Tramadol-induced hyponatraemia following unicompartmental knee replacement surgery

Risk of Hyponatremia after Tramadol/Acetaminophen Single-Pill Combination Therapy: A Real-World Study Based on the OMOP-CDM Database

BACKGROUND AND OBJECTIVE

Tramadol has been reported to cause hyponatremia but the evidence is conflicting. The risk of hyponatremia resulting from combination oral tramadol/acetaminophen (TA) therapy is thus unknown. This study examined whether, compared with acetaminophen (AA), TA use is associated with an increased risk of hyponatremia.

METHODS

Hospital data compatible with the Observational Medical Outcomes Partnership-Common Data Model (OMOP-CDM; version 5.3) for 30,999 patients taking TA or AA from 2011 through 2020 were analyzed. New-onset hyponatremia was defined as a serum sodium level < 135 mEq/L within 10 days after drug initiation. The incidence rate ratio was calculated based on crude and 1:1 propensity-score-matched models. Subgroup analyses compared patients taking TA extended-release (TA-ER) and TA immediate-release (TA-IR) formulations.

RESULTS

Among the 30,999 patients, 12,122 (39.1%) were aged > 65 years and 16,654 (53.7%) were male. Hyponatremia within 10 days developed in 1613 (8.4%) of the 19,149 patients in the TA group; the incidence rate was higher than in the AA group (4.2%; 493 out of 11,850 cases). In the propensity-score-matched model, the incidence rate of hyponatremia in the TA group was 6.8 per 1000 person-days (PD), which was 1.57-fold (1.31, 1.89) higher than that in the AA group (4.3 per 1000 PD). In both the crude and propensity-score-matched models, the incidence rate of hyponatremia was significantly higher in the TA-ER than TA-IR subgroup.

CONCLUSION

In this real-world study, hyponatremia was more frequently observed in the TA than AA group, and in the TA-ER than TA-IR subgroup. Therefore, it is imperative to prescribe tramadol cautiously and closely monitor electrolyte levels.

Evaluation of Low-Dose Versus High-Dose Opioid Pathway in Opioid-Naïve Patients After Total Knee Arthroplasty

Background

Pain control after total knee arthroplasty (TKA) remains challenging. Tramadol is a weak opioid with potentially lower side effects and risk for dependency than stronger opioids. The purpose of this study was to evaluate efficacy and safety of tramadol after TKA in opioid-naïve patients compared with stronger opioids.

Methods

A retrospective review of patients who underwent primary TKA was performed. In September 2018, opioid-naïve patients were prescribed tramadol instead of oxycodone. Patients receiving tramadol (low-opioid group) were matched to patients discharged with oxycodone before this transition (high-opioid group). We compared morphine milligram equivalent (MME) consumption and outcomes up to 3 months postoperatively.

Results

Two-hundred and five patients underwent TKA, with 126 receiving tramadol. Fourteen patients were converted to stronger opioid (11.2% conversion rate). Seventy patients from the low-opioid group were matched to 70 patients in the high-opioid group. Average daily inpatient MME consumption was higher in the high-opioid group (40.0 ± 27.4 vs 16.3 ± 10.9, P = .000). Outpatient prescribed MME was significantly higher in the high-opioid group (135.5 ± 71.5 vs 75.3 ± 51.3, P = .000) along with a higher number of refills (0.53 ± 1.1 vs 0.886 ± 0.94, P = .041). Knee range of motion was not statistically different at any timepoint postoperatively. There was higher adverse event rate in the low-opioid group (8.6% vs 5.7%) but not statically significant.

Conclusions

Low opioid regimen following TKA showed lower MME consumption than high opioid regimen with no effect on outcomes up to 3 months. Use of low opioid regimen should be considered for TKA surgery.

Factors influencing the occurrence of electrolyte disorders in cancer patients

Objective:

The objective of this study was to determine the magnitude of electrolyte disorders and influencing factors among cancer patients in Southwest Ethiopia.

Methods:

Facility-based cross-sectional study was conducted in Jimma Medical Center (JMC). Eighty-four cancer patients admitted to JMC were recruited for this study. A structured questionnaire and serum electrolyte measurements were used for data collection. Bivariate and multiple logistic regression was employed to determine the association between electrolyte disorders and associated factors among admitted cancer patients. P value ⩽ 0.05 was used as a cut point to declare statistical significance.

