted trough concentrations of antidepressants, antipsychotics, or antiepileptics in consecutive patients before and after bariatric surgery. Adherence to treatment over 2 weeks preceding each sampling was considered.

Results

In all, 85 participants were included (86% female, median age 45 years, median body mass index 42 kg/m²). They were being treated with 18 different psychotropic/antiepileptic drugs (7 substances: 6–17 individuals, 11 substances: 1–4 individuals) and contributed 237 samples over a median of 379 days after surgery. For four out of seven substances with pre-/post-surgery samples available from six or more individuals, the dose-adjusted concentration was reduced (sertraline: 51%, mirtazapine: 41%, duloxetine: 35%, citalopram: 19%). For sertraline and mirtazapine, the low-calorie-diet before surgery entirely explained this reduction. A consistent finding, irrespective of drug, was the association between the mean ratio of the post-/pre-diet dose-adjusted concentration and the lipophilicity of the drug (logD; correlation coefficient: −0.69, P = 0.0005), the low-calorie diet often affecting serum concentration more than the surgery itself.

Conclusions

Serum concentrations of psychotropic/antiepileptic drugs vary after bariatric surgery and can be hard to predict in individual patients, suggesting that therapeutic drug monitoring is of value. Conversely, effects of the pre-surgery, low-calorie diet appear generalizable, with decreased concentrations of highly lipophilic drugs and increased concentrations of highly hydrophilic drugs. Interaction effects (surgery/dose/concentration) were not evident but cannot be excluded.

Oral drug dosing following bariatric surgery: General concepts and specific dosing advice

Bariatric or weight‐loss surgery is a popular option for weight reduction. Depending on the surgical procedure, gastric changes like decreased transit time and volume and increased pH, decreased absorption surface in the small intestine, decreased exposure to bile acids and enterohepatic circulation, and decreased gastrointestinal transit time may be expected. In the years after bariatric surgery, patients will also substantially lose weight. As a result of these changes, the absorption, distribution, metabolism and/or elimination of drugs may be altered. The purpose of this article is to report the general influence of bariatric surgery on oral drug absorption, and to provide guidance for dosing of commonly used drugs in this special population. Upon oral drug administration, the time to maximum concentration is often earlier and this concentration may be higher with less consistent effects on trough concentrations and exposure. Additionally, prescription of liquid formulations to bariatric patients is supported by some reports, even though the high sugar load of these suspensions may be of concern. Studies on extended‐release medications result in an unaltered exposure for a substantial number of drugs. Also, studies evaluating the influence of timing after surgery show dynamic absorption profiles. Although for this group specific advice can be proposed for many drugs, we conclude that there is insufficient evidence for general advice for oral drug therapy after bariatric surgery, implying that a risk assessment on a case‐by‐case basis is required for each drug.

Pharmacokinetics of oral levonorgestrel and ethinylestradiol in women after Roux-en-Y gastric bypass surgery

BACKGROUND

Most patients undergoing Roux-en-Y gastric bypass (RYGB) are women in reproductive age. It is not known if bariatric surgery affects the pharmacokinetics of oral contraceptives.

OBJECTIVES

The primary objective was to evaluate ethinylestradiol (EE) and levonorgestrel (LNG) absorption in women undergoing RYGB, compared with nonoperated controls matched by age and body mass index (BMI). A secondary objective was to assess whether the time since surgery and BMI in the postoperative period influenced the absorption parameters.

SETTING

University hospital, Brazil.

METHODS

This study was designed to compare the maximum plasma concentration (Cmax), the time to the peak plasma level (Tmax), the area under the curve (AUC0-8 and AUC0-∞) after a single dose of a combined oral contraceptive with 0.03 mg EE and 0.15 mg LNG among 20 women after RYGB and 20 controls. Blood samples were obtained for 8 hours.

RESULTS

The mean LNG AUC0-8 and LNG AUC0-∞ were higher in RYGB group (P = .048 and P = .004, respectively). We found a positive correlation for LNG AUC0-8 (P = .045) and AUC0-∞ (P = .004) and the time since surgery, and we found a negative correlation for LNG Cmax (P = .018), AUC0-8 (P = .003), and AUC0-∞ (P = .001) and BMI.

CONCLUSION

No significant differences were found in oral EE pharmacokinetics. The operated group showed higher mean LNG AUC0-8 and AUC0-∞ but it was not considered clinically significant. The present study suggests that RYGB may not affect EE and LNG absorption.

Course of depressive symptomatology and its association with serum uric acid in one-anastomosis gastric bypass patients

The changes in depressive symptomatology during the first year following one-anastomosis gastric bypass (OAGB) were evaluated and its association with uric acid (sUA). Fifty patients were included in this analysis. Beck Depression Inventory (BDI) for measuring depressive symptomatology, blood samples, and anthropometric measurements were assessed before (T0), at 6 (T6), and 12 months (T12) after surgery. There was a significant reduction in BDI total score at T6 (− 5.6 (95% CI − 2.1, − 9.1) points; p = 0.001) and at T12 (− 4.3 (95% CI − 0.9, − 7.9) points; p = 0.011). BMI loss was unrelated to depressive symptomatology. Patients with moderate to severe depressive symptomatology presented lower sUA levels than patients with none or minimal to mild (p = 0.028). ROC analysis revealed that sUA levels below 5.0 at T6 and 4.5 mg/dl at T12 had a prognostic accuracy for depression severity. Furthermore, delta sUA was significantly associated with delta BMI (β = 0.473; p = 0.012) and delta waist circumference (β = 0.531; p = 0.003). These findings support an improvement in depressive symptomatology in the first year postoperatively, however, without relation to BMI loss. Patients with moderate to severe depressive symptomatology presented with lower sUA levels over time. Therefore, sUA could be useful to predict moderate to severe depressive symptomatology in patients undergoing OAGB in clinical practice.

