Taking it

The US guidelines recommend as standard d4T (stavudine, Zerit) dosing one 40mg capsule twice a day and one 30mg capsule twice a day in those weighing less than 60kg.

Because of toxicity concerns, in 2007 WHO issued an addendum to the 2006 treatment guidelines in adults and adolescents to advise d4T dosing at 30mg twice a day, regardless of weight. Formerly, someone with evidence of d4T-related toxicity was changed to a reduced dose, but the WHO recommendation now is to change to a regimen that does not contain d4T. All fixed-dose combinations containing d4T should be at the 30mg dose.¹

In the 2007 addendum, the WHO Guidelines Development Group wrote that this decision was based on a systematic review of nine randomised trials and six observational cohorts. They concluded that clinical and virologic efficacy was maintained at the 30mg twice-daily dose and that the reduced rate was associated with lower toxicity rates.

In one 48-week pilot study, the efficacy and safety of lower-dose d4T was examined in patients weighing over 60kg and with a viral load <400 copies/ml. Patients were switched from their regular 40mg twice-daily dose of d4T to 30mg twice-daily dosing. In this small study, clinical and laboratory parameters were either unchanged or improved. Total cholesterol, high-density lipoprotein cholesterol, and alanine aminotransferase levels were reduced at 48 weeks.²  

Because d4T is also available as a powder, it can be dissolved in water before being taken. Although the package information suggests that d4T should always be taken on an empty stomach for faster absorption, studies have shown that food does not make any difference to the total amount of d4T absorbed.

Use of d4T is not recommended for use in an initial antiretroviral regimen in Europe or the United States. It is also not recommended for anyone with lactose intolerance, as d4T contains lactose. In someone with impaired kidney function or peripheral neuropathy, the dose of d4T may be reduced to 15 or 20mg twice daily. Additionally, the combination of d4T/ddI should be avoided in people taking ribavirin for HCV, due to the risk of lactic acidosis. 

It is important to take d4T as prescribed to maintain the right level of the drug in the blood. If blood levels of the drug fall too low, this may allow the development of resistance to d4T and affect future treatment options. This drug comes in immediate release and extended release form.