Diphenhydramine Patient Tips
How it works
Diphenhydramine is an antihistamine that works on histamine receptors to block the allergic response.
- Used to treat allergic-type reactions including allergic conjunctivitis, urticaria (hives), and in addition to epinephrine for anaphylactic reactions.
- Also effective at relieving motion sickness.
- Good for controlling symptoms such as sneezing, itching, watery eyes, and runny nose.
- May also be used for elderly people with Parkinson's disease unable to tolerate more potent agents.
- Can be used as a night-time sleep aid.
If you are between the ages of 18 and 60, take no other medication or have no other medical conditions, side effects you are more likely to experience include:
- May cause drowsiness and sedation and impair judgement and affect ability to drive or operate machinery. Avoid alcohol.
- Other reasonably common side effects include dizziness, low blood pressure, a dry mouth, headache, rapid heart beat, disturbed coordination, abdominal symptoms and a thickening of bronchial secretions.
Notes: In general, seniors or children, people with certain medical conditions (such as liver or kidney problems, heart disease, diabetes, seizures) or people who take other medications are more at risk of developing a wider range of side effects. For a complete list of all side effects, click here.
- Do not drive or operate machinery if diphenhydramine makes you drowsy or affects your judgement. Avoid alcohol.
- When using for motion sickness, take diphenhydramine 30 minutes before exposure to motion. Take subsequent doses before meals or bed-time for duration of the exposure.
- Not recommended as a night-time sleep aid for children aged less than twelve.
Response and Effectiveness
Diphenhydramine is quickly absorbed with maximum activity occurring within one hour. Effects of diphenhydramine last from four to six hours.
Diphenhydramine [package insert]. Revised 07/2012. Pharmaceutical Associates, Inc. https://www.drugs.com/pro/diphenhydramine.html Accessed 02/2016
More about diphenhydramine
- Side Effects
- During Pregnancy or Breastfeeding
- Dosage Information
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- Drug class: anticholinergic antiemetics
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- Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use diphenhydramine only for the indication prescribed.
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