Composition
Each soft gelatin capsule contains:
Dutasteride... 0.5 mg
Dosage Form
Capsule
Pharmacology
Pharmacodynamics
Mechanism of Action
Dutasteride inhibits the conversion of testosterone to 5 alpha-dihydrotestosterone (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 two isoforms, type I and type II. The type II 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 I and type II isoforms of 5 alpha-reductase, 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.
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 1-2 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 benign prostatic hyperplasia (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 II 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 patients with BPH treated with dutasteride in a large randomized, double-blind, placebo controlled study; there was a median percent increase in the 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 and triglycerides) was unaffected by dutasteride. No clinically significant changes in adrenal hormone responses to ACTH stimulation were observed in a subset population (n=13) of the 1-year healthy volunteer study.
Pharmacokinetics
Absorption: Following administration of a single 0.5 mg dose of dutasteride, time to peak serum concentrations (Tmax) occurs within 2-3 hours. Absolute bioavailability in 5 healthy subjects is approximately 60% (range: 40% to 94%). When the drug is administered with food, the maximum serum concentrations were reduced by 10-15%. This reduction is of no clinical significance.
Distribution: Pharmacokinetic data following single and repeat oral doses show that dutasteride has a large volume of distribution (300-500 L). Dutasteride is highly bound to plasma albumin (99.0%) and alpha1-acid glycoprotein (96.6%). In a study 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.
Metabolism: 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. In human serum following dosing to a steady state, unchanged dutasteride, three major metabolites (4'-hydroxydutasteride, 1,2-dihydrodutasteride and 6-hydroxydutasteride) and two minor metabolites (6,4-dihydroxydutasteride and 15-hydroxydutasteride), as assessed by mass spectrometric response have been detected. in vitro, the 4-hydroxydutasteride and 1,2-dihydrodutasteride metabolites are much less potent than dutasteride against both isoforms of human 5 alpha-reductase. The activity of 6β hydroxydutasteride is comparable to that of dutasteride.
Excretion: Dutasteride and its metabolites were excreted mainly in the faeces. As a percent of dose, there was approximately 5% unchanged dutasteride (~1% to ~15%) and 40% as dutasteride-related metabolites (~2% to ~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 the 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 4–6 months after discontinuation of treatment.
Pharmacokinetics in Special Populations
Paediatric: Dutasteride pharmacokinetics has not been investigated in subjects younger than 18 years of age.
Geriatric: No dose adjustment is necessary in the elderly. The pharmacokinetics and pharmacodynamics of dutasteride were evaluated in 36 healthy male subjects aged between 24 and 87 years following adminisration of a single 5 mg dose of dutasteride. In this single-dose trial, dutasteride half-life increased with age (approximately 170 hours in men aged 20 to 49 years, approximately 260 hours in men aged 50 to 69 years, and approximately 300 hours in men older than 70 years). Of 2,167 men treated with dutasteride in the three pivotal trials, 60% were aged 65 years and over, and 15% were age 75 years and over. No overall differences in safety or efficacy were observed between these patients and younger patients.
Gender: Dutasteride is contraindicated in pregnancy and women of childbearing potential and is not indicated for use in other women. The pharmacokinetics of dutasteride in women has not been studied.
Race: The effect of race on dutasteride pharmacokinetics has not been studied.
Renal Impairment: The effect of renal impairment on dutasteride pharmacokinetics has not been studied. However, less than 0.1% of a steady-state 0.5 mg dose of dutasteride is recovered in human urine, so no adjustment in dosage is anticipated for patients with renal impairment.
Hepatic Impairment:
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.
Indications
DUPROST capsules are indicated for the treatment of symptomatic benign prostatic hyperplasia (BPH) in men with an enlarged prostate. Dutasteride is not approved for the prevention of prostate cancer.
Dosage and Administration
The recommended dose of DUPROST is one capsule taken orally once a day. The capsule should be swallowed whole. DUPROST capsules may be administered with or without food.
Special Populations
Renal Impairment
No dose adjustment is necessary for dutasteride in patients with renal impairment.
Hepatic Impairment
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.
