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Quick facts
- How it is given
- oral
- Type
- human prescription drug
- RxNorm ID
- 863669
We do not publish dosing. How much of this medicine to take, how often, and for how long depends on your age, weight, kidney and liver function, other conditions and other medicines. That is a decision for the person who prescribes or dispenses it. Follow the directions on your own pack and ask your pharmacist if anything is unclear.
What it is used to treat
Tamsulosin hydrochloride capsules are indicated for the treatment of the signs and symptoms of benign prostatic hyperplasia (BPH) [see Clinical Studies (14)]. Tamsulosin hydrochloride capsules are not indicated for the treatment of hypertension. Tamsulosin hydrochloride capsules are an alpha 1 adrenoceptor antagonist indicated for treatment of the signs and symptoms of benign prostatic hyperplasia (1) Tamsulosin hydrochloride capsules are not indicated for the treatment of hypertension (1)
About this medicine
Tamsulosin hydrochloride is an antagonist of alpha 1A adrenoceptors in the prostate. Tamsulosin hydrochloride is 5-[(2R)-2-[[2-(2-Ethoxyphenoxy)ethyl]amino]propyl]-2-methoxybenzenzenesulfonamide Hydrochloride. Tamsulosin hydrochloride is a white or almost white powder, melts with decomposition at approximately 230°C. It is freely soluble in formic acid, sparingly soluble in methanol, slightly soluble in water and in dehydrated alcohol and practically insoluble in ether. The empirical formula of tamsulosin hydrochloride is C 20 H 28 N 2 O 5 S·HCl. The molecular weight of tamsulosin hydrochloride is 444.97. Its structural formula is: Each tamsulosin hydrochloride capsules for oral administration contains tamsulosin hydrochloride, USP 0.4 mg, and the following inactive ingredients: sugar spheres (corn starch and sucrose), propyl gallate, methacrylic acid and ethyl acrylate copolymer, ethylcellulose, polyethylene glycol, talc, methacrylic acid and ethyl acrylate copolymer dispersion, hypromellose, colloidal silicon dioxide, gelatin, sodium lauryl sulphate and titanium dioxide. The capsules are printed with Black Ink TEK SW 9008 containing black iron oxide, potassium hydroxide, propylene glycol and shellac. FDA approved dissolution specifications differ from USP. structural formula
How it works
12.1 Mechanism of Action The symptoms associated with benign prostatic hyperplasia (BPH) are related to bladder outlet obstruction, which is comprised of two underlying components: static and dynamic. The static component is related to an increase in prostate size caused, in part, by a proliferation of smooth muscle cells in the prostatic stroma. However, the severity of BPH symptoms and the degree of urethral obstruction do not correlate well with the size of the prostate. The dynamic component is a function of an increase in smooth muscle tone in the prostate and bladder neck leading to constriction of the bladder outlet. Smooth muscle tone is mediated by the sympathetic nervous stimulation of alpha 1 adrenoceptors, which are abundant in the prostate, prostatic capsule, prostatic urethra, and bladder neck. Blockade of these adrenoceptors can cause smooth muscles in the bladder neck and prostate to relax, resulting in an improvement in urine flow rate and a reduction in symptoms of BPH. Tamsulosin, an alpha 1 adrenoceptor blocking agent, exhibits selectivity for alpha 1 receptors in the human prostate. At least three discrete alpha 1 adrenoceptor subtypes have been identified: alpha 1A , alpha 1B , and alpha 1D ; their distribution differs between human organs and tissue. Approximately 70% of the alpha 1 receptors in the human prostate are of the alpha 1A subtype. Tamsulosin hydrochloride capsules are not intended for use as an antihypertensive drug.
