Taste effects of antiretroviral drugs on chorda tympani responses in gerbil

In clinical reports, HIV-infected patients complain that antiretroviral drugs produce unpleasant tastes that affect compliance with their medication regimen. In this study, taste effects of seven antiretroviral drugs (protease inhibitors and nucleoside analogs) were investigated in a gerbil model. Electrophysiological recordings were obtained from the chorda tympani nerve after lingual application of HIV medications. The effect of adaptation of the tongue to HIV medications on other taste stimuli with salty, sweet, sour and bitter qualities was also determined to simulate the presence of drug in the saliva. Four drugs (ritonavir, lamivudine, indinavir and didanosine) produced taste responses in the chorda tympani nerve of the gerbil at 0.625 mM and higher. Zidovudine, saquinavir and stavudine gave no taste responses at concentrations below 10 mM. The protease inhibitors saquinavir (2 mM) and ritonavir (10 mM) suppressed most taste stimuli with the greatest effect on bitter and sweet qualities. The nucleoside analog lamivudine gave a taste response at 20 mM and produced the greatest suppression on sour tastes. Results show that protease inhibitors had a more potent effect on chorda tympani responses in gerbil than nucleoside analogs.