Please consult your physician before taking any medication. Generic Name: diphenhydramine (dye fen HYE dra meen) Brand Names: 40 Winks, Aler-Dryl, Banophen, Benadryl, Calm-Aid, Compoz Nighttime Sleep Aid, Diphedryl, Diphen, Genahist, Hydramine, Nu-Med, Nytol Caplet, Quenalin, Scot-Tussin Allergy Relief Formula, Sleep, Sleepinal, Sominex, Twilite, Unisom Sleepgels Maximum Strength What is Nytol Caplet (diphenhydramine)? Diphenhydramine is an antihistamine. Diphenhydramine blocks the effects of the naturally occurring chemical histamine in the body. Diphenhydramine is used to treat sneezing; runny nose; itching, watery eyes; hives; rashes; itching; and other symptoms of allergies and the common cold. Diphenhydramine is also used to suppress coughs, to treat motion sickness, to induce sleep, and to treat mild forms of Parkinson`s disease. Diphenhydramine may also be used for purposes other than those listed in this medication guide.