Dimenhydrinate is an antihistamine that reduces the effects of natural chemical histamine in the body.

Dimenhydrinate is used to treat or prevent nausea, vomiting, and dizziness associated with motion sickness.

Dimenhydrinate may also be used for purposes not listed in this medication guide.

Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

Dimenhydrinate comes as a tablet and chewable tablet to take by mouth with or without food. To prevent motion sickness, the first dose should be taken 30 minutes to 1 hour before you travel or begin motion activity. Adults and children older than age 12 may usually take dimenhydrinate every 4 to 6 hours as needed to prevent or treat motion sickness. Children under age 12 may usually be given dimenhydrinate every 6 to 8 hours as needed to prevent or treat motion sickness. Follow the directions on the package carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take dimenhydrinate exactly as directed. Do not take more or less of it or take it more often than directed by the package label.

Do not give dimenhydrinate to children younger than 2 years of age unless your doctor has told you to do so.

Use exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

For best results, take dimenhydrinate 30 to 60 minutes before traveling or before any activity that may trigger motion sickness.

You may take dimenhydrinate with or without food.

The chewable tablet must be chewed before you swallow it.

If you need surgery, tell the surgeon ahead of time if you have taken dimenhydrinate in the past few days.

Store at room temperature away from moisture and heat.

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

Ask a doctor or pharmacist if it is safe for you to use dimenhydrinate if you have other medical conditions, especially:

• liver or kidney disease;

• enlarged prostate and urination problems;

• heart disease, high pressure;

• a history of seizures;

• blockage in your digestive tract (stomach or intestines);

• overactive thyroid;

• glaucoma; or

• asthma, bronchitis, emphysema, or other breathing disorder.

Do not give this medicine to a child younger than 2 years old. Always ask a doctor before giving an antihistamine to a child. Death can occur from the misuse of antihistamines in very young children.

It is not known whether dimenhydrinate will harm an unborn baby. Do not use this medicine without a doctor's advice if you are pregnant.

It is not known whether dimenhydrinate passes into breast milk or if it could harm a nursing baby. Do not use this medicine without a doctor's advice if you are breast-feeding a baby.

Since dimenhydrinate is used when needed, you may not be on a dosing schedule. If you are on a schedule, use the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not use extra medicine to make up the missed dose.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include extreme drowsiness, irritability, dilated pupils, hallucinations, or seizure. In children, an overdose may cause irritability or restlessness followed by severe drowsiness.

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).

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

Unless your doctor tells you otherwise, continue your normal diet.

Avoid using a topical (for the skin) medicine that contains an antihistamine called diphenhydramine (commonly known as Benadryl).

dimenhydrinate may cause blurred vision and may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert and able to see clearly.

Drinking alcohol with this medicine can cause side effects.

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

Dimenhydrinate may cause serious side effects. Stop using dimenhydrinate and call your doctor at once if you have:

• little or no urination;

• confusion, mood changes;

• tremors, restlessness;

• a seizure (convulsions); or

• fast or irregular heartbeats.

Side effects such as dry mouth, constipation, and confusion may be more likely in older adults.

Common side effects of dimenhydrinate may include:

• drowsiness;

• dry mouth, nose, or throat;

• constipation;

• blurred vision; or

• feeling restless or excited (especially in children).

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

Ask a doctor or pharmacist before using this medicine if you are also using any other drugs, including prescription and over-the-counter medicines, vitamins, and herbal products. Some medicines can cause unwanted or dangerous effects when used together. Not all possible interactions are listed in this medication guide.

Taking this medicine with other drugs that make you sleepy or slow your breathing can worsen these effects. Ask your doctor before taking dimenhydrinate with a sleeping pill, narcotic pain medicine, muscle relaxer, or medicine for anxiety, depression, or seizures.

Ask your pharmacist any questions you have about dimenhydrinate.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.