ACTION AND MECHANISM

- [HISTAMINERGIC ANTAGONIST (H-1)]. Promethazine is a phenothiazine derivative that competitively, reversibly, and nonspecifically blocks H1 receptors, decreasing the systemic effects of histamine. It causes vasoconstriction and decreased vascular permeability, reducing the redness and edema associated with allergies. It partially mitigates symptoms associated with allergic processes such as eye redness or nasal congestion. It also reduces skin itching.

PATIENT ADVICE

PATIENT ADVICE: - Antihistamine products should not be used on children without a prescription. It is also advisable to avoid administration to large areas of skin. - Avoid contact with the eyes and mucous membranes. Wash hands thoroughly after application. If the product accidentally gets into the eyes, rinse thoroughly with water. - Avoid prolonged sun exposure of large areas of treated skin.

CONTRAINDICATIONS

- Hypersensitivity to any component of the medication. Cross-reactions with other antihistamines may occur, so the use of any H1 antihistamine is not recommended in patients who have previously exhibited hypersensitivity to any compound in this group. It is also not recommended for patients with [PHENOTHIAZINE ALLERGY]. - Moist eczema and infected dermatoses.

PREGNANCY

- It is unknown whether promethazine can be absorbed topically. Adequate and well-controlled studies in humans have not been conducted, so its use is only acceptable if the potential benefits outweigh the possible risks and as long as there are no safer therapeutic alternatives.

PHARMACOKINETICS

- Topical route: At the recommended dose, only a very small amount of the active ingredients will be absorbed. Percutaneous absorption of promethazine has not been quantified, and there are no specific data on its pharmacokinetics.

INDICATIONS

- [DERMATITIS] allergic and contact, [BURNS], [ITCHING], [INSECT BITES], [ERYTHEMA] solar and pernio, [DERMATITIS] due to X-rays.

INTERACTIONS

- It could enhance the photosensitizing effects of other active ingredients that lead to photosensitivity reactions.

LACTATION

- It is unknown whether topical promethazine is absorbed in sufficient quantities to be excreted in breast milk, nor are its possible adverse effects on the nursing infant known.

RULES FOR CORRECT ADMINISTRATION

- Apply a thin layer and rub gently.

POSOLOGY

DOSAGE:- Apply the cream 3 or 4 times a day.

PRECAUTIONS

- Avoid application to eroded, bleeding, blistered, wound or exuding skin, as this may result in percutaneous absorption, producing systemic effects.- Promethazine may cause photosensitivity, so it is recommended not to sunbathe during treatment and to protect yourself with sunscreen.- [PORPHYRIA]. H1 antihistamines have been associated with the onset of porphyric flares, so they are not considered safe in these patients.

ADVERSE REACTIONS

- The side effects of promethazine are usually mild and transient, being more frequent during the first days of treatment. There is great interindividual variability with respect to the frequency and intensity of symptoms, affecting mainly young children and the elderly. The most common adverse reactions are: * Allergic/dermatological. [HYPERSENSITIVITY REACTIONS] may rarely appear after topical administration. [PHOTOSENSITIVITY REACTIONS] may also appear after intense exposure to sunlight, with [CONTACT DERMATITIS], [PRURITUS], [EXANTHEMATOUS ERUPTIONS] and [ERYTHEMA]. If the administration of promethazine cream has produced sensitization, administration of its active ingredient, promethazine, by another route may produce cross-sensitization.

OVERDOSE

- Symptoms: Accidental ingestion of a substantial amount may lead to some of the symptoms of an H1-antihistamine overdose, which include: CNS depression with drowsiness (mainly in adults), CNS stimulation and antimuscarinic effects (especially in children), including excitability, ataxia, hallucinations, tonic-clonic spasms, mydriasis, dry mouth, facial flushing, urinary retention, and fever. Hypotension and cardiorespiratory collapse may also occur. - Treatment: There is no specific antidote for antihistamine overdose; usual emergency resuscitation should be carried out, including activated charcoal, saline laxatives, and cardiorespiratory support measures when necessary. Stimulants should not be given. Vasopressors can be used to treat hypotension.

COMPOSITION

PROMETHAZINE (TOPICAL): 20 MILLIGRAMS