Dutasteride

Dutasteride is a drug used to treat the symptoms of benign prostatic hyperplasia (BPH) in men. It is also used for hair loss in men and as part of hormone therapy in transgender women. It is usually taken orally and is available in capsule form.

It was first approved by the U.S. Food and Drug Administration (FDA) in 2001 and has since been widely used due to its good efficacy.

Pharmacodynamics and mechanism of action

BPH is a disease in which the prostate gland enlarges, causing symptoms such as frequent urination and difficulty urinating. Dutasteride belongs to the class of 5-alpha-reductase inhibitors and works by inhibiting the activity of the enzyme 5-alpha-reductase. This enzyme is responsible for converting testosterone into dihydrotestosterone (DHT), a hormone responsible for enlargement of the prostate. Inhibition of this enzyme decreases the formation of DHT, resulting in a reduction in the size of the prostate and significantly improving symptoms.

Pharmacokinetics

Dutasteride is rapidly and completely absorbed after oral administration, with maximum plasma concentrations reached within 2 to 3 hours. Dutasteride is approximately 99% bound to albumin. Dutasteride undergoes extensive hepatic metabolism mediated by the CYP3A4 and CYP3A5 enzymes and is excreted primarily in the feces. The plasma half-life is approximately 4-5 weeks.

Side effects

The most common side effects include:

• decreased libido
• Ejaculation problems
• Breast tenderness or enlargement.

More serious side effects may include allergic reactions, liver damage, and increased risk of prostate cancer.

Contraindications and precautions

Dutasteride is contraindicated in patients allergic to the drug and in women who are pregnant or breastfeeding. In addition, dutasteride should not be taken by patients with severe liver dysfunction.