Dutasterid is a double inhibitor of 5α-reductase, inhibits both type 1 and type 2 of 5o-reductase isoenzymes, which are responsible for the conversion of testosterone into 5α-dihydrotestosterone. Dihydrotestosterone is an androgen, which is primarily responsible for the hyperplasia of the prostate tissue. The maximum reduction in dihydrotestosterone levels while taking Avodart depends on the dose and is noted in the first 1-2 weeks. After the 1st and 2nd week of use of Avodart in a daily dose of 0.5 mg, the average concentration of dihydrotestosterone is reduced by 85 and 90%, respectively.
In patients with benign prostatic hyperplasia, who received 0.5 mg of dutasterid per day, the average decrease in dihydrotestosterone was 94% after 1 year and 93% after 2 years of treatment, the average testosterone increased by 19% after 1 and 2 years.
Pharmacokinetics. Dutasteride is used orally in the form of p-ra in soft gelatin capsules. After receiving a single dose of 0.5 mg Cmax of the drug in the blood plasma is achieved in 1-3 hours. The absolute bioavailability is 60% in the case of use by 2-hour intravenous infusion. Bioavailability does not depend on food intake.
Dutasteride after a single or repeated administration has a large volume of distribution (300–500 l). The percentage of protein binding is more than 99.5%.
Cases of Avodart overdose were not recorded in medical practice. In case of accidental overuse, you should flush the stomach, appoint the reception of sorbents.
When taking Avodart may experience side effects. In particular, an allergic skin reaction may occur, for example, urticaria, rash, itching. The most frequent side effect is erectile dysfunction, libido can be reduced. Local edema may also occur. In some patients, cases of gynecomastia have been observed (in some cases, the breast gland can increase in men. At the same time, the glands themselves increase, the growth of adipose tissue begins in this area. Gynecomastia usually occurs during puberty, which then disappears on its own. However, gynecomastia can be caused and hormonal disorders in adults, as well as in response to the use of certain drugs).
Terms and conditions of storage
Avodart is able to preserve its medicinal properties for a period of up to 4 years, under the conditions of storage – out of direct sunlight and the ambient temperature not higher than + 30 ° C.