metamizole

Action and Spectrum

Actions and Spectrum 

Actions: 

• Analgesic Effect: metamizole effectively reduces pain of varying intensity, from moderate to severe. It exerts its analgesic effects through multiple mechanisms, like inhibition of prostaglandin synthesis and modulation of pain pathways in the central nervous system. 
• Antipyretic Effect: metamizole helps lower elevated body temperature by acting on the hypothalamus, the body’s temperature-regulating center. It inhibits the synthesis of prostaglandins, which play a role in fever generation. 

Spectrum: 

• Pain Relief: metamizole is used to manage various types of pain, including postoperative pain, dental pain, musculoskeletal pain, headache, and pain associated with traumatic injuries. 
• Fever Reduction: It is used to lower fever in cases of infectious and non-infectious origins, such as common colds, flu, and other febrile illnesses. 
• Menstrual Pain: metamizole can effectively alleviate the pain associated with menstrual cramps (dysmenorrhea). 
• Renal Colic: Due to its spasmolytic properties, metamizole can be used to manage the intense pain caused by renal colic. 

Drug Interaction

Adverse Reaction

Frequency not defined 

Arrhythmias 

Kidney problems 

Shortness of breath 

Nausea and upset stomach 

Dizziness 

Rash 

Low blood pressure 

Chest pain

Black Box Warning

Black Box Warning: 

None 

Contraindication / Caution

Contraindication/Caution: 

Contraindications: 

• Hypersensitivity 
• Agranulocytosis 
• Porphyria 
• Pregnancy  
• Lactation 

Cautions: 

• Renal impairment 
• Liver impairment 
• Elderly patients 
• Asthma 
• Blood disorders 
• Drug Interactions 

Pregnancy / Lactation

Pregnancy consideration:  

Treatment with metamizole should not be given during 3rd trimester of pregnancy. 

Breastfeeding warnings:  

metamizole is contraindicated during lactation.  

Pregnancy category: 

Category A: Well-controlled and satisfactory studies show no risk to the fetus in the initial or later trimester. 

Category B: There was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women. 

Category C: There was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.    

Category D: adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.    

Category X: Drugs listed in this category outweigh the risks over benefits. Hence, these categories of drugs need to be avoided by pregnant women.    

Category N: No data is available for the drug under this category. 

Pharmacology

Pharmacology:  

metamizole inhibits the synthesis of prostaglandins, hormone-like compounds involved in pain, fever, and inflammation. Prostaglandins sensitize pain receptors, contribute to fever, and mediate inflammation. By inhibiting their production, metamizole helps alleviate pain and reduce fever. 

metamizole has been shown to exert a direct muscle relaxant effect, which can contribute to its effectiveness in relieving certain types of pain, such as renal colic (severe pain caused by kidney stones) and menstrual pain. 

Pharmacodynamics: 

metamizole’s analgesic effects are primarily attributed to the reduction in prostaglandin levels. Prostaglandins sensitize pain receptors and enhance pain perception. By reducing their production, metamizole diminishes the sensitization of pain receptors, resulting in pain relief. 

metamizole’s antipyretic effect is mediated by its impact on the hypothalamus, a brain region regulating body temperature. Prostaglandins contribute to the elevation of body temperature during fever by acting on the hypothalamus. metamizole reduces the production of prostaglandins, leading to a lowering of fever through the hypothalamic heat-regulating center. 

Pharmacokinetics: 

Absorption 

metamizole is rapidly absorbed after oral administration. 

Distribution 

It is distributed throughout the body and can cross the blood-brain barrier. 

Metabolism 

metamizole undergoes metabolism in the liver, with some of its metabolites being active and contributing to its effects. 

Elimination and Excretion 

The metabolites are primarily excreted through the urine. 

Adminstartion

Administration: 

metamizole (dipyrone) is typically administered orally as tablets or liquid formulations. The exact dosing and administration instructions may vary based on the formulation and the specific condition being treated. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: metamizole 

Pronounced as: meh-tah-mih-zole 

Why do we use metamizole? 

metamizole is effective in relieving moderate to severe pain. 

metamizole can relieve traumatic injuries, fractures, or other painful conditions until more definitive treatment can be administered. 

metamizole is sometimes used in children for pain relief and fever reduction.