Alerid D Tablet is an anti-allergic medicine that is used for the treatment of allergic symptoms like sneezing, runny nose, watery eyes and nasal congestion. It contains a combination of two active ingredients namely levocetirizine and phenylephrine.  Levocetirizine functions by blocking a chemical messenger called histamine that is responsible for  that is responsible for allergic symptoms while phenylephrine is a decongestant which provides temporary relief from congestion or stuffiness in the nose.

Serious side effects of Alerid D Tablet are uncommon, but they may include allergic reactions like rash, itching, swelling of the face, tongue, or throat, or difficulty breathing. Other potential serious side effects include rapid or irregular heartbeat, difficulty urinating, severe headache, or severe dizziness leading to fainting. If you experience any of these symptoms, it's important to seek immediate medical attention. Always consult your doctor if you have concerns about the medication or experience any unusual symptoms while taking it.