William W. McCloskey

Dietary vitamin K variability affects international normalized ratio (INR) coagulation indices

BACKGROUND Changes in daily vitamin K intake may contribute to marked variations in the International Normalized Ratio (INR) coagulation index in patients receiving oral warfarin anticoagulant therapy, with potentially serious adverse outcomes. Thus, patients receiving warfarin therapy are routinely counseled regarding this drug-nutrient interaction and are instructed to maintain consistent vitamin K intakes, though little quantitative information about this relationship is available. OBJECTIVE To determine the quantitative impact of variability in dietary vitamin K(1) (phylloquinone) intake, assessed by a validated patient self-monitoring instrument, on weekly INR in patients receiving warfarin anticoagulant therapy. METHODS A prospective dietary assessment study was conducted at the Massachusetts General Hospital in Boston. Sixty outpatients (37 males and 23 females) were selected with a mean age 60.3 +/- 16.8 years, who began oral warfarin anticoagulant therapy within 14 days prior to their first clinic visit to an outpatient anticoagulation therapy unit. Exclusion criteria included more than 2 drinks of alcohol per day, inability to speak English, and concurrent disease states affecting warfarin therapy such as liver disease and terminal illness. Over the five-week study period, participants recorded daily intakes in specified amounts of all food items appearing on a validated dietary self-assessment tool. Concomitant use of prescription and/or non-prescription medications was also obtained. Concurrent daily warfarin dose and adherence to the drug regimen, concomitant use of prescription and/or non-prescription medications known to interact with warfarin, and weekly INR were obtained. Week-to-week changes in vitamin K intake, warfarin dose, and INR were determined and cross-correlated. RESULTS Forty-three patients (28 males and 15 females) completed the study and 17 dropped out. Pearsons correlation coefficient revealed the variability in INR and changes in vitamin K intake were inversely correlated (r = -0.600, p < 0.01). Multiple regression analysis (r = 0.848) indicated that a weekly change of 714 mug dietary vitamin K significantly altered weekly INR by 1 unit (p < 0.01) and a weekly change of 14.5 mg warfarin significantly altered weekly INR by 1 unit (p < 0.01) after adjustment for age, sex, weight, height, and concomitant use of medications known to interact with warfarin. CONCLUSIONS Patients taking warfarin and consuming markedly changing amounts of vitamin K may have a variable weekly INR with potentially unstable anticoagulant outcomes.

An interprofessional service-learning course: uniting students across educational levels and promoting patient-centered care.

Recognizing the importance of interprofessional education, we developed a pilot interprofessional education course at our institution that included a total of 10 nursing, BS health psychology, premedical, and pharmacy students. Course goals were for students to: 1) learn about, practice, and enhance their skills as members of an interprofessional team, and 2) create and deliver a community-based service-learning program to help prevent or slow the progression of cardiovascular disease in older adults. Teaching methods included lecture, role-play, case studies, peer editing, oral and poster presentation, and discussion. Interprofessional student teams created and delivered two different health promotion programs at an older adult care facility. Despite barriers such as scheduling conflicts and various educational experiences, this course enabled students to gain greater respect for the contributions of other professions and made them more patient centered. In addition, inter-professional student teams positively influenced the health attitudes and behaviors of the older adults whom they encountered.

Risk of Gastric Injury with Enteric- versus Nonenteric-Coated Aspirin:

OBJECTIVE: To evaluate through clinical trials the risk of various aspirin preparations on the gastric mucosa. DATA SOURCES: Articles reporting clinical research were accessed through MEDLINE (1980–November 1998). Key search terms included enteric-coated aspirin, buffered aspirin, and gastrointestinal (GI) bleeding. DATA SYNTHESIS: Aspirin products are known to cause GI bleeding. Enteric-coated aspirin may provide an additional protective effect on gastric mucosa compared with buffered aspirin. An evaluation of studies comparing various aspirin preparations and the risk of gastric mucosal injury was conducted. CONCLUSIONS: For long-term use, enteric-coated aspirin may provide a safer alternative than buffered aspirin; however, further studies are necessary.

Combined Use of Online Tutorials and Hands-On Group Exercises in Bibliographic Instruction for Pharmacy Students

This study describes the new blended learning methodology implemented in a Drug Literature Evaluation course for pharmacy students that involves combined use of online tutorials and in-class group exercises. Assignment grades earned by 909 students enrolled in the course before and after the new methods were implemented (2008–2010) were studied to measure student performance. Course evaluations were analyzed in order to ascertain students’ perceptions. The hybrid approach used to deliver the course content allowed students to perform at the same level as traditional didactic teaching. Students’ evaluations reported a positive educational experience and favorable perceptions of the new course design.

An update on the pharmacological treatment of obesity

ABSTRACT Objective: To review the commonly utilized pharmacological options for the treatment of overweight and obese patients in the United States. Methods: A MEDLINE and EMBASE search, in English, between January 1995 and November 2005 was conducted using the terms, ‘anti-obesity agents’, ‘orlistat’, ‘sibutramine’, and ‘phentermine’. References cited in relevant studies and reviews were also examined for additional clinical trials to be included in the review. Results: There are several pharmacological options currently available for the treatment of overweight and obese individuals in the United States, including phentermine, sibutramine, and orlistat, with only sibutramine and orlistat being indicated for use in the long term (> 6 months). However, none of these medications have proven to be more effective than another for the indication of weight loss, each with a very similar maximum weight loss potential. Therefore choosing a weight loss medication should be patient specific and based on its pharmacological profile, including mechanism of action and potential adverse effects. Most importantly, it is imperative to realize that these agents are only indicated for use when combined with lifestyle modifications. Most studies have indicated that maximum benefits from any of these medications are only shown when taken in addition to a hypocaloric diet. Conclusion: It has been shown that the combination of lifestyle changes and pharmacological treatment leads to a greater decrease in total body weight loss. Treatment with anti-obesity agents is associated with side effects and an increased cost in health care. These factors must be weighed prior to initiating anti-obesity treatment.

Glutathione in Hypersensitivity to Trimethoprim/Sulfamethoxazole in Patients with HIV Infection

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Potentiation of Nephrotoxicity by H2-Antagonists in Patients Receiving Cyclosporine

The literature does not support a pharmacodynamic interaction between H2-antagonists and cyclosporine that would result in potentiation of cyclosporines nephrotoxicity. The increase in serum creatinine associated with cimetidine, in the majority of cases, is due to competition with creatinine for tubular secretion. Ranitidine is unlikely to produce a change in serum creatinine. Additionally, there is no support for a pharmacokinetic interaction. However, cimetidine may influence peak concentrations of cyclosporine. Besides the clinical data reviewed here, two abstracts concur with these findings. Information was unavailable regarding interactions between cyclosporine and either famotidine or nizatidine that potentiate nephrotoxicity in transplant patients. Furthermore, the drug manufacturers state that no evidence is available to support any interaction of their products with cyclosporine. Thus, interpretation of renal function may be confusing with concomitant administration of cimetidine and cyclosporine unless GFR is accurately monitored. On the basis of the information available at this time, ranitidine may be considered the H2-antagonist of choice in a patient treated with cyclosporine.