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 Cetinsaya 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 immunosuppression with dexannethasone 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 time-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.