Himale (Sildenafil)

Himale is prescribed for conditions that benefit from increased nitric oxide‑mediated vasodilation.

• Treatment of erectile dysfunction in adult males.
• Management of pulmonary arterial hypertension (PAH) to improve exercise capacity.
• Adjunct therapy in patients with heart failure where PAH is present.
• Use in combination with lifestyle modifications for erectile dysfunction, such as smoking cessation and weight loss.
• May be part of a comprehensive PAH regimen that includes endothelin receptor antagonists or prostacyclin analogues.
• Off‑label use may be considered for high‑altitude pulmonary edema under specialist guidance.

• Sildenafil selectively inhibits the enzyme phosphodiesterase type 5, which normally degrades cyclic guanosine monophosphate (cGMP). By blocking PDE5, intracellular cGMP levels rise, leading to relaxation of smooth muscle in the corpus cavernosum and pulmonary vasculature, thereby enhancing blood flow to these tissues.

Adverse reactions reported with sildenafil‑containing products vary in frequency and severity.

Common

• Headache, often described as mild to moderate and transient.
• Flushing, typically affecting the face and neck.
• Dyspepsia or indigestion, which may improve with food intake.

Serious

• Priapism, a prolonged erection lasting more than four hours that requires urgent medical attention.
• Sudden loss of vision, such as non‑arteritic anterior ischemic optic neuropathy.
• Severe hypotension, especially when combined with nitrates or other vasodilators.

Before initiating Himale, certain safety considerations should be reviewed.

• Patients with known cardiovascular disease should be evaluated for suitability.
• Use is contraindicated in individuals taking nitrates for chest pain.
• Caution is advised in patients with severe hepatic or renal impairment.
• Those with a history of non‑arteritic anterior ischemic optic neuropathy should discuss risks with a clinician.
• Inform the prescriber of any recent eye surgery or retinal disorders.
• Avoid use in patients with uncontrolled hypertension or hypotension.

Sildenafil can interact with several medication classes; awareness helps prevent adverse events.

Avoid

• Nitrate medications (e.g., nitroglycerin, isosorbide dinitrate) due to risk of profound hypotension.
• Guanylate cyclase stimulators used for PAH (e.g., riociguat) because combined vasodilation may be excessive.
• Certain potent CYP3A4 inhibitors (e.g., ketoconazole, clarithromycin) that can raise sildenafil plasma levels.

Use with caution

• Alpha‑blockers for hypertension or benign prostatic hyperplasia, as additive blood pressure effects may occur.
• Antihypertensive agents, especially when dose timing overlaps.
• Other PDE5 inhibitors or recreational drugs such as poppers (amyl nitrite).
• Medications that prolong the QT interval, though the interaction is less common.