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Didanosine

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Abstract

The evaluation and development of didanosine as a therapy for HIV-infection has demonstrated that results of cell-culture studies are only approximate predictors of clinical effects. Whereas the antiviral activity of didanosine is achieved in cell culture at concentrations much higher than those of zidovudine, the two drugs appear to achieve similar effects on markers of HIV-infection at similar clinical doses. The effect of the differing intracellular-half-life of the respective nucleoside triphosphates on the clinical effects is unknown. Similarly, preclinical toxicology studies, while suggesting a low potential for didanosine-induced haematological toxicities, did not predict the findings of peripheral neuropathy and pancreatitis in clinical studies. Thus, the results of controlled clinical studies are required in order to more fully define the therapeutic and safety profile of didanosine.
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