dutasteride

dutasteride,

a sex hormone 5 alpha-reductase inhibitor used to treat benign prostatic hyperplasia in men with an enlarged prostate gland.

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dutasteride Warning - Hazardous drug!

Avodart

Pharmacologic class: Synthetic 4-azasteroid compound

Therapeutic class: 5-alpha-reductase inhibitor, sex hormone

Pregnancy risk category X

Action

Inhibits 5-alpha-reductase, an intracellular enzyme present in liver, skin, and prostate that's required for conversion of testosterone to 5-alpha-dihydrotestosterone (DHT). DHT appears to be the principal androgen responsible for stimulating prostatic growth.

Availability

Capsules: 0.5 mg

⊘Indications and dosages

➣ Symptomatic benign prostatic hypertrophy

Adults: 0.5 mg P.O. daily

Contraindications

• Hypersensitivity to drug, its components, other 5-alpha-reductase inhibitors, xanthines (such as coffee, theobromine), or ethylenediamine
• Women
• Children

Precautions

Use cautiously in:
• hepatic impairment
• elderly patients.

Administration

☞ Wear gloves when handling and administering, because drug may be absorbed through skin.
• Don't handle drug if you're pregnant or plan to become pregnant.
• Don't open or crush capsule.
• Give without regard to food.

Route	Onset	Peak	Duration
P.O.	Rapid	2-3 hr	Unknown

Adverse reactions

GI: dyspepsia

GU: decreased libido, decreased ejaculatory volume, erectile dysfunction, gynecomastia

Interactions

Drug-drug. Cimetidine, ciprofloxacin, diltiazem, ketoconazole, other drugs metabolized by CYP450-3A4 pathway, ritonavir, verapamil: increased dutasteride blood level

Drug-diagnostic tests. Prostate-specific antigen (PSA): decreased level

Thyroid-stimulating hormone: increased level

Patient monitoring

• Monitor fluid intake and output. Assess for ease of starting urine stream and for urinary urgency or frequency.
• Check baseline PSA level; reevaluate at 3 to 6 months.

Patient teaching

• Tell patient to take drug with full glass of water without crushing or opening capsule.
• Instruct patient not to take capsule if it's cracked or leaking.
• Inform patient that drug decreases testosterone production in prostate.
• Tell patient to report dysuria and urinary urgency.
☞ Advise patient not to donate blood for at least 6 months after final dose.
• Inform patient that drug may decrease ejaculatory volume.
• Explain that sexual side effects eventually will subside.
• As appropriate, review all other significant adverse reactions and interactions, especially those related to the drugs and tests mentioned above.