Natrijev Metamizolat Krka (Metamizole Sodium Monohydrate)

Metamizole sodium is indicated for conditions where strong analgesia or antipyresis is required.

• Moderate to severe pain: provides rapid pain relief when weaker analgesics are insufficient.
• Post‑operative pain: helps control surgical pain during the immediate recovery period.
• Colic: reduces visceral pain associated with gastrointestinal spasm.
• High fever: lowers body temperature when antipyretic therapy is needed.

• Metamizole sodium acts as a non‑opioid analgesic by inhibiting cyclo‑oxygenase enzymes, thereby reducing prostaglandin synthesis. The decreased prostaglandin levels diminish peripheral sensitisation and central pain transmission. Additionally, the drug modulates central pain pathways, contributing to its antipyretic effect through hypothalamic temperature regulation.

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

Common Side Effects

• Injection site pain or erythema: local discomfort at the administration site.
• Nausea or vomiting: gastrointestinal upset following dosing.
• Dizziness or light‑headedness: transient vertigo or feeling faint.
• Transient hypotension: temporary drop in blood pressure after rapid IV administration.

Serious or Rare Side Effects

• Agranulocytosis: severe reduction of neutrophils, increasing infection risk.
• Severe skin reactions (e.g., Stevens‑Johnson syndrome): extensive rash or mucosal involvement.
• Anaphylactic reaction: sudden, life‑threatening allergic response.
• Hepatic enzyme elevation: abnormal liver function tests indicating possible liver injury.

Before initiating therapy, clinicians should assess patient suitability and monitor for adverse events.

• Baseline blood count: obtain complete blood count to detect pre‑existing leukopenia.
• Infection monitoring: watch for signs of infection, especially if agranulocytosis develops.
• Hypersensitivity: avoid in patients with known allergy to pyrazolones or Metamizole.
• Renal/hepatic impairment: use with caution and consider dose adjustment.
• Pregnancy: limit use to situations where benefit outweighs potential risk.
• Store at below 25°C: keep in the original packaging, protect from moisture and direct sunlight.

Metamizole sodium can interact with several drug classes, requiring careful management.

Major Interactions (Avoid)

• Other myelotoxic agents (e.g., chemotherapy): may compound risk of agranulocytosis.
• Anticoagulants (e.g., warfarin): can enhance bleeding tendency.
• Concurrent pyrazolone derivatives: increase risk of severe hematologic toxicity.

Moderate Interactions (Monitor Closely)

• ACE inhibitors or diuretics: may potentiate hypotensive effects.
• NSAIDs: additive renal stress and gastrointestinal irritation.
• Alcohol: can exacerbate dizziness and hypotension.