Metamizolo Sodico Abc (Metamizole Sodium)

Metamizole sodium is employed in the management of pain and fever, acting through inhibition of cyclooxygenase pathways.

• Pain: reduces moderate to severe acute pain when other analgesics are insufficient.
• Fever: lowers elevated body temperature associated with infectious or inflammatory conditions.
• Post‑operative discomfort: helps control pain after surgical procedures.

• Metamizole sodium inhibits cyclooxygenase enzymes, decreasing prostaglandin synthesis, and modulates additional inflammatory mediators. This dual action reduces nociceptive signaling and thermoregulatory set‑points, producing analgesic and antipyretic effects without strong anti‑inflammatory activity.

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

Common Side Effects

• Nausea: mild to moderate stomach upset.
• Dizziness: transient light‑headedness.
• Skin rash: erythematous or pruritic lesions.
• Headache: mild tension‑type pain.
• Hypotension: occasional drop in blood pressure.

Serious or Rare Side Effects

• Agranulocytosis: severe reduction in white blood cells, requiring immediate medical attention.
• Stevens‑Johnson syndrome: life‑threatening skin and mucous membrane reaction.
• Anaphylaxis: rapid onset of allergic shock with respiratory and circulatory compromise.

When prescribing or dispensing metamizole sodium, consider the following safety measures.

• Blood count monitoring: perform baseline and periodic leukocyte counts to detect agranulocytosis.
• Hypersensitivity: avoid in patients with known allergy to pyrazolones or previous severe reactions.
• Renal/hepatic impairment: use caution and adjust therapy as needed.
• Pediatric use: generally contraindicated in children under 3 months in many jurisdictions.
• Pregnancy and lactation: safety not established; weigh benefits against potential risks.
• Store at below 25°C: keep in the original container, protect from moisture and direct sunlight.

Metamizole sodium can influence the activity of several co‑administered medicines.

Major Interactions (Avoid)

• Warfarin: potentiates anticoagulant effect, increasing bleeding risk.
• Other myelosuppressive agents: additive risk of bone‑marrow depression.
• Allopurinol: may enhance risk of severe skin reactions.

Moderate Interactions (Monitor Closely)

• NSAIDs: combined use may increase gastrointestinal irritation.
• ACE inhibitors: possible additive hypotensive effect.
• Oral contraceptives: may reduce contraceptive efficacy.
• Lithium: may raise lithium serum levels, requiring monitoring.