INN monograph
Dutasteride/Tamsulosin
5-alpha Reductase Inhibitor [EPC] · POM
Source-linked · Updated 03 Aug 2026 · Source: Local active-ingredient clinical extract; FDA drug label via OpenFDA/DailyMed; Component monographs (multi-source pipeline); Professional class pharmacology (Therapeutic agent (verify pharmacological class))
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Contraindications
- 4 CONTRAINDICATIONS Dutasteride and tamsulosin hydrochloride capsules are contraindicated for use in: Pregnancy.
- Dutasteride use is contraindicated in females who are pregnant.
- In animal reproduction and developmental toxicity studies, dutasteride inhibited development of male fetus external genitalia.
- Therefore, dutasteride and tamsulosin hydrochloride capsules may cause fetal harm when administered to a pregnant female. [see Warnings and Precautions ( 5.6 ), Use in Specific Populations ( 8.1 ) ] .
- Patients with previously demonstrated, clinically significant hypersensitivity (e.g., serious skin reactions, angioedema, urticaria, pruritus, respiratory symptoms) to dutasteride, other 5-alpha-reductase inhibitors, tamsulosin, or any other component of dutasteride and tamsulosin hydrochloride capsules [see Adverse Reactions ( 6.2 ) ] .
- Pregnancy.
- Dutasteride use is contraindicated in females who are pregnant.
- ( 4 , 5.6 , 8.1 ) Patients with previously demonstrated, clinically significant hypersensitivity (e.g., serious skin reactions, angioedema, urticaria, pruritus, respiratory symptoms) to dutasteride, other 5-alpha-reductase inhibitors, tamsulosin, or any component of dutasteride and tamsulosin hydrochloride capsules.
Precautions
- 5 WARNINGS AND PRECAUTIONS Orthostatic hypotension and/or syncope can occur.
- Advise patients of symptoms related to postural hypotension and to avoid situations where injury could result if syncope occurs.
- ( 5.1 ) Do not use dutasteride and tamsulosin hydrochloride capsules with other alpha-adrenergic antagonists, as this may increase the risk of hypotension.
- ( 5.2 ) Dutasteride and tamsulosin hydrochloride capsules reduce serum prostate-specific antigen (PSA) concentration by approximately 50%.
- However, any confirmed increase in PSA while on dutasteride and tamsulosin hydrochloride capsules may signal the presence of prostate cancer and should be evaluated, even if those values are still within the normal range for untreated men.
- ( 5.3 ) Do not use dutasteride and tamsulosin hydrochloride capsules with strong inhibitors of cytochrome P450 (CYP) 3A4 (e.g., ketoconazole).
- Use caution in combination with moderate CYP3A4 inhibitors (e.g., erythromycin) or strong (e.g., paroxetine) or moderate CYP2D6 inhibitors, a combination of both CYP3A4 and CYP2D6 inhibitors, or known poor metabolizers of CYP2D6.
- Concomitant use with known inhibitors can cause a marked increase in drug exposure.
- ( 5.2 , 7.1 , 12.3 ) Exercise caution with concomitant use of phosphodiesterase-5 (PDE-5) inhibitors, as this may increase the risk of hypotension.
- ( 5.2 ) Drugs that contain dutasteride, including dutasteride and tamsulosin hydrochloride capsules, may increase the risk of high-grade prostate cancer.
- ( 5.4 , 6.1 ) Prior to initiating treatment with dutasteride and tamsulosin hydrochloride capsules, consideration should be given to other urological conditions that may cause similar symptoms.
- ( 5.5 ) Females who are pregnant or may be pregnant should not handle dutasteride and tamsulosin hydrochloride capsules due to potential risk to a male fetus.
Point of care
Dosing
Adult
2 DOSAGE AND ADMINISTRATION The recommended dosage of dutasteride and tamsulosin hydrochloride capsules is 1 capsule (0.5 mg dutasteride and 0.4 mg tamsulosin hydrochloride) taken once daily approximately 30 minutes after the same meal each day. The capsules should be swallowed whole and not chewed or opened. Contact with the contents of the dutasteride and tamsulosin hydrochloride capsule may result in irritation of the oropharyngeal mucosa. Take one capsule daily approximately 30 minutes after the same meal each day. ( 2 ) Swallow capsule whole. ( 2 )
Paediatric
8.4 Pediatric Use Dutasteride and tamsulosin hydrochloride capsules are not indicated for use in pediatric patients. Safety and effectiveness of dutasteride and tamsulosin hydrochloride capsules in pediatric patients have not been established.
Renal
Review renal impairment dosing; many agents need CrCl/eGFR adjustment.
- CrCl 0–120: Confirm renal dosing in product SmPC / primary label.
Hepatic
Review hepatic impairment dosing; monitor LFTs if agent is hepatically cleared or hepatotoxic.
Safety
Drug interactions
- Fixed-dose/multi-ingredient product.
- Clinical details partially inherited from component monographs: Dutasteride, Tamsulosin.
- Confirm combination SmPC for exact dosing.
Safety
Adverse effects
- 6 ADVERSE REACTIONS The most common adverse reactions, reported in ≥1% of subjects treated with coadministered dutasteride and tamsulosin are ejaculation disorders, impotence, decreased libido, dizziness, and breast disorders.
- ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact AvKARE at 1-855-361-3993 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience The clinical efficacy and safety of coadministered dutasteride and tamsulosin, which are individual components of dutasteride and tamsulosin hydrochloride capsules, have been evaluated in a multicenter, randomized, double-blind, parallel group trial (the Combination with Alpha-Blocker Therapy, or CombAT, trial).
- Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared with rates in the clinical trial of another drug and may not reflect the rates observed in practice.
- The most common adverse reactions reported in subjects receiving coadministered dutasteride and tamsulosin were impotence, decreased libido, breast disorders (including breast enlargement and tenderness), ejaculation disorders, and dizziness.
- Ejaculation disorders occurred significantly more in subjects receiving coadministration therapy (11%) compared with those receiving dutasteride (2%) or tamsulosin (4%) as monotherapy.
- Trial withdrawal due to adverse reactions occurred in 6% of subjects receiving coadministered dutasteride and tamsulosin and in 4% of subjects receiving dutasteride or tamsulosin as monotherapy.
- The most common adverse reaction in all treatment arms leading to trial withdrawal was erectile dysfunction (1% to 1.5%).
- In the CombAT trial, over 4,800 male subjects with BPH were randomly assigned to receive 0.5 mg dutasteride, 0.4 mg tamsulosin hydrochloride, or coadministration therapy (0.5 mg dutasteride and 0.4 mg tamsulosin hydrochloride) administered once daily in a 4-year double-blind trial.
- Overall, 1,623 subjects received monotherapy with dutasteride
- 1,611 subjects received monotherapy with tamsulosin
- and 1,610 subjects received coadministration therapy.
- The population was aged 49 to 88 years (mean age: 66 years) and 88% were white.
- Table 1 summarizes adverse reactions reported in at least 1% of subjects receiving coadministration therapy and at a higher incidence than subjects receiving either dutasteride or tamsulosin as monotherapy.
- Table 1.
Use
Indications
- 1 INDICATIONS AND USAGE Dutasteride and tamsulosin hydrochloride capsules are a combination of dutasteride, a 5-alpha-reductase inhibitor, and tamsulosin, an alpha-adrenergic antagonist, indicated for the treatment of symptomatic benign prostatic hyperplasia (BPH) in men with an enlarged prostate.
- ( 1.1 ) Limitations of Use: Dutasteride-containing products, including dutasteride and tamsulosin hydrochloride capsules, are not approved for the prevention of prostate cancer.
- ( 1.2 ) 1.1 Benign Prostatic Hyperplasia (BPH) Treatment Dutasteride and tamsulosin hydrochloride capsules are indicated for the treatment of symptomatic BPH in men with an enlarged prostate. 1.2 Limitations of Use Dutasteride-containing products, including dutasteride and tamsulosin hydrochloride capsules, are not approved for the prevention of prostate cancer.
Pharmacology
Mode of action
12.
Full mechanism text
12.1 Mechanism of Action Dutasteride and tamsulosin hydrochloride capsules are a combination of 2 drugs with different mechanisms of action to improve symptoms in patients with BPH: dutasteride, a 5-alpha-reductase inhibitor, and tamsulosin, an antagonist of alpha 1A -adrenoreceptors. Dutasteride Dutasteride inhibits the conversion of testosterone to DHT. DHT is the androgen primarily responsible for the initial development and subsequent enlargement of the prostate gland. Testosterone is converted to DHT by the enzyme 5-alpha-reductase, which exists as 2 isoforms, type 1 and type 2. The type 2 isoenzyme is primarily active in the reproductive tissues, while the type 1 isoenzyme is also responsible for testosterone conversion in the skin and liver. Dutasteride is a competitive and specific inhibitor of both type 1 and type 2 5-alpha-reductase isoenzymes, with which it forms a stable enzyme complex. Dissociation from this complex has been evaluated under in vitro and in vivo conditions and is extremely slow. Dutasteride does not bind to the human androgen receptor. Tamsulosin 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 3 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 human prostate are of the alpha 1A subtype. Tamsulosin is not intended for use as an antihypertensive.
