Some of the views expressed in the following notes on newly approved products should be regarded as preliminary, as there may have been limited published data at the time of publication, and little experience in Australia of their safety or efficacy. However, the Editorial Executive Committee believes that comments made in good faith at an early stage may still be of value. Before new drugs are prescribed, the Committee believes it is important that more detailed information is obtained from the manufacturer's approved product information, a drug information centre or some other appropriate source.
Zerit (Bristol-Myers Squibb)
15 mg, 20 mg, 30 mg and 40 mg capsules
Indication: HIV infection
Stavudine is an analogue of thymidine, similar to zidovudine. These nucleoside analogues act by inhibiting the reverse transcriptase of the human immunodeficiency virus.1
The drug is given twice a day by mouth. It is well absorbed, but absorption is reduced by high-fat meals. The significance of this reduced absorption is unclear as the relationship between plasma concentrations and antiviral activity is unknown. The metabolism of stavudine is also unknown, but as 40% of total clearance is by the kidneys, dose reductions are required if renal function is impaired. Stavudine has a half-life of approximately 1.5 hours.
As experience with stavudine is limited, its role in therapy is not yet clear. It has been approved for the treatment of HIV infection in adults. Although the safety and efficacy of stavudine has not been established in children, the drug is approved for use in children aged 12 years and over.
Many of the patients studied in trials of stavudine had previously taken zidovudine. Stavudine may therefore have a role in patients who are unable to tolerate or are not responding to zidovudine. The efficacy of stavudine has mainly been assessed by its effects on CD4 lymphocyte counts, HIV titres in mononuclear cells and p24 antigen concentrations.
Patients should be informed about the symptoms of peripheral neuropathy as this is the most common toxicity. Approximately 40% will develop symptoms and 21% will require their treatment to be interrupted. Other adverse events occurring in clinical trials include neutropenia, anaemia, altered liver function tests and pancreatitis.
- Locarnini S. Antiviral drugs - mechanisms of action. Aust Prescr 1993;16:78-81.