Contraindications
Dutasteride is Contraindicated for Use in the Following
- Pregnancy: In animal reproduction and developmental toxicity studies, dutasteride inhibited development of the external genitalia of the male foetus. Therefore, dutasteride may cause foetal harm when administered to a pregnant woman. If dutasteride is used during pregnancy or if the patient becomes pregnant while taking dutasteride, the patient should be apprised of the potential hazard to the foetus.
- Women of childbearing potential.
- Paediatric patients.
- Patients with previously demonstrated clinically significant hypersensitivity (e.g. serious skin reactions, angio-oedema) to dutasteride or other 5 alpha-reductase inhibitors.
Warnings and Precautions
General
Evaluation for Other Urological Diseases
Prior to initiating treatment with dutasteride, consideration should be given to other urological conditions that may cause similar symptoms. In addition, BPH and prostate cancer may coexist.
Increased Risk of High-grade Prostate Cancer
In men aged 50 to 75 years with a prior negative biopsy for prostate cancer and a baseline PSA between 2.5 ng/mL and 10.0 ng/mL, who were taking dutasteride in the 4-year Reduction by Dutasteride of Prostate Cancer Events (REDUCE) trial, there was an increased incidence of Gleason score 8-10 prostate cancer compared with men taking placebo (dutasteride 1.0% versus placebo 0.5%). In a 7-year, placebo-controlled clinical trial with another 5 alpha-reductase inhibitor (finasteride 5 mg) similar results for Gleason score 8-10 prostate cancer were observed (finasteride 1.8% versus placebo 1.1%). The 5 alpha-reductase inhibitors may increase the risk of development of high-grade prostate cancer. It has not been established as to whether the effect of 5 alpha-reductase inhibitors to reduce prostate volume, or study-related factors, impacted the results of these studies.
Exposure of Women - Risk to Male Foetus
DUPROST capsules should not be handled by a woman who is pregnant or who could become pregnant. Dutasteride is absorbed through the skin and could result in unintended foetal exposure. If a woman who is pregnant or who could become pregnant comes in contact with leaking dutasteride capsules, the contact area should be washed immediately with soap and water.
Blood Donation
Men being treated with dutasteride should not donate blood until at least 6 months have passed following their last dose, so as to prevent pregnant women from receiving dutasteride through blood transfusion.
Effects on Prostate-Specific Antigen (PSA) and the Use of PSA in Prostate Cancer Detection
In clinical studies, dutasteride reduced serum prostate-specific antigen (PSA) concentration by approximately 50% within 3-6 months of treatment. This decrease was predictable over the entire range of PSA values in patients with symptomatic BPH, although it may vary in individuals. Dutasteride may also cause decreases in serum PSA in the presence of prostate cancer. To interpret serial PSAs in men taking dutasteride, a new PSA baseline should be established at least 3 months after starting treatment and PSA monitored periodically thereafter. Any confirmed increase from the lowest PSA value while on dutasteride may signal the presence of prostate cancer and should be evaluated, even if PSA levels are still within the normal range for men not taking a 5 alpha-reductase inhibitor. Noncompliance with dutasteride may also affect the PSA test results.
To interpret an isolated PSA value in a man treated with dutasteride for 3 months or more, the PSA value should be doubled for comparison with normal values in untreated men.
The free-to-total PSA ratio (percent-free PSA) remains constant, even under the influence of dutasteride. If clinicians elect to use percent-free PSA as an aid in the detection of prostate cancer in men receiving dutasteride, no adjustment to its value appears necessary. Coadministration of dutasteride and tamsulosin resulted in similar changes to serum PSA as dutasteride monotherapy.
Effect on Semen Characteristics
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 reduction 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 time points remained within the normal ranges and did not meet predefined criteria for a clinically significant change (30%), two 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 dutasteride's effect on semen characteristics for an individual patient's fertility is not known.
Drug Interactions
CYP450 Inhibitors
Dutasteride is extensively metabolized in humans by the CYP3A4 and CYP3A5 isoenzymes. No clinical drug interaction trials have been performed to evaluate the impact of CYP3A enzyme inhibitors on dutasteride pharmacokinetics. However, based on in vitro data, blood concentrations of dutasteride may increase in the presence of inhibitors of CYP3A4/5 such as ritonavir, ketoconazole, verapamil, diltiazem, cimetidine, troleandomycin, and ciprofloxacin. Because of the potential for drug-drug interactions, use caution when prescribing dutasteride to patients taking potent, chronic CYP3A4 enzyme inhibitors.
