Febrex Plus Tablets 20’s contains Chlorpheniramine 2mg, Paracetamol/Acetaminophen 500mg and Phenylephrine 10mg. Chlorpheniramine is an anti-allergic. Paracetamol is a pain reliever and fever reducer. As a result, it blocks the release of certain chemical messengers in the brain that are responsible for pain and fever. Phenylephrine is a nasal decongestant that narrows the small blood vessels. Therefore, it provides relief from congestion or stuffiness in the nose.