Pharmacokinetics of Oral Levonorgestrel in Women After Roux-en-Y Gastric Bypass Surgery and in BMI-Matched Controls

BACKGROUND

Women are advised to primarily use non-oral contraceptive alternatives after Roux-en-Y gastric bypass since it is not known if the surgery affects the pharmacokinetics of oral contraceptives.

METHODS

This is a multi-center, open label, phase 2 pharmacokinetic study performed at the University Hospital of Linköping and the Clinical Trials Center, Department of Obstetrics and Gynecology, Danderyd Hospital, Karolinska Institutet, Stockholm, Sweden. Fifteen women aged 18-40 years who had previously undergone Roux-en-Y gastric bypass surgery and reached a BMI < 30 were included. Fifteen BMI-matched women with no previous history of Roux-en-Y gastric bypass surgery served as a control group. After administration of a single dose of a combined oral contraceptive containing 0.03 mg ethinylestradiol/0.15 mg levonorgestrel, serum levonorgestrel concentrations were determined during a 24-h period using ultra performance liquid chromatography/tandem mass spectrometry. The area under the plasma concentration time curve of levonorgestrel (AUC0-24h) was the main outcome measure.

RESULTS

There were no significant differences in the studied pharmacokinetic parameters, AUC0-24h, total AUC, peak serum concentration (Cmax), time to peak serum concentrations (Tmax), apparent oral clearances of levonorgestrel (CLoral), or terminal half-lives (t½) between the groups.

CONCLUSION

This is to our knowledge the first study to evaluate the pharmacokinetics of oral levonorgestrel in women with a BMI < 30 at least 1 year after RYGB compared with a BMI-matched group of women. We could not find any significant pharmacokinetic differences between the groups, suggesting that oral levonorgestrel may be used in non-obese women after Roux-en-Y gastric bypass once a stable body weight has been reached.

CLINICAL TRIAL NUMBER

EudraCT 2014-004677-17.

Population Pharmacokinetics of Sertraline in Healthy Subjects: a Model-Based Meta-analysis

Sertraline pharmacokinetics is poorly understood and highly variable due to large between-subject variability with inconsistent reports for oral bioavailability. The study objective was to characterize sertraline pharmacokinetics by developing and validating a sertraline population pharmacokinetic (PK) model in healthy subjects using published clinical PK data. We carried a systematic literature search in PubMed in October 2015 and identified 27 pharmacokinetic studies of sertraline conducted in healthy adult subjects and reported in the English language. Sixty mean plasma concentration-time profiles made of 748 plasma concentrations following IV, single, and multiple oral doses ranging from 5 to 400 mg were extracted and analyzed for dose proportionality by a log-linear model and fitted to a 2-compartment pharmacokinetic model in NONMEM using a model-based meta-analysis (MBMA) approach. After a single oral dose, sertraline C_max and AUC_∞ increased with dose proportionally between 50 and 200 mg, and bioavailability increased nonlinearly with dose from 5 to 50 mg and plateaued afterwards while T_max and t_1/2 did not change with dose. Following multiple oral doses, C_max and AUC_∞ increased proportionally with dose across the entire dose range (5-200 mg) while bioavailability, T_max, and t_1/2 remained constant with dose. Sertraline absorption was time-dependent and best described by a sigmoidal E_max function of time after dose. Study findings indicate that sertraline PK is linear in healthy adult subjects at doses ≥ 50 mg, and exposures were nonlinear only after single oral doses < 50 mg likely due to reduced bioavailability.

Psychiatric Management of Bariatric Surgery Patients: A Review of Psychopharmacological and Psychological Treatments and Their Impact on Postoperative Mental Health and Weight Outcomes

BACKGROUND

Bariatric surgery is an effective treatment for severe obesity; however, high rates of psychiatric comorbidity complicate bariatric surgery care. As a result, importance has been placed on the need for ongoing psychiatric support in patients undergoing bariatric surgery. Given the lack of conclusive presurgery psychosocial predictors of postoperative mental health outcomes, studies have now shifted their focus to understand the long-term psychosocial sequalae that arise after surgery. Increasing evidence has demonstrated the potential for psychiatric care to stabilize psychiatric symptoms and minimize patient distress.

OBJECTIVE

To review psychopharmacological and psychological interventions for patients undergoing bariatric surgery and their impact on mental health and weight outcomes after surgery.

METHODS

We performed a comprehensive literature search in Ovid MEDLINE for studies examining the impact of psychopharmacological and psychological treatments on bariatric patients' postoperative mental health and weight outcomes.

RESULTS

Overall, 37 studies were included in the review. Preliminary evidence suggests that psychiatric medications do not negatively impact weight loss or health-related quality of life in the short term; however, more rigorous research designs are needed. There are insufficient data on specific psychiatric medications and long-term impact on weight loss and psychosocial outcomes. Postoperative psychological interventions have evidence for improving eating psychopathology, anxiety, and depressive symptoms; however, effects on weight loss remain unclear.