Dutasteride does not inhibit the in vitro metabolism of model substrates for the major human CYP450 isoenzymes (CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A4) at a concentration of 1,000 ng/mL, 25 times greater than steady-state serum concentrations in humans.
Alpha-Adrenergic Antagonist
The administration of dutasteride in combination with tamsulosin or terazosin has no effect on the steady-state pharmacokinetics of either alpha-adrenergic antagonist. The effect of administration of tamsulosin or terazosin on dutasteride pharmacokinetic parameters was not evaluated; the percent change in DHT concentrations was similar for dutasteride alone compared with the combination treatment.
Calcium Channel Antagonists
In a population pharmacokinetics analysis, a decrease in clearance of dutasteride was noted when co-administered with the CYP3A4 inhibitors verapamil (37%, n=6) and diltiazem (44%, n=5). In contrast, no decrease in clearance was seen when amlodipine, another calcium channel antagonist that is not a CYP3A4 inhibitor, was co-administered with dutasteride (+7%, n=4).
The decrease in clearance and subsequent increase in exposure to dutasteride in the presence of verapamil and diltiazem is not considered to be clinically significant. No dose adjustment is recommended.
Cholestyramine
Administration of a single 5 mg dose of dutasteride followed 1 hour later by 12 g cholestyramine did not affect the relative bioavailability of dutasteride in 12 normal volunteers.
Digoxin
In a trial of 20 healthy volunteers, dutasteride did not alter the steady-state pharmacokinetics of digoxin when administered concomitantly at a dose of 0.5 mg/day for 3 weeks.
Warfarin
In a trial of 23 healthy volunteers, 3 weeks of treatment with dutasteride 0.5 mg/day did not alter the steady-state pharmacokinetics of the S- or R-warfarin isomers or alter the effect of warfarin on prothrombin time when administered with warfarin.
Other Concomitant Therapy
Although specific interaction trials were not performed with other compounds, approximately 90% of the subjects in the three randomized, double-blind, placebo-controlled safety and efficacy trials receiving dutasteride were taking other medications concomitantly. No clinically significant adverse interactions could be attributed to the combination of dutasteride and concurrent therapy when dutasteride was co-administered with anti-hyperlipidaemics, angiotensin-converting enzyme (ACE) inhibitors, beta-adrenergic blocking agents, calcium channel blockers, corticosteroids, diuretics, nonsteroidal anti-inflammatory drugs (NSAIDs), phosphodiesterase Type V inhibitors, and quinolone antibiotics.
Information for Patients
Physicians should inform patients that dutasteride reduces serum PSA levels by approximately 50% within 3-6 months of therapy, although it may vary for each individual. For patients undergoing PSA screening, increases in PSA levels while on treatment with dutasteride may signal the presence of prostate cancer and should be evaluated.
Physicians should inform patients that there was an increase in high-grade prostate cancer in men treated with 5 alpha-reductase inhibitors (which are indicated for BPH treatment), including dutasteride, compared with those treated with placebo in studies looking at the use of these drugs to reduce the risk of prostate cancer.
Physicians should inform patients that dutasteride capsules should not be handled by a woman who is pregnant or who could become pregnant because of the potential for absorption of dutasteride and the subsequent potential risk to a developing male foetus. Dutasteride is absorbed through the skin and could result in unintended foetal exposure. If a pregnant woman or woman of childbearing potential comes in contact with leaking dutasteride capsules, the contact area should be washed immediately with soap and water.
Physicians should inform men treated with dutasteride that they should not donate blood until at least 6 months following their last dose, so as to prevent pregnant women from receiving dutasteride through blood transfusion. Serum levels of dutasteride are detectable for 4-6 months after treatment ends.
Renal Impairment
No dose adjustment is necessary for dutasteride in patients with renal impairment
Hepatic Impairment
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 study 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.
Pregnancy
Pregnancy Category X
Dutasteride is contraindicated for use in women of childbearing potential and during pregnancy.
