Paracetamol is an analgesic (pain reliever) and antipyretic (fever reducer). It blocks the release of certain chemical messengers in the brain that cause pain and fever. Levocetirizine is an antiallergic which relieves allergy symptoms like runny nose, watery eyes and sneezing. Caffeine is a stimulant which increases the effectiveness of paracetamol and decreases sleepiness due to levocetirizine. Phenylephrine is a decongestant which narrows the small blood vessels providing temporary relief from congestion or stuffiness in the nose.