Retrospective, multicenter analysis of the safety and effectiveness of direct oral anticoagulants for the treatment of venous thromboembolism in obesity

BACKGROUND

Direct oral anticoagulants (DOACs) are the preferred treatment for venous thromboembolism (VTE). However, DOAC use in patients with a BMI greater than 40 kg/m2 has not been well studied despite the growing prevalence of obesity, and current literature is often underpowered.

METHODS

This multicenter, retrospective, observational study evaluated patients 18 years and older who received DOACs for acute VTE treatment. Patients receiving DOACs for recurrent VTE or for failure of another agent were excluded. The primary efficacy outcome was recurrent VTE and the primary safety outcome was major bleeding within 12 months (or one month after stopping anticoagulation therapy). A propensity score analysis was performed to balance patient characteristics and evaluate the primary endpoints by BMI group. Time-to-event outcomes were analyzed using weighted Kaplan-Meier curves.

RESULTS

There were 165 patients with a BMI of at least 40 kg/m2 and 320 patients with a BMI less than 40 kg/m2. The majority received apixaban (373, 77%). Recurrent VTE occurred in 5 (3.0%) and 13 (4.1%) of patients in the higher and lower BMI groups, respectively (adjusted OR: 0.66; 95% CI: 0.16-2.69). Major bleeding occurred in 5 (3.0%) and 15 (4.7%) of patients in the higher and lower BMI groups, respectively (adjusted OR: 1.19; 95% CI: 0.36-3.92).

CONCLUSION

There was no significant difference in VTE recurrence or major bleeding related to BMI among patients treated with DOACs. This study showed that DOACs may be a safe and effective VTE treatment option in patients with obesity.

Successful Anticoagulation With Warfarin After Switching From Rifampin to Rifabutin

PURPOSE

A case of a patient receiving warfarin for pulmonary embolism (PE) concomitantly with rifampin for treatment of active pulmonary tuberculosis (PTB) is presented. A successful clinical intervention whereby the patient achieved therapeutic anticoagulation after switching to an alternative rifamycin antibacterial, rifabutin, is described.

SUMMARY

The drug-drug interaction between warfarin and rifampin is well known and documented. However, to our knowledge, no case reports of the interaction between warfarin and rifabutin have been published, and literature describing this interaction is lacking. We describe the case of a 27-year-old African American female referred to a pharmacist-managed anticoagulation clinic for treatment of PE with warfarin. The patient was also being treated for active tuberculosis with rifampin, isoniazid, pyrazinamide, and ethambutol. Warfarin was initiated and over the course of 1 month was continuously increased to a total weekly dose (TWD) of 140 mg without ever achieving the target international normalized ratio (INR) of 2 to 3. In an attempt to reach the target INR, rifampin was switched to rifabutin to minimize the drug-drug interaction with warfarin. Six days after this switch, the target INR was achieved with a lower warfarin TWD of 115 mg. Rifabutin interacts with warfarin to a lesser degree than rifampin and may be considered as an alternative in patients taking warfarin who require treatment with a rifamycin.

CONCLUSION

For patients in whom therapeutic anticoagulation with warfarin has been difficult, the use of rifabutin may be considered in place of rifampin when the concomitant use of a rifamycin is required.

Temporomandibular Disorders: Rapid Evidence Review

Temporomandibular disorders affect between 5% and 12% of the population and present with symptoms such as headache, bruxism, pain at the temporomandibular joint, jaw popping or clicking, neck pain, tinnitus, dizziness, decreased hearing, and hyperacuity to sound. Common signs on physical examination include tenderness of the pterygoid muscles, temporomandibular joints, and temporalis muscles, and malocclusion of the jaw and crepitus. The diagnosis is based on history and physical examination; however, use of computed tomography or magnetic resonance imaging is recommended if the diagnosis is in doubt. Nonpharmacologic therapy includes patient education (e.g., good sleep hygiene, soft food diet), cognitive behavior therapy, and physical therapy. Pharmacologic therapy includes nonsteroidal anti-inflammatory drugs, cyclobenzaprine, tricyclic antidepressants, and gabapentin. Injections of the temporomandibular joints with sodium hyaluronate, platelet-rich plasma, and dextrose prolotherapy may be considered, but the evidence of benefit is weak. A referral to oral and maxillofacial surgery is indicated for refractory cases.

