Interaction of promethazine with other medicinal products
β-Adrenoblockers – increased (reciprocal) plasma concentrations, severe arterial hypotension, arrhythmias, irreversible retinopathy, tardive dyskinesia. Analgesics, sleeping pills, tranquilizers, neuroleptics, anesthetics, local anesthetics, m-cholinoblockers, hypotensive agents, other respiratory depressants – increased effects, requires dose adjustment. Barbiturates – acceleration of elimination and reduction of promethazine activity. Bromocriptine – weakening of its effects, increased serum prolactin concentration. Hepatotoxic agents – increase in hepatotoxicity. MAO inhibitors (simultaneous use is not recommended), phenothiazine derivatives – increased risk of arterial hypotension and extrapyramidal disorders. Ototoxic agents – increasing ototoxicity. Amphetamine derivatives, m-cholinomimetics, anticholinesterase drugs, ephedrine, guanethidine, levodopa, dopamine – weakening of their action. Riboflavin – it is necessary to increase its dose. Appetite suppressants – reduction of anorexigenic effect. Tricyclic antidepressants, anticholinergic agents – increase m-cholinoblocking activity. Quinidine – increased likelihood of cardiodepressant action. Epinephrine – blockade of α-adrenergic effect, risk of serious hypotension. Ethanol, clonidine, anticonvulsants – increased CNS depression.
Impaired platelet aggregation has occurred in neonates whose mothers have taken promethazine. Systematic general blood tests and control of liver function parameters are recommended during long-term treatment. Alcohol should be avoided during treatment. Use with caution in children with acute or chronic respiratory diseases as promethazine suppresses the cough reflex. It is not recommended for use in children to stop episodic vomiting of unspecified genesis. The use of promethazine in combination with opioid analgesics and tranquilizers for complex preoperative preparation of patients is possible only under strict medical supervision. During long-term treatment it is recommended to perform systematic general blood analysis and control of liver function parameters. The solution is not intended for intravenous and percutaneous administration. Some dosage forms of promethazine contain sodium metabisulfite, which may cause allergic reactions including anaphylactoid and asthmatic reactions. To prevent distorted results of skin scarification tests for allergens, it is necessary to cancel 72 h before allergy testing. False-positive pregnancy test results may occur during treatment. May suppress cough reflex, so caution is necessary in patients (especially children) with exacerbation of chronic respiratory diseases.
Caution is necessary when using in patients with liver dysfunction, cardiovascular system diseases and suppression of medullary hematopoiesis. In the elderly, caution is required when parenteral administration of high doses because extrapyramidal disorders and acute urinary retention are possible. As an antiemetic it should be used only in case of prolonged vomiting of known etiology. Caffeine administration is recommended to prevent CNS depression. Long-term use increases the risk of dental disease (caries, periodontitis, candidiasis) due to reduced salivation. May mask the ototoxic effect (tinnitus and dizziness) of co-administered drugs. Increases the need for riboflavin.
Do not use for drivers of vehicles and other persons whose occupation requires high concentration of attention (especially at the beginning of treatment).