Pre-exposure prophylaxis (PrEP) has been shown to reduce the risk of HIV transmission but has the potential to cause harm if not used properly. Pharmacists are well-positioned to foster PrEP's efficacy but little is known whether they would endorse it as an HIV prevention tool. The objective of the study was to determine Canadian HIV pharmacists' support for PrEP and to identify current barriers to promoting PrEP. Canadian pharmacists with experience in HIV care were invited to complete an online survey about their experiences, opinions, and learning needs regarding PrEP from December 2012 to January 2013. Among the 59 surveys received, 48 met criteria for final analysis. Overall, 33 (69%) respondents would provide education positively supporting the use of PrEP and 26 (54%) believed Health Canada should approve PrEP for use in Canada. Familiarity with the concept of PrEP and practice characteristics examined did not appear to be significantly associated with support for PrEP in univariable analyses. The principal barriers to promoting PrEP included inadequate drug coverage and insufficient knowledge to educate others. Many Canadian HIV pharmacists would endorse PrEP for high-risk patients; however, wider dissemination of information and lower drug costs may be needed to make PrEP more widely promoted.

The intrahepatic cholestasis attributed to parenteral nutrition (PN) in the adult patient is relatively rare and usually occurs in patients receiving long-term PN. This article reports the first case of an adult patient with cholestatic PN-associated liver disease without sepsis who received almost all her nutrition requirements through PN. Administration of an ω-3-enriched lipid emulsion added to the PN regimen reversed cholestasis and demonstrated histologic improvement on serial liver biopsy. The patient had failed to respond to other modalities of treatment for this condition and was deeply jaundiced. Liver biochemistry profiles returned to baseline, and follow-up liver biopsy showed that cholestasis had resolved and that the only residual changes were mild portal inflammation with no histochemical or ultrastructural progression. The PN regimen for the patient was restored to provide total estimated energy requirements and remains the principle source of the patient's nutrition to date.

Efavirenz (EFV) is primarily metabolized by cytochrome P450 (CYP) 2B6 and to a lesser extent by CYP3A4. Drugs that significantly inhibit or induce these enzymes would then be expected to increase or lower the levels of EFV potentially resulting in toxicity or therapeutic failure, respectively. The constituents of Ginkgo biloba extract have been demonstrated to induce gene expression of the CYP450 enzymes. We report a case in which a potential drug-herb interaction may have led to virological breakthrough in a patient that was maintained on the same regimen for 10 years. Therefore, a drug-herbal interaction may be expected when these agents are taken concurrently, and we advise clinicians to avoid this combination when possible.

The cytochrome P450 isoforms primarily involved in clobazam metabolism are CYP3A4 and 2C19. Drugs that modulate these enzymes would then be expected to alter the exposure of clobazam and its major metabolites. Etravirine, a second-generation non-nucleoside reverse transcriptase inhibitor has been shown to induce CYP3A4, while inhibiting CYP2C9 and CYP2C19. We report a case in which a potential drug interaction between clobazam and etravirine may have led to increased concentrations of clobazam and its pharmacologically active metabolite, N-desmethylclobazam, causing neurotoxic symptoms.

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