Cetrimol-D contain an analgesic-antipyretic paracetamol with decongestant phenylephrine and an antihistamine Cetirizine Hydrochloride. Paracetamol is a para-aminophenol derivative, produces antipyresis by acting on the hypothalamic heat regulating center and analgesia by elevating the pain threshold. Phenylephrine Hydrochloride is a selective α1-adrenergic receptor agonist used primarily as a decongestant. Cetirizine Hydrochloride is a piperazine derivative. Caffeine is a mild stimulant.