Result:

The overall prevalence of electrolyte disorders was 60.7%. The presence or absence of comorbid diseases, age, body mass index (BMI), nutritional status, and current prescribed medication use were associated with electrolyte disorders. Younger patients had lower odds for electrolyte disorders (odds ratio (OR) = 0.128 (P value = 0.05) and OR = 0.08 (P value = 0.033)) for the first and the second quartile, respectively. Underweight patients had a threefold likelihood to develop electrolyte disorders (OR = 3.13 (P value = 0.043)) than having normal BMI. Compared with those in need of nutritional intervention, patients not in need of nutritional intervention had lower odds for the disorders (OR = 0.109 (P value = 0.006)). Medication had increased the likelihood of electrolyte disorders by 5.5 times than with no medication (P value = 0.023). Those who had comorbid disease had 10 times likely to develop electrolyte disorders than those who did not have comorbid diseases (P value = 0.004).

Conclusion:

Electrolyte disorders were prevalent in cancer patients. Age, BMI, nutritional condition, comorbid disease, and prescribed drugs were the predictors of electrolyte disorders in cancer patients. Authors recommend routine screening of electrolyte disorders in cancer patients and special emphasis on controlling and managing risk factors.

Can patients with mild post-operative hyponatraemia following elective arthroplasty be discharged safely? A large-scale service evaluation suggests they can

BACKGROUND

Post-operative hyponatraemia is common following arthroplasty. Clinical hyponatraemia guidelines lack detail on when treatment is necessary, and there is a paucity of literature to guide best practice.

METHODS

Data were collected within retrospective service evaluations over two time periods in a single high throughput joint unit. The hospital's electronic database identified 1000 patients who were admitted electively between February 2012 and June 2013 and again between November 2018 and April 2019 for primary total hip, total knee or uni-compartmental knee arthroplasty. Hyponatraemia and non-hyponatraemia groups were compared. Logistic regression analysis was used to identify independent predictors of post-operative hyponatraemia, length of stay (LOS), re-attendance or re-admission to hospital.

RESULTS

Between 2012-2013 and 2018-2019, 32.1% and 25.7% of patients, respectively, developed post-operative hyponatraemia (serum sodium (s[Na]) ≤135 mmol/L). Those with post-operative hyponatraemia were significantly older, weighed less, were more comorbid and had lower pre-operative sodium. Multivariate analysis showed that increased age, knee surgery and lower pre-operative s[Na] independently predicted post-operative hyponatraemia. Post-operative hyponatraemia did not independently predict LOS, re-attendance or re-admission to hospital, within 90 days, in either cohort.

CONCLUSION

Post-operative hyponatraemia is common and may be a marker of pre-operative vulnerability. In these cohorts, it was not independently associated with LOS, re-attendance or re-admission to hospital. We suggest that otherwise well patients with mild hyponatraemia can be safely discharged earlier than is often the case and may not require extensive investigation. Further examination and research is required to develop a pre-operative approach to predict which patients will develop significant post-operative hyponatraemia.

Prevalence, risk factors, and complications associated with hyponatraemia following elective primary hip and knee arthroplasty

Background

Hyponatraemia, defined as a serum sodium [Na] concentration below 135 mmol/L, is common following surgery. As inpatient peri-operative stays shorten, there is a need to recognise pre-operative risk factors for post-operative hyponatraemia and complications associated with a peri-operative drop in Na. This audit aimed to investigate the prevalence of, risk factors for, and complications associated with hyponatraemia following elective primary hip and knee arthroplasty.

Methods

Data were collected within a retrospective audit of inpatient complications and unplanned reattendance or readmission at hospital in consecutive elective primary hip and knee arthroplasty patients in a single high throughput elective primary joint unit. The hospital’s electronic database identified 1000 patients who were admitted electively between February 2012 and June 2013 under the care of a single consultant orthopaedic surgeon for either total hip arthroplasty, total knee arthroplasty, or uni-compartmental knee arthroplasty. Groups were compared using appropriate tests, including chi-square analysis (or Fisher’s exact test), Mann-Whitney U test, Kruskal-Wallis test, and Wilcoxin signed-rank test. Logistic regression analysis was used to determine factors associated with hyponatraemia.

Results

Of the total 1000 patients, 217 (21.7%) developed post-operative hyponatraemia. Of these, 177 (81.6%) had mild (Na 130–134 mmol/L), 37 (17.1%) had moderate (Na 125–129 mmol/L), and 3 (1.4%) had severe (Na < 125 mmol/L) hyponatraemia. In multivariate analysis, age, pre-operative Na, and fasting glucose on day 1 remained significantly associated with having hyponatraemia post-operatively. There were no significant differences in reattendance at emergency departments and/or readmission within 90 days between those who had post-operative hyponatraemia whilst in hospital (39/217 = 18.0%) and those who did not (103/783 = 13.2%), or between those who were discharged with hyponatraemia (18/108 = 16.7%) and those discharged with normal Na (124/880 = 14.1%).

