Diphenhist

Diphenhist is an antihistamine that helps with sneezing, runny nose, watery eyes, hives, skin rash, itching, and other cold or allergy symptoms.

Diphenhist is also used to help with motion sickness, to help you sleep, and to treat some symptoms of Parkinson's disease. This sleep aid is not for use in children younger than 12 years old.

There are many brands and forms of diphenhydramine available. Not all brands are included in this leaflet.

Diphenhist may also be used for other purposes that are not listed in this medication guide.

Use exactly as directed on the label, or as prescribed by your doctor. Diphenhist is only for short-term use until your symptoms go away.

Taking too much Diphenhist can lead to serious heart issues, seizures, coma, or death.

Always follow the instructions on the medicine label when giving Diphenhist to a child. Do not use the medicine only to make a child sleepy. Death can happen from the misuse of antihistamines in very young children.

For motion sickness, take Diphenhist 30 minutes before you expect to experience motion sickness (like during a long car ride, airplane or boat travel, amusement park rides, etc). Keep taking this medicine with meals and at bedtime for the duration of your motion-sickness situation.

As a sleep aid, take Diphenhist within 30 minutes before going to bed.

You must chew the chewable tablet before swallowing it.

Measure the liquid medicine carefully. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).

Remove an orally disintegrating tablet from the package only when you are ready to take the medicine. Place the tablet in your mouth and let it dissolve, without chewing. Swallow several times as the tablet dissolves.

Call your doctor if the condition you are treating with Diphenhist does not get better, or if you have a fever along with a headache, cough, or skin rash.

Do not use Diphenhist for more than 2 weeks to treat sleep issues, or for more than 7 days to treat cold or allergy symptoms.

Diphenhist can affect the results of allergy skin tests. Inform any doctor who treats you that you are using Diphenhist.

Store at room temperature, away from moisture and heat.

Use Diphenhist exactly as directed. Taking too much Diphenhist can lead to serious heart problems, seizures, coma, or death.

Do not use this medicine to make a child sleepy. Diphenhist sleep aid medicine is not for use in children younger than 12 years old.

You should not use Diphenhist if you are allergic to it.

Ask a doctor or pharmacist if this medicine is safe to use if you have ever had:

• an enlarged prostate or problems urinating;
• asthma, chronic obstructive pulmonary disease (COPD), or other breathing issues;
• glaucoma; or
• a thyroid condition.

Ask a doctor before using this medicine if you are pregnant or breastfeeding. Diphenhist may slow down breast milk production.

Get emergency medical help if you have signs of an allergic reaction: hives; trouble breathing; swelling of your face, lips, tongue, or throat.

Diphenhist may cause serious side effects. Stop using Diphenhist and call your doctor right away if you have:

• severe drowsiness; or
• painful or difficult urination.

Side effects like dry mouth, constipation, and confusion may happen more often in older adults.

Common side effects of Diphenhist may include:

• drowsiness;
• dry eyes, blurred vision;
• dry mouth, nose, or throat;
• less urination;
• constipation;
• feeling restless or excited (especially in children); or
• daytime drowsiness or a "hangover" feeling after using it at night.

This is not a complete list of side effects and others may happen. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Since Diphenhist is taken as needed, you may not have a regular dosing schedule. If you miss a dose and it's almost time for your next dose, skip the missed dose. Do not take two doses at the same time.

Seek emergency medical help or call the Poison Help line at 1-800-222-1222. Taking too much diphenhydramine can be deadly.

Signs of an overdose may include vomiting, confusion, extreme drowsiness, ringing in your ears, not being able to urinate, very dry eyes and mouth, enlarged pupils, rapid heartbeat, shaking, agitation, hallucinations, or seizures.

Avoid driving or doing anything dangerous until you understand how Diphenhist affects you. Your reactions might be slowed down.

Drinking alcohol can make some side effects of diphenhydramine worse.

Check with a doctor or pharmacist before using any other medicine that could have Diphenhist in it. This includes medicines for sleep, cold/allergy symptoms, or anti-itch creams for the skin. Taking too much of this medicine could cause a fatal overdose.

Ask a doctor or pharmacist before using Diphenhist with any other medicines, especially those that can cause drowsiness (such as opioid medication, sleep medicine, a muscle relaxer, or medicine for anxiety or seizures). Inform your doctor about all your current medicines and any medicine you start or stop using. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here.