CONCLUSION

Evidence for psychopharmacological and psychological treatments remains preliminary. Consideration should be given to integrated, stepped-care models to provide personalized psychiatric interventions after surgery. Future research on expanding current psychiatric interventions, timing of delivery, and predictors of response is needed.

Risk of Suicide and Self-harm Is Increased After Bariatric Surgery-a Systematic Review and Meta-analysis

BACKGROUND

Bariatric surgery is endorsed by multiple societies as the most effective treatment for obesity. Psychosocial functioning has also been noted to improve for most patients after bariatric surgery. However, some studies have shown an increase in post-operative suicide risk. The aim of this study was to review the published literature and evaluate the association of bariatric surgery with suicide events and suicide/self-harm attempts in patients who have undergone weight loss surgery.

METHODS

MEDLINE and Embase were searched from inception through January 2018 for retrospective or prospective studies reporting mortality outcomes and self-harm or suicide rates after bariatric procedures. The primary outcome was the pooled event rate with 95% confidence interval (95% CI) for suicide. Secondary outcomes were suicide/self-harm attempts after bariatric surgery compared to same population prior to surgery and to matched control subjects, with the respective calculated odds ratios (OR) and 95% CI.

RESULTS

From 227 citations, 32 studies with 148,643 subjects were eligible for inclusion. The patients were predominantly females (76.9%). Roux-en-Y gastric bypass (RYGB) was the most commonly performed procedure (58.9%). The post-bariatric suicide event rate was 2.7/1000 patients (95% CI 0.0019-0.0038), while the suicide/self-harm attempt event rate was 17/1000 patients (95% CI 0.01-0.03). The self-harm/suicide attempt risk was higher after bariatric surgery within the same population with OR of 1.9 (95% CI 1.23-2.95), and compared to matched control subjects, OR 3.8 (95% CI, 2.19-6.59).

CONCLUSIONS

Post-bariatric surgery patients had higher self-harm/suicide attempt risk compared to age-, sex-, and BMI-matched controls. Various pre- and post-surgical psychosocial, pharmacokinetic, physiologic, and medical factors may be involved.

Effects of Bariatric Surgery Observed in Postmortem Toxicology Casework

Bariatric surgery has been on the rise and patients often have multiple indications for pre- and post-operative pharmacotherapy. Procedures target the stomach and/or small intestine and affect weight loss through restriction, malabsorption, or a combination of the two. The absorption and/or metabolism of drugs via the gastrointestinal tract could be altered by different mechanisms. Several cases at the North Carolina Office of the Chief Medical Examiner's Toxicology Laboratory (NCOCME) have raised questions about the potential impact of these procedures on the disposition of drugs in the body and how that altered disposition may affect cause and manner of death. Overmedication and postmortem redistribution are not enough to explain the phenomena seen in some NCOCME bariatric surgery-related casework. Case examples include a 46-year-old female with a history of Roux-en-Y gastric bypass (RYGB) who suffered a witnessed collapse. Toxicological findings included elevated concentrations of oxymorphone at 0.49 mg/L in vena cava blood. A 67-year-old female, who died from vomiting and bacterial gastritis one day after placement of two intragastric weight-loss balloons, had elevated concentrations of duloxetine at 1.4 mg/L in the iliac vein blood and 9.3 mg/kg in the liver. Her medication was strictly controlled by her sister and gastric contents were without intact tablets or residue at autopsy.

Effects of Obesity Surgery on Overall and Disease-Specific Mortality in a 5-Country Population-Based Study

BACKGROUND & AIMS

Bariatric surgery might reduce overall mortality from obesity. We investigated whether the survival times of patients who have had bariatric surgery are similar to those of the general population and are longer than of obese individuals who did not receive surgery.

METHODS

We performed a population-based cohort study of persons with a diagnosis of obesity listed in nationwide registries from Nordic countries from 1980 through 2012. Bariatric surgery was analyzed in relation to all-cause mortality and the obesity-related morbidities cardiovascular disease, diabetes, cancer, and suicide. Poisson models provided standardized mortality ratios (SMRs) with 95% confidence intervals (CIs). Multivariable Cox regression provided hazard ratios (HRs) for mortality in participants who did and did not have surgery.

RESULTS

Among 505,258 participants, 49,977 had bariatric surgery. Overall all-cause SMR was increased after surgery (1.94; 95% CI, 1.83-2.05) and increased with longer follow-up, to 2.28 (95% CI, 2.07-2.51) at ≥15 years after surgery. SMRs were increased for cardiovascular disease (2.39; 95% CI, 2.17-2.63), diabetes (3.67; 95% CI, 2.85-4.72), and suicide (2.39; 95% CI, 1.96-2.92) but not for cancer (1.05; 95% CI, 0.95-1.17); SMRs increased with time. In obese participants who did not have surgery, all-cause SMR was 2.15 (95% CI, 2.11-2.20), which remained stable during follow-up. Compared with obese participants who did not have surgery, patients who had bariatric surgery had decreased overall mortality from all causes (HR, 0.63; 95% CI, 0.60-0.66), cardiovascular disease (HR, 0.57; 95% CI, 0.52-0.63), and diabetes (HR, 0.38; 95% CI, 0.29-0.49) but increased mortality from suicide (HR, 1.68; 95% CI, 1.32-2.14). Cancer mortality was decreased overall (HR, 0.84; 95% CI, 0.76-0.93) but increased at ≥15 years of follow-up (HR, 1.20; 95% CI, 1.02-1.42).

