Prothiazine Tablets and Syrup

/ CTS

Route of administration: Oral.
Not for use in children under the age of 2 years.
For treatment of allergies:
Children aged 2-5 years:
5-15 ml of syrup in one dose, to be taken at night or 5 ml two to three times a day. Do not administer more than 15 ml per day.
Children aged 6-12 years:
10-25 ml of syrup in one dose to be taken at night, or 10 ml twice a day. Do not administer more than 25 ml per day.
Children above the age of 12 and adults:
Begin treatment by taking one tablet at night. The dosage can be increased to a maximum of one tablet twice a day, as required.
For treatment and prevention of nausea and vomiting:
Children aged 2-5 years:
5 ml of syrup every 4-6 hours up to a maximum of 15 ml per day.
Children aged 6-12 years:
A dose of 10 ml of syrup; wait 4-6 hours before administering another dose. Up to two doses per day can be administered (a total of 20 ml per day).
Children above the age of 12 and adults:
One tablet every 4-6 hours, up to a maximum of 4 tablets per day.
For short-term use as a sedative, with the doctor’s instruction only:
Children aged 2-5 years:
5-15 ml of syrup as a single dose to be taken at night, at bedtime.
Children aged 6-12 years:
10-20 ml of syrup as a single dose to be taken at night, at bedtime.
Children above the age of 12 and adults:
One to three tablets as a single dose, to be taken at night, at bedtime.

Antihistaminic, Antiemetic, Sedative.

• Hypersensitivity to the active substance promethazine, other phenothiazines or to any of the excipients
• Should not be used in patients in coma or suffering from CNS depression of any cause.
• Children less than two years of age.
• Should be avoided in patients taking monoamine oxidase inhibitors up to 14 days previously.

* Hypersensitivity reactions including anaphylaxis, urticaria and angioedema have been reported with Promethazine use. In case of allergic reaction, treatment with promethazine must be discontinued and appropriate symptomatic treatment initiated.
* Should be avoided in patients with liver or renal dysfunction, Parkinson’s disease, hypothyroidism, cardiac failure, pheochromocytoma, myasthenia gravis, or prostate hypertrophy, or in patients with a history of narrow angle glaucoma or agranulocytosis.
* Caution must be exercised when using H1-antihistamines such as promethazine due to the risk of sedation. Combined use with other sedative medicinal products is not recommended.
promethazine should not be used for longer than 7 days without seeking medical advice.
Caution should be used in patients with:
• Asthma, bronchitis or bronchiectasis. Promethazine may thicken or dry lung secretions and impair expectoration.
• Severe coronary artery disease
• Epilepsy
• Bladder neck or pyloro-duodenal obstruction.
Ototoxicity
Promethazine may mask the warning signs of ototoxicity caused by ototoxic drugs e.g. salicylates. It may also delay the early diagnosis of intestinal obstruction or raised intracranial pressure through the suppression of vomiting.
QT prolongation
Phenothiazine derivatives may potentiate QT interval prolongation which increases the risk of onset of serious ventricular arrhythmias of the torsade de pointes type, which is potentially fatal (sudden death). QT prolongation is exacerbated, in particular, in the presence of bradycardia, hypokalemia, and acquired (i.e. drug induced) QT prolongation. If the clinical situation permits, medical and laboratory evaluations should be performed to rule out possible risk factors before initiating treatment with a phenothiazine derivative and as deemed necessary during treatment.
Photosensitivity reactions
Due to the risk of photosensitivity, exposure to strong sunlight or ultraviolet light should be avoided during or shortly after treatment.
Paediatric population
The use of promethazine should be avoided in children and adolescents with signs and symptoms suggestive of Reye’s Syndrome.
Excipient(s) with known effect
* Syrup contain sucrose, sorbitol and glucose. Patients with rare hereditary problems of fructose intolerance, glucose-galactose malabsorption or sucrase-isomaltase insufficiency should not take this medicine.
* Phenothiazines may be additive with, or may potentiate the action of, other CNS depressants such as opiates or other analgesics, barbiturates or other sedatives, general anesthetics, or alcohol.
* The occurrence of unexplained infections or fever may be evidence of blood dyscrasia, and requires immediate hematological investigation.
* Treatment should be discontinued if any marked changes (hyperleucocytosis, granulocytopenia) are observed in the blood count.
See prescription for full details.