ADME
Pharmacokinetics & PD
| Onset | Product-specific |
|---|---|
| Duration | Product-specific |
| Route | See product SmPC |
| Absorption | The pharmacokinetic parameters of dutasteride and tamsulosin observed after administration of dutasteride and tamsulosin hydrochloride capsules in a single-dose, randomized, 3-period, partial cross-over trial are summarized in Table 2 below. Table 2. Arithmetic Means (SD) of Seru... |
| Distribution | differs between human organs and tissue. Approximately 70% of the alpha 1 -receptors in human prostate are of the alpha 1A subtype. Tamsulosin is not intended for use as an antihypertensive. 12.2 Pharmacodynamics Dutasteride Effect on 5-Alpha-Dihydrotestosterone and Testosterone:... |
| Metabolism | Dutasteride: Dutasteride is extensively metabolized in humans. In vitro studies showed that dutasteride is metabolized by the CYP3A4 and CYP3A5 isoenzymes. Both of these isoenzymes produced the 4’-hydroxydutasteride, 6-hydroxydutasteride, and the 6,4’-dihydroxydutasteride metabol... |
| Elimination | Dutasteride: Dutasteride and its metabolites were excreted mainly in feces. As a percent of dose, there was approximately 5% unchanged dutasteride (approximately 1% to approximately 15%) and 40% as dutasteride-related metabolites (approximately 2% to approximately 90%). Only trac... |
| Half-life | of dutasteride is approximately 5 weeks at steady state. The average steady-state serum dutasteride concentration was 40 ng/mL following 0.5 mg/day for 1 year. Following daily dosing, dutasteride serum concentrations achieve 65% of steady-state concentration after 1 month and app... |
Full PK/PD text
12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Dutasteride and tamsulosin hydrochloride capsules are a combination of 2 drugs with different mechanisms of action to improve symptoms in patients with BPH: dutasteride, a 5-alpha-reductase inhibitor, and tamsulosin, an antagonist of alpha 1A -adrenoreceptors. Dutasteride Dutasteride inhibits the conversion of testosterone to DHT. DHT is the androgen primarily responsible for the initial development and subsequent enlargement of the prostate gland. Testosterone is converted to DHT by the enzyme 5-alpha-reductase, which exists as 2 isoforms, type 1 and type 2. The type 2 isoenzyme is primarily active in the reproductive tissues, while the type 1 isoenzyme is also responsible for testosterone conversion in the skin and liver. Dutasteride is a competitive and specific inhibitor of both type 1 and type 2 5-alpha-reductase isoenzymes, with which it forms a stable enzyme complex. Dissociation from this complex has been evaluated under in vitro and in vivo conditions and is extremely slow. Dutasteride does not bind to the human androgen receptor. Tamsulosin 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 3 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 human prostate are of the alpha 1A subtype. Tamsulosin is not intended for use as an antihypertensive. 12.2 Pharmacodynamics Dutasteride Effect on 5-Alpha-Dihydrotestosterone and Testosterone: The maximum effect of daily doses of dutasteride on the reduction of DHT is dose-dependent and is observed within 1 to 2 weeks. After 1 and 2 weeks of daily dosing with dutasteride 0.5 mg, median serum DHT concentrations were reduced by 85% and 90%, respectively. In patients with BPH treated with dutasteride 0.5 mg/day for 4 years, the median decrease in serum DHT was 94% at 1 year, 93% at 2 years, and 95% at both 3 and 4 years. The median increase in serum testosterone was 19% at both 1 and 2 years, 26% at 3 years, and 22% at 4 years, but the mean and median levels remained within the physiologic range. In patients with BPH treated with 5 mg/day of dutasteride or placebo for up to 12 weeks prior to transurethral resection of the prostate, mean DHT concentrations in prostatic tissue were significantly lower in the dutasteride group compared with placebo (784 and 5,793 pg/g, respectively, P <0.001). Mean prostatic tissue concentrations of testosterone were significantly higher in the dutasteride group compared with placebo (2,073 and 93 pg/g, respectively, P <0.001). Adult males with genetically inherited type 2 5-alpha-reductase deficiency also have decreased DHT levels. These 5-alpha-reductase-deficient males have a small prostate gland throughout life and do not develop BPH. Except for the associated urogenital defects present at birth, no other clinical abnormalities related to 5-alpha-reductase deficiency have been observed in these individuals. Effects on Other Hormones: In healthy volunteers, 52 weeks of treatment with dutasteride 0.5 mg/day (n = 26) resulted in no clinically significant change compared with placebo (n = 23) in sex hormone-binding globulin, estradiol, luteinizing hormone, follicle-stimulating hormone, thyroxine (free T4), and dehydroepiandrosterone. Statistically significant, baseline-adjusted mean increases compared with placebo were observed for total testosterone at 8 weeks (97.1 ng/dL, P <0.003) and thyroid-stimulating hormone at 52 weeks (0.4 mcIU/mL, P <0.05). The median percentage changes from baseline within the dutasteride group were 17.9% for testosterone at 8 weeks and 12.4% for thyroid-stimulating hormone at 52 weeks. After stopping dutasteride for 24 weeks, the mean levels of testosterone and thyroid-stimulating hormone had returned to baseline in the group of subjects with available data at the visit. In subjects with BPH treated with dutasteride in a large randomized, double-blind, placebo-controlled trial, there was a median percent increase in luteinizing hormone of 12% at 6 months and 19% at both 12 and 24 months. Other Effects: Plasma lipid panel and bone mineral density were evaluated following 52 weeks of dutasteride 0.5 mg once daily in healthy volunteers. There was no change in bone mineral density as measured by dual energy x-ray absorptiometry compared with either placebo or baseline. In addition, the plasma lipid profile (i.e., total cholesterol, low density lipoproteins, high density lipoproteins, triglycerides) was unaffected by dutasteride. No clinically significant changes in adrenal hormone responses to adrenocorticotropic hormone (ACTH) stimulation were observed in a subset population (n = 13) of the 1 year healthy volunteer trial. 