Is diphenhydramine hydrochloride and doxylamine succinate ok together?

Caution Required: Both drugs have similar "mechanisms of action." therefore, the effects they produce are "additive" and, in theory, can pile up to create more effects than would be predicted if each drug were taken by itself...Almost as if 1+1=3! both drugs produce sedation and have anti-histamine properties. So, excessive sleepiness or agitation can happen. Be cautious..Speak to your provider or pharmacist!

Not a good idea: Both drugs are antihistamines that depress the central nervous system. Consequently they are often used as sleep aids. Although these are very safe drugs, they have similar effects on the body so taking both may be like taking twice the dose of one. Overdosage can produce side effects that range from minor (dry mouth, excessive sleepiness) to serious (high blood pressure, nausea) to death.