Diphenhydramine

Pronunciation: DYE-fen-HYE-dra-meen
Generic Name: Diphenhydramine
Brand Name: Unisom SleepMelts

Diphenhydramine is used for:

Treating occasional sleeplessness and reducing difficulty falling asleep.

Diphenhydramine is an antihistamine. It works in the brain to cause drowsiness.

Do NOT use Diphenhydramine if:

• you are allergic to any ingredient in Diphenhydramine or to other similar medicines


• you are taking sodium oxybate (GHB)


• you are using any other product that contains diphenhydramine (including products used on the skin)


• you are taking or have taken a monoamine oxidase inhibitor (MAOI) (eg, phenelzine) within the last 14 days


• you are breast-feeding

Contact your doctor or health care provider right away if any of these apply to you.

Before using Diphenhydramine:

Some medical conditions may interact with Diphenhydramine. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

• if you are pregnant, planning to become pregnant, or are breast-feeding


• if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement


• if you have allergies to medicines, foods, or other substances


• if you have asthma, chronic obstructive pulmonary disease (COPD), chronic bronchitis, emphysema, lung disease, shortness of breath, or sleep apnea


• if you have blockage of the stomach, intestine, or urinary tract; difficulty urinating; diabetes; ulcers; an enlarged prostate; glaucoma; heart disease; high blood pressure; porphyria; or thyroid disease

Some MEDICINES MAY INTERACT with Diphenhydramine.

• Sodium oxybate (GHB) because an increase in sleep duration and a decrease in the ability to breathe are likely to occur


• MAOIs (eg, phenelzine) because they can cause serious, sometimes fatal, reactions. Do NOT take MAOIs within 2 weeks of taking Diphenhydramine


• Beta-blockers (eg, propranolol) because the risk of their side effects may be increased by Diphenhydramine

This may not be a complete list of all interactions that may occur. Ask your health care provider if Diphenhydramine may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

How to use Diphenhydramine:

Use Diphenhydramine as directed by your doctor. Check the label on the medicine for exact dosing instructions.

• Take Diphenhydramine by mouth with or without food


• Place the medicine on your tongue. Allow it to dissolve in the mouth and then swallow. You may also chew the medicine before swallowing. Diphenhydramine can be taken with or without water.


• Use Diphenhydramine exactly as directed on the package, unless instructed differently by your doctor.


• Take at least 30 minutes before bedtime to help fall asleep.


• If you miss a dose of Diphenhydramine and you are taking it regularly, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.

Ask your health care provider any questions you may have about how to use Diphenhydramine.

Important safety information:

• Diphenhydramine may cause drowsiness or dizziness. These effects may be worse if you take it with alcohol or certain medicines. Use Diphenhydramine with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.


• Do not drink alcohol or use medicines that may cause drowsiness (eg, sleep aids, muscle relaxers) while you are using Diphenhydramine; it may add to their effects. Ask your pharmacist if you have questions about which medicines may cause drowsiness.


• Diphenhydramine may cause dizziness, lightheadedness, or fainting; alcohol, hot weather, exercise, or fever may increase these effects. To prevent them, sit up or stand slowly, especially in the morning. Sit or lie down at the first sign of any of these effects.


• Do not become overheated in hot weather or while you are being active; heatstroke may occur.


• Diphenhydramine may cause you to become sunburned more easily. Avoid the sun, sunlamps, or tanning booths until you know how you react to Diphenhydramine. Use a sunscreen or wear protective clothing if you must be outside for more than a short time.


• Diphenhydramine has diphenhydramine in it. Before you start any new medicine, check the label to see if it has diphenhydramine in it too. If it does or if you are not sure, check with your doctor or pharmacist.


• If sleeplessness persists for more than 2 weeks, contact your health care provider.


• Use Diphenhydramine with caution in the ELDERLY; they may be more sensitive to its effects, especially dizziness, sedation, and lightheadedness upon standing.


• Diphenhydramine should not be used in CHILDREN younger than 12 years old; safety and effectiveness in these children have not been confirmed.


• PREGNANCY and BREAST-FEEDING: If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using Diphenhydramine while you are pregnant. Diphenhydramine is found in breast milk. Do not breast-feed while taking Diphenhydramine.

Possible side effects of Diphenhydramine:

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:

Dizziness; drowsiness; dry mouth, throat, and nose; thickening of mucus in nose or throat.

Seek medical attention right away if any of these SEVERE side effects occur:

Severe allergic reactions (difficulty breathing; hives; itching; tightness in the chest; rash; swelling of the mouth, face, lips, or tongue); decreased alertness; excitability; fast heartbeat; hallucinations; seizures; tightness or pounding in the chest; tremor; wheezing.

This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088. You may also report side effects at http://www.fda.gov/medwatch .

If OVERDOSE is suspected:

Contact 1-800-222-1222 (the American Association of Poison Control Centers), your local poison control center, or emergency room immediately. Symptoms may include coma; excitement; hallucinations; loss of consciousness; muscle twitching; seizures; tremor; weakness.

Proper storage of Diphenhydramine:

Store Diphenhydramine at room temperature, between 68 and 77 degrees F (20 and 25 degrees C), or according to the directions on the package label. Store in the original package or container. Store away from heat, moisture, and light. Do not store in the bathroom. Keep Diphenhydramine out of the reach of children and away from pets.

General information:

• If you have any questions about Diphenhydramine, please talk with your doctor, pharmacist, or other health care provider.


• Diphenhydramine is to be used only by the patient for whom it is prescribed. Do not share it with other people.


• If your symptoms do not improve or if they become worse, check with your doctor.


• Check with your pharmacist about how to dispose of unused medicine.

This information is a summary only. It does not contain all information about Diphenhydramine. If you have questions about the medicine you are taking or would like more information, check with your doctor, pharmacist, or other health care provider.

Issue Date: February 1, 2012

Database Edition 12.1.1.002

Copyright © 2012 Wolters Kluwer Health, Inc.

More Diphenhydramine resources

• Diphenhydramine Use in Pregnancy & Breastfeeding
• Drug Images
• Diphenhydramine Drug Interactions
• Diphenhydramine Support Group
• 58 Reviews for Diphenhydramine - Add your own review/rating

• Diphenhydramine Prescribing Information (FDA)


• Benadryl Consumer Overview


• Children's Allergy Prescribing Information (FDA)


• Diphen Advanced Consumer (Micromedex) - Includes Dosage Information


• Diphenhydramine Hydrochloride Monograph (AHFS DI)


• Diphenoxylate Hydrochloride Monograph (AHFS DI)

Compare Diphenhydramine with other medications

• Allergic Reactions
• Cold Symptoms
• Cough
• Extrapyramidal Reaction
• Hay Fever
• Insomnia
• Motion Sickness
• Nausea/Vomiting
• Pruritus
• Urticaria