CONCLUSIONS

In a study of persons with a diagnosis of obesity listed in nationwide registries of Nordic countries, we found that obese patients who have bariatric surgery have longer survival times than obese individuals who did not have bariatric surgery, but their mortality is higher than that of the general population and increases with time. Obesity-related morbidities could account for these findings.

Mental Illness Has a Negative Impact on Weight Loss in Bariatric Patients: a 4-Year Follow-up

BACKGROUND

Mental health disorders are highly prevalent among bariatric surgery patients. Bariatric surgery induces weight loss with continuous health improvements. However, long-term follow-up data on weight loss and quality of life data of patients who have a mental illness after bariatric surgery are scarce, and it is not clear whether mental illness is associated with more pronounced weight regain. The aim was to investigate the impact of preoperative mental illness on the course of long-term weight changes after bariatric surgery.

METHODS

Patients with sleeve gastrectomy (SG) or Roux-en-Y gastric bypass surgery (RYGB) between 2005 and 2013 with a follow-up of at least 3 years were included. The study population was divided into two groups: patients with mental illness (MI) and patients without (No-MI). Weight loss outcomes over time were compared using mixed models up to 4 years after surgery.

RESULTS

In total, 254 patients (RYGB 61.0%, SG 39%) were included. The distribution of baseline characteristics was similar between the MI (n = 108) and No-MI groups (n = 146). The most prevalent mental illness was depressive disorder (63.9%). In the MI group, the percent of total weight loss (%TWL) was significantly smaller over the study period. After 36 months, the predicted mean group-difference of %TWL was 4.6% (95% CI 1.9, 7.2; p = 0.001), and the predicted odds ratio for weight regain was 4.9 (95% CI 1.6, 15.1) for patients in the MI group.

CONCLUSION

Preoperative mental illness leads to lower long-term weight loss and an increased risk of weight regain after bariatric surgery.

Prevalence and Factors Associated With Psychiatric Medication Use in Bariatric Surgery Candidates

OBJECTIVE

We aimed to describe the rates of psychiatric medication use in bariatric surgery candidates and factors associated with psychiatric medication use.

METHODS

Patients from the Toronto Western Hospital Bariatric Surgery Program were recruited from 2011 to 2014. Data extracted included demographics, clinical factors (e.g., mood disorder, anxiety disorder, eating disorder, Patient Health Questionnaire-9, Generalized Anxiety Disorder 7), and psychiatric medication use. Logistic regression analyses were used to examine the relationship between demographic variables, clinical factors, and psychiatric medication use. Multiple logistic regression was conducted to determine the predictors of clinical factors from demographic variables with psychiatric medication use.

RESULTS

A total of 262 (35.1%) patients were taking at least 1 psychiatric medication and 105 patients (14.1%) were taking more than 1 psychiatric medication. Antidepressants were the most common psychiatric medication reported. The majority of patients taking a psychiatric medication had a psychiatric illness, with 16.0% not having a lifetime diagnosis of a mental illness. Being male and being employed significantly predicted lower odds of being on a psychiatric medication. Older age significantly predicted higher odds of being on a psychiatric medication. Psychiatric disorders were significantly associated with psychiatric medication use independent of demographic variables.

CONCLUSION

Our study provides insights into clinical and demographic factors related to psychiatric medication use in bariatric surgery patients. The findings support careful screening and clarification of psychiatric medications, especially in patients without a formal psychiatric diagnosis.

Increased risk for major depressive disorder in severely obese patients after bariatric surgery - a 12-year nationwide cohort study

BACKGROUND

Bariatric surgery is associated with a significant improvement in depressive mood in the initial postoperative years, but the maintenance of the improvement is under debate.

AIM

To explore the association between bariatric surgery and major depressive disorder (MDD) in a 12-year nationwide cohort study.

METHOD

Using the National Health Insurance Research Database of Taiwan, we identified 2302 patients who underwent bariatric surgery in 2001-2009. These patients were matched by propensity score to 6493 obese patients who did not receive bariatric surgery. We followed the surgical and control cohorts until death, any diagnosis of MDD or 31 December 2012. We used Cox proportional hazard regression models to calculate the relative risk of MDD in those who received bariatric surgery.

RESULTS

Overall, there was a 1.70-fold (95% CI: 1.27-2.27) higher risk of MDD in the surgical group. Subjects receiving malabsorptive procedures showed a higher risk of MDD (3.01, 95% CI: 1.78-5.09) than those receiving restrictive procedures (1.51, 95% CI: 1.10-2.07). Stratified by follow-up period, there was a higher risk of MDD in the surgical group (2.92, 95% CI: 1.75-4.88) than in the restrictive group four years after bariatric surgery.

CONCLUSIONS

Bariatric surgery was significantly associated with an elevated risk of MDD. KEY MESSAGES Bariatric surgery is associated with a significant improvement in depressive mood in the initial postoperative years, but the improvement is not maintained. Less is known about the relationship between bariatric surgery and risk of major depressive disorder. This was the first nationwide cohort study which found that bariatric surgery was significantly associated with an elevated risk of MDD (aHR: 1.70; CI: 1.27-2.27), mainly with malabsorptive procedures (aHR: 3.01; CI: 1.78-5.09) and at time points more than four years after surgery (aHR: 2.92; CI: 1.75-4.88) compared with the risk in matched controls. These findings imply an association between long-term malabsorption and the postoperative incidence of MDD. Long-term malabsorption might be related to the incidence of major depressive disorder after bariatric surgery. The possible causal relationship between nutritional deficiency after bariatric surgery and major depressive disorder warrants further investigation.