Very common: Sedation or somnolence
See prescribing information for full details.

* Promethazine will enhance the action of any anticholinergic agent, tricyclic antidepressant, sedative or hypnotic.
* Promethazine may interfere with immunological urine pregnancy tests to produce false-positive or false-negative results.
* Promethazine should be discontinued at least 72 hours before the start of skin tests as it may inhibit the cutaneous histamine response thus producing false negative results.
* Special caution is required when promethazine is used concurrently with drugs known to cause QT prolongation (such as antiarrhythmics, antimicrobials, antidepressants, antipsychotics) to avoid exacerbation of risk of QT prolongation.
* Cytochrome P450 2D6 Metabolism: Some phenothiazines are moderate inhibitors of CYP2D6. There is a possible pharmacokinetic interaction between inhibitors of CYP2D6, such as phenothiazines, and CYP2D6 substrates. Co administration of promethazine with amitriptyline/amitriptylinoxide, a CYP2D6 substrate, may lead to an increase in the plasma levels of amitriptyline/amitriptylinoxide. Monitor patients for dose-dependent adverse reactions associated with amitriptyline/amitriptylinoxide.
* Promethazine should be avoided in patients taking monamine oxidase inhibitors within the previous 14 days, and monamine oxidase inhibitors should be avoided while using Promethazine.
* Seizure threshold-lowering drugs: Concomitant use of seizure-inducing drugs or seizure threshold-lowering drugs should be carefully considered due to the severity of the risk for the patient
* Gastro-intestinal agents that are not absorbed (magnesium, aluminium and calcium salts, oxides and hydroxides): Reduced gastro-intestinal absorption of phenothiazines may occur. Such gastro-intestinal agents should not be taken at the same time as phenothiazines (at least 2 hours apart, if possible).
* Concomitant use of promethazine with drugs with anticholinergic properties enhances the anticholinergic effect.

Pregnancy: The use of promethazine is not recommended during pregnancy and in women of childbearing potential not using contraception, unless the potential benefits outweigh the potential risks. When promethazine has been given in high doses during late pregnancy, promethazine has caused prolonged neurological disturbances in the infant.
Lactation: Promethazine is excreted in breast milk. There are risks of neonatal irritability and excitement. Promethazine is not recommended for use in breast-feeding.

Symptoms
Symptoms of severe overdosage are variable. They are characterised in children by various combinations of excitation, ataxia, incoordination, athetosis and hallucinations, intellectual disability and cognition deficit in children less than 6 years of age while adults may become drowsy and lapse into coma. Convulsions may occur in both adults and children: coma or excitement may precede their occurrence. Tachycardia may develop. Cardiorespiratory depression is uncommon. High doses (supratherapeutic doses) can cause ventricular arrhythmias including QT prolongation and torsade de pointes.
Management
If the patient is seen soon enough after ingestion, it should be possible to induce vomiting with ipecacuanha despite the antiemetic effect of promethazine; alternatively, gastric lavage may be used.
Treatment is otherwise supportive with attention to maintenance of adequate respiratory and circulatory status. Convulsions should be treated with diazepam or another suitable anticonvulsant.
In the event of overdose of promethazine, take all appropriate measures immediately.

Storage: Store below 25°C
Shelf life: Promethazine syrup after first opening- 22 days.
Because the duration of action may be up to 12 hours, patients should be advised that if they feel drowsy, dizzy and have blurred vision, they should not drive or operate heavy machinery.