Are there any side effects of diphenhydramine?

Side effects of diphenhydramine may include: constipation; dizziness; vomiting; nausea; headaches; dry mouth, nose or throat; nervousness; excitement; diarrhea; loss of appetite; and drowsiness. Serious side effects include: vision problems and painful or difficult urination. If either of these effects should occur, or if you experience an unusual side effect not listed here, you should contact your doctor immediately. Diphenhydramine may cause an allergic reaction. Symptoms of this include: hives; closing of your throat; swelling of face, tongue or lips; increased chest pain; and difficulty breathing. If this should occur, you should contact your doctor immediately.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.