Tamsulosin

Tamsulosin is used by men to treat the symptoms of an enlarged prostate (benign prostatic hyperplasia-BPH). It does not shrink the prostate, but it works by relaxing the muscles in the prostate and the bladder. This helps to relieve symptoms of BPH such as difficulty in beginning the flow of urine, a weak stream, and the need to urinate often or urgently (including during the middle of the night).

• Tamsulosin belongs to a class of drugs known as alpha-blockers.
• Do not use this medication to treat high blood pressure.
• Tamsulosin is available under the following different brand names: Flomax.

Dosage of Tamsulosin:

Dosage Forms and Strengths

Capsule

• 0.4mg

Dosing Considerations – Should be Given as Follows:

Benign Prostatic Hypertrophy

0.4 mg orally once daily, 30 minutes after the same meal each day; if the response is inadequate after 2-4 weeks, maybe increased to 0.8 mg once daily; if therapy is interrupted, should be resumed at 0.4 mg once daily

Bladder Outlet Obstruction

Relief of symptoms

• 0.4 mg orally once daily

Ureteral Stones

Facilitation of stone expulsion

• 0.4 mg orally once daily; discontinued after successful expulsion (average, 1-2 weeks)

Dosing Modifications

Renal impairment

• CrCl 10 mL/min or greater: Dosage adjustment not necessary
• CrCl less than 10 mL/min: Not studied

Hepatic impairment

• Mild to moderate: Dosage adjustment not necessary
• Severe: Not studied

Pediatric: Safety and efficacy not established

Common Side effects of Tamsulosin include:

• Headache
• Dizziness upon standing
• Runny and stuffy nose
• Abnormal ejaculation
• Dizziness
• Joint pain
• Infection
• Weakness and lack of energy
• Back pain
• Skin rash
• Sore throat
• Diarrhea
• Muscle pain
• Chest pain
• Cough
• Sleepiness
• Nausea
• Sinus infection (sinusitis)
• Abdominal discomfort
• Bitter taste
• Decreased sex drive
• Insomnia

Postmarketing side effects of tamsulosin reported include:

• Prolonged erection (rare)
• Signs and symptoms of low blood pressure, including lightheadedness and fainting
• Infrequent reports of shortness of breath, palpitations, low blood pressure (hypotension), atrial fibrillation, irregular heartbeat (arrhythmia), and fast heart rate
• Visual impairment
• During cataract and glaucoma surgery, a variant of small pupil syndrome known as Intraoperative Floppy Iris Syndrome (IFIS) has been reported in association with alpha1 blocker therapy
• Skin desquamation including reports of Stevens-Johnson syndrome, erythema multiforme, and dermatitis exfoliative
• Constipation, vomiting, and epistaxis
• Allergic-type reaction (e.g., skin rash, hives, itching, skin swelling, respiratory symptoms) have been reported with positive re-challenge
• Dry mouth

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.

If your doctor has directed you to use this medication, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider or pharmacist first.

Severe Interactions of tamsulosin include:

• boceprevir
• ombitasvir/paritaprevir/ritonavir
• ombitasvir/paritaprevir/ritonavir and dasabuvir

Tamsulosin has serious interactions with at least 31 different drugs.

Tamsulosin has moderate interactions with at least 73 different drugs.

Mild interactions of tamsulosin include:

• benazepril
• captopril

This information does not contain all possible interactions or adverse effects. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share this information with your doctor and pharmacist. Check with your health care professional or doctor for additional medical advice, or if you have health questions, concerns or for more information about this medicine.

Warnings

• This medication contains tamsulosin. Do not take Flomax if you are allergic to tamsulosin or any ingredients contained in this drug
• Keep out of reach of children
• In case of overdose, get medical help or contact a Poison Control Center immediately

Contraindications

• Hypersensitivity

Effects of Drug Abuse

• No information available

Short-Term Effects

• May cause lightheadedness and/or fainting (first-dose effect)
• See "What Are Side Effects Associated with Using Tamsulosin?"

Long-Term Effects

• See "What Are Side Effects Associated with Using Tamsulosin?"

Cautions

• Use with caution in coronary artery disease, liver disease, general anesthesia
• Orthostatic hypotension may occur
• Priapism rarely reported
• Prostatic cancer should be ruled out before therapy is initiated
• May cause syncope (first-dose effect)
• Discontinue if angina symptoms occur or worsen
• Intraoperative floppy iris syndrome has been reported in patients receiving alpha1 blockers at time of cataract surgery; association is unclear
• Patients with sulfa allergy have rarely developed allergic reaction; avoid use if previous sulfa allergy reactions have been life-threatening
• Not for use as antihypertensive drug
• May exacerbate heart failure

Pregnancy and Lactation

• Tamsulosin may be acceptable for use during pregnancy
• Either animal studies show no risk but human studies are not available, or animal studies showed minor risks and human studies were done and showed no risk
• Women are unlikely to use tamsulosin, so there is no information on use while breastfeeding
• Consult your doctor