Promethazine Theoclate
Antiemetic & Gastroprokinetic · H1 receptor antagonist
Indications
Motion sickness, nausea, vomiting, vertigo, labyrinthine disorders.
Dosage
Adults: Nausea, vertigo, labyrinthine disorders: 25 mg 1-3 times daily, max 100 mg daily. Motion sickness prevention: 25 mg at bedtime on night before travel or 1-2 hr before travel. Motion sickness treatment: 25 mg at onset then 25 mg at bedtime for 2 days. Children: Under 5 yr, not recommended. Nausea, vomiting, labyrinthine disorders: 5-10 yr, 12.5-37.5 mg daily; 10-18 yr 25-75 mg daily (max 100 mg). Motion sickness prevention: 5-10 yr, 12.5 mg at bedtime on night before travel or 12.5 mg 1-2 hr before travel; 10-18 yr, 25 mg at bedtime on night before travel or 25 mg 1-2 hr before travel. Motion sickness treatment: 5-10 yr, 12.5 mg at onset, then 12.5 mg at bedtime for 2 days; 10-18 yr, 25 mg at onset, then 25 mg at bedtime for 2 days.
Adverse Effects
Urticaria, drug rash, dryness of mouth, nose and throat, headache, drowsiness, restlessness, excitation, nervousness, disorientation, insomnia, euphoria, anorexia, nausea, vomiting, diarrhoea, constipation, hypotension, blurred vision, diplopia, vertigo, tinnitus, palpitation, tachycardia, change in urinary frequency, difficult urination, urinary retention, auditory and visual hallucination (particularly when dosage recommendation are exceeded, cholestatic jaundice). Anticholinergics effects, photosensitivity, hyperexcitability in children.
Risk Factor (Pregnancy/Lactation)
Pregnancy: Risk cannot be ruled out. Lactation: Contraindicated or not recommended. Contraindications: Coma, CNS depression. Precautions: May produce drowsiness, because of their anticholinergic action. Use with caution in patients with narrow angle glaucoma, obstructive disease of the GI or GU tract and in elderly males with possible prostatic hypertrophy. May have hypotensive actions. Asthma, bronchitis, bronchiectasis, severe coronary artery disease, epilepsy, renal or hepatic impairment. Reye's syndrome.
Interactions
CNS depressants, MAOIs, anticholinergics.
Advice to Patient
Use a calibrated device to ensure accurate doses of syrup. Contact prescriber if there is unusual weight gain, unresolved nausea or diarrhoea, chest pain or palpitations, excessive sedation or stimulation, sore throat, respiratory difficulty. Avoid alcohol and other CNS depressants during therapy. Be cautious while driving or doing tasks that require alertness unless full effects of medication are known. Take frequent meals if appetite changes occur. Use sunscreen and avoid direct sunlight to prevent photosensitivity.
Pharmacokinetics
Onset of action: Oral, IM: Approx. 20 min. IV: Approx. 5 min. Duration: Usually 4-6 hrs (up to 12 hrs). Absorption: Oral: Rapid and complete, large first pass effect limits systemic bioavailability. Metabolism: Hepatic. Bioavailability: Oral: Approx. 25%. Rectal: 21.7%-23.4%. Half-life elimination: IM: Approx. 10 hrs. IV: 9-16 hrs. Suppositories, syrup: 16-19 hrs. Time to maximum serum concentration: Oral (syrup): 2.8 ± 1.4 hrs. Rectal: 8.2 ± 3.4 hrs. Excretion: Urine, faeces as inactive metabolites.
Unlicensed Use
Severe vomiting during pregnancy: 25 mg at bedtime increased if necessary to max 100 mg daily.
Brands with this active ingredient
Compiled by Healify Pharmacy from published drug references. How we compile it →
Always consult a pharmacist or doctor.