Potential side effects of diphenhydramine include dizziness; drowsiness; nausea; vomiting; and dry mouth, nose and throat, states MedlinePlus. Constipation, headache, nervousness, muscle weakness and increased chest congestion are other side effects, and excitement may also occur, specifically in children. Reporting any severe or persistent side effects to a doctor is recommended.Continue Reading
Diphenhydramine sometimes causes serious side effects that require an immediate call to a doctor, including vision problems and difficult or painful urination, according to MedlinePlus. Because diphenhydramine can cause serious side effects and death in young children, it is not recommended for children younger than 4 years of age. Patients with a history of emphysema, asthma, glaucoma, heart disease or high blood pressure should speak to their doctors before taking diphenhydramine. Certain medications interact with diphenhydramine, including antidepressants, seizure medications, muscle relaxants, narcotic pain medications and sleeping pills.
Diphenhydramine is an antihistamine that treats runny nose, sneezing, and red, itchy or watery eyes caused by allergies or the common cold, explains MedlinePlus. It is also used to relieve cough, prevent and treat motion sickness, treat sleeping problems, and control abnormal movements in people with certain movement disorders. Diphenhydramine works by stopping the action of histamine, which is a substance that leads to allergic reactions.Learn more about Side Effects