Basic Drug Info
Active Substance: dutasteride
Drug Form: Gelatin capsules
Available Doses: 0.5mg
What is Avodart?
Avodart is the trade name of a drug based on dutasteride, an active ingredient belonging to the 5-alpha reductase enzyme inhibitor category. The drug is used to treat benign prostate hyperplasia (BPH), an age-related condition in male patients characterized by a variety of lower urinary tract symptoms.
How does Avodart work?
Avodart reduces circulating levels of dihydrotestosterone (DHT). This effect is achieved by inhibiting 5-alpha reductase isoenzymes. There are two types of these isoenzymes that make testosterone convert into DHT: type 1 and type 2; Avodart inhibits both responsible for testosterone conversion.
What is the dosage for Avodart?
Avodart should be taken as directed by healthcare specialist. The regular dose administered in BPH is 0.5mg taken daily.
Significant improvement of BPH symptoms can be observed within 1-2 weeks after Avodart therapy initiation.
In individuals affected by BPH and treated with 0.5 mg daily of dutasteride, the median decrease in serum DHT values was 94% at one year and 93% at two years and the increase in serum values median of testosterone was 19% at both one year and two.
Recommendations for use
Take one capsule of Avodart and wash it down with a glass of water with or without meals.
Meaningful reduction in prostate volume is observed one month after the start of treatment and continues until the twenty-fourth month.
Avodart vs Proscar
Proscar (finasteride) is another oral drug appointed for use in patients with BPH, but its mechanism of action is different from that of Avodart.
Prostate enlargement is caused by a powerful androgen, dihydrotestosterone (DHT). Type II 5α-reductase is an enzyme that converts testosterone into dihydrotestosterone (DHT) in the prostate and hair follicles. Finasteride contained in Proscar blocks the enzyme 5α-reductase type II at 70%, reducing the prostate volume in 6-12 months.
Proscar can cause, in 5% of patients, sexual dysfunctions such as reduced libido and decreased volume of ejaculated liquid. Gynecomastia is reported in 0.5% of patients using Proscar.
The choice between Avodart and Proscar should be made by prescriber proceeding from individual response and tolerance of the substances. Both of the drugs can give side effects, which are more or less the same, but different patients tend to respond differently to either of the two medications. Also, Avodart is most commonly used in combination with Flomax (tamsulosin) and rarely as monotherapy.
Avodart vs Flomax
Flomax (tamsulosin) has the same indication as Avodart, but its active component and therefore its mechanism of action is different. It is not uncommon for prescribers to appoint both medication for combined therapy of BPH, thus ensuring maximal health benefits provided by both substances whose effects complete each other.
Tamsulosin exerts a postsynaptic selective alpha1 blocking action, inhibiting the binding of noradrenaline to alpha1 receptors. Tamsulosin has a preferential selectivity for alpha1a and alpha1d subtypes, causing smooth muscle relaxation in the lower urinary tract, thus improving urinary flow while having only minimal effects on the cardiovascular system compared to other drugs of the same class that block all three subtypes alpha1a, alpha1b, alpha1d such as Doxazosin, Alfuzosin and Terazosin. Flomax is thus less likely to cause orthostatic hypotension than Terazosin and Doxazosin
Dose-dependent sexual dysfunction is reported as one of Flomax side effects (delayed ejaculation, reduced ejaculate volume or painful ejaculation), the incidence is almost 6% at a dose of 0.4 mg
Flomax is often prescribed to be taken alongside with Avodart as a combination therapy. Their concomitant use gives better health results than monotherapy with either one of them.
Avodart vs Tamsulosin
Tamsulosin is the nonproprietary name for the drug that is marketed under the name of Flomax, a medication described in the section above.
Avodart vs Duodart
Duodart is a combinatory therapy drug that contains two active components: dutasteride and tamsulosin, whose mutually complementary effects make for an optimal BPH therapy used jointly as one preparation. In contrast to Duodart, Avodart is used in monotherapeutic treatment of BPH or in combination of BPH drugs belonging to other pharmacological classes.
Taking Avodart may cause the following side effects:
- ED (inability to get or maintain an erection)
- decreased libido (sexual desire)
- difficulty in ejaculation
- swelling or breast tenderness.
In these cases it is usually not necessary to stop taking Avodart, but it is advisable to inform your doctor or pharmacist. Sexual side effects (impotence, decreased libido, difficulty ejaculation) may eventually persist even after stopping treatment with Avodart.
In very rare cases (in less than 1 in 10,000 patients), pain and swelling of the testicles, depressed mood and allergic reactions may also occur, including rash, itching, hives and allergic swelling of the skin and mucous membranes (edema).
If you notice any side effects not described here, you should inform your doctor or pharmacist.
As in case with finasteride, the major concern during treatment with dutasteride is the possibility that the drug may interfere with the early diagnosis of prostate cancer. In fact the serum concentration of PSA (prostate specific antigen), which represents a marker of great importance for detecting the presence of any prostate cancer, is influenced by dutasteride therapy. This decreases the average PSA concentration by about 50% after about 6 months of treatment, although further reductions can occur up to 36 months from the start of treatment. Therefore, subjects treated with dutasteride must perform a new PSA dosage after 6 months from the start of treatment, and this value can be considered the new basal PSA value in that subject (PSA nadir).
The risk to benefit ratio of Avodart use in combination with other BPH drugs should be evaluated each time when such therapy is taken into consideration. Prescriber should compare risks and benefits of combination therapy to monotherapy with Avodart, especially against the background of existing risks of cardiac failure.
Avodart use is not approved in the following subcategories of patients:
- women, pediatric population and individuals under 18 years of age
- those with increased sensitivity towards dutasteride or other drugs in its class, as well as known allergic reactions to soy, peanuts or any of the other excipients present in the preparation
- patients with severe hepatic impairment.
- Dutas – Dr. Reddys Laboratories Ltd
- Dupecia – Cipla Ltd.
- Duprost – Cipla Ltd.
- Dutagen – Dr. Reddys Laboratories Ltd.
- Dutagen (Ranbaxy) – Ranbaxy Laboratories Ltd.
- Sterdu – Alkem Laboratories Ltd.