Finasteride

Registered South African indications:

• Benign prostatic hyperplasia
• Androgenic alopecia

Contraindications

• Hypersensitivity to the active ingredient or any of its excipients
• Pregnancy
• Breastfeeding
• Female patients
• Children and adolescents
• Coadministration with any other 5α-reductase inhibitor for benign prostatic hyperplasia or any other condition

Cautions

• Men of childbearing potential
• Hepatic impairment
• Large residual urine volume
• Severely diminished urinary flow
• Prostate specific antigen >10ng/mL
• Sustained increase in prostate specific antigen levels
• History of depression
• Galactose intolerance
• Lapp lactase deficiency
• Glucose-galactose malabsorption

Forms avail. in SA and covered in this monograph: tab 

Benign prostatic hyperplasia
- Regression of the enlarged prostate
- Improve urinary flow
- Improve symptoms associated with benign prostatic hyperplasia
- Decrease the incidence of acute urinary retention
- Decrease the incidence of surgery including prostatectomy and transurethral resection of the prostate

• Oral (tab): 5mg, dly

Although early improvement in symptoms may be seen, treatment for ≥6 months may be necessary to assess whether a beneficial response has been achieved. Thereafter, treatment should be continued long term

Finasteride can be administered alone or in combination with doxazosin

Early signs of androgenetic alopecia
- Increase hair growth and prevent further hair loss
- Increase the density of hair in the vertex and anterior mid-scalp area

• Oral (tab): 1mg, dly

There is no evidence that an increase in dosage will result in increased efficacy

3-6 months of treatment are required before evidence of stabilisation of hair loss can be expected

Continuous use is recommended to sustain benefit

If treatment is stopped, the beneficial effects begin to reverse by 6 months and return to baseline by 9-12 months

Contraindicated

Pregnancy 

• Contraindicated
• Finasteride is contraindicated in women when they are or may potentially be pregnant.  Because of the ability of type II 5α-reductase inhibitors to inhibit the conversion of testosterone to dihydrotestosterone, these drugs, including finasteride, may cause abnormalities of the external genitalia of a male foetus when administered to a pregnant woman
• In animal developmental studies, dose-dependent development of hypospadias were observed in the male offspring of pregnant rats given finasteride at doses ranging from 100 μg/kg/day to 100 mg/kg/day, at an incidence of 3.6% to 100%. Additionally, pregnant rats produced male offspring with decreased prostatic and seminal vesicular weights, delayed preputial separation, transient nipple development and decreased anogenital distance, when given finasteride at doses below the recommended human dose. The critical period during which these effects can be induced has been defined in rats as days 16-17 of gestation
• The changes described above are expected pharmacological effects of Type II 5 α-reductase inhibitors. Many of the changes, such as hypospadias, observed in male rats exposed in utero to finasteride are similar to those reported in male infants with a genetic deficiency of Type II 5 α-reductase. It is for these reasons that finasteride is contraindicated in women who are or may potentially be pregnant. No effects were seen in female offspring exposed in utero to any dose of finasteride
• Exposure to finasteride - risk to a male foetus: Women should not handle crushed or broken tablets of finasteride when they are or may potentially be pregnant because of the possibility of absorption of finasteride and the subsequent potential risk to a male foetus. Finasteride tablets which are coated will prevent contact with the active ingredient during normal handling, provided that the tablets have not been broken or crushed. Small amounts of finasteride have been recovered from the semen in subjects receiving finasteride 5 mg/day. It is not known whether a male foetus may be adversely affected if his mother is exposed to the semen of a patient being treated with finasteride. When the patient's sexual partner is or may potentially be pregnant, the patient is recommended to minimise exposure of his partner to semen

Breastfeeding 

• Contraindicated
• Finasteride is not indicated for use in women. It is not known whether finasteride is excreted in human milk

Fertility

• Long-term data on fertility in humans is lacking, and specific studies in subfertile men have not been conducted. The male patients who were planning to father a child were initially excluded from clinical trials
• Although animal studies did not show relevant negative effects on fertility, spontaneous reports of infertility and/or poor seminal quality were received post-marketing. In some of these reports, patients had other risk factors that might have contributed to infertility. Normalisation or improvement of seminal quality has been reported after discontinuation of finasteride

