Pizotifene.
Indications.
Basic treatment of migraine.
Posology and method of administration.
Reserved for adults and children over 12 years old.
A short period of adaptation of the patient to the drug is usually necessary because of the drowsiness and the feeling of tiredness which may occur at the start of treatment.
Accordingly, the dosage should be increased up to an average dosage:
the first 3 days: 1 tablet in the evening,
the following 3 days: 1 tablet in the morning and 1 tablet in the evening,
from the 7th day: 1 tablet, or even 2, morning, noon and evening.
The usually sufficient effective dosage is 3 tablets per day; it can be increased up to 6 tablets.
This basic treatment is a permanent daily treatment.
In children:
Children from 12 years old:
Exceptionally when the migraine is disabling: 2 tablets per day.
Children under 12:
The use of pizotifen in children under 12 years of age is contraindicated (see Contraindications).
Contraindications.
- Hypersensitivity to pizotifen or to any of the constituents of the drug.
- Angle-closure glaucoma.
- Urethroprostatic disorders.
- Child under 12 years old.
Side effects.
- Immune system disorders: Very rare: hypersensitivity reactions, facial edema.
- Metabolism and nutrition disorders: Very common: increased appetite and weight gain.
- Psychiatric disorders:
- Very rare: depression, stimulation of the central nervous system (agitation, aggressiveness, etc.).
- Not known: hallucinations, withdrawal symptoms such as depressed mood, tremors, nausea, dizziness, anxiety, sleep disturbances observed on sudden discontinuation of pizotifen (see Warnings and Precautions for use ).
- Nervous system disorders:
- Very common: sedation (including drowsiness).
- Common: dizziness.
- Uncommon: paresthesia.
- Not known: epileptic seizures in patients with epilepsy.
- Gastrointestinal disorders:
- Common: nausea, dry mouth.
- Uncommon: constipation.
- Liver disorders:Not known: liver damage ranging from simple elevation of liver enzymes to severe hepatitis.
- Skin and subcutaneous tissue disorders:Very rare: hives, rash.
- Musculoskeletal and connective tissue disorders:Very rare: myalgia.
- General disorders:Very common: asthenia.
Overdose.
An overdose results in:
- Drowsiness, dizziness,
- nausea, dry mouth, constipation,
- tachycardia, arterial hypotension,
- restlessness, convulsions
- respiratory depression, coma.
The administration of activated charcoal is recommended; within an hour of taking it, gastric lavage may be considered.
In the event of a significant overdose, symptomatic treatment including monitoring of the cardiovascular and respiratory systems is necessary.
In case of agitation or convulsions, benzodiazepines may be used.
Mechanisms of action.
Pizotifen is a tricyclic derivative (antidepressant).
It has antiserotonergic, antihistamine and weakly anticholinergic properties.
It modifies the migraine terrain by opposing on several levels the chemical mediators responsible for the migraine crisis.
It has a mild antidepressant effect causing a moderate increase in thymia (mood).