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 or pharmacist.
Important Safety Information
This service operates under German pharmaceutical law (HWG). For risks and side effects, read the package leaflet and consult your doctor or pharmacist. All medications are dispensed from a licensed pharmacy in Germany.