Dutasteride peak plasma levels are observed 2-3 hours post 0.5mg dose of the medication. The bioavailability of the medication ranged from 40 to 94%. The concomitant administration of Dutasteride with food produces insignificant reduction in the serum concentrations. Dutasteride has a large volume of distribution (300 to 500 L). It is highly bound to plasma proteins. Dutasteride is extensively metabolized in the body by the CYP3A4 and CYP3A5 isoenzymes. The medication and its main metabolites are eliminated in feces. The terminal elimination half-life of Avodart is 5 weeks. Due to the long half-life of Dutasteride, serum concentrations present for up to 4 - 6 months after treatment is stopped. For older men no dose adjustment is necessary. Avodart is not used in women. Pregnant women and breastfeeding women should not use this medication. Dutasteride can harm an unborn baby and cause birth defects in an unborn.