What is metamizole?
Metamizol (active ingredient from Novalgin®) is a highly effective painkiller from the pyrazolone group. It affects pain-relieving, fever-lowering and additionally cramp-resolving (spasmolytic) on the smooth muscles.
In Germany, Metamizol is subject to prescription, in many other countries even taken from the market – due to the rare but serious risk of a agonulocytosis (strong waste of white blood cells).
Despite this risk, Metamizol is widely used in Germany and is estimated as a strong analgesic, especially in colic and postoperative pain. The droplet shape (Novalgin® drop) allows a flexible dosage.
Active Ingredients & Mechanism of Action
Active ingredient: Metamizol-Natrium
The mechanism of action of Metamizol is not fully clarified:
Suggested mechanisms:
- Inhibition of cyclooxygenase (COX) in the central nervous system
- Activation of the descending pain-inhibiting system
- inhibition of prostaglandin E2 synthesis
- Direct spasmolytic action on smooth muscles
Wirkprofil:
- Stark analgesic: Stronger than Paracetamol and NSAR
- Stark antipyretic: Very effective with high fever
- Spasmolytically: Sold cramps of smooth muscles (coliken)
- Not anti-inflammatory: No clinically relevant antiphlogistic effect
Pharmacokinetics:
- Effective entry: 30–60 minutes (oral)
- duration of action: 4–6 hours
Who is it suitable for?
Metamizol is suitable for:
- Strong pain if other means are not sufficient
- Colic pain (Galle, kidney, intestine)
- Postoperative pain
- tumor pain
- High fever that does not respond to other measures
Advantages:
- Stronger action as paracetamol and NSAR
- No GI toxicity (no gastric ulcer risk)
- No impairment of kidney function
- No respiratory depression (other than opioids)
- Cramping effect in colic
Not suitable:
- In bone marrow diseases
- In genetically caused glucose-6-phosphate dehydrogenase deficiency
- In acute hepatic porphyry
- In pregnancy (1st and 3rd Trimenon)
Available Dosages
Tropfen (Novalgin® drops):
- 500 mg/ml (20 drops = about 500 mg)
Tablets: 500 mg
Use dosage (adults):
- 500–1000 mg as single dose
- Up to 4 times a day
- Maximum daily dose: 4000 mg (4 g)
Dip dosing:
- 20–40 drops as single dose
- equivalent to 500–1000 mg
How to Take
Tropfen:
- Take in some water or on a slice of sugar
- Count the exact number of drops
Tablets:
- Taking enough water
- Independent meals
Important notes:
- Do not take permanently without medical control
- At fever or throat pain during treatment immediately consult doctor (Agranulozytose!)
- Regular blood-image controls for long-term use
- Can reddish the urine (harmless)
Contraindications
**Metamizol must not be taken at:* *
- hypersensitivity to pyrazolones
- Disorders of bone marrow function
- Genetic glucose-6-phosphate dehydrogenase deficiency
- Acute of hepatic porphyry
- In the 1st and 3rd third pregnancy
- Still time
Preview at:
- Asthma bronchiale or chronic urticaria
- Hypotension (blood pressure drop possible)
- Kidney or liver failure
- Simultaneous intake of ciclosporin
Possible Side Effects
Occasionally:
- Skin rash, Urtikaria
- Blood pressure drop (dose dependent)
Selten but severe:
- Agranulozytose: Strong decline of white blood cells
- Frequency: approx. 1:1 million per application
- Symptoms: fever, throat pain, mucous membrane ulcer
- Pick up a doctor and control blood count!
- Can be fatal
- Anaphylactic reactions
- Heavy skin reactions (Stevens-Johnson syndrome)
** Agranulocytosis is not dose-dependent and can also occur after one-time intake. It is the reason for the restrictive handling in many countries.
Interactions
Relevant interactions:
- Ciclosporin - Mirrors can sink
- Methotrexate - increased toxicity possible
- chlorpromazine – increased hypothermia
Advantage:
- No relevant interactions with anticoagulants
- No GI toxicity combined with corticosteroids
- No increased bleeding risk
Combination possible with:
- Paracetamol (additive action)
- NSAR (different mechanisms of action)
- Weak opioids
Frequently Asked Questions
Similar Medications
Is metamizole right for you?
A licensed doctor will review your information and issue a prescription if suitable. Discreet and secure.
Important Notice
This information does not replace medical advice. If you have questions about your health or the suitability of this medication, please consult a doctor. Read the package leaflet before use.