the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.methadoneMonitor Closely (1)methadone increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.methimazoleMonitor Closely (1)methimazole increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.metronidazoleMonitor Closely (1)metronidazole increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Dose reduction may be needed for coadministered drugs that are predominantly metabolized by CYP3A.mifepristoneMonitor Closely (1)mifepristone will increase the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.mitotaneMonitor Closely (1)mitotane decreases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Mitotane is a strong inducer of cytochrome P-4503A4; monitor when coadministered with CYP3A4 substrates for possible dosage adjustments.nafcillinMonitor Closely (1)nafcillin will decrease the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.nefazodoneMonitor Closely (1)nefazodone increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)nefazodone increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.nelfinavirSerious - Use Alternative (1)nelfinavir increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.nicardipineMonitor Closely (1)nicardipine increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)nicardipine increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.nirmatrelvir/ritonavirSerious - Use Alternative (1)nirmatrelvir/ritonavir will increase the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Tamsulosin metabolized mainly by CYP3A4 and to a lesser extent by CYP2D6. Pause tamsulosin and restart 3 days after completing nirmatrelvir/ritonavir given that CYP3A4 inhibition takes several days to resolve. ombitasvir/paritaprevir/ritonavir & dasabuvir (DSC)Contraindicated (1)ombitasvir/paritaprevir/ritonavir & dasabuvir (DSC) will increase the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Increased risk for hypotensiooxymetazoline topicalMonitor Closely (1)oxymetazoline topical increases and tamsulosin decreases sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Effect of interaction is not clear, use caution. Use Caution/Monitor.paroxetineMonitor Closely (1)paroxetine increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.phenobarbitalSerious - Use Alternative (1)phenobarbital will decrease the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.phenoxybenzamineSerious - Use Alternative (1)phenoxybenzamine, tamsulosin. Either increases effects of the other by additive vasodilation. Avoid or Use Alternate Drug. Risk of hypotension.phentolamineSerious - Use Alternative (1)phentolamine, tamsulosin. Either increases effects of the other by additive vasodilation. Avoid or Use Alternate Drug. Risk of hypotension.phenytoinSerious - Use Alternative (1)phenytoin will decrease the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.posaconazoleSerious - Use Alternative (1)posaconazole increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.prazosinSerious - Use Alternative (1)prazosin, tamsulosin. Either increases effects of the other by additive vasodilation. Avoid or Use Alternate Drug. Risk of hypotension.primidoneSerious - Use Alternative (1)primidone will decrease the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.pseudoephedrineMonitor Closely (1)pseudoephedrine decreases effects of tamsulosin by sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.pyrimethamineMonitor Closely (1)pyrimethamine increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.quinidineMonitor Closely (1)quinidine increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)quinidine increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.quinineMonitor Closely (1)quinine increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.ranolazineMonitor Closely (1)ranolazine increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.ribociclibMonitor Closely (1)ribociclib will increase the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.rifabutinMonitor Closely (1)rifabutin will decrease the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.rifampinSerious - Use Alternative (1)rifampin will decrease the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.rifapentineMonitor Closely (1)rifapentine will decrease the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.ritonavirMonitor Closely (1)ritonavir increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)ritonavir increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.rolapitantMonitor Closely (1)rolapitant will increase the level or effect of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Rolapitant may increase plasma concentrations of CYP2D6 substrates for at least 28 days following rolapitant administration.rucaparibMonitor Closely (1)rucaparib will increase the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Adjust dosage of CYP3A4 substrates, if clinically indicated.saquinavirSerious - Use Alternative (1)saquinavir increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.secobarbitalSerious - Use Alternative (1)secobarbital will decrease the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.sertralineMonitor Closely (1)sertraline increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.sildenafilMonitor Closely (1)sildenafil, tamsulosin. Either increases effects of the other by additive vasodilation. Use Caution/Monitor. Risk of hypotension.silodosinSerious - Use Alternative (1)silodosin, tamsulosin. Either increases effects of the other by additive vasodilation. Avoid or Use Alternate Drug. Risk of hypotension.stiripentolMonitor Closely (1)stiripentol, tamsulosin. