Papaverină Arena (Papaverine Hydrochloride)

Papaverine is used primarily for its vasodilatory and smooth‑muscle relaxing actions in several clinical contexts.

• Coronary artery spasm: Relieves the spasm and improves blood flow during cardiac catheterisation.
• Gastrointestinal spasm: Reduces muscle tone in the gastrointestinal tract during endoscopic procedures.
• Peripheral vascular spasm: Helps dilate peripheral vessels to improve perfusion during diagnostic angiography.
• Erectile dysfunction (rare off‑label use): May facilitate local vasodilation when administered intra‑arterially.

• 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 availability, producing relaxation of vascular and non‑vascular smooth muscle and resulting in vasodilation.

Papaverine may cause a range of adverse reactions, most of which are dose‑dependent and reversible.

Common Side Effects

• Flushing
• Headache
• Nausea
• Dizziness
• Hypotension
• Mild abdominal discomfort

Serious or Rare Side Effects

• Severe hypotension
• Cardiac arrhythmias
• Hepatic dysfunction
• Allergic anaphylaxis
• Local injection site necrosis

When using Papaverine, clinicians should consider several safety measures.

• Contraindication: Patients with known hypersensitivity to papaverine or its excipients.
• Cardiovascular monitoring: Observe for significant blood‑pressure drops and arrhythmias.
• Liver function: Assess baseline hepatic enzymes in patients with liver disease.
• Pregnancy: Use only if clearly beneficial to the mother and fetus under specialist guidance.
• Breastfeeding: Caution as the drug may enter milk; weigh benefits against risks.
• Store at below 25°C: keep in the original vial or ampoule and protect from moisture.

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

Major Interactions (Avoid)

• Nitrates: Combined use may cause profound hypotension.
• Alpha‑blockers: May lead to additive blood‑pressure lowering effects.
• Other phosphodiesterase inhibitors: Heightened risk of severe vasodilation.

Moderate Interactions (Monitor Closely)

• Antihypertensives: May require dose adjustment.
• Anticoagulants: Potential for increased bleeding if vascular integrity is compromised.
• CYP450‑modulating drugs: May affect papaverine metabolism and plasma levels.