Elevated international normalized ratio with the consumption of grapefruit and use of warfarin

A 65-year-old male with documented atrial flutter who was taking warfarin chronically returned to the anticoagulation clinic for follow-up, after having been on 10 mg daily for approximately 2 weeks. He had a previous sub-therapeutic international normalized ratio of 1.7 on a dose of 65 mg/week. The international normalized ratio at this visit was now 4.77 via venipuncture, after just an 8% increase in weekly dosing. He self-reported adherence to the new warfarin dosing but had begun eating grapefruit since last visit. The patient had no active bleeding and was told to decrease his dose to 8 mg daily. He also stopped eating the grapefruit. One week later, he returned to the clinic and the international normalized ratio was 2.1. He is currently back on warfarin 65 mg/week, and his international normalized ratio has been within therapeutic range for the past 4 months. Clinicians should have a heightened awareness of the potential for elevated international normalized ratio when grapefruit juice is consumed in a patient who is taking warfarin.

Evaluation of patient perceptions and outcomes related to anticoagulation point-of-care testing in ambulatory care clinics

Until recently, Prothrombin Time/International Normalized Ratio (PT/INR) measurements have typically been used to monitor patients on warfarin through institutional laboratories via venous puncture. The Point-of-Care Testing (POCT) device has revolutionized the patient care process by allowing for laboratory testing outside of the central laboratory.

Objective:

To analyze humanistic and clinical outcomes in patients currently treated with warfarin and monitored through a pharmacist-managed anticoagulation clinic using point-of-care testing (POCT) device versus venipuncture within ambulatory care clinics at our institution.

Methods:

All patients currently treated with warfarin therapy who were managed by clinical pharmacists for anticoagulation monitoring at the Medical University of South Carolina (MUSC) Family Medicine Center and University Diagnostic Center, were enrolled. Patients were asked to complete a satisfaction survey regarding their anticoagulation monitoring. In addition, data related to emergency department (ED) visits, hospitalizations and percent of time in the INR therapeutic range for 6 months pre- and post-implementation of POCT device was collected. This information was obtained through an electronic patient information database, Oacis.

Results:

A total of 145 patients were included in the data collection from the two clinics. The majority (41%) of these patients were taking warfarin for atrial fibrillation. Satisfaction surveys were completed by 86 (59 %) of patients. The surveys revealed that POCT device was preferred over venipuncture in 95% of patients. Reasons for the preference included more face-to-face interaction, less wait time, less pain, less blood needed, and quicker results. Of the 145 patients who were included in the objective data analysis, no significant differences were found in the number of hospitalizations, ED visits, or percent of time in the INR therapeutic range pre- and post-implementation of POCT device.

Conclusion:

The results of this study demonstrate improvement in patient satisfaction with POCT compared to venipuncture, with limited value in clinical outcomes.

Effect of patient-specific factors on weekly warfarin dose

OBJECTIVE

To determine the influence of various patient-specific factors, use of concomitant medications, and weekly vitamin K intake on total weekly warfarin maintenance dose (TWD).

METHODS

Information collected, via retrospective chart review, included TWD, general demographics, vitamin K consumption, target INR range, use of alcohol, tobacco, and cytochrome P450 (CYP)-inducing medications, and concomitant medications and diseases.

RESULTS

The majority of patients (n = 131) were Caucasian (71%), with more females (55%) than males. Use of CYP-inducing medications resulted in the largest correlation coefficient (r = 0.30). The sample was divided into high warfarin dose (TWD >/= 50 mg) and low warfarin dose (TWD </= 25 mg) patient populations to discern areas where the two populations differed. Age and amiodarone use were the only statistically significant differences between the two groups, with high dose patients tending to be younger and to use less amiodarone. Age and CYP-inducing medications were found to be the only statistically significant predictors of TWD in the regression analysis. The TWD was 2.4 mg less for each additional decade of patient age. The coefficient on CYP-inducing medications indicates that the concomitant use of a CYP inducer is associated with an increase in TWD of 17.2 additional milligrams, adjusting for all other variables in the model.

CONCLUSION

We found concomitant use of CYP inducer, age, height, and ethnicity to have the greatest influence on TWD. Positive relationships were found between TWD and the use of CYP450 inducer, height, and African American ethnicity. Although it did appear that women required a lower TWD than men, this factor contributed mildly. Further studies with a greater sample size may more precisely predict the effect of patient-specific factors on TWD, thus uncovering additional relationships.

Assessment of patient knowledge of diabetic goals, self-reported medication adherence, and goal attainment

Background:

Medication adherence is an integral aspect of disease state management for patients with chronic illnesses, including diabetes mellitus. It has been hypothesized that patients with diabetes who have poor medication adherence may have less knowledge of overall therapeutic goals and may be less likely to attain these goals.

