HIV-positive pregnant women should take a higher-than-normal dose of Kaletra (lopinavir/ritonavir) during the three months leading up to delivery, according to a study published online in the Journal of Acquired Immune Deficiency Syndromes (JAIDS). These results explain increasing dosing recommendations by the U.S. Department of Health and Human Services (DHHS) in order to help reduce the risk of treatment failure and drug resistance during the third trimester of pregnancy.

The preferred protease inhibitor for HIV-positive pregnant women is Kaletra, according to the DHHS. Because blood levels of lopinavir—the active protease inhibitor in Kaletra—can drop by as much as 50 percent during the third trimester, DHHS recommends taking four Kaletra capsules twice a day during the final three months of pregnancy to circumvent this.

The JAIDS article, authored by Mark Mirichnick, MD, of Boston University School of Medicine and his colleagues and published November 22, highlights the data from a Pediatric AIDS Clinical Trials Group study (PACTG 1026s) that led to this important recommendation. Whereas the usual Kaletra dose, using the original formulation of the drug, is three capsules twice a day, the dose needed to maintain necessary drug levels in 26 women in the final three months of their pregnancies was four capsules twice a day.

The researchers also found that the standard dose of Kaletra capsules, used during the second trimester of pregnancy, also resulted in lower-than-normal blood levels in some women.   

The DHHS embraced the PACTG study results and now recommends that all HIV-positive women take four Kaletra capsules twice a day during the third trimester of pregnancy. The researchers go one step further and suggest that women in the second trimester consider bumping their Kaletra dose as well.

Dosing recommendations involving the newer tablet formulation of Kaletra—containing higher concentrations of both lopinavir and ritonavir—will depend on the results of ongoing studies. Until then, the older Kaletra capsules remain available and may still be prescribed by health care providers during pregnancy.