Dutasteride is a 5 alpha-reductase inhibitor that prevents conversion of testosterone to DHT, a hormone necessary for the normal development of male genitalia. In animal reproduction and developmental toxicity studies, dutasteride inhibited normal development of external genitalia in male foetuses. Therefore, dutasteride may cause foetal harm when administered to a pregnant woman. If dutasteride is used during pregnancy or if the patient becomes pregnant while taking dutasteride, the patient should be apprised of the potential hazard to the foetus.
Abnormalities in the genitalia of male foetuses is an expected physiological consequence of inhibition of the conversion of testosterone to DHT by 5 alpha-reductase inhibitors. These results are similar to observations in male infants with genetic 5 alpha-reductase deficiency. Dutasteride is absorbed through the skin. To avoid potential foetal exposure, women who are pregnant or may become pregnant should not handle dutasteride capsules. If contact is made with leaking capsules, the contact area should be washed immediately with soap and water. Dutasteride is secreted into male semen. The highest measured semen concentration of dutasteride in treated men was 14 ng/mL. Assuming exposure of a 50 kg woman to 5 mL of semen and 100% absorption, the woman's dutasteride concentration would be about 0.175 ng/mL. This concentration is more than 100 times less than concentrations producing abnormalities of male genitalia in animal studies. Dutasteride is highly protein-bound in human semen (>96%), which may reduce the amount of dutasteride available for vaginal absorption.
Lactation
DUPROST capsules are contraindicated for use in women of childbearing potential, including nursing women. It is not known whether dutasteride is excreted in human milk.
Paediatric Use
DUPROST capsules are not indicated for use in the paediatric population. Safety and effectiveness in the paediatric population have not been established.
Geriatric Use
Of 2,167 male subjects treated with dutasteride in three clinical trials, 60% were aged 65 years and older and 15% were aged 75 years and older. No overall differences in safety or efficacy were observed between these subjects and younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out.
Undesirable Effects
Clinical Trials Experience
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 dutasteride were impotence, decreased libido, breast disorders (including breast enlargement and tenderness), and ejaculation disorders.
Study withdrawal due to adverse reactions occurred in 4% of subjects receiving dutasteride, and 3% of subjects receiving placebo in placebo-controlled trials with dutasteride. The most common adverse reaction leading to study withdrawal was impotence (1%).
Monotherapy
Over 4,300 male subjects with BPH were randomly assigned to receive placebo or 0.5 mg daily doses of dutasteride in three identical 2-year, placebo-controlled, double-blind, Phase 3 treatment trials, each followed by a 2-year, open-label extension. During the double-blind treatment period, 2,167 male subjects were exposed to dutasteride, including 1,772 exposed for 1 year and 1,510 exposed for 2 years. When including the open-label extensions, 1,009 male subjects were exposed to dutasteride for 3 years and 812 were exposed for 4 years. The population was aged 47 to 94 years (mean age: 66 years) and greater than 90% were Caucasian. Table 1 summarizes clinical adverse reactions reported in at least 1% of subjects receiving dutasteride and at a higher incidence than subjects receiving placebo.
|
|
|||
0-6 |
7-12 |
13-18 |
19-24 |
|
Placebo (n) |
(n=2,158) |
(n=1,922) |
(n=1,714) |
(n=1,555) |
Dutasteride Placebo |
1.7% |
1.5% |
0.5% |
0.9% |
Dutasteride Placebo |
1.4% |
0.6% |
0.2% |
0.1% |
Dutasteride Placebo |
0.5% |
0.3% |
0.1% |
0.0% |
Dutasteride Placebo |
0.2% |
0.3% |
0.3% |
0.1% |
a These sexual adverse reactions are associated with dutasteride treatment (including monotherapy and combination with tamsulosin). These adverse reactions may persist after treatment discontinuation. The role of dutasteride in this persistence is unknown.
b Includes breast tenderness and breast enlargement.