Objective:

The purpose of this study was to assess self-reported medication adherence, knowledge of therapeutic goals (hemoglobin A1C [A1C], low density lipoprotein cholesterol [LDL-C] and blood pressure [BP]), and goal attainment in adult patients with diabetes.

Methods:

A survey was created to assess medication adherence, knowledge of therapeutic goals, and goal attainment for adult patients with diabetes followed at an internal medicine or a family medicine clinic. Surveys were self-administered prior to office visits. Additional data were collected from the electronic medical record. Statistical analysis was performed.

Results:

A total of 149 patients were enrolled. Knowledge of therapeutic goals was reported by 14%, 34%, and 18% of survived patients for LDL-C, BP, and A1C, respectively. Forty-six percent, 37%, and 40% of patients achieved LDL-C, BP, and A1C goals, respectively. Low prescribing of cholesterol-lowering medications was an interesting secondary finding; 36% of patients not at LDL-C goal had not been prescribed a medication targeted to lower cholesterol. Forty-eight percent of patients were medication non-adherent; most frequently reported reasons for non-adherence were forgot (34%) and too expensive (14%). Patients at A1C goal were more adherent than patients not at goal (p=0.025).

Conclusion:

The majority did not reach goals and were unknowledgeable of goals; however, most were provided prescriptions to treat these parameters. Goal parameters should be revisited often amongst multidisciplinary team members with frequent and open communications. Additionally, it is imperative that practitioners discuss the importance of medication adherence with every patient at every visit.

Warfarin and royal jelly interaction

An 87-year-old African-American man came to the internal medicine clinic for a routine anticoagulation management visit. He had no complaints. His medical history was significant for stage IV-A follicular non-Hodgkin's lymphoma, atrial fibrillation, and hypertension. His long-term drug therapy consisted of warfarin, felodopine, lisinopril-hydrochlorothiazide, controlled-release diltiazem, potassium chloride, and oxycodone. He reported adherence with his prescribed drugs and denied taking any over-the-counter or herbal products. Overall, the patient's drug therapy had been consistent during the preceding 3 months, no significant changes had occurred in his clinical status, and no significant changes had been noted in his diet; his international normalized ratio (INR) had ranged from 1.9-2.4 (therapeutic range 2-3). He denied tobacco use, alcohol consumption, and recent travel. Four weeks later, the patient came to the emergency department with hematuria. He denied dysuria, taking more than the prescribed amount of warfarin, any changes in his diet, taking any over-the-counter or herbal products, and any other bleeding. On admission to the hospital, his INR was 6.88, which increased to 7.29 during his hospital stay. On further investigation, the patient admitted that he had started taking an herbal supplement, royal jelly, 1 week earlier. When asked specifically about the ingredients in the supplement, he stated that royal jelly was the only component. Relative to the patient's denial of any other changes in his condition or drug regimen, the most probable explanation for his elevated INR and subsequent bleeding is a possible interaction between royal jelly and warfarin. To our knowledge, no case reports concerning royal jelly and warfarin taken concomitantly have been reported. Clinicians should be proactive and repeatedly provide education regarding the potential dangers of dietary supplements taken with conventional drugs.

Assessment of patient knowledge of diabetic goals, self-reported medication adherence, and goal attainment

BACKGROUND

Medication adherence is an integral aspect of disease state management for patients with chronic illnesses, including diabetes mellitus. It has been hypothesized that patients with diabetes who have poor medication adherence may have less knowledge of overall therapeutic goals and may be less likely to attain these goals.

OBJECTIVE

The purpose of this study was to assess self-reported medication adherence, knowledge of therapeutic goals (hemoglobin A1C [A1C], low density lipoprotein cholesterol [LDL-C] and blood pressure [BP]), and goal attainment in adult patients with diabetes.

METHODS

A survey was created to assess medication adherence, knowledge of therapeutic goals, and goal attainment for adult patients with diabetes followed at an internal medicine or a family medicine clinic. Surveys were self-administered prior to office visits. Additional data were collected from the electronic medical record. Statistical analysis was performed.

RESULTS

A total of 149 patients were enrolled. Knowledge of therapeutic goals was reported by 14%, 34%, and 18% of survived patients for LDL-C, BP, and A1C, respectively. Forty-six percent, 37%, and 40% of patients achieved LDL-C, BP, and A1C goals, respectively. Low prescribing of cholesterol-lowering medications was an interesting secondary finding; 36% of patients not at LDL-C goal had not been prescribed a medication targeted to lower cholesterol. Forty-eight percent of patients were medication non-adherent; most frequently reported reasons for non-adherence were forgot (34%) and too expensive (14%). Patients at A1C goal were more adherent than patients not at goal (p=0.025).

