Mostrafin (Finasteride)

Finasteride is indicated for conditions that involve androgen‑dependent tissue growth, primarily within the prostate and scalp.

• Benign prostatic hyperplasia: reduces prostate volume and improves urinary flow in men with an enlarged prostate.
• Male pattern hair loss: decreases scalp dihydrotestosterone levels to slow hair thinning and promote regrowth in androgenic alopecia.

• Finasteride selectively inhibits the type II isoform of the enzyme 5‑alpha‑reductase. By blocking this enzyme, the conversion of testosterone to the more potent androgen dihydrotestosterone (DHT) is reduced in target tissues such as the prostate gland and hair follicles. Lower DHT concentrations diminish androgen‑driven cellular proliferation and miniaturization, leading to clinical improvement in prostate enlargement and androgenic alopecia.

Finasteride may cause a range of adverse reactions, which are categorized by frequency and severity.

Common Side Effects

• Decreased libido: reduced sexual desire.
• Erectile dysfunction: difficulty achieving or maintaining an erection.
• Ejaculation disorder: decreased volume or pain during ejaculation.
• Breast tenderness or enlargement: mild swelling of male breast tissue.

Serious or Rare Side Effects

• Allergic reactions: rash, itching, swelling, or anaphylaxis.
• Breast cancer: rare cases of male breast malignancy reported.
• High‑grade prostate cancer: potential increase in aggressive prostate cancer risk.

Before initiating therapy with Finasteride, several precautionary measures should be considered.

• Pregnancy contraindication: drug is teratogenic (Category X) and must not be used by women.
• Breastfeeding restriction: contraindicated for nursing mothers due to potential infant exposure.
• Sexual dysfunction monitoring: assess for decreased libido, erectile or ejaculatory issues during treatment.
• Prostate cancer evaluation: perform baseline prostate‑specific antigen testing and digital exam before use.
• Drug interaction review: check concomitant medications for potential pharmacokinetic or pharmacodynamic effects.
• Store at ambient temperature: keep below 25 °C in the original packaging, protect from moisture and light.

Finasteride can interact with other medicines, and the significance of these interactions varies.

Major Interactions (Avoid)

• Potent CYP3A4 inhibitors (e.g., ketoconazole, itraconazole): may increase finasteride plasma concentrations.
• Concurrent use of other 5‑alpha‑reductase inhibitors (e.g., dutasteride): additive hormonal effects.
• Hormonal therapies that alter androgen levels (e.g., testosterone replacement): may diminish therapeutic benefit.

Moderate Interactions (Monitor Closely)

• Anticoagulants (e.g., warfarin): possible alteration of bleeding risk.
• Alpha‑blockers (e.g., tamsulosin): additive hypotensive effect may require blood pressure monitoring.
• Antidepressants (e.g., SSRIs, SNRIs): may exacerbate sexual side effects.