Avomine25 mg

Avomine is a phenothiazine-derivative antihistamine used mainly for its antiemetic and antivertigo effects.

• Established/guideline-supported uses: Prevention and treatment of nausea, vomiting, and dizziness associated with motion sickness (travel sickness).
• Established use: Symptomatic relief of nausea, vomiting, and vertigo arising from vestibular disorders, including Meniere's disease.
• Established use: Prevention and treatment of post-operative nausea and vomiting, as an adjunct to standard perioperative care.

Avomine is not indicated for the treatment of nausea and vomiting due to unrelated causes (e.g., chemotherapy-induced vomiting) where other agents are preferred.

Each tablet of Promethazine Theoclate contains Promethazine Theoclate INN 25 mg as the active ingredient, along with pharmaceutically approved excipients to form a film-coated or sugar-coated tablet.

Avomine is a phenothiazine derivative that acts as a potent H1-receptor antihistamine with additional anticholinergic and antiemetic properties. The theoclate (teoclate) salt form is used specifically in formulations intended for the prevention and treatment of motion sickness, nausea, vomiting, and vertigo. It is available in Bangladesh as an oral tablet.

Avomine belongs to the therapeutic class of antihistamines (H1-receptor antagonists) with antiemetic and antivertigo activity; it is a phenothiazine-derivative agent used mainly for motion sickness and vestibular disorders.

Promethazine Theoclate works chiefly by blocking histamine H1-receptors in the vomiting centre and vestibular pathways of the central nervous system, thereby suppressing the nausea and vomiting reflex triggered by disturbances of the inner ear (as occurs in motion sickness and vestibular disorders). It also has pronounced central anticholinergic activity, which further reduces vestibular stimulation and contributes to its antivertigo effect, and it produces sedation through central H1 blockade.

After oral administration, Promethazine Theoclate is absorbed from the gastrointestinal tract, undergoes hepatic metabolism, and has a relatively long duration of action, allowing once- or twice-daily dosing in most indications.

Avomine tablets are for oral use. They should be swallowed whole with a glass of water and may be taken with or without food; taking with food may reduce mild stomach upset. For prevention of motion sickness, the dose of Avomine should be timed as advised (the night before, or 1–2 hours before travel) so that peak effect coincides with the journey. Because Avomine can cause drowsiness, the first dose is best taken when the patient does not need to drive or operate machinery afterward.

Avomine has clinically significant interactions with the following:

• CNS depressants (alcohol, sedatives, hypnotics, opioids, benzodiazepines): Concomitant use with Avomine can produce additive central nervous system and respiratory depression; concurrent use should be avoided or closely supervised.
• Monoamine oxidase inhibitors (MAOIs): Concurrent use with Avomine, or use within 14 days of stopping an MAOI, may intensify and prolong the anticholinergic and CNS-depressant effects of Avomine and is generally avoided.
• Other anticholinergic drugs and tricyclic antidepressants: Combining these with Avomine can increase anticholinergic effects such as dry mouth, blurred vision, constipation, and urinary retention.
• Pregnancy testing: Avomine may cause false-positive or false-negative results in some immunologic pregnancy tests based on hCG/LH interaction.

The most common side effects of Avomine relate to its sedating and anticholinergic properties.

• Common: Drowsiness, sedation, dizziness, headache, and psychomotor impairment.
• Anticholinergic effects: Dry mouth, blurred vision, urinary retention, and constipation.
• Less common: Restlessness or paradoxical excitation (particularly in children), nightmares, and photosensitivity skin reactions.
• Rare but serious: Severe respiratory depression (especially in young children – see Contraindications), extrapyramidal reactions, blood dyscrasias, jaundice, and hypersensitivity reactions including anaphylaxis.

Pregnancy: Avomine should be used in pregnancy only if clearly needed and the potential benefit justifies the potential risk to the fetus; use should be under medical supervision. Use of phenothiazine-related compounds, including Avomine, close to delivery has been associated with neonatal irritability and other neonatal effects, so use in the final weeks before delivery should be avoided unless considered essential by a physician.

