Many workers cite side effects in dropping PEP

CDC issues final postexposure registry report

About half the health care workers who discontinue postexposure prophylaxis (PEP) to prevent HIV infection cited nausea and other side effects as their reason for abandoning drug regimens, the Centers for Disease Control and Prevention reports.

The CDC recently released the final report on the HIV PEP registry, reflecting data collected from Oct. 17, 1996, through March 31, 1999. The registry was closed to new enrollments on Dec. 31, 1998, but collection of follow-up information continued through March.

The registry included data on 492 health care workers. Of those enrolled, 71% were female, and the overall median age was 37 years. The median time for exposure treatment was 1.75 hours. The majority (63%) of PEP regimens administered consisted of three or more drugs. Of the 449 workers for whom four to six weeks follow-up were available, the median therapy duration for at least one of the PEP drugs prescribed was 28 days.

Overall, 195 (43%) of workers completed all the drugs in the PEP regimens as initially prescribed. In contrast, 197 (44%) discontinued all PEP drugs and did not complete the regimen. Also, 39 (9%) discontinued one or more drugs and/or modified drug dosage and/or added a drug but did complete a course of PEP. The remaining 16 workers (4%) completed modified regimens, which did not involve discontinuation of any of the drugs in the original regimen. Of the 197 workers who discontinued PEP drugs, 95 (48%) did so because the source patient tested HIV-negative. (See table, p. 144.)

Overall, 76% of workers with four to six weeks of follow-up reported some adverse symptoms. The most frequently cited symptoms were nausea (57 %); fatigue/malaise (38%); headache (18%); vomiting (16%); and diarrhea (14%). (See table, p. 145.)

Of those workers who discontinued PEP drugs, 50% cited the symptoms and side effects as their reasons for doing so. The median time from start of PEP to onset of the five most frequently reported symptoms was three to four days. Serious adverse events were reported to the registry for six health care workers, but five of those had resolved at six months’ follow-up. The one listed as a continuing problem in the report involved a worker who was experiencing intermittent problems with eye focus.

The CDC and its advisors concluded that there was not adequate statistical power in the registry to draw any definitive conclusions on rates of occurrence of toxicity or to imply problems with any particular drug. "Even though side effects were reported frequently, these limited data suggest that toxicity was not generally severe/serious," the report concludes. "In addition, the reported adverse events appeared to be consistent with those listed in the product labeling for each respective agent."

(Editor’s note: The CDC report is available on the Internet at www.cdc.gov/ncidod/hip/default.htm.)