Menero (Tadalafil)

Tadalafil is indicated for several conditions that involve smooth‑muscle relaxation mediated by the nitric‑oxide/cGMP pathway.

• Erectile dysfunction: improves ability to achieve and maintain an erection sufficient for sexual activity.
• Benign prostatic hyperplasia: reduces urinary urgency and improves flow by relaxing prostatic smooth muscle.
• Pulmonary arterial hypertension: lowers pulmonary vascular resistance and improves exercise capacity.

• Tadalafil selectively inhibits phosphodiesterase type 5 enzymes, preventing the breakdown of cyclic guanosine monophosphate (cGMP) in smooth‑muscle cells. Elevated cGMP levels lead to relaxation of vascular smooth muscle in the corpus cavernosum, pulmonary vasculature, and prostatic tissue, enhancing blood flow and reducing vascular resistance. The inhibition is dose‑dependent and reversible, allowing controlled modulation of the nitric‑oxide signaling pathway. The effect persists for up to 36 hours, providing a prolonged therapeutic window.

Tadalafil may cause a range of adverse reactions, most of which are mild and transient.

Common Side Effects

• Headache: mild to moderate pain often occurring within hours of dosing.
• Flushing: transient warmth and redness of the face or neck.
• Dyspepsia: indigestion or upset stomach.
• Nasal congestion: blocked or runny nose.

Serious or Rare Side Effects

• Sudden vision loss: may indicate non‑arteritic anterior ischemic optic neuropathy.
• Priapism: prolonged erection lasting more than 4 hours requiring medical attention.
• Severe hypotension: marked drop in blood pressure especially when combined with nitrates.

When prescribing tadalafil, clinicians should consider several precautionary measures to minimize risk.

• Cardiovascular assessment: evaluate for recent myocardial infarction, unstable angina, or severe heart failure.
• Concomitant nitrate use: avoid because of risk of profound hypotension.
• Visual disorders: caution in patients with retinitis pigmentosa or a history of non‑arteritic anterior ischemic optic neuropathy.
• Hepatic or renal impairment: dose adjustment may be required in moderate to severe dysfunction.
• Drug interactions: review all concomitant medications for potential interactions.
• Store at ambient temperature: keep below 25 °C in the original packaging, protect from moisture and direct sunlight.

Tadalafil interacts with several drug classes; understanding the interaction level guides clinical decisions.

Major Interactions (Avoid)

• Nitrates (e.g., nitroglycerin, isosorbide dinitrate): can cause severe hypotension.
• Alpha‑blockers (e.g., doxazosin, prazosin) in high doses: risk of additive blood pressure lowering.
• Guanylate cyclase stimulators (e.g., riociguat): may lead to excessive vasodilation.

Moderate Interactions (Monitor Closely)

• CYP3A4 inhibitors (e.g., ketoconazole, erythromycin): increase tadalafil plasma levels.
• CYP3A4 inducers (e.g., rifampin, carbamazepine): reduce tadalafil effectiveness.
• Antihypertensives (e.g., ACE inhibitors, beta‑blockers): may enhance blood pressure‑lowering effect.