Metamizole Kalceks (Metamizole Sodium Monohydrate)

• Metamizole Kalceks, a pyrazolone analgesic, is used to manage pain and fever across several clinical situations.
• Pain: provides analgesia for moderate to severe acute pain, including musculoskeletal and visceral sources, when other analgesics are insufficient.
• Fever: reduces elevated body temperature by inhibiting prostaglandin‑mediated thermoregulation, useful in high‑grade febrile states.
• Postoperative pain: controls discomfort after surgical procedures, facilitating early mobilization and recovery under clinical supervision.

• Metamizole sodium inhibits cyclooxygenase enzymes, leading to decreased synthesis of prostaglandins that mediate pain, inflammation, and fever. The reduction of prostaglandin levels diminishes peripheral nociceptor sensitization and central thermoregulatory signaling, producing analgesic and antipyretic effects. The precise contribution of additional pathways remains under investigation.

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

Common Side Effects

• Injection site pain or irritation
• Nausea or vomiting
• Dizziness or light‑headedness
• Transient hypotension
• Skin rash or itching
• Mild headache

Serious or Rare Side Effects

• Agranulocytosis (dangerously low white‑blood‑cell count)
• Anaphylactic or severe allergic reactions
• Stevens‑Johnson syndrome or toxic epidermal necrolysis
• Hepatic dysfunction or elevated liver enzymes
• Severe blood dyscrasias
• Hemolytic anemia

• When prescribing Metamizole Kalceks, clinicians should consider several safety measures.
• Assess renal function: evaluate kidney status before initiating therapy.
• Monitor blood counts: perform regular complete‑blood‑count tests to detect early hematologic changes.
• Use cautiously in hepatic impairment: adjust therapy if liver disease is present.
• Avoid in known hypersensitivity: do not administer to patients with documented allergy to metamizole or related pyrazolones.
• Do not use in patients with a history of agranulocytosis or severe bone‑marrow suppression.
• Store at ambient temperature: keep in the original container, protect from moisture and direct sunlight.

Metamizole Kalceks can interact with other medicines, requiring attention to potential additive effects.

Major Interactions (Avoid)

• Concurrent use with other pyrazolone derivatives: increased risk of hematologic toxicity.
• Combination with bone‑marrow suppressants (e.g., chemotherapy agents): may exacerbate cytopenias.
• Co‑administration with anticoagulants: heightened bleeding tendency.
• Use with other NSAIDs or COX inhibitors: amplified gastrointestinal and renal adverse effects.

Moderate Interactions (Monitor Closely)

• Diuretics: possible reduction in renal clearance, monitor electrolytes.
• Antihypertensives: additive hypotensive effect, observe blood pressure.
• CYP450 substrates: metamizole may alter metabolism of certain drugs, adjust dosing as needed.