Evaluation of Terbinafine Activity on Pneumocystis carinii in the Rat Model

Objective: The purpose of this study was to test the hypothesis thThis study was planned to investigate the antipneumocystis activity of terbinafine in a rat model. Material and Methods: Rats were obtained from the Hakan Çetinsaya Experimental and Clinical Research Institutions, Erciyes University, Kayseri, Turkey. Terbinafine administered orally in doses of 40, 80, 120 and 160 mg/kg/day after nine weeks of immunosuppres- sion with dexamethasone to facilitate the development of acute Pneumocystis carinii penumoniae (PCP). Results: Untreated animals showed P. carinii infection levels with a mean (±standard deviation) log number of cysts per gram of lung tissue of 4.6±1.6 at the end of the experiment. Terbinafine administered at a dose of 160 mg/kg/day significantly reduced the log number of cysts per gram to 2.2±1.5. The therapeutic efficacy of terbinafine administered at 160 mg/kg/day (log 2.2±1.5 cysts/lung) was similar to that obtained with trime- thoprim-sulfamethoxazole (TMP-SMX), 50/250 mg/kg/ day (p 0.001). A reduction in the number of cysts was also observed in infected animals treated with 80, and 120 mg of terbinafine/kg/day, although the results were not statistically significant (p 0.05). Conclusion: In our model, the efficacy of terbinafine in PCP has been found to be dose dependent.