Ziagen Use In Pregnancy & Lactation

Abacavir has been evaluated in the Antiretroviral Pregnancy Registry in over 2000 women during pregnancy and postpartum. Available human data from the Antiretroviral Pregnancy Registry do not show an increased risk of major birth defects for abacavir compared to the background rate (see Pharmacology: Pharmacodynamics: Clinical Studies under Actions). However, there are no adequate and well-controlled trials in pregnant women and the safe use of ZIAGEN in human pregnancy has not been established. Abacavir has been associated with findings in animal reproductive studies (see Pharmacology: Toxicology: Pre-clinical Safety Data under Actions). Therefore administration of ZIAGEN in pregnancy should be considered only if the benefit to the mother outweighs the possible risk to the foetus.
There have been reports of mild, transient elevations in serum lactate levels, which may be due to mitochondrial dysfunction, in neonates and infants exposed in utero or peri-partum to NRTIs. The clinical relevance of transient elevations in serum lactate is unknown. There have also been very rare reports of developmental delay, seizures and other neurological disease. However, a causal relationship between these events and NRTI exposure in utero or peri-partum has not been established. These findings do not affect current recommendations to use antiretroviral therapy in pregnant women to prevent vertical transmission of HIV.
Health experts recommend that where possible HIV infected women do not breast feed their infants in order to avoid transmission of HIV. In settings where formula feeding is not feasible, local official lactation and treatment guidelines should be followed when considering breast feeding during antiretroviral therapy.
In a study after repeat oral administration of 300 mg abacavir twice daily (given as TRIZIVIR), the breast milk:maternal plasma ratio was 0.9. Most infants (8 out of 9) had non-detectable levels of abacavir (assay sensitivity 16ng/mL). Intracellular carbovir triphosphate (active metabolite of abacavir) levels in breastfed infants were not measured therefore the clinical relevance of the serum concentrations of the parent compound measured is unknown.