dutasteride: clinical use

Prescribing considerations

• Confirm the cause and severity of lower urinary tract symptoms and assess for prostate cancer before treatment.
• Clinical benefit develops gradually; set expectations accordingly.
• Use caution in mild to moderate hepatic impairment.
• Assess benefits and risks before combining with an alpha-blocker.
• Discuss possible sexual, fertility, breast and mood effects.

Contraindications and cautions

• Women, children and adolescents
• Hypersensitivity to dutasteride, another 5-alpha-reductase inhibitor or an excipient
• Severe hepatic impairment

Monitoring

• Assess for prostate cancer before treatment and periodically thereafter.
• Establish a new PSA baseline after treatment has affected PSA and monitor subsequent trends.
• Evaluate any confirmed PSA rise from the treatment nadir, even within the usual untreated range.
• Review new mood symptoms, sexual dysfunction, breast changes and suspected adverse reactions.

Clinical pharmacology

Dutasteride inhibits type 1 and type 2 5-alpha-reductase. It is highly protein-bound, extensively metabolised by CYP3A4 and CYP3A5, eliminated mainly in faeces and has a long terminal half-life.

Formulation and product differences

• The selected product is a soft gelatin capsule containing an oily liquid.
• Capsules must remain intact because their contents may irritate mucosa and be absorbed through skin.
• The capsule shell contains gelatin, glycerol, titanium dioxide and yellow iron oxide.

Capsule

Route: Oral

Strengths: 0.5 mg