Metamizole Sodium Kalceks (Metamizole Sodium)

Metamizole Sodium is a pyrazolone analgesic used to manage pain and fever through inhibition of prostaglandin synthesis.

• Pain: Provides rapid relief of moderate to severe acute pain, especially after trauma or surgery.
• Fever: Reduces elevated body temperature in febrile conditions, aiding patient comfort and reducing metabolic demand.
• Postoperative analgesia: Controls pain following surgical procedures, facilitating early mobilization and recovery.
• Colic: Alleviates visceral pain associated with gastrointestinal colic, improving patient tolerance.

• Metamizole Sodium exerts its effect primarily by inhibiting cyclooxygenase enzymes, leading to reduced synthesis of prostaglandins that mediate pain and fever. It may also influence central opioid and cannabinoid pathways, contributing to its analgesic and antipyretic actions, although the exact mechanisms remain incompletely defined. The drug’s peripheral and central actions together produce a pronounced decrease in nociceptive signaling and thermoregulatory responses.

Metamizole Sodium may be associated with a range of adverse reactions, which are categorized by frequency and severity.

Common Side Effects

• Hypotension: Transient low blood pressure, especially after rapid IV administration.
• Nausea: Mild to moderate nausea occurring shortly after dosing.
• Rash: Skin erythema or mild urticaria.
• Dizziness: Light‑headedness or vertigo.

Serious or Rare Side Effects

• Agranulocytosis: Severe reduction of white blood cells, potentially life‑threatening.
• Anaphylaxis: Immediate hypersensitivity reaction with respiratory compromise.
• Stevens‑Johnson syndrome: Severe mucocutaneous reaction with skin detachment.
• Hepatotoxicity: Elevated liver enzymes indicating liver injury.

When using Metamizole Sodium, several precautions should be observed to minimize risk.

• Patient assessment: Evaluate for history of blood dyscrasias before initiating therapy.
• Monitoring: Perform regular complete blood counts during prolonged treatment.
• Renal function: Adjust use in patients with severe renal impairment.
• Concomitant drugs: Avoid use with other myelosuppressive agents.
• Pregnancy and lactation: Use only if clearly indicated, as safety data are limited.
• Store at 2-8°C: Keep refrigerated, protect from light, do not freeze or shake.

Metamizole Sodium can interact with other medicines, affecting efficacy or safety.

Major Interactions (Avoid)

• Anticoagulants: May increase bleeding risk; monitor coagulation parameters.
• Immunosuppressants: Potential additive bone‑marrow suppression.

Moderate Interactions (Monitor Closely)

• NSAIDs: Combined use may enhance gastrointestinal irritation.
• ACE inhibitors: May potentiate hypotensive effects.
• Diuretics: May increase risk of electrolyte imbalance.
• Antidepressants (MAOIs): Possible additive central nervous system effects.