Blast is an antihistamine medication. It is used in the treatment of allergy symptoms such as such as itching, swelling and rashes. Blast can be taken one hour before or two hours after food, but take it at the same time to get the most benefit. It should be taken as your doctor's advice. The dose and how often you take it depends on what you are taking it for. Your doctor will decide how much you need to improve your symptoms. Remember dosage is decided on the basis of the type of medicine (tablet or syrup ), age and...