Flomax Side Effects

Generic name: tamsulosin

Medically reviewed by Drugs.com. Last updated on May 30, 2024.

Note: This document provides detailed information about Flomax Side Effects associated with tamsulosin. Some dosage forms listed on this page may not apply specifically to the brand name Flomax.

Applies to tamsulosin: oral capsule.

Serious side effects of Flomax

Along with its needed effects, tamsulosin (the active ingredient contained in Flomax) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking tamsulosin:

More common

• cough or hoarseness
• fever or chills
• lower back or side pain
• painful or difficult urination

Less common

• chest pain

Rare

• dizziness or lightheadedness
• dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
• fainting
• feeling of constant movement of self or surroundings
• painful or prolonged erection of the penis
• sensation of spinning

Incidence not known

• blistering, peeling, or loosening of the skin
• blurred vision
• confusion
• diarrhea
• difficult or labored breathing
• fast, pounding, or irregular heartbeat or pulse
• itching
• joint or muscle pain
• large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
• red skin lesions, often with a purple center
• red, irritated eyes
• sore throat
• sores, ulcers, or white spots in the mouth or on the lips
• sweating
• tightness of the chest
• unusual tiredness or weakness

Other side effects of Flomax

Some side effects of tamsulosin may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

• abnormal ejaculation
• back pain
• body aches or pain
• congestion
• headache
• lack or loss of strength
• sneezing
• stuffy or runny nose
• tender, swollen glands in the neck
• trouble swallowing
• voice changes

Less common

• decreased interest in sexual intercourse
• decreased sexual drive or performance
• drowsiness
• inability to have or keep an erection
• increased cough
• loss in sexual ability, desire, drive, or performance
• nausea
• pain or tenderness around the eyes and cheekbones
• sleepiness or unusual drowsiness
• tooth disorder
• trouble sleeping

Incidence not known

• constipation
• hives or welts, skin rash
• redness of the skin
• vomiting

For healthcare professionals

Applies to tamsulosin: oral capsule.

General

The most commonly reported side effects were abnormal ejaculation, influenza-like symptoms, headache, dizziness, and rhinitis.^[Ref]

Immunologic

• Very common (10% or more): Infection (up to 10.8%)
• Uncommon (0.1% to 1%): Flu like symptoms
• Rare (less than 0.1%): Angioedema^[Ref]

Cardiovascular

• Common (1% to 10%): Chest pain
• Uncommon (0.1% to 1%): Orthostatic hypotension
• Rare (less than 0.1%): Syncope
• Postmarketing reports: Palpitations, hypotension, atrial fibrillation, arrhythmia, tachycardia^[Ref]

Dermatologic

• Uncommon (0.1% to 1%): Rash, pruritus, urticaria
• Postmarketing reports: Stevens-Johnson syndrome, erythema multiforme, exfoliative dermatitis, skin desquamation^[Ref]

Nervous system

• Very common (10% or more): Headache (21%), dizziness (17%)
• Common (1% to 10%): Somnolence, insomnia
• Frequency not reported: Vertigo^[Ref]

Genitourinary

• Very common (10% or more): Abnormal ejaculation (18%)
• Common (1% to 10%): Ejaculation disorders (e.g., retrograde ejaculation, ejaculation failure), decreased libido
• Uncommon (0.1% to 1%): Semen volume reduced, ejaculation delayed
• Postmarketing reports: Priapism^[Ref]

Respiratory

• Very common (10% or more): Rhinitis (up to 17.9%)
• Common (1% to 10%): Pharyngitis, Increased cough, sinusitis
• Uncommon (0.1% to 1%): Nasal congestion
• Postmarketing reports: Dyspnea, epistaxis^[Ref]

Musculoskeletal

• Common (1% to 10%): Back pain^[Ref]

Gastrointestinal

• Common (1% to 10%): Diarrhea, nausea, tooth disorder
• Uncommon (0.1% to 1%): Constipation, vomiting
• Frequency not reported: Dry mouth^[Ref]

Ocular

• Common (1% to 10%): Blurred vision
• Postmarketing reports: Visual impairment, intraoperative Floppy Iris Syndrome (IFIS)^[Ref]

Other

• Common (1% to 10%): Asthenia
• Uncommon (0.1% to 1%): Fatigue^[Ref]

Psychiatric

• Common (1% to 10%): Insomnia^[Ref]

Further information

Flomax side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.

Medical Disclaimer