Systematic review of drug bioavailability following gastrointestinal surgery

PURPOSE

Inter- and intraindividual pharmacokinetics variability in humans affects the way in which drugs act on the body. Gastrointestinal surgery has an impact on this variability and significantly alters the kinetics of drugs in post-surgical patients. The way in which pharmacokinetic profiles are modified depends on the type of operative procedure performed. The extent to which the absorption of different groups of drugs is affected varies according to the site and length of intestinal resections.

METHODS

A literature search was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol. Three databases were searched: MEDLINE, Embase, and the Cochrane Library. For each drug, potential changes in absorption were described, including recommendations extracted from the results of the studies and collected according to authors' criteria as practical conclusions, and grades of recommendation were determined by levels of evidence using the Oxford Centre for Evidence-Based Medicine scale.

RESULTS

Sixty-eight articles were collected during the selection process after the bibliographic search. The main outcomes for 60 drugs from the various studies were classified according to each type of surgery.

CONCLUSIONS

Modifications in the digestive tract secondary to gastrointestinal surgery may compromise the bioavailability of drugs. Decreased absorption surface, gastric emptying speed, and gastric pH alteration are factors to be taken into account in the management of pharmacological treatment after surgery. Evidence supported by data in clinical practice is scarce, but after studying the pharmacokinetic profile of some molecules, it is possible to offer recommendations for its adaptation to the patient's clinical situation.

All disease begins in the gut: Influence of gastrointestinal disorders and surgery on oral drug performance

The term "disease" conjures a plethora of graphic imagery for many, and the use of drugs to combat symptoms and treat underlying pathology is at the core of modern medicine. However, the effects of the various gastrointestinal diseases, infections, co-morbidities and the impact of gastrointestinal surgery on the pharmacokinetic and pharmacodynamic behaviour of drugs have been largely overlooked. The better elucidation of disease pathology and the role of underlying cellular and molecular mechanisms have increased our knowledge as far as diagnoses and prognoses are concerned. In addition, the recent advances in our understanding of the intestinal microbiome have linked the composition and function of gut microbiota to disease predisposition and development. This knowledge, however, applies less so in the context of drug absorption and distribution for orally administered dosage forms. Here, we revisit and re-evaluate the influence of a portfolio of gastrointestinal diseases and surgical effects on the functionality of the gastrointestinal tract, their implications for drug delivery and attempt to uncover significant links for clinical practice.

The Effect of Roux-en-Y Gastric Bypass Surgery in Morbidly Obese Patients on Pharmacokinetics of (Acetyl)Salicylic Acid and Omeprazole: the ERY-PAO Study

BACKGROUND

Data on the absorption of orally administered drugs following Roux-en-Y gastric bypass (RYGB) surgery in obese patients are limited and inconclusive. As it is difficult to predict changes in absorption, studies on frequently used drugs in this population are necessary. Acetylsalicylic acid (ASA) and omeprazole are two commonly prescribed drugs in obese patients.

METHODS

In this repeated measures study, omeprazole and salicylic acid (SA) serum concentrations were measured before and after RYGB in 34 morbidly obese subjects. Time to maximum concentration (Tmax), lag time (Tlag), maximum concentration (Cmax), and area under the serum concentration versus time curve (AUC) were calculated for both drugs to determine possible differences in drug absorption after the procedure.

RESULTS

For SA, Tmax significantly decreased after RYGB, while both Cmax and AUC0-24 significantly increased. For omeprazole, both Tmax and Tlag significantly decreased after RYGB, while Cmax significantly increased. Mean AUC0-12 significantly decreased post-surgery. The difference in AUC0-12 before and after surgery varied between subjects.

CONCLUSIONS

Our study shows a faster absorption of both ASA and omeprazole after RYGB. The exposure to ASA is higher post-surgery, but the standard dose of 80 mg does not need to be modified, considering its range in effective dose. The exposure to omeprazole is, on average, decreased after surgery. Clinicians should be aware to increase the dose of omeprazole if symptoms suggest inadequate response.

RYGB and Drug Disposition: How to Do Better? Analysis of Pharmacokinetic Studies and Recommendations for Clinical Practice

An important issue in the follow-up of patients with bariatric surgery remains to determine whether their therapeutic management should be different after surgery. In this article, we first reviewed all pharmacokinetic studies involving at least four subjects who underwent the Roux-en-Y gastric bypass (RYGB) bariatric surgery. Twenty-five publications were selected and, overall, 25 drugs were studied. Drug solubility and permeability parameters for each drug were defined using different parameters or classifications. Increased rates of oral drug absorption were predominantly observed. Conversely, drug exposure differed from one drug to another. Considering the galenic formulation and the Biopharmaceutics Classification System (BCS) class may help the prediction of oral drug exposure outcome after RYGB. We propose a strategy aiming to guide prescription and drug monitoring in patients with RYGB. But further research is clearly needed due to the unique characteristics of the bariatric population. Priority should be given to drugs that do not have clinical or biological surrogates for dose adaptation.