Who should not take it
Tamsulosin hydrochloride capsules are contraindicated in patients known to be hypersensitive to tamsulosin hydrochloride or any component of tamsulosin hydrochloride capsules. Reactions have included skin rash, urticaria, pruritus, angioedema, and respiratory symptoms [see Adverse Reactions (6.2)] . Contraindicated in patients known to be hypersensitive to tamsulosin hydrochloride or any component of tamsulosin hydrochloride capsules (4, 6.2)
Warnings and cautions
Advise patients about the possibility of symptoms related to postural hypotension and to avoid situations where injury could result should syncope occur (5.1) Should not be used in combination with strong inhibitors of CYP3A4. Use with caution in combination with moderate inhibitors of CYP3A4, with strong or moderate inhibitors of CYP2D6, in patients known to be CYP2D6 poor metabolizers, or in combination with other cytochrome P450 inhibitors. (5.2, 7.1, 12.3) Should not be used in combination with other alpha adrenergic blocking agents (5.2, 7.2, 12.3) Exercise caution with concomitant administration of warfarin (5.2, 7.4, 12.3) Advise patients about the possibility and seriousness of priapism (5.3) Intraoperative Floppy Iris Syndrome has been observed during cataract and glaucoma surgery in some patients. Advise patients considering cataract or glaucoma surgery to tell their ophthalmologist that they have taken tamsulosin hydrochloride capsules. (5.5) Advise patients to be screened for the presence of prostate cancer prior to treatment and at regular intervals afterwards (5.4) 5.1 Orthostasis The signs and symptoms of orthostasis (postural hypotension, dizziness, and vertigo) were detected more frequently in tamsulosin hydrochloride capsule-treated patients than in placebo recipients. As with other alpha adrenergic blocking agents there is a potential risk of syncope [see Adverse Reactions (6.1)] . Patients beginning treatment with tamsulosin hydrochloride capsules should be cautioned to avoid situations in which injury could result should syncope occur. 5.2 Drug Interactions Tamsulosin is extensively metabolized, mainly by CYP3A4 and CYP2D6. Tamsulosin hydrochloride capsules 0.4 mg should not be used in combination with strong inhibitors of CYP3A4 (e.g., ketoconazole) [see Drug Interactions (7.1) and Clinical Pharmacology (12.3)] . […]
Reported side effects
The most common adverse events (≥2% of patients and at a higher incidence than placebo) with the 0.4 mg dose or 0.8 mg dose were headache, dizziness, rhinitis, infection, abnormal ejaculation, asthenia, back pain, diarrhea, pharyngitis, chest pain, cough increased, somnolence, nausea, sinusitis, insomnia, libido decreased, tooth disorder, and blurred vision (6.1) To report SUSPECTED ADVERSE REACTIONS, contact XLCare Pharmaceuticals, Inc. at 1-866-495-1995 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical studies are conducted under widely varying conditions, adverse reactions rates observed in the clinical studies of a drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in practice. The incidence of treatment-emergent adverse events has been ascertained from six short-term U.S. and European placebo-controlled clinical trials in which daily doses of 0.1 to 0.8 mg tamsulosin hydrochloride capsules were used. These studies evaluated safety in 1783 patients treated with tamsulosin hydrochloride capsules and 798 patients administered placebo. Table 1 summarizes the treatment-emergent adverse events that occurred in ≥2% of patients receiving either tamsulosin hydrochloride capsules 0.4 mg or 0.8 mg and at an incidence numerically higher than that in the placebo group during two 13-week U.S. trials (US92-03A and US93-01) conducted in 1487 men. Table 1 Treatment-Emergent* Adverse Events Occurring in ≥2% of Tamsulosin Hydrochloride Capsules or Placebo Patients in Two U.S. […]
Interactions with other medicines
• Tamsulosin hydrochloride capsules 0.4 mg should not be used with strong inhibitors of CYP3A4 (e.g., ketoconazole). Tamsulosin hydrochloride capsules should be used with caution in combination with moderate inhibitors of CYP3A4 (e.g., erythromycin), in combination with strong (e.g., paroxetine) or moderate (e.g., terbinafine) inhibitors of CYP2D6, or in patients known to be CYP2D6 poor metabolizers, particularly at a dose higher than 0.4 mg (e.g., 0.8 mg). ( 5.2 , 7.1 , 12.3 ) • Concomitant use of PDE5 inhibitors with tamsulosin can potentially cause symptomatic hypotension ( 5.2 , 7.3 , 12.3 ). 