Promethazine (HCl)
Promethazine (HCl) is antihistimine, used in treatment of allergic rhinitis and allergic conjunctivitis and for prevention of allergic reactions to blood or plasma in patients with a known history of such reactions and also used for pre-operative and post-operative sedation. Promethazine (HCl) is also used as an antiemetic drug to prevent nausea and vomiting.
Primary Characteristics
It is of Synthetic origin and belongs to Phenothiazine.
It belongs to H1-antagonist pharmacological group on the basis of mechanism of action. It is also classified under Antiemetic/Antivertigo Agents .
Molecular Weight: 320.9 · pKa: 9.1 · Solubility in Water: 1 in 9 · Solubility in Alcohol: 1 in 0.6 · Non-proprietary name: Promethazine (HCl).
Pharmacokinetics
Absorption: Promethazine (HCl) has an oral bioavailability is 85% (±5%), pre-systemic (first-pass) metabolism accounts for 75%.
Distribution: Promethazine (HCl) has a volume of distribution is 13.4 l/kg. plasma protein binding is 76-93%.
Elimination: it is metabolised via hepatic, plasma half-life is 7-14 hr, renal excretion is > 0.6%.
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Indications
Promethazine (HCl) is primarily indicated in conditions like Acceleration of myeloid recovery following bone marrow transplantation, Adjunct in ganciclovir treatment, Advanced ovarian cancer, All forms of epilepsy, Allergy, Anaphylactic reactions, Dermatologicals, Haemolytic disease of newborn, Insect bites, Insomnia, Metastatic germ cell cancers (seminoma and teratoma), Motion sickness, Myoclonus, Nausea, vertigo, labyrinthine disorders, NSAID associated ulceration, Parkinsonism, Prevention of hypokalaemia, Severe vomiting in pregnancy, Transcervical operative procedures in first trimester, Urticaria.
Promethazine (HCl) is also indicated for secondary conditions like Epilepsy, Night sedation and insomnia, Pain, Severe nausea, vomiting (acute attacks).
Contraindications
Promethazine (HCl) is contraindicated in conditions like Epilepsy, Glucoma, Prostatic hypertrophy.
Dosage
Promethazine (HCl)'s dosage details are as follows:
| Dose | Single Dose | Frequency | Route | Instructions |
|---|---|---|---|---|
| Adult Dosage | ||||
| 17.5 mg | 17.5 mg | Every 4h | PO.IV,IM | |
| Paediatric Dosage (20kg) | ||||
| 0.75 mg/kg | 0.75 mg/kg | Every 12h | Oral | - |
| Neonatal Dosage (3kg) | ||||
| 0.468 mg/kg | 0.468 mg/kg | Every 12h | Oral | |
Drug Interactions
Always consult your physician for the change of dose regimen or an alternative drug of choice that may strictly be required.
Side Effects
Promethazine (HCl) in overdosage may give rise to further complications which include Pheochromocytoma.
The signs and symptoms that are produced after acute overdosage of Promethazine (HCl) are Seizures, Blurred vision, Respiratory depression, Hallucinations , Delirium, Ataxia, CNS stimulation, Anxiety , Deep sleep, Akathisia , Hyperexcitability .
Promethazine (HCl) is known to cause more or less tolerable side effects which are usually transient. These include Anxiety, Blurred vision, CNS depression, CNS excitation, Confusion, Dry mouth, Incoordination , Insomnia, Nervousness, Sedation .
Warnings / Precautions
Interference in Pathology
Promethazine (HCl) may interfere in the diagnosis of It may interfere with immunological urinary pregnancy tests giving false positive results. .
Available Brands
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Multi-Ingredient Combinations
Storage Conditions
Drug Classification
- 1.3 — Anti-allergics (Antihistamines) and drugs used in anaphylaxis
- 2.17.2 — Antiemetics & antinauseants