Clinical

Didanosine plus ribavirin can be toxic in HIV patients treated for hepatitis C

Last Updated: 2005-10-06 13:21:17 -0400 (Reuters Health)

By David Douglas

NEW YORK (Reuters Health) - The use of didanosine in HIV patients receiving hepatitis C virus (HCV) therapy with interferon and ribavirin increases the risk of symptomatic mitochondrial toxicity, according to French researchers.

"Clinicians should be aware of the potential overlapping toxicity of treatments for HCV and HIV infection," lead investigator Dr. Firouze Bani-Sadr told Reuters Health. "If the two treatments must be administered concomitantly, didanosine should be avoided. Ribavirin is known to enhance didanosine phosphorylation. "

In the September 1st issue of the Journal of Acquired Immunodeficiency Syndromes, Dr. Bani-Sadr of Hopital Saint Antoine, Paris and colleagues note that there have been reports that HCV therapy can cause symptomatic mitochondrial toxicity in HIV patients receiving highly active antiretroviral therapy.

To evaluate associated risk factors, the researchers reviewed data on HIV and HCV coinfected patients taking part in a trial of interferon and ribavirin treatment.

Eleven of 283 patients who received at least one dose of HCV treatment developed symptomatic mitochondrial toxicity. This manifested itself as symptomatic hyperlactatemia in six patients and pancreatitis in five patients.

The overall incidence was 47.5 per 1000 patient-years. In patients receiving didanosine, however, the incidence was 200.2 per 1000 patient-years. With didanosine, there was a 46-fold increase in the relative risk of symptomatic mitochondrial toxicity. No increase was seen in patients on regimens that did not contain didanosine.

Given these findings, the researchers conclude that coadministration of ribavirin and didanosine should be avoided, "if unavoidable," they add, "patients should be monitored closely for signs of mitochondrial toxicity."

J Acquir Immune Defic Syndr 2005;40:47-52.