Lamivudine can heighten transplacental zidovudine toxicity.(Brief Article)

2002 JUN 6 - (NewsRx.com & NewsRx.net) -- by Michael Greer, senior medical writer - The antiretroviral agent lamivudine may increase the toxicity of zidovudine when the two drugs are used to prevent peripartum transmission of HIV, researchers in the United States warn.

"Antiretroviral nucleoside analogue drugs are a major constituent of highly active antiretroviral therapy (HAART), the most advanced form of treatment for HIV-1 infection," explained Dr. Ofelia A. Olivero and colleagues at the National Cancer Institute in Bethesda and BioQual Inc. in Rockville, Maryland. "Currently, HAART combinations that include zidovudine (ZDV) and lamivudine (3TC) are highly effective in preventing HIV-1 vertical transmission; most children are born with no evident adverse clinical effects."

However, animals exposed to this drug combination in utero showed genetic damage that could lead to long-term sequelae, Olivero and coauthors found.

The researchers evaluated the effects of zidovudine and/or lamivudine in Erythrocebus patas monkeys. Animals treated with prepartum zidovudine alone showed few signs of toxicity, they said.

However, monkeys exposed to both zidovudine and lamivudine demonstrated DNA damage at least double that shown by singly treated animals. Moreover, monkeys treated with both antiretroviral agents in utero displayed a significant amount of telomere shortening in cells from a number of organs, study data showed.

Telomere shortening was seen only occasionally ...