Generic
Phenylephrine + Promethazine
2 brands available in the market
At a glance
Phenylephrine + Promethazine is a combination syrup used for temporary relief of upper respiratory symptoms, including nasal congestion, associated with allergy or the common cold.
Description
Phenylephrine is a potent postsynaptic α-receptor agonist that causes vasoconstriction of nasal mucosal blood vessels, relieving nasal congestion. Promethazine is an H1 receptor-blocking agent that provides antihistaminic, sedative, and antiemetic effects.
Indications
- Upper respiratory symptoms including nasal congestion associated with allergy or common cold
Therapeutic class
Sedating Anti-histamine
Pharmacological class
Antihistamine + Decongestant
Pharmacology
Phenylephrine is an α-adrenergic agonist that constricts nasal mucosal blood vessels to relieve nasal congestion. Promethazine is an H1 receptor antagonist that reduces allergic reactions and provides sedative and antiemetic effects.
Mechanism of action
Phenylephrine constricts blood vessels and promethazine blocks H1 receptors to relieve allergy symptoms.
Dosage
Adults and ≥12 years: 1 teaspoonful (5 mL) every 4-6 hours; max 6 teaspoonfuls (30 mL)/24 hours
6-12 years: ½-1 teaspoonful (2.5-5 mL) every 4-6 hours; max 6 teaspoonfuls (30 mL)/24 hours
2-6 years: ¼-½ teaspoonful (1.25-2.5 mL) every 4-6 hours
Under 2 years: Not recommended
Administration
- Take the prescribed dose every 4-6 hours
- Do not exceed the recommended dose
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:
- Drowsiness/sedation
- Dizziness
- Dry mouth
- Nausea
- Vomiting
- Blurred vision
- Confusion
- Extrapyramidal symptoms
- Increased or decreased blood pressure
- Rash
- Photosensitivity
Precautions & warnings
- May impair driving ability; do not drive if drowsy or dizzy
- Alcohol, narcotic analgesics, sedatives, hypnotics, TCAs, tranquilizers: Additive sedative effects
- Caution in cardiovascular disease, hypertension
- Caution in liver function impairment
- May lower seizure threshold
- Caution in narrow-angle glaucoma, stenosing peptic ulcer, prostatic hypertrophy
Contraindications
- Hypersensitivity to promethazine or other phenothiazines
- Hypertension (phenylephrine)
- Peripheral vascular insufficiency
- Patients receiving MAOI therapy
Drug interactions
- Promethazine: Alcohol, narcotic analgesics, sedatives, hypnotics, TCAs, tranquilizers: Additive sedative effects; barbiturate dose should be reduced by half; morphine/meperidine dose reduced by one-quarter to half
- Phenylephrine: MAOI: Cardiac pressor response potentiated (acute hypertensive crisis); TCAs: Pressor response increased; Ergot alkaloids: Excessive rise in blood pressure; Bronchodilator sympathomimetics/epinephrine: Tachycardia/arrhythmias; Atropine: Pressor response enhanced; β-blockers: Cardio-stimulating effects blocked; α-blockers: Pressor response decreased; Diet preparations (amphetamines/phenylpropanolamine): Synergistic adrenergic response
Food interactions
Caution is advised when consuming alcohol with Phenylephrine + Promethazine.
Use in pregnancy
Use in Pregnancy: Pregnancy Category C; use only if clearly needed.
Pregnancy Category: C — always consult a doctor before taking during pregnancy.
Use in lactation
Use in Lactation: Pregnancy Category C; caution required.
Pediatric use
Not recommended in children under 2 years.
Geriatric use
Caution required in elderly patients; consult your doctor.
Renal / hepatic impairment
Renal Impairment: Caution in kidney disease; consult your doctor.
Hepatic Impairment: Caution in liver disease; consult your doctor.
Overdose effects
Overdose: From mild CNS and cardiovascular depression to profound hypotension, respiratory depression, unconsciousness, sudden death, hypertension, headache, convulsions, cerebral hemorrhage, and vomiting. Treatment: Activated charcoal; sodium or magnesium sulfate as a cathartic.
Storage conditions
Do not store above 30°C; keep away from light; keep out of reach of children.
Chemical structure
Phenylephrine + Promethazine