tamsulosin hydrochloride

tamsulosin hydrochloride

(tam soo low' sin)

Flomax

Pregnancy Category B

Drug class

Alpha-adrenergic blocker (peripherally acting)

Therapeutic actions

Blocks the smooth muscle alpha₁-adrenergic receptors in the prostate, prostatic capsule, prostatic urethra, and bladder neck, leading to relaxation of the bladder and prostate and improving the flow of urine in cases of BPH

Indications

·        Treatment of the signs and symptoms of BPH

Contraindications and cautions

·        Contraindicated with hypersensitivity to tamsulosin, prostate cancer, pregnancy, lactation.

·        Use cautiously with hypotension.

Available forms

Capsules—0.4 mg

Dosages

ADULTS

0.4 mg PO daily 30 min after the same meal each day; if response is not satisfactory in 2–4 wk, dosage may be increased to 0.8 mg PO daily 30 min after the same meal each day. If therapy is interrupted for any reason for several days, resume dosing at 0.4 mg PO daily.

PEDIATRIC PATIENTS

Safety and efficacy not established.

Pharmacokinetics

Route	Onset	Peak
Oral	Varies	4–6 hr

Metabolism: Hepatic; T_1/2: 9–15 hr

Distribution: May cross placenta; enters breast milk

Excretion: Feces, urine

Adverse effects

·        CNS: Somnolence, insomnia

·        CV: Orthostatic hypotension, syncope

·        GI: Nausea, dyspepsia

·        GU: Abnormal ejaculation, decreased libido, increased urinary frequency

·        Other: Cough, sinusitis, rhinitis, increased risk of intraoperative floppy iris sydrome with cataract surgery

Interactions

Drug-drug

·        Increased hypotensive effects with other alpha-adrenergic antagonists

·        Risk of increased toxic effects of cimetidine

Nursing considerations

CLINICAL ALERT!

Name confusion has occurred between Fosamax (alendronate) and Flomax (tamsulosin); use caution.

Assessment

·        History: Allergy to tamsulosin; pregnancy, lactation; prostatic cancer, hypotension

·        Physical: Body weight; skin color, lesions; orientation, affect, reflexes; ophthalmologic examination; P, BP, orthostatic BP; R, adventitious sounds, status of nasal mucous membranes; voiding pattern, normal output, urinalysis

Interventions

·        Ensure that patient does not have prostatic cancer before beginning treatment.

·        Administer once a day, 30 min after the same meal each day.

·        Resume therapy at 0.4 mg daily if therapy is interrupted for any reason.

·        Ensure that patient does not crush, chew, or open capsule. Capsule should be swallowed whole.

·        Monitor patient carefully for orthostatic hypotension; chance of orthostatic hypotension, dizziness, and syncope is high with the first dose. Establish safety precautions as appropriate.

·        Alert surgeon that patient is on this drug if patient is going to have cataract surgery; increased risk of intraoperative floppy iris syndrome may require additional surgical intervention.

Teaching points

·        Take this drug exactly as prescribed, once a day. Do not chew, crush, or open capsules; capsules must be swallowed whole. Use care when beginning therapy; the chance of dizziness or syncope is greatest at that time. Change position slowly to avoid increased dizziness. Take the drug 30 minutes after the same meal each day.

·        Tell your surgeon that you are taking this drug if you are considering cataract surgery.

·        You may experience these side effects: Dizziness, weakness (more likely when you change position, in the early morning, after exercise, in hot weather, and when you have consumed alcohol; some tolerance may occur after you have taken the drug for a while; avoid driving or engaging in tasks that require alertness; change position slowly, use caution in climbing stairs, lie down if dizziness persists); GI upset (eat frequent small meals); impotence (discuss this with your health care provider); stuffy nose. Most of these effects will disappear gradually with continued therapy.

·        Report frequent dizziness or fainting, worsening of symptoms.

Adverse effects in Italic are most common; those in Bold are life-threatening.