CONCLUSION

The majority did not reach goals and were unknowledgeable of goals; however, most were provided prescriptions to treat these parameters. Goal parameters should be revisited often amongst multidisciplinary team members with frequent and open communications. Additionally, it is imperative that practitioners discuss the importance of medication adherence with every patient at every visit.

5-Year Evaluation of Electronic Medical Record Flag Alerts for Patients Warranting Secondary Prevention of Coronary Heart Disease

STUDY OBJECTIVES

To assess the effect of flag alerts that were placed in electronic medical records on patients' adherence with National Cholesterol Education Program (NCEP) guidelines for secondary prevention of coronary heart disease. A secondary objective was to identify the proportion of patients who were prescribed lipid-lowering agents and assess the barriers of patients who did not reach low-density lipoprotein cholesterol (LDL) goals 5.6 years after the intervention.

DESIGN

Retrospective analysis of a prospective medical record intervention.

SETTING

University-based primary care clinic.

PATIENTS

Eighty-nine adult patients with atherosclerotic vascular disease.

INTERVENTION

For each patient identified as needing secondary prevention for coronary heart disease according to NCEP guidelines, flags were inserted into the patient's electronic medical record.

MEASUREMENTS AND MAIN RESULTS

Baseline patient data were collected. After 5.6 years, we performed a retrospective analysis. At that time, 72 patients were evaluated; 17 were lost to follow-up. Fifty-four percent of patients (39 of 72 patients) had reached their LDL goal compared with 25% (16 of 64 patients for whom complete lipid panels had been obtained) at baseline (p=0.001). The proportion of patients prescribed lipid-lowering agents rose from 16% at baseline to 75% at follow-up (p=0.0001). However, 33 patients (46%) were above their LDL goal levels at follow-up. Reasons for failure to reach LDL goal were as follows: drug dosage not titrated (10 patients [30%]), adverse drug reaction (four patients [12%]), planned to adjust therapy in the future (three patients [9%]), high drug cost (two patients [6%]), drug contraindicated (two patients [6%]), and non-compliance (one patient [3%]). In 11 patients (33%), the reason for failure was not addressed in the progress notes. Thus, inadequate drug dosage titration (dosage not titrated, planned to adjust therapy, and reason not addressed [assume no action]) occurred in more than 70% of these patients.

CONCLUSIONS

These findings emphasize the need for regular evaluation of patients' lipid panels followed by appropriate therapy titration to reach LDL goals. Further study of factors influencing cholesterol management and methods to improve adherence is needed.

Effectiveness of Pharmacist-Administered Diabetes Mellitus Education and Management Services

STUDY OBJECTIVES

To evaluate the effectiveness of pharmacist-administered diabetes mellitus education and management services on selected diabetes performance measures. Additional goals were to compare outcomes with goals specified for patients with diabetes by the National Committee for Quality Assurance (NCQA) and identify areas for improvement.

DESIGN

One-year observational study.

SETTING

Three university-based primary care clinics.

PATIENTS

One hundred ninety-one patients with diabetes. Intervention. Pharmacist-provided diabetes education and management services.

MEASUREMENTS AND MAIN RESULTS

Each patient was assessed for hemoglobin A1c (A1C) values, blood pressure, low-density lipoprotein cholesterol (LDL) levels, and aspirin use at baseline and at 1 year after enrollment. Cost avoidance comparators were calculated for those patients with reductions in A1C of at least 1%. Average A1C at 1 year was 7.8% (range 4.5-13.9%) versus 9.5% (range 5.4-19%) at baseline (change -1.7%, p<0.05). Seventy-two patients (38%) experienced a 1% or greater reduction in A1C. Average blood pressure decreased over the study period from 141/79 to 135/75 mm Hg (p=0.007), but average LDL levels did not change to a statistically significant extent (114 to 112 mg/dl, p>0.05). Aspirin use increased from 34% at baseline to 73% at 1 year (p<0.0001). The program achieved the A1C and LDL values required to qualify for NCQA diabetes recognition. Based on an estimated savings of $820 for each 1% decrease in A1C, cost avoidance was calculated as $59,040.

CONCLUSION

Diabetes management services from clinical pharmacists achieved significant improvements in A1C values, blood pressure, and aspirin use. Continued efforts in diabetes education and management are needed to further improve clinical, economic, and humanistic outcomes.

