Switching from efavirenz to nevirapine to avoid CNS side effects

Although guidelines widely recommend use of efavirenz (EFV, Sustiva, Stocrin) plus two nucleosides for initial therapy a percentage of patients find the associated CNS side effects substantially reduces their quality of life.

Ward and colleagues from a private practice in Washington DC performed a retrospective review of 34 patients with undetectable viral load <50 copies/mL, and three patients with 50-1000 copies/mL, who switched from efavirenz to nevirapine due to CNS-related side effects or lipid problems. The two viral load tests prior to the switch were compared to most results in October 2003.

In the absence of data on the interaction between the two drugs, and the specific effect on the pharmacokinetic induction of metabolism, nevirapine was started at a dose of 200mg once-daily for two weeks, overlapping efavirenz therapy. Efavirenz was then stopped and nevirapine increased to the 200mg twice-daily dose.

All patients who were undetectable at the switch have remained <50 copies after a median of 25 months (range 6-59). Two of the intermittently detectable patients have remained between 50-1000 copies/mL and one has become persistently <50 copies/mL.

Patients who previously reported psychiatric problems (depression, anxiety or fatigue, with or without sleep disturbance) all resolved or significantly improved. Four patients with previous isolated sleep disturbance all had significant improvement in quality of sleep.

One patient, the only woman in the cohort, switched to nevirapine in order to become pregnant, had artificial insemination and delivered a healthy HIV-negative baby boy.

Ward DJ, Curtain JM. Substitution of nevirapine for efavirenz in virologically controlled patients intolerant of efavirenz. 9th EACS, Warsaw. 25-29 October 2003. Abstract 7.5/1.