12.3 Pharmacokinetics The pharmacokinetics of dutasteride and tamsulosin from dutasteride and tamsulosin hydrochloride capsules are comparable to the pharmacokinetics of dutasteride and tamsulosin when administered separately. Absorption The pharmacokinetic parameters of dutasteride and tamsulosin observed after administration of dutasteride and tamsulosin hydrochloride capsules in a single-dose, randomized, 3-period, partial cross-over trial are summarized in Table 2 below. Table 2. Arithmetic Means (SD) of Serum Dutasteride and Tamsulosin in Single-Dose Pharmacokinetic Parameters under Fed Conditions Component N AUC (0-t) (ng h/mL) C max (ng/mL) T max (h) a t ½ (h) Dutasteride 92 39.6 (23.1) 2.14 (0.77) 3.00 (1.00-10.00) Tamsulosin 92 187.2 (95.7) 11.3 (4.44) 6.00 (2.00-24.00) 13.5 (3.92) b a Median (range). b N = 91. Dutasteride: Following administration of a single 0.5 mg dose of a soft gelatin capsule, time to peak absolute bioavailability in 5 healthy subjects is approximately 60% (range: 40% to 94%). Tamsulosin: Absorption of tamsulosin is essentially complete (>90%) following oral administration of 0.4 mg tamsulosin hydrochloride capsules under fasting conditions. Tamsulosin exhibits linear kinetics following single and multiple dosing, with achievement of steady-state concentrations by the fifth day of once-daily dosing. Effect of Food Food does not affect the pharmacokinetics of dutasteride following administration of dutasteride and tamsulosin hydrochloride capsules. However, a mean 30% decrease in tamsulosin C max was observed when dutasteride and tamsulosin hydrochloride capsules was administered with food, similar to that seen when tamsulosin monotherapy was administered under fed versus fasting conditions. Distribution Dutasteride: Pharmacokinetic data following single and repeat oral doses show that dutasteride has a large volume of distribution (300 to 500 L). Dutasteride is highly bound to plasma albumin (99.0%) and alpha-1 acid glycoprotein (AAG, 96.6%). In a trial of healthy subjects (n = 26) receiving dutasteride 0.5 mg/day for 12 months, semen dutasteride concentrations averaged 3.4 ng/mL (range: 0.4 to 14 ng/mL) at 12 months and, similar to serum, achieved steady-state concentrations at 6 months. On average, at 12 months 11.5% of serum dutasteride concentrations partitioned into semen. Tamsulosin: The mean steady-state apparent volume of distribution of tamsulosin after intravenous administration to 10 healthy male adults was 16 L, which is suggestive of distribution into extracellular fluids in the body. Tamsulosin is extensively bound to human plasma proteins (94% to 99%), primarily AAG, with linear binding over a wide concentration range (20 to 600 ng/mL). The results of 2-way in vitro studies indicate that the binding of tamsulosin to human plasma proteins is not affected by amitriptyline, diclofenac, glyburide, simvastatin plus simvastatin-hydroxy acid metabolite, warfarin, diazepam, or propranolol. Likewise, tamsulosin had no effect on the extent of binding of these drugs. Metabolism Dutasteride: Dutasteride is extensively metabolized in humans. In vitro studies showed that dutasteride is metabolized by the CYP3A4 and CYP3A5 isoenzymes. Both of these isoenzymes produced the 4’-hydroxydutasteride, 6-hydroxydutasteride, and the 6,4’-dihydroxydutasteride metabolites. In addition, the 15-hydroxydutasteride metabolite was formed by CYP3A4. Dutasteride is not metabolized in vitro by human cytochrome P450 isoenzymes CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP2E1. In human serum following dosing to steady state, unchanged dutasteride, 3 major metabolites (4’-hydroxydutasteride, 1,2-dihydrodutasteride, and 6-hydroxydutasteride), and 2 minor metabolites (6,4’-dihydroxydutasteride and 15-hydroxydutasteride), as assessed by mass spectrometric response, have been detected. The absolute stereochemistry of the hydroxyl additions in the 6 and 15 positions is not known. In vitro , the 4’-hydroxydutasteride and 1,2-dihydrodutasteride metabolites are much less potent than dutasteride against both isoforms of human 5α-reductase. The activity of 6β-hydroxydutasteride is comparable to that of dutasteride. Tamsulosin: There is no enantiomeric bioconversion from tamsulosin [R(-) isomer] to the S(+) isomer in humans. Tamsulosin is extensively metabolized by cytochrome P450 enzymes in the liver and less than 10% of the dose is excreted in urine unchanged. However, the pharmacokinetic profile of the metabolites in humans has not been established. In vitro studies indicate that CYP3A4 and CYP2D6 are involved in metabolism of tamsulosin as well as some minor participation of other CYP isoenzymes. Inhibition of hepatic drug metabolizing enzymes may lead to increased exposure to tamsulosin [see Drug Interactions ( 7.1 ) ] . The metabolites of tamsulosin undergo extensive conjugation to glucuronide or sulfate prior to renal excretion. Incubations with human liver microsomes showed no evidence of clinically significant metabolic interactions between tamsulosin and amitriptyline, albuterol, glyburide, and finasteride. However, results of the in vitro testing of the tamsulosin interaction with diclofenac and warfarin were