What side effects can Promethazine have?
Below you will find the most important information about possible known side effects of promethazine.
These side effects do not occur, but you can. Because every person reacts differently to medication. Please also note that the type and frequency of side effects may vary depending on the drug formulation (eg tablet, syringe, ointment).
Very common side effects:
tiredness, weakness, sleepiness and drowsiness, drowsiness, restlessness, dizziness, movement disorders such as gaze spasms, jerky tongue sticking out, involuntary facial movements and head movements (dyskinesia), Parkinson’s syndrome such as sedentary lifestyle, tremor, muscle stiffness , Early dyskinesias (predominantly in the head-neck-shoulder area) and other involuntary movements such as akathisias.
Common side effects:
Low blood pressure (hypotension) or increased standing blood pressure drop (orthostatic circulatory disorder), increased heart rate, cardiac arrhythmias, cardiac conduction disturbances, prolactin level elevations, breast tenderness, milk flow, cycle disturbances to loss of menstruation, Orgasmic disorders, impotence, impotence, asthma, mucus thickening.
Uncommon side effects:
Dizziness, lethargy, headache, depression, agitation, seizures, speech disorders, memory disorders, itching skin allergies, increased blood levels of the liver, white blood cell deficiency, sugar metabolism disorders such as increased blood sugar, dry mouth, constipation, disorders in the blood Urination, weight gain.
Rare side effects:
Hypersensitivity reactions of the skin such as skin discoloration on light-exposed areas or sensitivity to light, sweating, nausea and vomiting, liver dysfunction.
Very rare and occasional side effects:
Liver diseases with gall congestion, visual disturbances such as disorders of acute vision, intraocular pressure increase (glaucoma) or pigment deposits in the cornea and lens, hematopoietic disorders, hair loss, connective tissue reactions, intestinal obstruction, laryngeal swelling, thrombosis.
In very rare cases, treatment with promethazine may lead to a neuroleptic malignant syndrome. This symptom is life-threatening and manifests itself in fever, muscle rigidity, circulatory collapse, tachycardia, high blood pressure, loss of consciousness until coma. Therefore, especially in case of high fever, a careful medical examination must take place and if necessary the active substance promethazine should be discontinued.
Especially at the start of treatment, muscle cramps around the face, mouth, neck and arms occur and there may be side effects such as lack of facial expression, slowing movement, shaking, joint stiffness and difficulty sleeping.
After prolonged treatment with the active ingredient, involuntary facial movements and head movements (dyskinesias) and Parkinson’s syndrome are very common, as well as blood cell damage (eg agranulocytosis).
The administration of promethazine to the veins may be indicated if reassurance of the patient is required in acute allergic reactions of the immediate type (shock). In addition, it is used in acute restlessness and agitation in the context of psychiatric disorders. In this application form of promethazine must be expected with severe tissue damage (up to tissue death), which also make amputations necessary.
What interactions does promethazine show?
Please note that the interactions may vary depending on the drug formulation of a drug (eg tablet, syringe, ointment).
Concomitant use of other CNS depressants such as morphine derivatives, barbiturates, benzodiazepines, anxiolytics (drugs used to treat anxiety disorders), certain H1 antihistamines, analgesics (analgesics) and other neuroleptics will increase the effectiveness of each other. Above all, the sleep-promoting and breathing-impeding effects of the active ingredients are intensified.
Simultaneous alcohol consumption during treatment with promethazine may increase the alcohol effect and lower the blood pressure.
The concomitant use of antihypertensive agents (hypotensive agents) increases their effects and can lead to a serious drop in blood pressure.
In the case of guanethidine, clonidine and alpha-methyldopa, however, promethazine reduces their hypotensive effect.
Concomitant use of anticonvulsants to treat epilepsy such as pentetrazole or phenytoin may cause increased seizures. In particular, the antiepileptic drugs carbamazepine, phenobarbital and phenytoin as well as rifampicin also lead to an efficacy attenuation of promethazine with simultaneous administration.
In combination with anticholinergics (such as atropine, benzatropine, trihexyphenidyl) their effects can be enhanced and the promethazine effect can be weakened.
The dopamine receptor agonists bromocriptine and amantadine are attenuated when administered concurrently by promethazine. The simultaneous treatment with the Parkinson’s drug Levodopa leads to a mutual weakening of the respective active substances, therefore the two active substances should not be taken together.
While the dopamine receptor antagonists metoclopramide, bromopride and alizapride increase side effects of the muscles. In particular, muscle spasms and involuntary muscle twitching occur more frequently with concomitant administration of promethazine.
So-called MAO inhibitors, drugs used inter alia for the treatment of Parkinson’s disease, can lead to high blood pressure and to the enhancement of some side effects of promethazine when concomitant with promethazine. They should not be taken at the same time.
In combination with propranolol or tricyclic antidepressants and promethazine, the levels of these drugs in the blood are increased. This can lead to an increased occurrence of side effects of these drugs.
In particular, the combination of promethazine and lithium leads to a sharp increase in motor side effects (extrapyramidal symptoms). These side effects mainly affect the arms and legs and manifest as gait disturbances or disorders of the musculature (fuselage hyperkinesia, tremor and rigor).
In combination with epinephrine, there may be an increased drop in blood pressure (paradoxical hypotension) and side effects may also increase.
Caffeine weakens the effects of promethazine. The simultaneous intake of tea or coffee should therefore be avoided during the treatment in order to avoid an efficacy reduction of promethazine.
Women taking anti-Babypille (oral contraceptives) are expected to be more likely to experience unwanted side effects. In a pregnancy test also a false positive result is possible.
The concomitant use of agents that also prolong the QT interval, such as macrolide antibiotics, class I and III antiarrhythmic agents, malaria drugs, antihistamines, antidepressants or other neuroleptics, may lead to potassium deficiency (hypokalemia). As a result, cardiac arrhythmias may occur.
Polypeptide antibiotics such as capreomycin, colistin or polymyxin B in combination with promethazine may potentiate promethazine-induced respiratory distress (respiratory depression). Some other antibiotics (anti-bacterial agents) can cause muscular dysfunction when promethazine is taken at the same time.
The action of gonadorelin in combination with promethazine is attenuated due to promethazine-induced elevation of the milk-producing hormone prolactin.
Selective serotonin reuptake inhibitors (for example, fluoxetine, paroxetine) may require dose reduction of promethazine by the physician with concomitant administration.