Diphenhydramine Oral (patient information)
Why this medication is prescribed
Diphenhydramine, an antihistamine, relieves red, irritated, itchy, watery eyes; sneezing; and runny nose caused by hay fever, allergies, and the common cold. It also may relieve the itching of insect bites, sunburns, bee stings, poison ivy, poison oak, and minor skin irritation. Diphenhydramine is also used to prevent and treat motion sickness, induce sleep, treat Parkinson's disease, and relieve cough caused by minor throat or airway irritation.
This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.
How this medication should be used
Diphenhydramine comes as a tablet, capsule, and liquid to take by mouth. It usually is taken three or four times a day. For motion sickness, diphenhydramine is taken 30 minutes before departure and, if needed, before meals and at bedtime. Diphenhydramine is taken at bedtime for sleep. Follow the directions on the package or on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take diphenhydramine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
Do not give diphenhydramine to a child younger than 6 years of age unless directed to do so by a doctor.
Special precautions
Before taking diphenhydramine:
- tell your doctor and pharmacist if you are allergic to diphenhydramine or any other drugs.
- tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially other medications for colds, hay fever, or allergies; medications for depression or seizures; muscle relaxants; narcotics (pain medications); sedatives; sleeping pills; tranquilizers; and vitamins.
- tell your doctor if you have or have ever had asthma, lung disease, glaucoma, ulcers, difficulty urinating (due to an enlarged prostate gland), heart disease, high blood pressure, seizures, or an overactive thyroid gland.
- tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking diphenhydramine, call your doctor.
- if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking diphenhydramine.
- you should know that this drug may make you drowsy. Do not drive a car or operate machinery until you know how this drug affects you.
- remember that alcohol can add to the drowsiness caused by this drug.
What to do if you forget a dose
Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.
Side effects
Minor side effects
Diphenhydramine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- dry mouth, nose, and throat
- drowsiness
- upset stomach
- chest congestion
- headache
Severe side effects
If you experience any of the following symptoms, call your doctor immediately:
- vision problems
- difficulty urinating
- muscle weakness
- excitement (especially in children)
- nervousness
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at http://www.fda.gov/MedWatch/report.htm] or by phone [1-800-332-1088].
Storage conditions needed for this medication
Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.
In case of emergency/overdose
In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.
Other information
Keep all appointments with your doctor.
Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.
Brand names
- AllerMax®
- AllerMax® Caplets®
- Benadryl®
- Benadryl® Allergy
- Benadryl® Allergy Chewables Children' s
- Benadryl® Allergy Kapseals®
- Benadryl® Allergy Ultratab®
- Benadryl® Dye-Free Allergy Children' s
- Benadryl® Dye-Free Allergy Liqui-Gels®
- Compoz® Nighttime Sleep Aid
- Compoz® Nighttime Sleep Aid Gelcaps®
- Diphen® AF Elixir
- Diphenhist®
- Diphenhist® Captabs®
- Diphenhydramine Hydrochloride Caplets®
- Excedrin P.M.® Caplets®
- Excedrin P.M.® Geltabs®
- Excedrin P.M.® Tablets
- Genahist®
- Genahist® Elixir
- Goody's® PM Powder
- Hydramine® Cough Syrup
- Hydramine® Elixir
- Miles® Nervine Nighttime Sleep-Aid
- Nytol® QuickCaps® Caplets®
- Nytol® Quickgels® Maximum Strength
- Simply Sleep® Nighttime Sleep Aid Caplets®
- Sleepinal® Night-time Sleep Aid Softgels®
- Sominex® Caplets®Maximum Strength
- Sominex® Nighttime Sleep Aid
- Twilite® Caplets®
- Unisom® SleepGels® Maximum Strength
Brand names of combination products
- Alka-Seltzer PM® Pain Reliever and Sleep Aid containing Diphenhydramine Citrate and Aspirin
- Bayer® PM Extra Strength Caplets® containing Diphenhydramine Hydrochloride and Aspirin
- Benadryl® Allergy & Cold Caplets® containing Diphenhydramine Hydrochloride, Acetaminophen, and Pseudoephedrine Hydrochloride
- Benadryl® Allergy & Cold Fcontaining Diphenhydramine Citrate and Pseudoephedrine Hydrochloride
- Benadryl® Allergy & Sinus containing Diphenhydramine Hydrochloride and Pseudoephedrine Hydrochloride
- Benadryl® Allergy & Sinus Children's containing Diphenhydramine Hydrochloride and Pseudoephedrine Hydrochloride
- Benadryl® Allergy & Sinus Fcontaining Diphenhydramine Citrate and Pseudoephedrine Hydrochloride
- Benadryl® Allergy & Sinus Headache Caplets® Maximum Strength containing Diphenhydramine Hydrochloride, Acetaminophen, and Pseudoephedrine Hydrochloride
- Benadryl® Severe Allergy & Sinus Headache Caplets® Maximum Strength containing Diphenhydramine Hydrochloride, Acetaminophen, and Pseudoephedrine Hydrochloride
- Doan's® P.M. Extra Strength Caplets® containing Diphenhydramine Hydrochloride and Magnesium Salicylate
- Legatrin PM® Caplets® containing Diphenhydramine Hydrochloride and Acetaminophen
- Percogesic® Aspirin-Free Caplets® Extra Strength containing Diphenhydramine Hydrochloride and Acetaminophen
- Sine-Off® Night Time Relief Sinus Cold & Flu Medicine GelCaplets® containing Diphenhydramine Hydrochloride, Acetaminophen, and Pseudoephedrine Hydrochloride
- Sominex® Pain Relief Formula containing Diphenhydramine Hydrochloride and Acetaminophen
- Sudafed® Sinus Nighttime Plus Pain Relief Caplets® containing Diphenhydramine Hydrochloride, Acetaminophen, and Pseudoephedrine Hydrochloride
- Tylenol® Allergy Sinus NightTime Maximum Strength Caplets® containing Diphenhydramine Hydrochloride, Acetaminophen, and Pseudoephedrine Hydrochloride
- Tylenol® Allergy-D Children's containing Diphenhydramine Hydrochloride, Acetaminophen, and Pseudoephedrine Hydrochloride
- Tylenol® Flu NightTime Maximum Strength Gelcaps® containing Diphenhydramine Hydrochloride, Acetaminophen, and Pseudoephedrine Hydrochloride
- Tylenol® PM Extra Strength Caplets® containing Diphenhydramine Hydrochloride and Acetaminophen
- Tylenol® PM Extra Strength Gelcaps® containing Diphenhydramine Hydrochloride and Acetaminophen
- Tylenol® PM Extra Strength Geltabs® containing Diphenhydramine Hydrochloride and Acetaminophen
- Tylenol® Severe Allergy Caplets® containing Diphenhydramine Hydrochloride and Acetaminophen