Tamsulosin

INTRODUCTION

Indications

Management of outflow obstruction in male patients with prostatic hyperplasia.

Action

Decreases contractions in smooth muscle of the prostatic capsule by preferentially binding to alpha₁-adrenergic receptors. Therapeutic Effects: Decreased symptoms of prostatic hyperplasia (urinary urgency, hesitancy, nocturia).

Adverse Reactions/Side Effects

CNS: dizziness, headache. EENT: rhinitis. CV: orthostatic hypotension. GU: retrograde/diminished ejaculation.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

• Monitor signs of benign prostatic hyperplasia (BPH) such as difficulty starting a urine stream, painful urination, weak urine flow, feeling that the bladder is not completely empty, frequent nighttime urination, and an urge to urinate again soon after urinating. Document any change in BPH symptoms to help assess the effects of drug therapy.

• Assess blood pressure (BP) when patient assumes a more upright position (lying to standing, sitting to standing, lying to sitting). Document orthostatic hypotension and contact the physician when systolic BP falls >20 mm Hg or diastolic BP falls >10 mm Hg.

• Assess dizziness that might affect gait, balance, and other functional activities (See Appendix C). Report balance problems and functional limitations to the physician, and caution the patient and family/caregivers to guard against falls and trauma.

Interventions

• Avoid physical therapy interventions that cause systemic vasodilation (large whirlpool, Hubbard tank). Additive effects of this drug and the intervention may cause a dangerous fall in BP.

• To minimize orthostatic hypotension, advise patient to move slowly when assuming a more upright position.

Patient/Client-Related Instruction

• Advise patient that urinary symptoms (retention, dribbling, hesitancy, urgency) should improve, and to contact the physician if these symptoms continue to worsen.

• Instruct patient or family/caregivers to report other bothersome side effects such as severe or prolonged headache, nasal irritation, or problems with ejaculation.

Pharmacokinetics

Absorption: Slowly absorbed after oral administration.

Distribution: Widely distributed.

Protein Binding: 94–99%.

Metabolism and Excretion: Extensively metabolized by the liver; <10% excreted unchanged in urine.

Half-life: 14 hr.

Contraindications/Precautions

Contraindicated in: Hypersensitivity.

Use Cautiously in: Patients at risk for prostate carcinoma (symptoms may be similar).

Interactions

Drug-Drug: Cimetidine may ↑ blood levels and the risk of toxicity. ↑ risk of hypotension with other peripherally acting antiadrenergics (doxazosin, prazosin, terazosin); concurrent use should be avoided.