tamsulosin

Absorption: >90% absorbed after oral administration.

Distribution: Widely distributed to tissues.

Protein Binding: 94–99%.

Metabolism/Excretion: Primarily metabolized by the liver via the CYP3A4 and CYP2D6 isoenzymes; the CYP2D6 enzyme system exhibits genetic polymorphism (∼7% of population may be poor metabolizers and may have significantly ↑ tamsulosin concentrations and an ↑ risk of adverse effects).<10% excreted unchanged in urine.

Half-Life: 14 hr.

Time/Action Profile ⬆ ⬇

(↑ in urine flow)

ROUTE		ONSET		PEAK		DURATION
PO		unknown		2 wk		unknown

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity.

Use Cautiously in:

Patients at risk for prostate cancer (symptoms may be similar);
Patients undergoing cataract surgery (↑ risk of intraoperative floppy iris syndrome);
Sulfa allergy;
CYP2D6 poor metabolizers (especially when using higher dose of 0.8 mg/day).

Adv. Reactions/Side Effects ⬆ ⬇

CV: orthostatic hypotension

EENT: intraoperative floppy iris syndrome, rhinitis

GU: priapism, retrograde/diminished ejaculation

Neuro: dizziness, headache

Interactions ⬆ ⬇

Drug-drug:

Cimetidine may ↑ levels and the risk of toxicity.
↑risk of hypotension with doxazosin, prazosin, and terazosin; concurrent use should be avoided.
↑risk of hypotension with sildenafil, tadalafil, and vardenafil.
Strong CYP3A4 inhibitors and CYP2D6 inhibitors may ↑ levels and the risk of toxicity; concurrent use should be avoided.

Route/Dosage ⬆ ⬇

PO (Adults ): 0.4 mg once daily after a meal; may ↑ after 2–4 wk to 0.8 mg/day.

Availability ⬆ ⬇

(Generic available)

Capsules: 0.4 mg
In combination with:
dutasteride (Jalyn); see Combination Drugs.

Assessment ⬆ ⬇

Assess patient for symptoms of BPH (urinary hesitancy, feeling of incomplete bladder emptying, interruption of urinary stream, impairment of size and force of urinary stream, terminal urinary dribbling, straining to start flow, dysuria, urgency) before and periodically during therapy.
Assess patient for 1st-dose orthostatic hypotension and syncope. Incidence may be dose related. Observe patient closely during this period and take precautions to prevent injury. Monitor BP (lying and standing) and during initial therapy and periodically thereafter.
Monitor intake and output ratios and daily weight, and assess for edema daily, especially at beginning of therapy. Report weight gain or edema.
Rectal exams prior to and periodically throughout therapy to assess prostate size are recommended.
Rule out prostate cancer before initiating therapy; symptoms are similar.

Implementation ⬆ ⬇

Do not confuse tamsulosin with tacrolimus.
PO: Administer 30 min after the same meal each day. DNC: Swallow capsules whole; do not open, crush, or chew.
- If dose is interrupted for several days at either the 0.4-mg or 0.8-mg dose, restart therapy with the 0.4-mg/day dose.

Patient/Family Teaching ⬆ ⬇

Explain the purpose and side effects of tamsulosin. Instruct to take as directed with the same meal each day. Emphasize the importance of continuing to take this medication, even if feeling well. If a dose is missed, take as soon as remembered unless almost time for next dose. Do not double doses. Advise patient to read Patient Information before starting therapy and with each Rx refill in case of changes.
- Emphasize the importance of follow-up visits to determine effectiveness of therapy.
- May cause dizziness. Advise patient to avoid driving or other activities requiring alertness until response to medication is known.
- Caution patient to change positions slowly to minimize orthostatic hypotension, especially patients with low BP or concurrently taking antihypertensives. Assess risk for falls; instruct patient and family in preventing falls at home.
- Instruct patient to notify health care provider of all Rx or OTC medications, vitamins, or herbal products being taken and consult health care provider before taking any new medications, especially cough, cold, or allergy remedies.
- Tamsulosin is not indicated for use in women. Abnormal ejaculation, including ejaculation failure, retrograde ejaculation, and ↓ ejaculation have occurred with tamsulosin use in men. May impair male fertility. Symptoms are reversible when medication is discontinued.

section name header

Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇

Pharmacokinetics ⬆ ⬇

Time/Action Profile ⬆ ⬇

Contraind./Precautions ⬆ ⬇

Adv. Reactions/Side Effects ⬆ ⬇

Interactions ⬆ ⬇

Route/Dosage ⬆ ⬇

Availability ⬆ ⬇

Assessment ⬆ ⬇

Implementation ⬆ ⬇

Patient/Family Teaching ⬆ ⬇

Evaluation/Desired Outcomes ⬆ ⬇

US Brand Names ⬆ ⬇

Canadian Brand Names ⬆ ⬇

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