Renal Impairment

• No dose adjustment recommended

Hepatic Impairment 

• Caution; no information available 
  Use with caution as finasteride undergoes extensive hepatic metabolism

Elderly 

• No dose adjustment recommended

Porphyria Information

• Possibly porphyrinogenic (PSP)

Drugs in Sport

• Permitted - No warnings

Central Nervous System Disorders

• Depression
• Anxiety
• Decreased libido

Cardiovascular Disorders 

• Palpitations

Hepatobiliary Disorders

• Increased hepatic enzymes

Genitourinary Disorders 

• Erectile dysfunction
• Ejaculation disorder
• Breast tenderness and enlargement
• Testicular pain
• Haematospermia
• Infertility
• Poor seminal quality
• Impotence
• Decreased volume of ejaculate
• Male breast cancer

Skin and Subcutaneous Tissue Disorders 

• Rash
• Pruritus
• Urticaria
• Angioedema

Immune, Blood and Lymphatic System Disorders

• Hypersensitivity reactions, including swelling of the lips, tongue, throat and face

No information available

• Prostate specific antigen level
• Digital rectal examination
• Mental status

Effects on prostate specific antigen (PSA) and prostate cancer detection

• No clinical benefit has yet been demonstrated in patients with prostate cancer treated with finasteride
• Patients with benign prostatic hyperplasia and elevated serum PSA were monitored in controlled clinical studies. In these studies, finasteride did not appear to alter the rate of prostate cancer detection, and the overall incidence of prostate cancer was not significantly different in patients treated with finasteride or placebo
• Digital rectal examination, as well as other evaluations for prostate cancer, are recommended prior to initiating therapy with finasteride and periodically thereafter. Serum PSA is also used for prostate cancer detection
• Finasteride causes a decrease in serum PSA concentrations by approximately 50% in patients with benign prostatic hyperplasia, even in the presence of prostate cancer. This decrease in serum PSA levels in patients with benign prostatic hyperplasia treated with finasteride should be considered when evaluating PSA data and does not rule out concomitant prostate cancer
• In patients treated with finasteride 5mg for six months or more, PSA values should be doubled for comparison with normal ranges in untreated men. Any sustained increase in PSA levels of patients treated with finasteride 5mg should be carefully evaluated, including consideration of non-compliance to therapy with finasteride

Breast cancer in men

• Breast cancer has been reported in men taking finasteride during clinical trials and the post-marketing period
• Physicians should instruct their patients to promptly report any changes in their breast tissue such as lumps, pain, gynaecomastia or nipple discharge

Finasteride is a competitive and specific inhibitor of type II 5α-reductase. Finasteride has no affinity for the androgen receptor and has no androgenic, anti-androgenic, oestrogenic, anti-oestrogenic, or progestational effects. Inhibition of this enzyme blocks the peripheral conversion of testosterone to the androgen DHT, resulting in significant decreases in serum and tissue DHT concentrations. Finasteride produces a rapid reduction in serum DHT concentration, reaching significant suppression within 24 hours of dosing. In benign prostatic hyperplasia (BPH), enlargement of the prostate gland is dependent upon the conversion of testosterone to DHT within the prostate. Finasteride is highly effective in reducing circulating and intraprostatic DHT. Hair follicles contain type II 5α-reductase. In men with male pattern hair loss, the balding scalp contains miniaturised hair follicles and increased amounts of DHT. Administration of finasteride decreases scalp and serum DHT concentrations in these men. Men with a genetic deficiency of type II 5α-reductase do not suffer from male pattern hair loss. Finasteride inhibits a process responsible for miniaturisation of the scalp hair follicles, which can lead to reversal of the balding process.

Tablet 1mg

• Finpecia (Cipla Medpro)
• Profina (Accord)
• Propecia (MSD) orginator

Tablet 5mg

• Accord Finasteride (Accord)
• Finide (Zydus)
• Fenryde (Brimpharm)
• Fincar (Cipla Medpro)
• Intas Finasteride (Accord)
• Proscar (MSD) originator