equivocal. Excretion Dutasteride: Dutasteride and its metabolites were excreted mainly in feces. As a percent of dose, there was approximately 5% unchanged dutasteride (approximately 1% to approximately 15%) and 40% as dutasteride-related metabolites (approximately 2% to approximately 90%). Only trace amounts of unchanged dutasteride were found in urine (<1%). Therefore, on average, the dose unaccounted for approximated 55% (range: 5% to 97%). The terminal elimination half-life of dutasteride is approximately 5 weeks at steady state. The average steady-state serum dutasteride concentration was 40 ng/mL following 0.5 mg/day for 1 year. Following daily dosing, dutasteride serum concentrations achieve 65% of steady-state concentration after 1 month and approximately 90% after 3 months. Due to the long half-life of dutasteride, serum concentrations remain detectable (greater than 0.1 ng/mL) for up to 4 to 6 months after discontinuation of treatment. Tamsulosin: On administration of the radiolabeled dose of tamsulosin to 4 healthy volunteers, 97% of the administered radioactivity was recovered, with urine (76%) representing the primary route of excretion compared with feces (21%) over 168 hours. Following intravenous or oral administration of an immediate-release formulation, the elimination half-life of tamsulosin in plasma ranges from 5 to 7 hours. Because of absorption rate-controlled pharmacokinetics with tamsulosin hydrochloride capsules, the apparent half-life of tamsulosin i
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Special populations
Pregnancy & lactation
Pregnancy
8.1 Pregnancy Risk Summary Dutasteride and tamsulosin hydrochloride capsules are contraindicated for use in pregnancy because it may cause harm to the male fetus [see Contraindications (4) ] . Dutasteride and tamsulosin hydrochloride capsules are not indicated for use in females. Dutasteride, a component of dutasteride and tamsulosin hydrochloride capsules, is a 5-alpha-reductase inhibitor that prevents conversion of testosterone to dihydrotestosterone (DHT), a hormone necessary for normal development of male genitalia. Abnormalities in the genitalia of male fetuses are an expected physiological consequence of inhibition of this conversion. These results are similar to observations in male infants with genetic 5-alpha-reductase deficiency. In animal reproduction studies, dutasteride inhibited normal development of external genitalia in male offspring when given to rats or rabbits during organogenesis at less than the maximum recommended human dose (MRHD) of 0.5 mg daily, in the absence of maternal toxicity. At 15 times the MRHD, prolonged pregnancy, decreased reproductive organ weights, and delayed puberty in male offspring were observed in rats, with no-effect levels less than the MRHD of 0.5 mg daily. Increased placental weights in rabbits were also observed, with no-effect levels less than the MRHD of 0.5 mg daily (see Data) . Although dutasteride is secreted into human semen, the drug concentration in the human female partner is approximately 100 times less than concentrations producing abnormalities of male genitalia in animal studies (see Data) . In monkeys dosed during organogenesis at blood concentrations comparable to or above levels to which a human female partner is estimated to be exposed, male offspring external genitalia was not adversely affected. No feminization occurred in male offspring of untreated female rats mated to treated male rats even though detectable blood levels of dutasteride were observed in the female rats [see Nonclinical Toxicology (13.1) ] . No adverse developmental effects were observed in animal studies in which tamsulosin hydrochloride was administered to rats or rabbits during the period of organogenesis (see Data). Data Human Data: Dutasteride: The highest measured semen concentration of dutasteride in treated men was 14 ng/mL. Although dutasteride is detected in semen, assuming exposure of a 50 kg female to 5 mL of semen and 100% absorption, the female’s expected dutasteride blood concentration through semen would be about 0.0175 ng/mL. This concentration is approximately 100 times less than blood concentrations producing abnormalities of male genitalia in animal studies. Dutasteride is highly protein bound in human semen (greater than 96%), which may reduce the amount of dutasteride available for vaginal absorption. Animal Data: Dutasteride: In an embryo-fetal development study in rats, oral administration of dutasteride at 10 times less than the MRHD of 0.5 mg daily (based on average blood levels in men) resulted in feminization of male genitalia in the fetus (decreased anogenital distance at 0.05 mg/kg/day with a lack of a no-effect level) in the absence of maternal toxicity. In addition, nipple development, hypospadias, and distended preputial glands occurred in fetuses of dams treated at doses of 2.5 mg/kg/day or greater (approximately 15 times the MRHD). Reduced fetal body weight and associated delayed ossification in the presence of maternal toxicity (decreased body weight gain) were observed at maternal exposure approximately 15 times the MRHD (dose of 2.5 mg/kg/day or greater). An increase in stillborn pups was observed in dams treated at 30 mg/kg/day (approximately 111 times the MRHD), with a no- effect level of 12.5 mg/kg/day. In a rabbit embryo-fetal development study, doses 28 times the MRHD (doses of 30mg/kg/day or greater), based on average blood levels in men, were administered orally on Gestation Days 7 to 29 (during organogenesis and the late period of external genitalia development). Histological evaluation of the genital papilla of fetuses revealed evidence of feminization of the male fetus as well as fused skull bones and increased