An analgesic is a drug used to achieve analgesia, relief from pain. Codeine is an important analgesic. A tranquilizer refers to a drug which is designed for the treatment of anxiety, fear, tension, agitation, and disturbances of the mind, specifically to reduce states of anxiety and tension. Phenalzine is a tranquilizer. An antibiotic is a type of antimicrobial substance active against bacteria and is the most important type of antibacterial agent for fighting bacterial infections. Protonsil is an antibiotic. Antihistamines are drugs which treat allergic rhinitis and other allergies. Terfenadine is an antihistamine.