Papaverina Cloridrato Galenica Senese (Papaverine Hydrochloride)

Papaverine hydrochloride is used primarily for conditions involving smooth‑muscle spasm within the vascular and gastrointestinal systems.

• Coronary artery spasm: Relieves chest‑type pain by dilating coronary vessels.
• Peripheral vascular spasm: Improves blood flow in limbs.
• Gastrointestinal spasm: Reduces intestinal cramping and facilitates diagnostic procedures.

• Papaverine inhibits phosphodiesterase enzymes, leading to an accumulation of cyclic AMP and cyclic GMP within smooth‑muscle cells. The rise in these second messengers reduces intracellular calcium, causing relaxation of vascular and gastrointestinal smooth muscle and vasodilation.

Papaverine may cause a range of adverse reactions, from mild to severe.

Common Side Effects

• Flushing: Warm sensation and reddening of the skin.
• Headache: Mild to moderate pain, often throbbing.
• Nausea: Queasy feeling, sometimes with vomiting.
• Dizziness: Light‑headedness or loss of balance.
• Hypotension: Lowered blood pressure, especially with rapid IV administration.

Serious or Rare Side Effects

• Myocardial infarction: Heart attack due to coronary vasospasm rebound.
• Severe hypotension: Marked drop in blood pressure requiring medical intervention.
• Arrhythmias: Abnormal heart rhythms that can be life‑threatening.
• Anaphylaxis: Acute allergic reaction with airway compromise.
• Hepatotoxicity: Liver enzyme elevations indicating possible liver injury.

When using papaverine, clinicians should consider several safety measures.

• Contraindications: Avoid in patients with known hypersensitivity to papaverine.
• Cardiovascular monitoring: Observe for signs of hypotension or arrhythmia during IV infusion.
• Renal impairment: Adjust dosing or monitor closely in severe kidney dysfunction.
• Hepatic dysfunction: Use with caution in patients with liver disease.
• Drug interactions: Review concomitant medications for additive vasodilatory effects.
• Store at ambient temperature: Keep in original container, protect from moisture and direct sunlight.

Papaverine can interact with several drug classes, altering its efficacy or safety profile.

Major Interactions (Avoid)

• Nitrates: Combined vasodilatory effect may cause severe hypotension.
• Beta‑blockers: May blunt compensatory heart rate response to hypotension.

Moderate Interactions (Monitor Closely)

• Calcium channel blockers: Additive smooth‑muscle relaxation may enhance hypotensive risk.
• Anticholinergic agents: May reduce gastrointestinal motility benefits.
• MAO inhibitors: Potential for unpredictable cardiovascular effects.