Histan Syrup 100mL is an antihistamine medication containing chlorpheniramine maleate used to relieve allergy symptoms such as sneezing, runny nose, itching, rashes, and watery eyes. The liquid syrup formulation comes in a 100mL amber glass bottle for convenient administration. This medication should be stored at room temperature between 20-25°C and kept out of reach of children. It is intended for adults and children over 2 years old, with specific dosing based on age. Common side effects may include drowsiness. Do not take if you have narrow-angle glaucoma, enlarged prostate, urinary/intestinal obstruction, or during acute asthma attacks. Consult your doctor before use if you have liver/kidney disease, seizures, thyroid issues or cardiovascular problems. Avoid alcohol while taking this medication. Seek immediate medical attention if you experience difficulty breathing or severe allergic reactions.