Lactation: Avomine passes into breast milk in small amounts. Because of the possibility of sedation or irritability in the nursing infant, it should be used during breastfeeding only on the advice of a physician, with the infant monitored for drowsiness or unusual irritability.

Avomine should be used with the following precautions:

• Young children: Severe, potentially fatal respiratory depression has been reported with phenothiazine-type antihistamines in young children; Avomine must not be used under 2 years of age, and the lowest effective dose should be used with caution in older children (see Pediatric Uses).
• Sedation: Avomine can cause drowsiness, dizziness, or impaired coordination; patients should avoid driving or operating machinery until they know how it affects them, and should avoid alcohol.
• Anticholinergic caution: Use with care in patients with narrow-angle glaucoma, prostatic hypertrophy, or urinary retention, as Avomine may worsen these conditions.
• Seizure disorders: Avomine may lower the seizure threshold; use cautiously in patients with a history of epilepsy or other seizure disorders.
• Cardiac, hepatic, or renal disease: Use Avomine with caution and physician guidance in patients with significant cardiac, liver, or kidney impairment.
• Photosensitivity: Avomine may increase sensitivity to sunlight; sun protection is advised during treatment.
• Diagnostic interference: Avomine should be discontinued about 72 hours before allergy skin testing and may interfere with certain pregnancy test results (see Interactions).

Overdose with Avomine is a medical emergency. In children, overdose may present with excitation, hallucinations, involuntary movements, and convulsions; in adults, marked drowsiness, confusion, and coma are more typical, and convulsions may also occur in either age group. Severe overdose can cause dangerous respiratory depression and cardiovascular effects.

Anyone suspected of having taken an overdose of Avomine should seek immediate medical attention or contact emergency services/a poison control center without delay. Treatment is supportive and should be provided in a hospital setting, with monitoring and support of breathing and circulation as needed; specific decisions about gastric decontamination should be made only by treating medical professionals.

Store Avomine at room temperature (below 30°C), protected from light and moisture. Keep out of the reach and sight of children.

Renal/hepatic impairment: Avomine should be used with caution and under medical supervision in patients with significant renal or hepatic impairment, as reduced clearance may increase sedative and anticholinergic effects; no formally established dose-adjustment schedule exists, so dose should be individualized.

Elderly: Elderly patients may be more sensitive to the sedative, anticholinergic, and hypotensive effects of Avomine; the lowest effective dose is recommended.

Pediatric: See Pediatric Uses.

Pregnancy and lactation: See Pregnancy and Lactation.

For motion sickness prevention, Avomine is typically used for the duration of travel only (a single dose or a few doses around the journey). For vertigo or vestibular disorders such as Meniere's disease, treatment with Avomine is usually short-term and symptom-directed, with the need for continued use reassessed periodically by a physician rather than used as an indefinite daily medication.

Phenothiazine derivative; H1-receptor antihistamine; antiemetic/antivertigo agent.

Promethazine Theoclate competitively blocks histamine at H1-receptors in the central vomiting centre and vestibular nuclei, interrupting the signalling pathway that triggers nausea and vomiting from vestibular (inner ear) disturbance. Its strong central anticholinergic activity further dampens vestibular input, contributing to its effectiveness against vertigo, while its antihistaminic action in the brain also produces the sedation commonly seen with Promethazine Theoclate.

Use of Avomine in children requires strict age-based caution because of the risk of severe respiratory depression in young children.

• Under 2 years: Avomine is contraindicated; safety and efficacy have not been established, and there is a recognized risk of severe, potentially fatal respiratory depression.
• 2 to under 5 years: Avomine should be avoided or used only under close medical supervision at the lowest effective dose, given the same respiratory depression concerns.
• 5 to 10 years: Half the adult dose of Avomine is generally used, under medical guidance.
• 10 years and older: The adult dose of Avomine may generally be used.