The following interactions occur when combining some medications with promethazine:
- Levodopa, m-cholinomimetics, dopamine, anticholinesterase drugs, ephedrine, guanethidine – their effects are weakened;
- Sleeping pills, hypotensive drugs, analgesics, local anesthetics, neuroleptics, m-cholinoblockers, tranquilizers, anesthetics – their effects are enhanced;
- with beta-adrenoblockers there is a mutual increase in blood plasma concentrations;
- barbiturates decrease activity and accelerate excretion of promethazine;
- bromocriptine – attenuates the effects of promethazine;
- Tricyclic antidepressants contribute to increased m-cholinergic activity of promethazine;
- clopheline, antiepileptics, ethyl alcohol increase the CNS-depressant ability of promethazine;
- quinidine increases the cardiodepressant potency of promethazine;
- monoamine oxidase inhibitors increase the risk of hypotension and extrapyramidal disorders.
The drug is discontinued if allergic testing is necessary. Cancellation is made three days before the procedure. The use of the drug may lead to distorted results during pregnancy testing.
The drug in solution form should not be given subcutaneously or intra-arterially.
The administration of Promethazine requires caution:
When there are respiratory diseases of a chronic nature; when the patient suffers from vomiting of an unclear nature; together with narcotic analgesics, codeine and tranquilizers.
Driving vehicles or other activities that involve mechanisms are prohibited during treatment.
Promethazine in pregnancy
Promethazine is contraindicated in pregnancy. Breastfeeding women are also not recommended to combine breastfeeding with treatment because Promethazine penetrates into milk and may cause extrapyramidal disorders in the infant.
The contraindications that the drug has must not be overlooked when prescribing it. Prometazine is not recommended for use in the following conditions and diseases: hypersensitivity; when the patient has episodic vomiting, the origin of which is not clear; if the patient is taking monoamine oxidase inhibitors and within two weeks after their withdrawal; if the patient suffers from nighttime apnea syndrome; in the presence of closed-angle glaucoma in coma; in detected renal or hepatic insufficiency; in intoxication with sleeping pills, narcotic analgesics and alcohol.
Also, the drug should not be prescribed to lactating and pregnant women. Babies under six years of age (when taking the drug orally) and infants under two months of age (when injecting) fall into the same category.
Form, composition, packaging
The drug Prometazine is available in several dosage forms.
In tablet form in promethazine concentration 0.025; 0.05 and 0.1 grams. In pelleted form with a concentration of the active substance promethazine 0.05 and 0.025 grams. Injectable solution (2.5%) in 2-milliliter ampoules.
Shelf life and storage conditions
Prometazine in any of its forms should be stored in rooms where it is dark, cool and not humid. The shelf life for the solution is five years, for tablet forms – no more than three years.
You can buy the drug only if you have a doctor’s prescription.