Pharmacokinetics pentamide

Fresh solutions of pentamidine are administered intramuscularly or as an aerosol [Note: The IV route is avoided because of severe adverse reactions, such as a sharp fall in blood pressure and tachycardia.] The drug is concentrated and stored in the liver and kidney for a long period of time. Because it does not enter the CSF, it is ineffective against the meningoencephalitic stage of trypanosomiasis. The drug is not metabolized, and it is excreted very slowly into the urine. Its half-life in the plasma is about 5 days.