7.1 Cytochrome P450 Inhibition Strong and Moderate Inhibitors of CYP3A4 or CYP2D6 Tamsulosin is extensively metabolized, mainly by CYP3A4 and CYP2D6. Concomitant treatment with ketoconazole (a strong inhibitor of CYP3A4) resulted in an increase in the C max and AUC of tamsulosin by a factor of 2.2 and 2.8, respectively [see Warnings and Precautions (5.2) and Clinical Pharmacology (12.3)]. The effects of concomitant administration of a moderate CYP3A4 inhibitor (e.g., erythromycin) on the pharmacokinetics of tamsulosin hydrochloride have not been evaluated [see Warnings and Precautions (5.2) and Clinical Pharmacology (12.3)]. Concomitant treatment with paroxetine (a strong inhibitor of CYP2D6) resulted in an increase in the C max and AUC of tamsulosin by a factor of 1.3 and 1.6, respectively [see Warnings and Precautions (5.2) and Clinical Pharmacology (12.3)]. A similar increase in exposure is expected in CYP2D6 poor metabolizers (PM) as compared to extensive metabolizers (EM). Since CYP2D6 PMs cannot be readily identified and the potential for significant increase in tamsulosin exposure exists when tamsulosin hydrochloride capsules 0.4 mg is coadministered with strong CYP3A4 inhibitors in CYP2D6 PMs, tamsulosin hydrochloride capsules 0.4 mg should not be used in combination with strong inhibitors of CYP3A4 (e.g., ketoconazole) [see Warnings and Precautions (5.2) and Clinical Pharmacology (12.3)]. […]
Use in specific groups
• Pediatric Use: Not indicated for use in pediatric populations ( 8.4 , 12.3 ) • Geriatric Use: No overall differences in efficacy or safety vs. younger patients, but greater sensitivity of some older adults cannot be ruled out ( 8.5 , 12.3 ) • Renal Impairment: Has not been studied in patients with end-stage renal disease ( 8.6 , 12.3 ) • Hepatic Impairment: Has not been studied in patients with severe hepatic impairment ( 8.7 , 12.3 ) 8.1 Pregnancy Risk Summary Tamsulosin hydrochloride is not indicated for use in women. There are no adequate data on the developmental risk associated with the use of tamsulosin hydrochloride in pregnant women. No adverse developmental effects were observed in animal studies in which tamsulosin hydrochloride was administered to rats or rabbits during the period of organogenesis (GD 7 to 17 in the rat and GD 6 to 18 in the rabbit) [see Data]. In the U.S. general population, the estimated background risk of major birth defects and of miscarriage in clinically recognized pregnancies is 2%–4% and 15%–20%, respectively. Data Administration of tamsulosin hydrochloride to pregnant female rats during the period of organogenesis at dose levels up to approximately 50 times the human therapeutic AUC exposure (300 mg/kg/day) revealed no evidence of harm to the fetus. Administration of tamsulosin hydrochloride to pregnant rabbits during the period of organogenesis at dose levels up to 50 mg/kg/day produced no evidence of fetal harm. 8.2 Lactation Tamsulosin hydrochloride is not indicated for use in women. There are no data on the presence of tamsulosin hydrochloride in human milk, the effects of tamsulosin hydrochloride on the breastfed infant, or the effects of tamsulosin hydrochloride on milk production. Tamsulosin hydrochloride is present in the milk of lactating rats [see Data]. Data Oral administration of radiolabeled tamsulosin hydrochloride to rats demonstrated that tamsulosin hydrochloride and/or its metabolites are excreted into the milk of rats. […]
If too much is taken
Should overdosage of tamsulosin hydrochloride capsules lead to hypotension [see Warnings and Precautions (5.1) and Adverse Reactions (6.1)], support of the cardiovascular system is of first importance. Restoration of blood pressure and normalization of heart rate may be accomplished by keeping the patient in the supine position. If this measure is inadequate, then administration of intravenous fluids should be considered. If necessary, vasopressors should then be used and renal function should be monitored and supported as needed. Laboratory data indicate that tamsulosin hydrochloride is 94% to 99% protein bound; therefore, dialysis is unlikely to be of benefit.
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This page is built from the openFDA record of the U.S. Food and Drug Administration's approved labelling for this product, effective 1 January 2026. Label text has been shortened and reformatted for readability; safety wording has not been altered in meaning. FDA labelling describes products approved in the United States — brand names, strengths, formulations and approved uses may differ in your country. Always read the leaflet that comes with your own pack. PocketsInfo is not affiliated with, and is not endorsed by, the FDA. Retrieved 2026-07-30.