dutasteride + tamsulosin: clinical use

Prescribing considerations

• Confirm symptoms are attributable to benign prostate enlargement and assess for prostate cancer or other causes.
• Assess benefit against the increased adverse-effect burden compared with monotherapy.
• Ask about orthostatic symptoms, cardiovascular disease, mood disorders, sexual dysfunction and planned cataract surgery.
• Advise patients to report breast changes, depression, suicidal thoughts and troublesome sexual effects.

Contraindications and cautions

• Women, children and adolescents
• Hypersensitivity to dutasteride, other 5-alpha-reductase inhibitors, tamsulosin or listed excipients, including soya or peanut
• History of orthostatic hypotension
• Severe hepatic impairment

Monitoring

• Establish an appropriate PSA baseline after dutasteride has taken effect; investigate a confirmed rise from the lowest value.
• Reassess prostate-cancer risk and urinary symptoms.
• Monitor postural blood-pressure symptoms, sexual effects, mood changes and breast changes.
• Use caution in mild to moderate hepatic impairment and severe renal impairment, where evidence is limited.

Clinical pharmacology

Dutasteride inhibits type 1 and type 2 5-alpha reductase and has a long terminal half-life. Tamsulosin antagonises prostatic alpha-1A and alpha-1D receptors. The fixed combination is bioequivalent to the separate components under studied conditions.

Formulation and product differences

• The hard gelatin outer capsule contains a dutasteride soft capsule and modified-release tamsulosin pellets.
• The capsule must remain intact to preserve modified release and prevent contact with irritating dutasteride contents.
• The selected product may contain traces of soya lecithin.

Capsule

Route: Oral

Strengths: 0.5 mg + 0.4 mg