Conclusion

Approximately one fifth of elective joint arthroplasty patients had post-operative hyponatraemia. In these patients, older age, lower pre-operative Na and higher fasting glucose predicted post-operative hyponatraemia. We found no evidence that those discharged with hyponatraemia had more reattendance at emergency departments or readmission to hospital. We suggest that otherwise well patients with mild hyponatraemia can safely be discharged and followed up in the community.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13741-021-00197-1.

Central diabetes insipidus and pain medications - a risky combination

Background

Central Diabetes Insipidus (CDI) results from decreased production of antidiuretic hormone (ADH) leading to an inability to concentrate urine. CDI is treated with desmopressin (DDAVP). Rarely reported in the literature, opioids and non-steroidal anti-inflammatories (NSAIDs) can induce hyponatremia in individuals treated for CDI.

Case presentation

A 10-year-old boy with septo-optic dysplasia and CDI was treated with DDAVP 1.6 mg orally TID maintaining normal sodium levels. Post admission for a femur fracture, he was discharged on ibuprofen and hydromorphone. Sodium was 136 mmol/l two days before discharge.

He returned to the ED after having a seizure at home. He was euvolemic and mildly lethargic. Sodium was low at 108 mmol/l. DDAVP and hydromorphone were held and he was fluid restricted, but the sodium remained low. Sodium began to rise when Ibuprofen was stopped. Intermittent small doses of DDAVP were given to facilitate gradual correction of hyponatremia. At discharge, sodium had normalized.

Conclusion

Hyponatremia has occasionally been described as a side effect of opioids and rarely of NSAIDs in patients with CDI. Stimulation of the thirst centre may play a role with opioids while a decrease in urine output may be the mechanism with NSAIDs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40842-021-00124-9.

Can tramadol really induce hyponatraemia? A pharmacovigilance study

Several papers have described hyponatraemia with tramadol. However, in most reports, several confounding factors can be found. We used the WHO pharmacovigilance database (VigiBase®) to investigate if tramadol alone could be associated with hyponatraemia. All 1992-2019 ICSRs (individual case safety reports) with the preferred term (PT) "hyponatraemia" and tramadol were included. Two disproportionality analyses were performed: (1) after inclusion of all reports, and (2) after exclusion of concomitant hyponatraemic drugs. Results are expressed as reporting odds ratios (ROR; 95% CI) and information component (IC). Of 19 747 604 ICSRs, 225 575 were included. A significant association was found between tramadol use and reports of hyponatraemia (ROR = 1.49 [1.39-1.60], IC = 0.57 [IC₀₂₅ = 0.47]). After exclusion of hyponatraemic drugs, the previously found association disappeared. The study failed to find any pharmacovigilance signal of hyponatraemia with tramadol alone. We suggest that reports of hyponatraemia with tramadol can be explained principally by other underlying causes of hyponatraemia, especially other concomitant hyponatraemic drugs.

Tramadol- and codeine-induced severe hyponatremia: A Swedish population-based case-control study

BACKGROUND

Although tramadol and codeine occasionally have been reported to cause hyponatremia the evidence is scarce. The objective of this investigation was to study the association between weak opioids (tramadol and codeine) and hospitalization due to hyponatremia.

METHODS

This was a register-based case-control study of the general Swedish population. Those hospitalized with a principal diagnosis of hyponatremia (n = 14,359) were compared with matched controls (n = 57,383). Multivariable logistic regression adjusting for co-medication, diseases, previous hospitalizations and socioeconomic factors was used to explore the association between severe hyponatremia and the use of tramadol or codeine. Furthermore, newly initiated (≤90 days) and ongoing use was investigated separately.

RESULTS

Compared to controls, the unadjusted OR (95%CI) for hospitalization due to hyponatremia was 2.45 (2.26-2.66) for tramadol and 3.19 (2.92-3.47) for codeine. However, after adjustment for confounding factors the risk decreased (adjusted OR: 1.17 [1.08-1.26] and 1.14 [1.03-1.26], respectively). Newly initiated treatment with tramadol or codeine showed a significant association (adjusted OR 2.34 [95%CI 2.01-2.72] and 2.20 [95%CI 1.87-2.60], respectively). In contrast, for ongoing therapy the corresponding adjusted ORs were not elevated (adjusted OR: 0.70 [95%CI 0.61-0.80] and 1.14 [95%CI 0.99-1.30, respectively).