placental weights at all doses in the absence of maternal toxicity. A second embryo-fetal development study in rabbits dosed throughout pregnancy (organogenesis and later period of external genitalia development [Gestation Days 6 to 29]) at 0.3 times the MHRD doses of 0.05 mg/kg/day or greater, with no no-effect level),) also produced evidence of feminization of the genitalia in male fetuses and increased placental weights at all doses in the absence of maternal toxicity. In an embryo-fetal development study, pregnant rhesus monkeys were exposed intravenously during organogenesis (Gestation Days 20 to 100) to a dutasteride blood level comparable to or above the estimated dutasteride exposure of a human female partner. Dutasteride was administered on Gestation Days 20 to 100 (during organogenesis) at doses of 400, 780, 1,325, or 2,010 ng/day (12 monkeys/group). No feminization of male external genitalia of monkey offspring was observed. Reduction of fetal adrenal weights, reduction in fetal prostate weights, and increases in fetal ovarian and testis weights were observed at the highest dose tested. Based on the highest measured semen concentration of dutasteride in treated men (14 ng/mL), these doses in the monkey represent up to 16 times the potential maximum exposure of a 50 kg human female to 5 mL of semen daily from a dutasteride-treated male, assuming 100% absorption. The dose levels (on a ng/kg basis) administered to monkeys in this study are 32 to 186 times the nominal (ng/kg) dose to which a female would potentially be exposed via the semen. It is not known whether rabbits or rhesus monkeys produce any of the major human metabolites. In an oral pre- and post-natal development study in rats, feminization of the male genitalia was observed. Decreased anogenital distance was observed at 0.05 times the MRHD and greater (0.05 mg/kg/day and greater), with a lack of a no-effect level, based on average blood levels in men as an estimation of AUC. Hypospadias and nipple development were observed at 2.5 mg/kg/day or greater (14 times the MRHD or greater, with a no-effect level at 0.05 mg/kg/day). Doses of 2.5 mg/kg/day and greater also resulted in prolonged gestation in the parental females, an increase in time to balano-preputial separation in male offspring, a decrease in time to vaginal patency for female offspring, and a decrease in prostate and seminal vesicle weights in male offspring. Increased stillbirths and decreased neonatal viability in offspring were noted at 30 mg/kg/day (102 times the MRHD in the presence of maternal toxicity [decreased body weights]). Tamsulosin: Administration of tamsulosin hydrochloride to pregnant female rats during the period of organogenesis (Gestation Days 7 to 17) 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 (Gestation Days 6 to 18) at dose levels up to 50 mg/kg/day produced no evidence of fetal harm.
Lactation
8.1 Pregnancy Risk Summary Dutasteride and tamsulosin hydrochloride capsules are contraindicated for use in pregnancy because it may cause harm to the male fetus [see Contraindications (4) ] . Dutasteride and tamsulosin hydrochloride capsules are not indicated for use in females. Dutasteride, a component of dutasteride and tamsulosin hydrochloride capsules, is a 5-alpha-reductase inhibitor that prevents conversion of testosterone to dihydrotestosterone (DHT), a hormone necessary for normal development of male genitalia. Abnormalities in the genitalia of male fetuses are an expected physiological consequence of inhibition of this conversion. These results are similar to observations in male infants with genetic 5-alpha-reductase deficiency. In animal reproduction studies, dutasteride inhibited normal development of external genitalia in male offspring when given to rats or rabbits during organogenesis at less than the maximum recommended human dose (MRHD) of 0.5 mg daily, in the absence of maternal toxicity. At 15 times the MRHD, prolonged pregnancy, decreased reproductive organ weights, and delayed puberty in male offspring were observed in rats, with no-effect levels less than the MRHD of 0.5 mg daily. Increased placental weights in rabbits were also observed, with no-effect levels less than the MRHD of 0.5 mg daily (see Data) . Although dutasteride is secreted into human semen, the drug concentration in the human female partner is approximately 100 times less than concentrations producing abnormalities of male genitalia in animal studies (see Data) . In monkeys dosed during organogenesis at blood concentrations comparable to or above levels to which a human female partner is estimated to be exposed, male offspring external genitalia was not adversely affected. No feminization occurred in male offspring of untreated female rats mated to treated male rats even though detectable blood levels of dutasteride were observed in the female rats [see Nonclinical Toxicology (13.1) ] . No adverse developmental effects were observed in animal studies in which tamsulosin hydrochloride was administered to rats or rabbits during the period of organogenesis (see Data). Data Human Data: Dutasteride: The highest measured semen concentration of dutasteride in treated men was 14 ng/mL. Although dutasteride is detected in semen, assuming exposure of a 50 kg female to 5 mL of semen and 100% absorption, the female’s expected dutasteride blood concentration through semen would be about 0.0175 ng/mL. This concentration is approximately 100 times less than blood concentrations producing abnormalities of male genitalia in animal studies. Dutasteride is highly protein bound in human semen (greater than 96%), which may reduce the amount of dutasteride available for vaginal absorption. Animal Data: Dutasteride: In an embryo-fetal development