PHENERGAN
Generic Name: Promethazine Hydrochloride
Strength & Packaging: 5 mg/5 mL oral solution
Dosage Form: Oral solution
Category: Sedating antihistamine with antiemetic and short-term sedative use. The official UK SmPC identifies this presentation as Phenergan Elixir 5 mg/5 mL Oral Solution, with each 5 mL containing 5 mg promethazine hydrochloride.

Product Name & Packaging

Product Name: Phenergan
Generic Name: Promethazine Hydrochloride
Strength: 5 mg/5 mL
Form: Oral solution
Packaging: The official UK product information describes an amber glass bottle containing 100 mL, fitted with a child-resistant cap. Since your product details only specify the strength, local market pack size should still be verified against the supplied carton.

Description

Phenergan contains promethazine hydrochloride, a phenothiazine-derived antihistamine with additional antiemetic, central sedative, and anticholinergic properties. It is used for symptomatic relief of allergic conditions, for nausea and vomiting, and for short-term sedation-related uses in appropriate patients.

Indications

Indicated for:

Symptomatic treatment of allergic conditions of the upper respiratory tract and skin, including allergic rhinitis and urticaria
Antiemetic use, including travel sickness
Short-term treatment of insomnia in adults
Short-term paediatric sedative use

The patient leaflet also describes use for hay fever, rashes such as hives, nausea, vomiting, and short-term sedation.

Dosage & Administration

Administration: Oral use. Dosage depends on the indication and age group. Official UK prescribing information states:

Allergy:
Children 6–10 years: 10–25 mg as a single dose or 5–10 mg twice daily; maximum 25 mg/day
Children over 10 years and adults: start with 10 mg twice daily, increasing up to 20 mg three times daily if required
Antiemetic / travel sickness:
Children 6–10 years: 10 mg the night before travel, repeated after 6–8 hours if needed
Children over 10 years and adults: 25 mg the night before travel, repeated after 6–8 hours if needed
Short-term insomnia in adults / short-term paediatric sedation:
Children 6–10 years: 20–25 mg at night
Children over 10 years and adults: 25–50 mg at night

The SmPC notes that Phenergan tablets may be more suitable for some higher doses. It also states the medicine should not be used for longer than 7 days without medical advice.

Mechanism of Action

Promethazine is a potent, long-acting antihistamine. It works by blocking histamine-mediated effects involved in allergic reactions and also has central sedative and antiemetic activity, including a direct calming effect on the brain.

Precautions

Important precautions:

Contraindicated in patients with hypersensitivity to promethazine, other phenothiazines, or any component of the formulation
Contraindicated in patients in coma or with CNS depression
Do not use in children under 6 years because of the risk of fatal respiratory depression
Avoid use with MAO inhibitors or within 14 days of stopping an MAOI
Use caution in patients with asthma, bronchitis, epilepsy, liver or kidney impairment, glaucoma, prostate hypertrophy, severe coronary disease, or QT-prolongation risk
Avoid alcohol and other sedative medicines, as sedative effects may be enhanced
The product is not recommended during pregnancy and not recommended during breastfeeding
May cause drowsiness, dizziness, or blurred vision, so driving and machinery use should be avoided if affected.

Side Effects

Very common side effect:

Sedation / somnolence

Other reported side effects may include:

Dizziness and headache
Dry mouth, constipation, and other anticholinergic effects
Blurred vision
Rash and photosensitivity
Agitation, confusional state, or anxiety
Hypotension, palpitations, and rare arrhythmias/QT prolongation
Respiratory depression
Urinary retention and tiredness

Serious hypersensitivity reactions such as anaphylaxis, urticaria, and angioedema have also been reported.

Storage

Storage: Store below 25°C. Keep the bottle in the outer carton to protect it from light. Official UK labeling states a shelf life of 2 years unopened and 1 month after opening.