Long-Term Treatment (Up to 4 Years)
High-grade Prostate Cancer: The REDUCE trial was a randomized, double-blind, placebo-controlled trial that enrolled 8,231 men aged 50 to 75 years with a serum PSA of 2.5 ng/mL to 10 ng/mL and a negative prostate biopsy within the previous 6 months. Subjects were randomized to receive placebo (N=4,126) or 0.5 mg daily doses of dutasteride (N=4,105) for up to 4 years. The mean age was 63 years and 91% were Caucasian. Subjects underwent protocol-mandated scheduled prostate biopsies at 2 and 4 years of treatment or had 'for-cause biopsies' at non-scheduled times if clinically indicated. There was a higher incidence of Gleason score 8-10 prostate cancer in receiving dutasteride (1.0%) compared with men on placebo (0.5%). In a 7-year placebo-controlled clinical trial with another 5 alpha-reductase inhibitor (finasteride 5 mg), similar results for Gleason score 8-10 prostate cancer were observed (finasteride 1.8% versus placebo 1.1%). No clinical benefit has been demonstrated in patients with prostate cancer treated with dutasteride.
Reproductive and Breast Disorders
In the three pivotal placebo-controlled BPH trials with dutasteride, each of 4 years in duration, there was no evidence of increased sexual adverse reactions (impotence, decreased libido, and ejaculation disorder) or breast disorders with increased duration of treatment. Among these three trials, there was one case of breast cancer in the dutasteride group and one case in the placebo group. No cases of breast cancer were reported in any treatment group in the 4-year CombAT trial or the 4-year REDUCE trial. The relationship between the long-term use of dutasteride and male breast neoplasia is currently unknown.
Combination with Alpha-Blocker Therapy
Over 4,800 male subjects with BPH were randomly assigned to receive 0.5-mg dutasteride, 0.4-mg tamsulosin, or combination therapy (0.5-mg dutasteride plus 0.4-mg tamsulosin) 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 combination therapy. The population was aged 49 to 88 years (mean age: 66 years) and 88% were Caucasian.
The most common adverse reactions reported in subjects receiving combination therapy (dutasteride plus tamsulosin) were impotence, decreased libido, breast disorders (including breast enlargement and tenderness), ejaculation disorders, and dizziness. Ejaculation disorders occurred significantly more in subjects receiving combination 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 combination therapy (dutasteride plus tamsulosin) and 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%).
Cardiac Failure: In a trial with combination therapy with dutasteride and alpha-blocker, after 4 years of treatment, the incidence of the composite term cardiac failure in the combination therapy group (12/1,610; 0.7%) was higher than in either monotherapy group: dutasteride, 2/1,623 (0.1%) and tamsulosin, 9/1,611 (0.6%). Composite cardiac failure was also examined in a separate 4-year placebo-controlled trial evaluating dutasteride in men at risk for development of prostate cancer. The incidence of cardiac failure in subjects taking dutasteride was 0.6% (26/4,105) compared with 0.4% (15/4,126) in subjects on placebo. A majority of subjects with cardiac failure in both trials had comorbidities associated with an increased risk of cardiac failure. Therefore, the clinical significance of the numerical imbalances in cardiac failure is unknown. No causal relationship between dutasteride alone or in combination with tamsulosin and cardiac failure has been established. No imbalance was observed in the incidence of overall cardiovascular adverse events in either trial.
Postmarketing Experience
The following adverse reactions have been identified during post-approval use of dutasteride. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. These reactions have been chosen for inclusion due to a combination of their seriousness, frequency of reporting or potential causal connection to dutasteride.
Immune system disorders: Hypersensitivity reactions, including rash, pruritus, urticaria, localized oedema, serious skin reactions, and angioedema.
Neoplasms: Male breast cancer.
Psychiatric Disorders: Depressed mood.
Reproductive System and Breast Disorders: Testicular pain and testicular swelling.
Overdosage
In volunteer studies, single doses of dutasteride up to 40 mg (80 times the therapeutic dose) for 7 days have been administered without significant safety concerns. In a clinical study, daily doses of 5 mg (10 times the therapeutic dose) were administered to 60 subjects for 6 months with no additional adverse effects to those seen at therapeutic doses of 0.5 mg.
There is no specific antidote for dutasteride. Therefore, in cases of suspected overdosage symptomatic and supportive treatment should be given as appropriate, taking the long half-life of dutasteride into consideration.
Storage And Handling Instructions
Store at 25°C
Packaging Information
DUPROST: Blister pack of 10 capsules