Comparison of Bioavailability of Single-Dose Extended-Release Venlafaxine Capsules in Obese Patients Before and After Gastric Bypass Surgery

STUDY OBJECTIVE

The extended-release (ER) form of venlafaxine is preferred because of improved patient adherence, but the immediate-release (IR) form is frequently used after Roux-en-Y gastric bypass (RYGB) surgery because of concerns for malabsorption. The objective of this study was to determine whether a statistically significant and predictable change in the bioavailability of venlafaxine ER capsules occurs after RYGB.

DESIGN

Prospective nonblinded single-dose pharmacokinetic study.

SETTING

Clinical research unit at a large tertiary care medical practice.

PATIENTS

Ten adult pre-bariatric surgery patients who met the criteria for noncomplicated RYGB were enrolled and served as their own controls.

INTERVENTIONS

Patients were administered one venlafaxine ER 75-mg capsule at two visits-the first visit at least 1 week before undergoing RYGB and the second visit 3-4 months after RYGB. Blood samples were collected at predetermined intervals over 48 hours after each dose, and the pharmacokinetics of venlafaxine were measured.

MEASUREMENTS AND MAIN RESULTS

Plasma levels of venlafaxine and its primary metabolite, O-desmethylvenlafaxine (ODV), were compared at baseline and 3-4 months after RYGB. The areas under the serum concentration-time curves from 0-24 hours (AUC_0-24 ) for venlafaxine (mean ± SD 734 ± 602 vs 630 ± 553 ng·hr/ml, p=0.22) and ODV (mean ± SD 894 ± 899 vs 1083 ± 972 ng·hr/ml, p=0.07) were similar before and after RYGB. Using a bioequivalence approach, differences in pre-RYGB and post-RYGB values of AUC_0-24 , peak serum concentration, and time to peak serum concentration were not statistically significant for either venlafaxine or ODV.

CONCLUSION

This study suggests that RYGB does not significantly alter the amount of venlafaxine or its active metabolite, ODV, absorbed from a venlafaxine ER capsule or the time over which it is absorbed.

Oral drug therapy following bariatric surgery: an overview of fundamentals, literature and clinical recommendations

Bariatric surgery is the most effective solution for severe obesity and obesity with comorbidities, and the number of patients going through bariatric surgery is rapidly and constantly growing. The modified gastrointestinal anatomy of the patient may lead to significant pharmacokinetic alterations in the oral absorption of drugs after the surgery; however, because of insufficient available literature and inadequate awareness of the medical team, bariatric surgery patients may be discharged from the hospital with insufficient instructions regarding their medication therapy. In this article, we aim to present the various mechanisms by which bariatric surgery may influence oral drug absorption, to provide an overview of the currently available literature on the subject, and to draw guidelines for the recommendations bariatric surgery patients should be instructed before leaving the hospital. To date, and until more robust data are published, it is essential to follow and monitor patients closely for safety and efficacy of their medication therapies, both in the immediate and distant time post-surgery.

Long-term pharmacotherapy considerations in the bariatric surgery patient

PURPOSE

Pharmacists' role in optimizing long-term pharmacotherapy for bariatric surgery patients is detailed.

SUMMARY

Bariatric surgery patients provide a difficult challenge in terms of many pharmacotherapy issues, especially in the chronic care setting, where data on long-term effects of bariatric surgery are limited. The most common procedures are Roux-en-Y gastric bypass (RYGB), adjustable gastric banding, and sleeve gastrectomy. Sleeve gastrectomy has become the most common procedure in the United States, primarily because it has less overall chronic malabsorption effects than RYGB. Pharmacotherapy management is complicated by rapid weight loss combined with a number of pharmacokinetic changes, such as decreased absorption of some medications due to altered gastrointestinal tract anatomy and potentially increased concentrations of some medications due to a decreased volume of distribution resulting from weight loss. Nutritional and metabolic supplementation are of the utmost importance in order to limit deficiencies that can lead to a number of conditions. Many chronic diseases, including hypertension, diabetes, gastroesophageal reflux disease, and urinary incontinence, are improved by bariatric surgery but require close monitoring to ensure the effectiveness of maintenance pharmacotherapy and avoidance of adverse effects. Psychotropic medication management is also an important pharmacotherapy concern, as evidenced by antidepressants being the most commonly used medication class among preoperative bariatric surgery patients.

CONCLUSION

Pharmacists have an increasing role in the chronic management of the bariatric surgery patient due to their knowledge of medication dosage forms and expertise in disease states affected by bariatric surgery.

Psychiatric Disorders and Weight Change in a Prospective Study of Bariatric Surgery Patients: A 3-Year Follow-Up

OBJECTIVES

To document changes in Axis I psychiatric disorders after bariatric surgery and examine their relationship with postsurgery weight loss.

METHODS

As part of a three-site substudy of the Longitudinal Assessment of Bariatric Surgery Research Consortium, 199 patients completed the Structured Clinical Interview for DSM-IV before Roux-en-Y gastric bypass or laparoscopic adjustable gastric band. At 2 or 3 years after surgery, 165 (83%) patients completed a follow-up assessment (presurgery median body mass index = 44.8 kg/m, median age = 46 years, 92.7% white, 81.1% female). Linear-mixed modeling was used to test change in prevalence of psychiatric disorders over time, report remission and incidence, and examine associations between psychiatric disorders and weight loss.

