Promethazine Hydrochloride

Promethazine Hydrochloride is a sedating antihistamine and antiemetic medicine available in Bangladesh under many brand names. Below are its uses, dosage, side effects and precautions — and all brands with their current prices.

• Relief of allergic conditions such as hay fever, urticaria and allergic skin itching.
• Prevention and treatment of motion sickness.
• Management of nausea and vomiting when an antihistamine antiemetic is appropriate.
• Short-term sedation and premedication before or after procedures, as directed by a doctor.
• Adjunctive treatment in severe allergic reactions after emergency measures have been started; it is not a substitute for adrenaline in anaphylaxis.

Adult dosing depends on the indication, route, formulation, age, weight, other medicines and medical conditions. It is commonly given as an oral tablet or syrup, often when sedation is acceptable such as in the evening, or before travel for motion sickness; injections should be administered only by trained healthcare professionals. Follow the exact dose and schedule prescribed by the doctor and do not increase the dose or combine it with other sedatives without medical advice.

• Common: drowsiness, dizziness, dry mouth, blurred vision, constipation, nausea, headache and impaired coordination.
• May cause confusion, agitation or paradoxical excitement, especially in children or older adults.
• Can cause urinary retention, worsening of glaucoma symptoms, low blood pressure or palpitations.
• Serious: breathing depression, severe allergic reaction, severe skin reactions, jaundice, blood disorders, seizures, neuroleptic malignant syndrome, and abnormal movements or muscle stiffness.
• Injection-related serious injury can occur if injected incorrectly, including tissue damage; injections must be given only by qualified staff.

Use extra caution in older adults and in people with asthma or chronic breathing disease, sleep apnoea, epilepsy, liver disease, heart disease, enlarged prostate or urinary retention, narrow-angle glaucoma, stomach obstruction, or a history of severe reaction to antihistamines or phenothiazines. It may cause strong drowsiness; avoid driving, operating machinery and alcohol until its effects are known. Children are more vulnerable to breathing problems and unusual excitement; do not use in children under 2 years. Use under a registered doctor's or pharmacist's guidance.

• Alcohol, sleeping tablets, opioids, benzodiazepines, sedating antidepressants and other CNS depressants can greatly increase drowsiness and breathing depression.
• Other anticholinergic medicines, such as some antihistamines, tricyclic antidepressants, antipsychotics, bladder medicines and Parkinson's medicines, can increase dry mouth, constipation, blurred vision and urinary retention.
• Monoamine oxidase inhibitors may increase anticholinergic and sedative effects.
• Medicines that lower blood pressure may have stronger effects, increasing dizziness or fainting.
• Promethazine may interfere with allergy skin testing; inform the doctor before testing.
• Avoid alcohol while taking this medicine.

• Known hypersensitivity to promethazine, other phenothiazines, or any component of the product.
• Children under 2 years of age because of the risk of fatal respiratory depression.
• Comatose states or severe central nervous system depression.
• Use for lower respiratory tract symptoms, including asthma attacks.
• Promethazine injection must not be given by intra-arterial or subcutaneous routes.

During pregnancy, Promethazine Hydrochloride should be used only when clearly needed and prescribed by a doctor; use near delivery may cause excessive sedation or breathing difficulty in the newborn. During breastfeeding, it may cause infant drowsiness or irritability and may affect milk production, so medical advice is needed before use.

Store at room temperature away from excess heat, moisture and direct light. Keep the container tightly closed and out of the reach of children. Do not use after the expiry date, and have injection products stored and handled according to healthcare facility requirements.