Azithromycin and warfarin interaction

A 57-year-old Caucasian woman came to the clinic with symptoms of an upper respiratory tract infection. She was treated with a 5-day course of oral azithromycin 500 mg on day 1, then 250 mg/day for 4 days. During this period, the patient decreased her cigarette smoking from 1 pack/day to 1 pack every 3 days. No additional confounding variables were present. Two days after the completion of therapy, her international normalized ratio (INR) was 8.32. Six case reports documented in the literature have suggested an azithromycin-warfarin interaction with a resultant increase in INR. Many confounding variables existed in each of these cases, such as hepatic dysfunction, poor appetite, and concomitant drugs that resulted in an increased anticoagulant response. We report a case that involved only one potential confounding variable. Continued documentation of azithromycin-warfarin interactions is valuable considering no mention of this drug interaction exists in most tertiary references and in the package insert for azithromycin, the demonstration that no drug interaction occurred in a retrospective review of 52 cases, and the widespread use of azithromycin in the community. Clinicians should be mindful when prescribing azithromycin in combination with warfarin, and INR values should be monitored.

Atomoxetine, a Novel Treatment for Attention-Deficit–Hyperactivity Disorder

Atomoxetine is the first nonstimulant drug approved by the United States Food and Drug Administration (FDA) for the treatment of attention-deficit-hyperactivity disorder (ADHD), and the only agent approved by the FDA for the treatment of ADHD in adults. Atomoxetine is a norepinephrine transport inhibitor that acts almost exclusively on the noradrenergic pathway. Its mechanism of action in the control and maintenance of ADHD symptoms is thought to be through the highly specific presynaptic inhibition of norepinephrine. Clinical trials to evaluate the short-term effects of atomoxetine in children and adults have shown that atomoxetine is effective in maintaining control of ADHD. Likewise, long-term trials have determined that atomoxetine is effective in preventing relapse of ADHD symptoms without an increase in adverse effects. A comparative trial of atomoxetine with methylphenidate in school-aged children indicated similar safety and efficacy without the abuse liability associated with some psychostimulants. The most commonly reported adverse effects in children and adolescents are dyspepsia, nausea, vomiting, decreased appetite, and weight loss. The rates of adverse events in the trials were similar for both the once- and twice-daily dosing regimens. The discontinuation rate was 3.5% in patients treated with atomoxetine versus 1.4% for placebo and appeared to be dose dependent, wit a higher percentage of discontinuation at dosages greater than 1.5 mg/kg/day. In clinical trials involving adults, the emergence of clinically significant or intolerable adverse events was low. The most common adverse events in adults were dry mouth, insomnia, nausea, decreased appetite, constipation, urinary retention or difficulties with micturition, erectile disturbance, dysmenorrhea, dizziness, and decreased libido. Sexual dysfunction occurred in approximately 2% of patients treated with atomoxetine. Atomoxetine should be used with caution in patients who have hypertension or any significant cardiovascular disorder. Overall, atomoxetine therapy in patient with ADHD appears to be effective in controlling symptoms and maintaining remission, with the advantages being comparable efficacy with that of methylphenidate, a favorable safety profile, and non-controlled substance status. Additional long-term studies are needed to determine its continued efficacy for those who require lifelong treatment, and comparative trials against other stimulant and nonstimulant agents.

National survey of pharmacist certified diabetes educators

We sought to determine the demographics of pharmacists who were certified diabetes educators (CDEs) and information about their training, professional affiliations, and types of diabetes education services that they provide. We also queried these pharmacists about clinical activities, reimbursement, impact of certification, and intent to pursue CDE recertification. A list of pharmacists who were CDEs as of August 31, 2000, was obtained from the National Certification Board for Diabetes Educators. We then sent a six-page anonymous survey to 415 pharmacist CDEs; 233 surveys (56.1%) were returned. Of these respondents, 140 are women and 93 are men, with a mean age of 41.5 years. Most reside in Southern or Western states. Average time since pharmacist licensure was 17 years, and average time as a CDE was 5 years. Most had completed postgraduate training, including residencies and/or fellowships; 52.8% had faculty appointments; 46.7% stated they were billing for their services; and 45.9% were obtaining reimbursement. Most pharmacists (84.4%) stated that they intended to pursue CDE recertification. Providing details about pharmacist CDEs and their clinical activities may motivate other pharmacists to pursue this credential. Pharmacists are often the most accessible of all health care providers, and earning the CDE credential may be an important contribution to diabetes care and education.