Allergic diseases and reactions: rash, itching, eczema, medicated rash, serum sickness, Quincke’s edema, hay fever, anaphylactic shock, bronchoobstructive syndrome (as part of complex therapy). Promethazine is used for skin diseases (including eczema, neurodermatitis, diathesis, contact dermatitis and toxicoderma). In anesthesiology: as a sedative before and after surgical interventions, as an aid in conjunction with analgesic drugs, to prevent and treat nausea and vomiting during anesthesia and surgical interventions in an artificial hibernation. As part of combined therapy or as an additional agent: kinetosis, migraine, sleep disorders, states of agitation- gastric and duodenal ulcer. In pediatrics: change of skin and mucous membranes in infants against exudative diathesis, eczema, asthmatic bronchitis, false croup, various types of allergic dermatosis, serum sickness.
Blocker of histamine H1-receptors, has high antihistamine activity and pronounced blocking effect on the CNS. Causes a sedative effect and has an antiemetic effect. It also has a pronounced adrenoblocking, moderate peripheral and central cholinoblocking effect. The effect begins to develop 20 minutes after intake and lasts for 6 hours, sometimes up to 12 hours. After oral administration it is rapidly and well absorbed from the gastrointestinal tract.
Binding to plasma proteins is more than 90%. It penetrates through the placental barrier. It is metabolized in the liver to form mainly sulfoxides and N-demethylated promethazine derivatives. It is excreted mainly by the kidneys and to a lesser extent by the intestine.
Simultaneous use of promethazine potentiates the effect of opioid analgesics, hypnotics and local anaesthetics. Simultaneous use of promethazine with tricyclic antidepressants may increase the m-cholinoblocking effect as well as CNS depressant effect and with antihypertensive drugs may increase the effect of the latter.
Drug side effects
Digestive system: moderate pronounced numbness of the oral mucosa, dry mouth, nausea, constipation, diarrhea, discomfort – rarely – jaundice.
CNS and peripheral nervous system: drowsiness, dizziness, anxiety, lethargy, fatigue, movement coordination disorders, visual disturbances – rarely – tinnitus, euphoria, nervousness, insomnia, seizures, oculogyric crisis, catatonic status, hysteria, psychomotor agitation, extrapyramidal disorders, headache, nystagmus.
Cardiovascular system: rarely – tachycardia, bradycardia, palpitation, syncope, arterial hypotension (when injected intravenously), arrhythmias.
Dermatological reactions: rare – contact dermatitis, photosensitization, urticaria.
Blood system: rare – leukopenia, agranulocytosis, aplastic anemia, thrombocytopenic purpura.
Allergic reactions: rare – exanthema, urticaria, angioedema, anaphylactic reactions.
Other: rare – irregular breathing, urinary retention.
Local reactions: painful infiltrates may occur during injection.