Reuters 19 Oct. 2001

New York -- As many as two-thirds of patients on HIV drug combinations may suffer a medication side effect that could affect their adherence to therapy, new study results suggest.

Antiretroviral therapy for HIV is known to carry side effects of varying severity, from elevated cholesterol levels to abnormal body- fat deposits and certain blood disorders, but exactly how common these problems are has been unclear.

In a study of 1,160 patients on at least three HIV drugs, Swiss researchers found that more than two-thirds suffered symptoms such as vomiting, diarrhea or sleep disturbance, or showed problems in lab results, such as potentially serious abnormalities in blood cells, proteins or cholesterol.

All of these conditions could have been due to the patients' HIV therapy, the investigators report in the October 20th issue of The Lancet.

A "significant proportion'' of these side effects were serious or severe, according to Dr. Jacques Fellay, of the University Hospital of Lausanne, and his colleagues.

Of the lab abnormalities, 16% were serious or severe, the researchers report. A few patients had been hospitalized for conditions such as kidney dysfunction and severe fatigue that were "probably or definitely'' due to their HIV treatment.

Side effects varied based on the specific drugs in a patient's regimen. Among the "unexpected'' side effects, the researchers note, were a blood-clotting disorder called thrombocytopenia that was linked to the drug saquinavir and mood disorders associated with the drug lamivudine.

They acknowledge, however, that because the study patients were being seen frequently in a clinic--some specifically for problems with drug side effects--the results may not reflect HIV patients as a whole.

Still, Fellay's team calls for more study of HIV drugs' toxic effects and how to make them more tolerable.

"It should be underscored,'' they write, "that more than two-thirds of patients might have complaints if precisely questioned and that adverse events have an effect on adherence and on development of viral resistance, which might lead to treatment discontinuation or failure.''

Source: The Lancet 2001;358:1322-1327.