Nezyr (Finasteride)

Finasteride acts on androgen‑dependent conditions, reducing the effects of dihydrotestosterone.

• Androgenetic alopecia (male pattern hair loss): helps slow hair loss and may promote regrowth in men.
• Benign prostatic hyperplasia: decreases prostate volume and improves urinary flow in men with BPH.
• Prostate enlargement due to BPH: reduces symptoms such as urinary urgency and hesitancy.

• Finasteride selectively inhibits type II 5‑alpha‑reductase, the enzyme that converts testosterone to the more potent androgen dihydrotestosterone (DHT). By lowering DHT levels in target tissues such as the scalp and prostate, it diminishes androgen‑driven cellular activity, leading to reduced hair follicle miniaturisation and decreased prostate gland growth.

Finasteride may cause a range of adverse reactions, from mild to serious.

Common Side Effects

• Decreased libido: reduced sexual desire.
• Erectile dysfunction: difficulty achieving erection.
• Ejaculation disorder: decreased volume or difficulty.
• Breast tenderness or enlargement.
• Headache: mild to moderate.
• Rash: skin irritation or itching.

Serious or Rare Side Effects

• Allergic reactions: swelling, hives, or anaphylaxis.
• Male breast cancer: rare malignant growth.
• Severe depression or mood changes.
• Testicular pain: persistent discomfort.
• Elevated liver enzymes: potential hepatic injury.
• Priapism: prolonged painful erection.

Finasteride requires careful consideration of several safety factors.

• Pregnancy contraindication: avoid use in women who are or may become pregnant.
• Women of child‑bearing potential: should not handle crushed tablets due to teratogenic risk.
• Monitor PSA levels: periodic testing recommended for prostate health.
• Liver function assessment: evaluate before initiating therapy.
• Mood monitoring: watch for signs of depression or suicidal thoughts.
• Store at below 25°C: keep in the original packaging, protect from moisture and direct sunlight.

Finasteride can interact with other medicines, influencing efficacy or safety.

Major Interactions (Avoid)

• Concurrent 5‑alpha‑reductase inhibitors: additive hormonal suppression.
• Strong CYP3A4 inhibitors (e.g., ketoconazole): may increase finasteride plasma concentrations.
• Testosterone replacement therapy: can counteract finasteride's effect on DHT.

Moderate Interactions (Monitor Closely)

• Anticoagulants (e.g., warfarin): monitor bleeding parameters.
• Antidepressants (SSRIs, SNRIs): observe for mood changes.
• Alpha‑blockers (e.g., tamsulosin): watch for blood pressure fluctuations.