CONCLUSIONS

Associations were found between tramadol or codeine usage and hospitalization due to hyponatremia which were markedly increased in those newly initiated. The risk associated with long-term use was not increased. The association may be causally related to the drugs, although an effect due to pain, nausea or the underlying disease cannot be excluded.

Opioid-induced hyponatremia in a patient with central diabetes insipidus: independence from ADH

Hyponatremia can be a complication of opioid therapy, which has been postulated to occur secondary to inappropriate antidiuretic hormone secretion (syndrome of inappropriate antidiuretic hormone secretion [SIADH]). We report severe hyponatremia following wisdom teeth extraction with opioid analgesia in a 19-year-old female with diabetes insipidus (DI) and acquired panhypopituitarism that challenges this theory. As this patient has DI, we believe opioid treatment caused severe hyponatremia by the following mechanisms: (1) Opioids have a direct antidiuretic effect independent of changes in ADH, as demonstrated in Brattleboro rats with central DI. (2) Hydrocodone may have stimulated this patient's thirst center contributing to hyponatremia, as demonstrated in animal studies. Opioid use can cause hyponatremia in patients independent of ADH. It is important for clinicians to be aware of this so that patients can be appropriately counseled.

Tramadol for noncancer pain and the risk of hyponatremia

BACKGROUND

Case reports have signaled a possible association between tramadol, a weak opioid analgesic, and hyponatremia. The objective of this study was to determine whether the use of tramadol is associated with an increased risk of hyponatremia, when compared with codeine.

METHODS

Using the UK Clinical Practice Research Datalink and Hospital Episodes Statistics database, a population-based cohort of 332,880 patients initiating tramadol or codeine was assembled from 1998 through 2012. Cox proportional hazards models were used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) of hospitalization for hyponatremia associated with the use of tramadol, compared with codeine, in the first 30 days after initiation. A similar analysis was conducted within a highly restricted sub-cohort, which additionally excluded patients with any serum sodium level abnormality in the year before cohort entry. All models were adjusted for propensity score quintiles.

RESULTS

The incidence rates of hospitalization for hyponatremia were 4.6 (95% CI, 2.4-8.0) and 1.9 (95% CI, 1.4-2.5) per 10,000 person-months for tramadol and codeine users, respectively. In the adjusted model, the use of tramadol was associated with a 2-fold increased risk of hospitalization for hyponatremia, compared with codeine (adjusted HR 2.05; 95% CI, 1.08-3.86). In the highly restricted sub-cohort, the use of tramadol was associated with an over 3-fold increased risk of hospitalization for hyponatremia, compared with codeine (adjusted HR 3.54; 95% CI, 1.32-9.54).

CONCLUSIONS

In this first population-based study, the use of tramadol was associated with an increased risk of hyponatremia requiring hospitalization.

[New frequent adverse reaction of PPI in older adults: mild hyponatremia]

Hyponatremia is a rare side effect described in the product characteristics of proton pump inhibitors (PPIs). Hyponatremia in the elderly (>65 years) was assessed in patients with exposure to PPIs for at least one year compared to controls not exposed to PPIs counterparts. Included 145 patients, twenty-four patients (16.6%) had moderate hyponatremia ([120-134] mEq/L). Forty-eight patients (33.1%) were treated with PPIs. In the end, 31.3% [18.7%-46.3%] of the treated population for more than a year by PPI suffered moderate hyponatremia against only 9.3% [14.3%-16.9%] in the rest of the population, giving an odds ratio of 4.4 ([1.8-11.1], p=0.001). The relationship between hyponatremia dose was not significant (R2=0.05, p=0.74). By our study, we show that the risk of moderate hyponatremia is increased by chronic use of PPI in the elderly population. We also specify a notion of prevalence between 18.7% and 46.3%.

Codeine-induced syndrome of inappropriate antidiuretic hormone: case report

BACKGROUND

The syndrome of inappropriate antidiuretic hormone was first described in 1957 by Schwartz, and is characterised by hyponatraemia, inappropriately increased urine osmolality and urine sodium, and decreased serum osmolality in a euvolemic patient without edema. A patient with the syndrome of inappropriate antidiuretic hormone should have normal cardiac, renal, adrenal, hepatic, and thyroid functions and should not take any diuretics.

CASE REPORT

We present a case of the syndrome of inappropriate antidiuretic hormone caused by codeine and associated with reduced urine volume, increased urine sodium, and decreased serum sodium concentration.