RESULTS

Compared with status presurgery, the prevalence of any Axis I psychiatric disorder was significantly lower at 2 and 3 years after surgery (30.2% versus 16.8% [p = .003] and 18.4% [p = .012], respectively). Adjusting for site, age, sex, race, presurgery body mass index, and surgical procedure, presurgery mood, anxiety, eating or substance use disorders (lifetime or current) were not related to weight change, nor were postsurgery mood or anxiety disorders (p for all > .05). However, having a postsurgery eating disorder was independently associated with less weight loss at 2 or 3 years (β = 6.7%, p = .035).

CONCLUSIONS

Bariatric surgery was associated with decreases in psychiatric disorders through 3 years after surgery. Postsurgical eating disorders were associated with less weight loss after surgery, adding to the literature suggesting that disordered eating after surgery is related to suboptimal weight loss.

Understanding the role of psychopathology in bariatric surgery outcomes

Bariatric surgery is the most effective treatment for morbid obesity; however, a subset of patients who undergo this procedure regain weight or achieve suboptimal weight loss results. A large number of studies have examined whether psychological variables play a role in weight loss surgery outcome. Although presurgical psychopathology has been found to be associated with suboptimal results in some studies, this literature is equivocal. These inconsistent findings are reviewed and considered in the context of contemporary models of psychopathology. More specifically, the review focuses on the limitations of atheoretical, descriptive diagnostic systems and examines whether comorbidity within the mood/anxiety disorders, impulse control/substance use disorders and thought disorders can account for the inconsistent findings reported to date. Contemporary models of psychopathology are highlighted and linked to the Research Domain Criteria, which have been advanced by the National Institute of Health. Means for assessing psychological constructs congruent with these models are reviewed. Recommendations are made for standardizing approaches to investigating how psychopathology contributes to suboptimal bariatric surgery outcomes.

Psychopharmacology and Bariatric Surgery

Currently, it has been demonstrated that psychotropic drugs, particularly antidepressants, are frequently prescribed for patients who seek bariatric surgery. Many bariatric surgery patients have a history of a mood disorder. Unlike medications for diabetes, hypertension or hyperlipidemia, which are generally reduced and at times discontinued, postsurgery antidepressants use is only slightly reduced. The Roux-en-Y procedure is most frequently associated with alteration in drug exposure. Medication disintegration, dissolution, absorption, metabolism and excretion have been found to be altered in postbariatric patients, although data are sparse at this time. This paper will review the current evidence regarding the effect of bariatric surgery on drug treatment including mechanism of interference as well as the extent of changes identified to date. Data will be presented as controlled trials followed by case series and reports.

Medication Use Among Patients Prior to Bariatric Surgery

Purpose: The aims of this study were to describe the most common medications reported by candidates for weight loss surgery and to consider the potential implications for patient care. Methods: A secondary data analysis of data from bariatric surgery patients enrolled in a randomized, controlled trial. At study entry, participants recorded their use of prescription medications they had taken in the previous 90 days. The Anatomical Therapeutic Chemical (ATC)/Defined Daily Dose (DDD) Index 2014 was used to classify medications. Results: Participants (n=265) were 85.7% female and 83.0% white. Mean body mass index was 47.9±6.5 kg/m², and age was 45.1±11 years. The average number of medications was 4.4±4.1, and the median was 3. The top three anatomical main groups were the cardiovascular system, alimentary tract and metabolism, and nervous system (28.2%, 21.6%, and 21.3% of all medications, respectively). The top therapeutic subgroups were drugs used in diabetes, psychoanaleptics, and agents acting on the renin-angiotensin system (12%, 11.3%, and 8.2% of all medications, respectively). Conclusions: Candidates for weight loss surgery report taking medications associated with obesity-related comorbidities such as diabetes, depression, and hypertension. Although many may be able to eliminate these medications, others will require close monitoring and dosage adjustment after surgery.

The impact and treatment of obesity in kidney transplant candidates and recipients

The prevalence of obesity in patients with chronic kidney failure and renal transplant candidates has paralleled the epidemic in the general population. The associated risks of surgical complications and long-term cardiovascular death are significant: most transplant centers consider obesity a relative contra-indication for transplant.

Few studies have focused on conservative weight loss strategies in transplant patients. Studies using administrative databases have found that only a minority of wait-listed patients lose weight and with no apparent benefit to transplant outcomes. The only clinical trial in this area found that an intensive weight-loss program had significantly better success (to listing) than self-directed weight loss. However, only a minority that succeeded with the help of a program (36 %), while the “diet and exercise” group had negligible results.

Laparoscopy has radically shortened the recovery time and decreased the complications associated with bariatric surgery. Reports in transplant patients, who were previously deemed too medically complex, have demonstrated a dramatic and rapid weight loss. The only randomized clinical trial in patients with CKD, which compared sleeve gastrectomy to best medical care clearly favoured the surgical arm for weight loss, but was too small to assess other outcomes. The emerging experience is small but quite promising.

Surgical complications and the effect on immunosuppression remain the chief concerns regarding the use of bariatric surgery in transplant patients. Rigorous prospective studies will be essential to properly evaluate the expected weight loss and the effect on pharmacokinetics of immunosuppressive medications. A routine role for bariatric surgery in transplantation would require evidence of improvements in patient-important outcomes and evidence of safety.

