Generic
Promethazine Theoclate
1 brands available in the market
At a glance
Promethazine Theoclate is an anti-emetic drug used to prevent and treat nausea and vomiting, including travel sickness, and vertigo. It works by blocking histamine receptors in the vomiting center of the brain.
Description
Promethazine Theoclate works by stopping histamine from binding to its receptors in the vomiting center. The vomiting center is responsible for feelings of sickness and the vomiting reflex. It is activated when it receives nerve messages from the vestibular apparatus. By blocking histamine receptors, it prevents disturbances in the middle ear from activating the vomiting center.
Indications
- Prevention and treatment of nausea and vomiting (including travel sickness)
- Vertigo
- Post-operative nausea
Therapeutic class
Anti-emetic drugs, Miscellaneous sedatives & hypnotics, Sedating Anti-histamine
Pharmacological class
Phenothiazine (H1 Antagonist)
Pharmacology
Promethazine Theoclate blocks histamine receptors in the vomiting center of the brain. The vomiting center is activated by nerve messages from the vestibular apparatus and causes nausea and vomiting. By blocking H1 receptors, it prevents middle ear disturbances from activating the vomiting center.
Mechanism of action
Prevents nausea and vomiting by blocking H1 receptors in the vomiting center.
Dosage
Adult Dose (Oral):
- Nausea/vomiting: 25 mg at night; may increase to 50-75 mg at night or 25 mg 2-3 times daily; max 100 mg daily
- Motion sickness prophylaxis: 25 mg at night or 1-2 hours before travel
Pediatric Dose (Oral):
- Nausea/vomiting (5-10 years): 12.5-37.5 mg daily
- Motion sickness (5-10 years): 12.5 mg daily (at night or 1-2 hours before travel)
Administration
- May be taken with or without food; take at a fixed time
- Swallow tablet whole; do not chew, crush, or break
Missed dose
If you miss a dose, take it as soon as you remember; skip if it's almost time for next dose; do not double the dose.
Side effects
Side Effects:
- Dry mouth
- Blurred vision
- Headache
- Dizziness
- Drowsiness
- Extrapyramidal effects (muscle spasms, tic-like movements of head and face)
- Anaphylaxis
- Jaundice
- Blood dyscrasias
- Photosensitivity
Precautions & warnings
- May affect driving ability; do not drive if drowsy or dizzy
- Avoid alcohol (excessive drowsiness)
- May increase sensitivity to sunlight; use sunscreen
- Do not use for more than 7 days
- Discontinue 72 hours before allergy testing
Contraindications
- Hypersensitivity to promethazine or phenothiazines
- Coma
- Porphyria
- Cardiac disease
- Hypokalemia
- Intra-arterial or SC injection
Drug interactions
- Aminoglycoside antibiotics: Masks ototoxicity
- Alcohol, hypnotics, barbiturates, opioids: Enhanced sedative effects
- Drugs that prolong QT interval: Ventricular arrhythmias
Food interactions
Alcohol with Promethazine Theoclate may cause excessive drowsiness.
Use in pregnancy
Use in Pregnancy: May be unsafe during pregnancy; animal studies have shown harmful effects; use only if clearly needed.
Pregnancy Category: C — always consult a doctor before taking during pregnancy.
Use in lactation
Use in Lactation: Probably safe; limited human data suggests no significant risk; observe baby for excessive sleepiness with prolonged or repeated doses.
Pediatric use
Caution in children under 5 years; consult your doctor.
Geriatric use
Elderly are particularly susceptible to anticholinergic effects and confusion; caution required.
Renal / hepatic impairment
Renal Impairment: Safe in kidney disease; dose adjustment may not be needed; severe kidney disease may cause excessive sleepiness; consult your doctor.
Hepatic Impairment: Caution in liver disease; dose adjustment may be needed; consult your doctor.
Overdose effects
Overdose: Children: excitation, ataxia, athetosis, hallucinations; Adults: drowsiness, coma; convulsions may occur; treatment: ipecacuanha or gastric lavage, supportive care, diazepam for convulsions.
Storage conditions
Protect from light; do not use after expiry date; keep out of reach of children.
Chemical structure
Promethazine Theoclate