study in rats, oral administration of dutasteride at 10 times less than the MRHD of 0.5 mg daily (based on average blood levels in men) resulted in feminization of male genitalia in the fetus (decreased anogenital distance at 0.05 mg/kg/day with a lack of a no-effect level) in the absence of maternal toxicity. In addition, nipple development, hypospadias, and distended preputial glands occurred in fetuses of dams treated at doses of 2.5 mg/kg/day or greater (approximately 15 times the MRHD). Reduced fetal body weight and associated delayed ossification in the presence of maternal toxicity (decreased body weight gain) were observed at maternal exposure approximately 15 times the MRHD (dose of 2.5 mg/kg/day or greater). An increase in stillborn pups was observed in dams treated at 30 mg/kg/day (approximately 111 times the MRHD), with a no- effect level of 12.5 mg/kg/day. In a rabbit embryo-fetal development study, doses 28 times the MRHD (doses of 30mg/kg/day or greater), based on average blood levels in men, were administered orally on Gestation Days 7 to 29 (during organogenesis and the late period of external genitalia development). Histological evaluation of the genital papilla of fetuses revealed evidence of feminization of the male fetus as well as fused skull bones and increased placental weights at all doses in the absence of maternal toxicity. A second embryo-fetal development study in rabbits dosed throughout pregnancy (organogenesis and later period of external genitalia development [Gestation Days 6 to 29]) at 0.3 times the MHRD doses of 0.05 mg/kg/day or greater, with no no-effect level),) also produced evidence of feminization of the genitalia in male fetuses and increased placental weights at all doses in the absence of maternal toxicity. In an embryo-fetal development study, pregnant rhesus monkeys were exposed intravenously during organogenesis (Gestation Days 20 to 100) to a dutasteride blood level comparable to or above the estimated dutasteride exposure of a human female partner. Dutasteride was administered on Gestation Days 20 to 100 (during organogenesis) at doses of 400, 780, 1,325, or 2,010 ng/day (12 monkeys/group). No feminization of male external genitalia of monkey offspring was observed. Reduction of fetal adrenal weights, reduction in fetal prostate weights, and increases in fetal ovarian and testis weights were observed at the highest dose tested. Based on the highest measured semen concentration of dutasteride in treated men (14 ng/mL), these doses in the monkey represent up to 16 times the potential maximum exposure of a 50 kg human female to 5 mL of semen daily from a dutasteride-treated male, assuming 100% absorption. The dose levels (on a ng/kg basis) administered to monkeys in this study are 32 to 186 times the nominal (ng/kg) dose to which a female would potentially be exposed via the semen. It is not known whether rabbits or rhesus monkeys produce any of the major human metabolites. In an oral pre- and post-natal development study in rats, feminization of the male genitalia was observed. Decreased anogenital distance was observed at 0.05 times the MRHD and greater (0.05 mg/kg/day and greater), with a lack of a no-effect level, based on average blood levels in men as an estimation of AUC. Hypospadias and nipple development were observed at 2.5 mg/kg/day or greater (14 times the MRHD or greater, with a no-effect level at 0.05 mg/kg/day). Doses of 2.5 mg/kg/day and greater also resulted in prolonged gestation in the parental females, an increase in time to balano-preputial separation in male offspring, a decrease in time to vaginal patency for female offspring, and a decrease in prostate and seminal vesicle weights in male offspring. Increased stillbirths and decreased neonatal viability in offspring were noted at 30 mg/kg/day (102 times the MRHD in the presence of maternal toxicity [decreased body weights]). Tamsulosin: Administration of tamsulosin hydrochloride to pregnant female rats during the period of organogenesis (Gestation Days 7 to 17) 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 (Gestation Days 6 to 18) at dose levels up to 50 mg/kg/day produced no evidence of fetal harm. 8.2 Lactation Risk Summary Dutasteride and tamsulosin hydrochloride capsules are not indicated for use in females. 8.3 Females and Males of Reproductive Potential Infertility Dutasteride: Males: The effects of dutasteride 0.5 mg/day on semen characteristics were evaluated in normal volunteers aged 18 to 52 years (n = 27 dutasteride, n = 23 placebo) throughout 52 weeks of treatment and 24 weeks of post-treatment follow-up. At 52 weeks, the mean percent reductions from baseline in total sperm count, semen volume, and sperm motility were 23%, 26%, and 18%, respectively, in the dutasteride group when adjusted for changes from baseline in the placebo group. Sperm concentration and sperm morphology were unaffected. After 24 weeks of follow-up, the mean percent change in total sperm count in the dutasteride group remained 23% lower than baseline. While mean values for all semen parameters at all timepoints remained within the normal ranges and did not meet predefined criteria for a clinically significant change (30%), 2 subjects in the dutasteride group had decreases in sperm count of greater than 90% from baseline at 52 weeks, with partial recovery at the 24-week follow-up. The clinical significance of these effects on semen characteristics for an individual patient’s fertility is not known [see Warnings and Precautions ( 5.11 ) ] . Tamsulosin: Males: Abnormal ejaculation including ejaculation failure, ejaculation disorder, retrograde ejaculation, and decreased ejaculation has been associated with tamsulosin hydrochloride . Studies in rats revealed significantly reduced fertility in males, considered to be due to impairment of ejaculation, which was reversible [see Nonclinical Toxicology ( 13.1 ) ]. 