Alervil Syrup

Pheniramine competes with histamine for the histamine H1 receptor, acting as an inverse agonist once bound. The reduction in H1 receptor activity is responsible for reduced itching as well as reduced vasodilation and capillary leakage leading to less redness and edema. This can be seen in the suppression of the histamine-induced wheal (swelling) and flare (vasodilation) response. Inverse agonism of the H1 receptor in the CNS is also responsible for the sedation produced by first-generation antihistamines like pheniramine. The binding of pheniramine to H4 receptors, and subsequent inverse agonism, may also contribute to reduced itching by antagonizing inflammation.

Doses must be individually determined in all cases and should be taken with or soon after food. Treatment should be commenced at the lowest possible dose because experience has shown that antihistamines are often effective at low doses. The maximum dose of 3 mg/kg per day should not be exceeded. Elderly patients should use the adult dose with caution.

To prevent travel sickness, it is recommended that the first dose be taken at least 30 minutes before traveling. Due to the risk of drowsiness, the patient should not drive a motor vehicle or operate machinery after taking a dose.

Pheniramine Maleate tablets:

• In adults and children over 10 years of age: Treatment is commenced with half a tablet taken up to three times daily. This dose may be increased to one tablet taken up to three times daily if required.
• Children 5-10 years of age: Half a tablet up to three times daily. Pheniramine Maleate tablets are not recommended in children under 5 years of age.