Treating mood disorders in patients with a history of intestinal surgery: a systematic review

Bariatric surgery is increasingly being performed, with the intended benefits of significant and durable weight loss. Radical surgical resection can result in short bowel syndrome (SBS), a rare and devastating condition. Psychological distress is common in these patients. Relevant articles were identified by searching Pubmed and EMBASE databases with the following keywords: 'Bariatrics'[Mesh] OR 'Short Bowel Syndrome' AND 'Antidepressive Agents' OR 'Psychotropic Drugs'[Mesh]. One in-vitro study, four clinical studies and six relevant case reports were identified. Most clinical studies on antidepressant focused on the Roux-en-Y gastric bypass (RYGB); these results are somewhat conflicting for a variety of reasons including different methodologies and small sample sizes. One month after RYGB, in patients receiving serotonin or serotonin/noradrenaline reuptake inhibitors, antidepressant levels decrease to 50% of preoperative levels and return to baseline (or greater) by 6 months in almost all patients. Other pharmacokinetic studies have shown that, 1 year after RYGB, duloxetine and sertraline levels are significantly reduced in comparison with the control population. Paradoxically, in patients with SBS and a few years after surgery, high concentration to dose ratios have been reported for citalopram and escitalopram; this may be because of an intestinal adaptation. Surgery of the intestine is likely to modify absorption and first-pass metabolism of drugs; managing the treatment of depression and anxiety in bariatric and SBS patients therefore presents a major challenge. Close clinical follow-up, associated with therapeutic drug monitoring when available, should enable the optimization of treatment response and modulate the risk of adverse events.

Clinicians' prescribing practices for bariatric surgery patients: is there an issue?

WHAT IS KNOWN AND OBJECTIVES

Patients undergoing Roux-en-Y gastric bariatric (RYGB) surgery present a reduced absorption site, and special attention should therefore be taken when prescribing oral-dosage forms. This study was carried out to investigate the extent to which non-bariatric clinicians are aware of this issue when prescribing medicines for this population, and what type of information is available to aid them in their decision-making.

METHODS

Two questionnaires were created, one for non-bariatric clinicians and another for their patients who had undergone RYGB surgery, to gather information about the prescription practices for this population. Additionally, a literature search of pharmacokinetic studies on bariatric patients and recommended prescription practices was carried out.

RESULTS AND DISCUSSION

Of the 62 non-bariatric clinicians surveyed, 50% believed RYGB surgery interferes with drug absorption; however, 68% still prescribed tablets as the first choice form of dosage. Young clinicians (35%) were less likely to believe that RYGB surgery could affect drug absorption than experienced clinicians (43%). The main reasons for changing dosage forms were patient complaints about efficacy or difficulty in swallowing tablets. Of the 73 patients, 43 were taking drugs in tablet form after the surgery, 24 of whom had health issues unrelated to the surgery. None of the journals read by the clinicians contained pharmacokinetics (PK) studies involving bariatric surgery patients or presented recommendations for the prescription of oral-dosage forms for this population. The literature search revealed a total of 22 drugs that had undergone PK studies in RYGB patients. Fifteen of them were reported to have decreased effects, 12 of which were administered as tablets.

WHAT IS NEW AND CONCLUSION

There is still a relative lack of clinical evidence to guide clinicians when prescribing medicines for bariatric patients. It is therefore recommended that pharmacists should have greater participation in the prescription process to advise non-bariatric clinicians and educate RYGB surgery patients to help avoid therapeutic failure.

Review article: The nutritional and pharmacological consequences of obesity surgery

BACKGROUND

Obesity surgery is acknowledged as a highly effective therapy for morbidly obese patients. Beneficial short-term effects on common comorbidities are practically undisputed, but a growing data pool from long-term follow-up reveals increasing evidence of potentially severe nutritional and pharmacological consequences.

AIMS

To assess the prevalence, causes and symptoms of complications after obesity surgery, to elucidate and compare therapy recommendations for macro- and micronutrient deficiencies, and to explore surgically-induced effects on drug absorption and bioavailability, discussing ramifications for long-term therapy and prophylaxis.

METHODS

PubMed, Embase and MEDLINE were searched using terms including, but not limited to, bariatric surgery, gastric bypass, obesity surgery and Roux-en-Y, coupled with secondary search terms, e.g. anaemia, micronutrients, vitamin deficiency, bacterial overgrowth, drug absorption, pharmacokinetics, undernutrition. All studies in English, French or German published January 1980 through March 2014 were included.

RESULTS

Macro- and micronutrient deficiencies are common after obesity surgery. The most critical, depending on surgical technique, are hypoalbuminemia (3-18%) and deficiencies of vitamins B1 (≤49%), B12 (19-35%) and D (25-73%), iron (17-45%) and zinc (12-91%). Many drugs commonly administered to obese patients (e.g. anti-depressants, anti-microbials, metformin) are subject to post-operative and/or PPI-associated changes affecting bioavailability and absorption.

CONCLUSIONS

Complications are associated with pre-operative and/or post-operative malnutrition or procedure-related changes in intake, absorption and drug bioavailability. The high prevalence of nutrient deficiencies after obesity surgery makes life-long nutritional monitoring and supplementation essential. Post-operative changes to drug absorption and bioavailability in bariatric patients cast doubt on the validity of standard drug dosage and administration recommendations.