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Metabolic abnormalities associated with the treatment of human immunodeficiency virus (HIV) infection are well-recognized problems that increase cardiovascular risk. As a result of the complexity of treating both HIV- and antiretroviral-related comorbidities, strategies that improve adverse drug events while maintaining viral control are in critical need. Although guidelines have somewhat helped in the general approach and in first-line strategies for managing dyslipidemia in patients receiving antiretrovirals, a paucity of data exist to guide clinicians in treating patients whose conditions are refractory to first-line options or who are at substantial risk for cardiovascular events. Further complicating the choice of lipid-lowering strategy is the lack of randomized controlled data from the HIV-affected population and a concern about clinically significant drug-drug interactions. We describe an HIV-infected patient with efavirenz-associated dyslipidemia at very high cardiovascular risk who had not achieved his primary or secondary lipid goals despite 2 years of treatment in a lipid specialty clinic. Lipid control was accomplished in 10 weeks with a targeted, stepwise approach of switching efavirenz to nevirapine, followed by rosuvastatin 20 mg/day, which was sustained for at least 10 months. Of most importance, this outcome was achieved without any clinically significant alteration in virologic or immunologic control. This case report highlights the potential for a pharmacist-guided, multistep approach that addresses HIV-related dyslipidemia and incorporates the pharmacokinetic literature to guide lipid-lowering therapy and promote the attainment of goals based on current standards of care.

Background Atazanavir (ATV), an HIV protease inhibitor (PI) that may be preferred for the treatment of HIV-infected patients with cardiovascular comorbidities because of its favourable effects on plasma lipids, has been associated with cardiac rhythm disturbances. Objective To quantify the effect of ATV on corrected QT (QTc) and QTc dispersion (QTd), markers of the potential for cardiac dysrhythmia, in patients switching from other PIs to ATV. Methods In this prospective, single-centre, open-label study, 12-lead electrocardiograms were performed for subjects at baseline, 2 h after the first dose of ATV, and 1 month after initiation of ATV. Results Twenty-one patients (19 received ritonavir-boosted ATV) completed the study. There was a trend towards an increase in the QTc at 2 h after the first dose [mean±standard deviation 3.19±8.0 ms; 95% confidence interval (CI) −0.47 to 6.85 ms; P=0.084]. There was no difference between QTc values at baseline and at 1 month (−1.5±8.75 ms; 95% CI −5.50 to 2.46; P=0.43). There was a nonsignificant decrease in the QTd between baseline and 2 h (−5.1±15.19 ms; 95% CI −13.22 to 2.96; P=0.197) and between baseline and 1 month (−0.61±15.04 ms; 95% CI −8.1 to 6.87; P=0.865). A significant increase in the PR interval (7.4±10.7 ms; 95% CI 2.5 to 12.25 ms; P=0.005) was observed at 1 month. Conclusions The use of ATV did not result in increases in the QTc interval or QTd. However, PR interval monitoring may be warranted in patients with underlying heart block or those treated with atrioventricular nodal blocking agents.

Atazanavir is the first once-daily protease inhibitor for the treatment of human immunodeficiency virus type 1 infection and should be used only in combination therapy, as part of a highly active antiretroviral therapy (HAART) regimen. In addition to being the most potent protease inhibitor in vitro, atazanavir has a distinct cross-resistance profile that does not confer resistance to other protease inhibitors. However, resistance to other protease inhibitors often confers clinically relevant resistance to atazanavir. Currently, atazanavir is not a preferred protease inhibitor for initial HAART regimens. In treatment-naive patients, atazanavir can be given as 400 mg/day. However, atazanavir should be pharmacologically boosted with ritonavir in treatment-experienced patients or when coadministered with either tenofovir or efavirenz. Patients who receive atazanavir experience similar rates of adverse events compared with patients receiving comparator regimens. An exception is an increased risk of asymptomatic hyperbilirubinemia, which is due to competitive inhibition of uridine diphosphate-glucuronosyltransferase 1A1. Although hyperbilirubinemia is a common adverse drug reaction of atazanavir therapy (22-47%), fewer than 2% of patients discontinue atazanavir therapy because of this adverse effect. Common adverse effects reported with atazanavir include infection, nausea, vomiting, diarrhea, abdominal pain, headache, peripheral neuropathy, and rash. Of significance, fewer abnormalities have been observed in plasma lipid profiles in patients treated with atazanavir compared with other protease inhibitor-containing regimens. As with other protease inhibitors, atazanavir is also a substrate and moderate inhibitor of the cytochrome P450 (CYP) system, in particular CYP3A4 and CYP2C9. Clinically significant drug interactions include (but are not limited to) antacids, proton pump inhibitors, histamine type 2 receptor antagonists, tenofovir, diltiazem, irinotecan, simvastatin, lovastatin, St. John's wort, and warfarin. We conclude that atazanavir is a distinctively characteristic protease inhibitor owing to its in vitro potency, once-daily dosing, distinct initial resistance pattern, and infrequent association with metabolic abnormalities.

Unfractionated heparin and warfarin have been the mainstay of treatment of venous thromboembolism (VTE) for approximately half a century. However, both agents are difficult to dose accurately, require frequent blood testing and dosage adjustment, and can cause serious adverse effects. Oral direct thrombin inhibitors may provide more predictable anticoagulation with oral dosing, without the need for frequent blood test monitoring and without the adverse effects seen with conventional agents. The oral direct thrombin inhibitor closest to being marketed is ximelagatran, which has been through phase III trials. Available data thus far suggest that the efficacy and safety of this agent may allow it to replace both heparin (and low-molecular-weight heparin) and warfarin for VTE treatment and long-term prophylaxis. Concerns about ximelagatran that require further study are a 5-9% rate of transient elevation in liver enzyme levels, drug interactions, how patient adherence can be ensured in the absence of blood tests, and whether alterations in renal or hepatic function will require dosage adjustments. Although there is more to learn about ximelagatran, available data suggest that it is likely to be the most significant therapeutic advance in this area in over 50 years.

Serotonin (5-hydroxytryptamine [5-HT])1 receptor agonists, such as those used for treating migraine, can cause coronary artery contraction, coronary spasm, and even myocardial infarction. Tegaserod maleate is a relatively new 5-HT4 receptor agonist with moderate affinity for the 5-HT1 receptor. Currently, it is approved only for treatment of irritable bowel syndrome in women who have constipation as the primary symptom. However, it is also being administered as a promotility agent in patients with gastroparesis. Since tegaserod has affinity for the 5-HT1 receptor, it is plausible that tegaserod could cause the same types of cardiovascular adverse events seen with agents prescribed for management of migraine. We report the first case of a man who experienced a myocardial infarction after receiving only two 6-mg doses of tegaserod; we also provide a hypothesis regarding this event. When considering prescribing a drug with 5-HT1 receptor agonist activity, clinicians should review the patient's medical history specifically for the presence of underlying cardiovascular risk factors.