Manifold (Tadalafil)

Tadalafil is used to manage conditions related to the nitric‑oxide/cGMP pathway that affect vascular smooth muscle tone.

• Erectile dysfunction: Improves ability to achieve and maintain an erection sufficient for sexual activity.
• Benign prostatic hyperplasia: Relieves urinary symptoms such as decreased flow and urgency associated with prostate enlargement.
• Pulmonary arterial hypertension: Enhances exercise capacity by lowering pulmonary arterial pressure.

• Tadalafil selectively inhibits phosphodiesterase type 5 (PDE5), the enzyme responsible for degrading cyclic guanosine monophosphate (cGMP) in smooth‑muscle cells. By preventing cGMP breakdown, intracellular cGMP concentrations rise, leading to relaxation of smooth muscle in the corpus cavernosum, prostate and pulmonary vasculature, and thereby improving blood flow to these tissues. The increased vasodilation enhances oxygen delivery and reduces vascular resistance, which underlies its therapeutic effects in erectile dysfunction, benign prostatic hyperplasia, and pulmonary arterial hypertension.

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

Common Side Effects

• Headache
• Flushing
• Indigestion or dyspepsia
• Nasal congestion
• Back pain or muscle aches
• Vision changes such as a blue‑tinted hue

Serious or Rare Side Effects

• Priapism (prolonged erection lasting more than 4 hours)
• Sudden loss of vision in one or both eyes
• Sudden loss of hearing or ringing in the ears
• Severe hypotension or cardiovascular events
• Allergic reactions including rash, swelling, or difficulty breathing

Before prescribing Manifold, clinicians should consider several safety measures.

• Assess cardiovascular status: evaluate for recent myocardial infarction or unstable angina before prescribing.
• Avoid use with nitrates: concurrent use can cause severe hypotension.
• Dose adjust in severe hepatic impairment: consider lower dose or avoid.
• Monitor in patients with retinitis pigmentosa: may exacerbate visual disturbances.
• Counsel about sexual activity timing: effect may last up to 36 hours.
• Store at ambient temperature: keep below 25 °C in the original pack, protect from moisture.

Tadalafil can interact with several medicines, requiring careful review of a patient’s medication list.

Major Interactions (Avoid)

• Nitrates (e.g., nitroglycerin) – risk of profound hypotension.
• Guanylate cyclase stimulators (e.g., riociguat) – additive vasodilatory effect.
• Potent CYP3A4 inhibitors (e.g., ketoconazole, itraconazole) – may increase tadalafil exposure.

Moderate Interactions (Monitor Closely)

• CYP3A4 inducers (e.g., rifampin) – may reduce efficacy.
• Antihypertensive agents – potential for enhanced blood‑pressure lowering.
• Alcohol – may increase dizziness or hypotension.
• Protease inhibitors – possible increase in plasma levels.
• Diuretics – additive effect on blood pressure.