Histan Syrup is an antihistamine medication containing Chlorpheniramine Maleate used to relieve allergy symptoms like sneezing, runny nose, itching, and watery eyes. The syrup comes in a 100ml bottle format suitable for both adults and children over 2 years old. This medication should be taken as prescribed by your doctor. The typical dosage varies by age: adults and children over 12 years take 4mg every 6 hours (max 24mg/day), children 6-12 years take 2mg every 6 hours (max 12mg/day), and children 2-6 years take 1mg every 6 hours (max 6mg/day). Store at room temperature between 20-25°C. Common side effects may include drowsiness. Consult your doctor before use if you have conditions like asthma, liver/kidney disease, or cardiovascular problems.