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP3A4 inhibitor and inducer. Monitor CYP3A4 substrates coadministered with stiripentol for increased or decreased effects. CYP3A4 substrates may require dosage adjustment.tadalafilMonitor Closely (1)tadalafil, tamsulosin. Either increases effects of the other by additive vasodilation. Use Caution/Monitor. Risk of hypotension.tazemetostatMonitor Closely (1)tazemetostat will decrease the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.tecovirimatMonitor Closely (1)tecovirimat will decrease the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Tecovirimat is a weak CYP3A4 inducer. Monitor sensitive CYP3A4 substrates for effectiveness if coadministered.terazosinSerious - Use Alternative (1)terazosin, tamsulosin. Either increases effects of the other by additive vasodilation. Avoid or Use Alternate Drug. Risk of hypotension.terbinafineMonitor Closely (1)terbinafine will increase the level or effect of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Assess need to reduce dose of CYP2D6-metabolized drug.thioridazineMonitor Closely (1)thioridazine increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.ticlopidineMonitor Closely (1)ticlopidine increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.tipranavirSerious - Use Alternative (1)tipranavir increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.tranylcypromineMonitor Closely (1)tranylcypromine increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.trazodoneMonitor Closely (1)trazodone increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.tucatinibSerious - Use Alternative (1)tucatinib will increase the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid concomitant use of tucatinib with CYP3A substrates, where minimal concentration changes may lead to serious or life-threatening toxicities. If unavoidable, reduce CYP3A substrate dose according to product labeling.vardenafilMonitor Closely (1)vardenafil, tamsulosin. Either increases effects of the other by additive vasodilation. Use Caution/Monitor. Risk of hypotension.voriconazoleSerious - Use Alternative (1)voriconazole increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.voxelotorSerious - Use Alternative (1)voxelotor will increase the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Voxelotor increases systemic exposure of sensitive CYP3A4 substrates. Avoid coadministration with sensitive CYP3A4 substrates with a narrow therapeutic index. Consider dose reduction of the sensitive CYP3A4 substrate(s) if unable to avoid. >10% Headache (19-21%) Orthostatic hypotension (6-19%) Rhinitis (13-18%) Abnormal ejaculation (8-18%) Dizziness (15-17%) Arthralgia (11%) Infection (9-11%) 1-10% Asthenia (8%) Back pain (7-8%) Skin rash (7%) Pharyngitis (5-6%) Diarrhea (4-6%) Myalgia (5%) Chest pain (4%) Cough (3-4%) Somnolence (3-4%) Nausea (2-4%) Sinusitis (2-4%) Abdominal discomfort (2-3%) Bitter taste (2-3%) Decreased libido (1-2%) Insomnia (1-2%) Postmarketing Reports Priapism (rare) Signs and symptoms of orthostasis, including syncope Infrequent reports of dyspnea, palpitations, hypotension, atrial fibrillation, arrhythmia, and tachycardia 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 reactions (eg, skin rash, urticaria, pruritus, angioedema, respiratory symptoms) have been reported with positive rechallenge Dry mouth Contraindications Hypersensitivity 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 No data are available on use in pregnant women No adverse developmental effects observed in animal studies administering tamsulosin to rats or rabbits during organogenesis Infertility Males: Abnormal ejaculation including ejaculation failure, ejaculation disorder, retrograde ejaculation, and ejaculation decrease has been associated with therapy; studies in rats revealed significantly reduced fertility in males considered to be due to impairment of ejaculation, which was reversible Females: Drug is not indicated for use in women; female fertility in rats was significantly reduced, considered to be due to impairment of fertilization Lactation There are no data on presence of drug in human milk, effects on breastfed infant, or on milk production No data are available; owing to potential of tamsulosin to cause hypotension, breastfeeding is not recommended if taking tamsulosinPregnancy Categories A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk. B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available. Mechanism of Action Blocks alpha1a adrenergic receptor in smooth muscle of prostate, decreasing bladder neck and urethral resistance Absorption Bioavailability: Fasting, 30% Onset: 4-8 hr Peak plasma time: With food, 6-7 hr; fasting, 4-5 hr Distribution Protein bound: 90% Vd: 0.2 L/kg or 16 L Metabolism Metabolized in liver Metabolites: Glucuronide and sulfate conjugates (inactive) Elimination Half-life: 14-15 hr Excretion: Urine (76%), feces (21%) Oral Administration Administer 30 minutes after same meal each day Do not crush, chew, or open capsules BRAND FORM. UNIT PRICE PILL IMAGE tamsulosin oral- 0.4 mg capsuletamsulosin oral- 0.4 mg capsuletamsulosin oral- 0.4 mg capsuletamsulosin oral- 0.4 mg capsuletamsulosin oral- 0.4 mg capsuletamsulosin oral- 0.4 mg capsuletamsulosin oral- 0.4 mg capsuletamsulosin oral- 0.4 mg capsuletamsulosin oral- 0.4 mg capsuleFlomax oral- 0.4 mg capsuleCopyright © 2010 First DataBank, Inc.Print Patient Educationtamsulosin oral TAMSULOSIN CAPSULE - ORAL (tam-SOO-loe-sin) COMMON BRAND NAME(S): Flomax USES: 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, 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. HOW TO USE: Read the Patient Information Leaflet if available from your pharmacist before you start taking this medication and each time you get a refill. If you have any questions, ask your doctor or pharmacist.Take this medication by mouth as directed by your doctor, usually once daily, 30 minutes after the same meal each day. Swallow this medication whole. Do not crush, chew, or open the capsules.The dosage is based on your medical condition and response to treatment.Tamsulosin may cause a sudden drop in your blood pressure, which could lead to dizziness or fainting. This risk is higher when you first start taking this drug, after your doctor increases your dose, or if you restart treatment after you stop taking it. During these times, avoid situations