CONCLUSION

The syndrome of inappropriate antidiuretic hormone is a disease that can lead to morbidity and even mortality. Clinicians should measure serum electrolytes intermittently in order to avoid missing the diagnosis of the syndrome of inappropriate antidiuretic hormone in patients using opioid.

["Serious" adverse drug reactions with tramadol: a 2010-2011 pharmacovigilance survey in France]

OBJECTIVE

Tramadol is a weak opioid used as a step 2 analgesic, approved in France for moderate to severe pain. After dextropropoxyphene withdrawal, a national pharmacovigilance follow-up of tramadol was decided by the French Drug Agency.

METHODS

All Serious Adverse Drug Reactions (SADR) notified with tramadol to the French PharmacoVigilance Centres (CRPV) and pharmaceutical companies between August 1(st), 2010 and July 31(th), 2011 were analyzed.

RESULTS

During the study period, 296 cases of SADR were notified to CRPV and 59 to pharmaceutical companies. Apart from opiate-related SADR, tramadol induced serotoninergic SADR, including seizures or serotoninergic syndromes. Several « unlabelled » SADR were also identified: some of them, like hyponatremia or hypoglycemia, are poorly known by health professionals. Other were never published: peripheral edema or pancreatitis.

CONCLUSION

This study shows that besides well-known opioid or serotoninergic ADR, tramadol can also induce 2 other relatively unknown ADR: hypoglycemia and hyponatremia.

Evaluation of the efficacy and safety for use of two sedation and analgesia protocols to facilitate assisted ventilation of healthy dogs

OBJECTIVE

To determine the effectiveness and safety of 2 sedative-analgesic protocols to facilitate assisted ventilation in healthy dogs.

ANIMALS

12 healthy dogs.

PROCEDURES

Dogs were randomly assigned to 2 groups. Mean dosages for protocol 1 were diazepam (0.5 mg/kg/h [n = 3 dogs]) or midazolam (0.5 mg/kg/h [3]), morphine (0.6 mg/kg/h [6]), and medetomidine (1.0 microg/kg/h [6]). Mean dosages for protocol 2 were diazepam (0.5 mg/kg/h [n = 3]) or midazolam (0.5 mg/kg/h [3]), fentanyl (18 microg/kg/h [6]), and propofol (2.5 mg/kg/h [6]). Each dog received the drugs for 24 consecutive hours. All dogs were mechanically ventilated with adjustments in minute volume to maintain normocapnia and normoxemia. Cardiorespiratory variables were recorded. A numeric comfort score was assigned hourly to assess efficacy. Mouth care, position change, and physiotherapy were performed every 6 hours. Urine output was measured every 4 hours.

RESULTS

Use of both protocols maintained dogs within optimal comfort ranges > 85% of the time. The first dog in each group was excluded from the study. Significant decreases in heart rate, oxygen consumption, and oxygen extraction ratio were evident for protocol 1. Cardiac index values in ventilated dogs were lower than values reported for healthy unsedated dogs. Oxygen delivery, lactate concentration, and arterial base excess remained within reference ranges for both protocols.

CONCLUSIONS AND CLINICAL RELEVANCE

Use of both protocols was effective for facilitating mechanical ventilation. A reduction in cardiac index was detected for both protocols as a result of bradycardia. However, oxygen delivery and global tissue perfusion were not negatively affected.

Survival in a patient with severe paraneoplastic hyponatremia: a case report

Background

Hyponatremia is a common and potentially life threatening problem in patients with neuroendocrine tumors.

Case presentation

A 54-year-old female with a history of smoking and narcotic dependency presented to her primary care physician with nausea, vomiting, fatigue, malaise, ataxia and a serum sodium of 100 mEq/L. A chest computerized tomography (CT) revealed a 4.1 × 4.9 cm precarinal/pretracheal mass encircling the right brachiocephalic vein. A mediastinal biopsy found a malignant, intermediate-size small cell (oat cell) carcinoma. Saline infusion along with intravenous furosemide successfully corrected her hyponatremia. Unfortunately, the patient later died of complications related to her cancer and cancer therapy.

Conclusion

Paraneoplastic hyponatremia can be severe, but even severe cases may be successfully treated.

Hyponatrémie due au tramadol

We reported a 92-year-old woman with hyponatremia (117 mmol/l) occurring three days after the introduction of tramadol. Diagnosis of inappropriate antidiuretic hormone secretion was based on blood and urinary analysis and dosage of antidiuretic hormone. Natremia became normal after tramadol cessation and fluid restriction. Natremia must be measured when neurological abnormality occurs with tramadol treatment.