Comparison of Patients Receiving Long-Term Metformin Therapy and Vitamin B12 Monitoring.

Background: Metformin may cause vitamin B12 deficiency that can present with symptoms of peripheral neuropathy. Lack of vitamin B12 serum concentration monitoring could result in vitamin B12 deficiency progression, worsening of symptoms, and unnecessary medication. Objectives: The purpose of this study was to (a) compare the influence of the rate of symptoms consistent with vitamin B12 deficiency on obtaining vitamin B12 serum concentrations in patients using metformin; (b) assess if vitamin B12 serum concentrations were ordered as a routine monitoring parameter. Methods: This retrospective case-control study evaluated patients receiving metformin. Patients in the case group had documented symptoms or diagnosis of peripheral neuropathy or macrocytic anemia, while those in the control group did not. The primary outcome was frequency of vitamin B12 serum concentration assessment. The secondary outcomes included frequency of vitamin B12 serum concentration assessment for patients presenting with symptoms or diagnosis of peripheral neuropathy or macrocytic anemia. Results: Analysis included 355 patients (116 cases, 239 controls). The cases were 5 times more likely to have a serum vitamin B12 serum concentrations drawn versus controls (odds ratio [OR] = 5.83, 95% confidence interval [CI] = 3.47-9.77, P < .001). Patients with a diagnosis of peripheral neuropathy or macrocytic anemia were 4 times more likely to have a serum vitamin B12 concentration drawn than those who did not (peripheral neuropathy: OR = 4.92, 95% CI = 2.95-8.21, P < .001; macrocytic anemia: OR = 5.41, 95% CI = 1.30-20.97, P = .007). Conclusions: Cases were more likely to have vitamin B12 serum concentrations assessed than patients without symptoms. The majority of patients taking metformin did not have routine vitamin B12 serum concentration assessments for medication adverse event monitoring.

Impact of pharmacists' interventions and simvastatin dose restrictions.

BACKGROUND: On June 8, 2011, the United States Food and Drug Administration (FDA) reported safety concerns regarding statin-related myopathies and advised further restrictions on simvastatin dosing. These restrictions reduced the maximum dose for specific patient characteristics, primarily certain concomitant medications. OBJECTIVE: The purpose of this study was to compare the effectiveness of 2 different pharmacist-conducted educational interventions on appropriate simvastatin use in the primary care setting. METHODS: This retrospective cohort analysis was conducted in 2 academic medical center clinics. Patients prescribed simvastatin before June 8, 2011, requiring dosage adjustment based on labeling changes were evaluated for study inclusion. The pharmacists' interventions included: 30-minute didactic session for prescribers or patient-specific recommendation communicated with the physician during the patient's follow-up visit. Primary outcomes were the number of patients prescribed FDA-recommended simvastatin doses after pharmacist intervention and the intervention's impact on low-density lipoprotein (LDL). RESULTS: Medical record review identified 1173 patients prescribed simvastatin prior to June 8, 2011; 126 patients qualified for study inclusion. After controlling for baseline characteristics, the likelihood of patients being prescribed an appropriate dose postintervention increased if they were in the patient-specific recommendation group (odds ratio [OR] = 10.59; 95% CI = 3.43-32.69; P < .0001). LDL change occurred at a similar rate between intervention groups (P = .652). CONCLUSION: Following FDA labeling changes for simvastatin, patient-specific recommendations made by pharmacists correlated with a greater likelihood of appropriate simvastatin dosing compared with a one-time didactic education session. Patient-specific recommendations positively affect prescribing habits and making steps to improve patient safety.

ß-Blocker use and incidence of chronic obstructive pulmonary disease exacerbations.

BACKGROUND: ß-Adrenergic antagonist (ß-blocker) use in patients with chronic obstructive pulmonary disease (COPD) has been avoided as a result of potential risk of pulmonary adverse effects. However, recent studies indicate that ß-blocker use in patients with COPD can decrease outpatient visits and either decrease or have no effect on the number of hospitalizations. Long-term treatment with ß-blockers has been shown to increase survival and decrease exacerbations in patients with COPD. OBJECTIVE: To assess the impact of ß-blocker use on the incidence of exacerbations in patients with COPD. METHODS: In a retrospective cohort study of patients with COPD from 2 academic primary care practice sites who were seen in 2010, patients were identified using International Classification of Diseases, 9th revision, Clinical Modification codes for COPD and reviewing active medication lists for COPD-specific medications (tiotropium). Patients were classified as either a ß-blocker user or a nonuser. Primary outcomes were incidence and severity of COPD exacerbations. Secondary outcomes included COPD exacerbations distinguished by ß-blocker cardioselectivity and all-cause hospitalizations. RESULTS: The study enrolled 412 patients. Of those, 166 patients were ß-blocker users and 246 were ß-blocker nonusers. ß-Blocker users were less likely to have a COPD exacerbation (OR 0.61, 95% CI 0.40-0.93) and had fewer mild exacerbations (OR 0.56; 95% CI 0.34-0.89). There was no significant difference in COPD exacerbations based on ß-blocker cardioselectivity (OR 0.84, 95% CI 0.38-1.83). When controlled for, using a backwards stepwise logistic regression, ß-blocker use was a variable in the model that predicted exacerbations but alone was not statistically significant (adjusted OR 0.62, 95% CI 0.39-1.01). CONCLUSIONS: Patients with COPD prescribed a ß-blocker were significantly less likely to have a COPD exacerbation and had fewer mild COPD exacerbations.