Stavudine vs. Zidovudine as antiretroviral therapy

Stavudine (d4T) and zidovudine (AZT) belong to nucleoside reverse transcriptase inhibitor (NRTI) group of drugs and they are the core drugs with lamivudine (3TC) as the first-line therapy. d4T is reported to cause a number of long-term metabolic and morphologic adverse drug reactions (ADR). In this study, the incidence and pattern of ADR due to d4T and AZT were compared. Ninety cases on antiretroviral treatment (ART) were studied prospectively over a period of 2 years. Forty-two cases were on AZT-based regimen, and 48 cases were on d4T-based regimen. In all cases, baseline investigations, serum lipid profile and lactate levels (if required) were carried out. Cases were evaluated monthly, and investigations were repeated quarterly for any ADR. Out of the 42 cases on AZT-based regimen, 21 had ADR; while 23 out of the 48 cases on d4T had ADR. Anemia (42.8%) and nail hyperpigmentation (30.9%) were the commonest ADR due to AZT. Peripheral neuropathy (PN) (39.6%) was the commonest ADR with d4T, followed by lipodystrophy (LD) (22.9%). Change of therapy was required in 1 case on AZT with severe anemia and in 5 cases on d4T with LD, PN or lactic acidemia. The severe ADR with d4T needed a change of regimen to AZT in 5 cases. Moreover, d4T requires monitoring for long-term metabolic changes, which may lead to morphologic disfigurement which are particularly distressing to females. As the cost of both the regimens is now almost equal, preference should be given to AZT-based regimen.