What is Dutasteride?
Originally dutasteride 0.5mg or Avodart 0.5mg is approved for the treatment of the BPH (symptomatic benign prostate hyperplasia. Dutasteride is not approved by FDA for hair loss but it is available as ‘off-label’ hair loss treatment for men at a dose of 0.5mg. However, Dutasteride is approved for hair loss in South Korea after clinical trials on Korean population. It is also approved in US, Japan and is not approved in Europe yet.
Why Dutasteride for hair loss should be used?
Scientific researchers have discovered that men who are suffering from either male pattern hair loss or benign prostatic hyperplasia, have an increased level of the DHT (dihydrotestosterone) in their body. The hormone testosterone is converted into the dihydrotestosterone after the enzymatic action of 5-alpha reductase. DHT causes the hair follicles to shrink resulting in hair fall. Dutasteride acts on the DHT hormone and promotes the hair growth by increasing the number of hair follicles.
How Dutasteride stops hair loss?
Dutasteride is the first dual inhibitor of the reductase enzymes. Its dual mechanism of action results in the DHT synthesis and catalytic activity of 5-alpha reductase type 1&2 enzymes. This dual action leads to the complete suppression of the serum DHT levels more than 90%. When this transmission of DHT to the hair follicles is stopped, then there is no miniaturization of the hair follicles. When there is no transmission of the DHT to the hair follicles, this results in the elongated anagen phase (growing phase) and faster hair growth.
Dutasteride Vs. Finasteride
Both Finasteride & Dutasteride are 5 alpha reductase inhibitors but dutasteride reduces the larger amount of dihydrotestosterone levels than finasteride. Less DHT levels mean more chances of reduction in hair loss but the reduction in the DHT levels can cause other hormonal imbalances or physiological changes in the body. Unlike finasteride, dutasteride prevents both types of 5 alpha reductase enzymes from undergoing a metabolic process. Finasteride is an old drug used for the treatment of male pattern baldness while dutasteride is relatively a new drug for hair loss and is still under clinical trials.
Comparison of Dutasteride and Finasteride
|Primary use||Treatment of Benign Prostate Hyperplasia (BPH)||Treatment of Benign Prostate Hyperplasia (BPH)|
|Secondary use||Hair loss or Male Pattern Baldness (MPB)||Hair loss or Male Pattern Baldness (MPB)|
|Is a generic version available?||Yes||Yes|
|How often should it take?||Once daily||Once daily|
Clinical Trials on Dutasteride:
Dutasteride resulted in scalp and serum dihydrotestosterone levels to decrease but increases the testosterone levels in a dose dependent manner. Dutasteride can decreases serum DHT levels by more than 90% whereas finasteride can decreases serum DHT levels by 70%.
Medical Uses of Dutasteride:
Dosage of Dutasteride:
The off-label recommended dosage of dutasteride for hair loss if 0.5mg per day. It has been clinically proven in some trials that dutasteride 0.5mg per day improves more hair growth in men to a greater extent than finasteride at 2.5mg per day.
If you miss dose of dutasteride, then no need to worry. You can skip this dosage and continue to your next dosage as recommended by the doctor. Do not take excessive dosage or double dose of dutasteride to balance your missed dose.
Overdose of Dutasteride:
In case of over dosage of dutasteride, if you start feeling any discomfort or side effects, talk to your doctor or rush to the clinic immediately.
Dutasteride Side Effects:
The side effects of dutasteride is similar to the finasteride. Dutasteride, oral 5-alpha reductase inhibitor do not reduces the DHT levels in the target area only as they reduces DHT levels systematically. It reduces the hormone levels where DHT expression is observed.
Interactions of Dutasteride:
5 alpha-reductase inhibitors like Dutasteride, can also stop the formation of the neurosteroid metabolites like allopregnanolone from progesterone. As a result of which it may reduce or even block the sedative, anticonvulsant, anxiolytic and different other effects of progesterone, particularly in the case of oral progesterone.
Contraindications of Dutasteride:
Women who are pregnant or are planning of pregnancy, should not take dutasteride. Dutasteride can result in birth defects, specifically ambiguous genitalia and under-masculinization, in male fetuses. This is because of its anti-androgenic activity and is mostly observed in the case of 5 alpha-reductase deficiency. If you are taking dutasteride, do not donate the blood at least for 6 months after your treatment has stopped. In the case of children or other people having hypersensitivity like serious skin reactions or angioedema, to dutasteride, should not take it.
Anatomy and Structure of Dutasteride:
Dutasteride is a synthetically derived androstane steroid and a 4-azasteroid. It is chemically known as N- [2,5-bis(trifluoromethyl)phenyl]-3-oxo-4-aza-5α-androst-1-ene-17β-carboxamide. It is an analogue of finasteride in which the tert-butyl amide moiety has been replaced with a 2,5-bis(tri-fluoromethyl)phenyl group.
Dutasteride is a white to pale yellow powder with a melting point of 242° to 250°C. It is soluble in ethanol (44 mg/ml), methanol (64 mg/ml), and polyethylene glycol 400 (3 mg/ml), but it is insoluble in water.
|Clinical data||Legal status||Pharmacokinetic data||Chemical &physical data|
|Trade names – Avodart, others; Combodart, Duodart (with tamsulosin)||UK: POM
|Bioavailability – 60%||Formula C27H30F6N2O2|
category – X (will cause birth defects). Not to be used in pregnancy
|US: ℞-only||Protein Binding – 99%
(All three active)
|Molar mass 528.54 g·mol−1|
|Routes of administration – By mouth||Elimination Half Life: 4-5 weeks|
|ATC code – G04CB02||Excretion – Feces: 40% (metabolites) Urine: 5% (unchanged)|
According to clinical trials, it is generally well tolerated. Most side effects were mild, and generally went away while on treatment in both the Dutasteride and placebo groups.
Drug-related side effects during the first six months were as follows:
- Decreased libido
- Breast tenderness and breast enlargement (gynecomastia)
- Ejaculation disorders
DHT or dihydrotestosterone is a male hormone which is responsible for the male pattern hair loss. DHT causes;
- Shortening of the growth phase of the hair cycle
- Progressive miniaturization of hair follicles
- Decreasing number of visible hairs