8.4 Pediatric Use Dutasteride and tamsulosin hydrochloride capsules are not indicated for use in pediatric patients. Safety and effectiveness of dutasteride and tamsulosin hydrochloride capsules in pediatric patients have not been established. 8.5 Geriatric Use Of 1,610 male subjects treated with coadministered dutasteride and tamsulosin in the CombAT trial, 58% of enrolled subjects were aged 65 years and older and 13% of enrolled subjects were aged 75 years and older. No overall differences in safety or efficacy were observed between these subjects and younger subjects but greater sensitivity of some older individuals cannot be ruled out [see Clinical Pharmacology ( 12.3 )] . 8.6 Renal Impairment The effect of renal impairment on dutasteride and tamsulosin pharmacokinetics has not been studied using dutasteride and tamsulosin hydrochloride capsules. Because no dosage adjustment is necessary for dutasteride or tamsulosin in patients with moderate-to-severe renal impairment (10≤ CL cr <30 mL/min/1.73 m 2 ), no dosage adjustment is necessary for dutasteride and tamsulosin hydrochloride capsules in patients with moderate-to-severe renal impairment. However, patients with end-stage renal disease (CL cr <10 mL/min/1.73 m 2 ) have not been studied [see Clinical Pharmacology ( 12.3 ) ] . 8.7 Hepatic Impairment The effect of hepatic impairment on dutasteride and tamsulosin pharmacokinetics has not been studied using dutasteride and tamsulosin hydrochloride capsules. The following text reflects information available for the individual components. Dutasteride The effect of hepatic impairment on dutasteride pharmacokinetics has not been studied. Because dutasteride is extensively metabolized, exposure could be higher in hepatically impaired patients. However, in a clinical trial where 60 subjects received 5 mg (10 times the therapeutic dose) daily for 24 weeks, no additional adverse events were observed compared with those observed at the therapeutic dose of 0.5 mg [see Clinical Pharmacology ( 12.3 ) ] . Tamsulosin Patients with moderate hepatic impairment do not require an adjustment in tamsulosin dosage. Tamsulosin has not been studied in patients with severe hepatic impairment [see Clinical Pharmacology ( 12.3 ) ] .
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Food & alcohol
- Drug & food interactions (label) 7 DRUG INTERACTIONS There have been no drug interaction trials using dutasteride and tamsulosin hydrochloride capsules. The following sections reflect information available for the individual components. 7.1 Cytochrome P450 Inhibition Dutasteride Dutasteride is extensively metabolized in humans by the CYP3A4 and CYP3A5 isoenzymes. The effect of potent CYP3A4 inhibitors on dutasteride has not been studied. Because of the potential for drug-drug interactions, use caution when prescribing a dutasteride-containing product, including dutasteride and tamsulosin hydrochloride capsules, to patients taking potent, chronic CYP3A4 enzyme inhibitors (e.g., ritonavir) [see Clinical Pharmacology ( 12.3 ) ] . Tamsulosin Strong and Moderate Inhibitors of CYP3A4 or CYP2D6: Tamsulosin is extensively metabolized, mainly by CYP3A4 or CYP2D6. Concomitant treatment with ketoconazole (a strong inhibitor of CYP3A4) resulted in increases in the C max and AUC of tamsulosin by factors of 2.2 and 2.8, respectively. Concomitant treatment with paroxetine (a strong inhibitor of CYP2D6) resulted in increases in the C max and area under the concentration-time curve (AUC) of tamsulosin by factors of 1.3 and 1.6, respectively. A similar increase in exposure is expected in poor metabolizers (PM) of CYP2D6 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 0.4 mg is coadministered with strong CYP3A4 inhibitors in CYP2D6 PMs, tamsulosin 0.4 mg capsules should not be used in combination with strong inhibitors of CYP3A4 (e.g., ketoconazole). The effects of coadministration of both a CYP3A4 and a CYP2D6 inhibitor with tamsulosin have not been evaluated. However, there is a potential for significant increase in tamsulosin exposure when tamsulosin 0.4 mg is coadministered with a combination of both CYP3A4 and CYP2D6 inhibitors [see Warnings and Precautions ( 5.2 ), Clinical Pharmacology ( 12.3 ) ] . Cimetidine : Treatment with cimetidine resulted in a moderate increase in tamsulosin hydrochloride AUC (44%) [see Warnings and Precautions ( 5.2 ), Clinical Pharmacology ( 12.3 ) ] . 7.2 Warfarin Dutasteride Concomitant administration of dutasteride 0.5 mg/day for 3 weeks with warfarin does not alter the steady-state pharmacokinetics of the S- or R-warfarin isomers or alter the effect of warfarin on prothrombin time [see Clinical Pharmacology ( 12.3 ) ] . Tamsulosin A definitive drug-drug interaction trial between tamsulosin hydrochloride and warfarin was not conducted. Results from limited in vitro and in vivo studies are inconclusive. Caution should be exercised with concomitant administration of warfarin and tamsulosin-containing products, including dutasteride and tamsulosin hydrochloride capsules [see Warnings and Precautions ( 5.2 ), Clinical Pharmacology ( 12.3 ) ] . 7.3 Nifedipine, Atenolol, Enalapril Tamsulosin Dosage adjustments are not necessary when tamsul
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Source: Local active-ingredient clinical extract; FDA drug label via OpenFDA/DailyMed; Component monographs (multi-source pipeline); Professional class pharmacology (Therapeutic agent (verify pharmacological class))
Clinical review date not recorded.
Decision support only — not a substitute for clinical judgment, product SmPC, or Kenya STG/EML.