Motion sickness, nausea, vomiting, dizziness, and spinning sensation (vertigo): The usual adult dose of the tablets is 50 mg to 100 mg taken every 4 hours as needed. Do not take more than 400 mg in a 24-hour period. The dose of the long-acting form of dimenhydrinate tablets is 100 mg every 8 to 12 hours, with a maximum of 3 tablets in a 24-hour period. The usual adult dose of dimenhydrinate suppository is 50 mg to 100 mg every 6 to 8 hours as needed.

If you are taking dimenhydrinate for motion sickness, the first dose should be taken at least 30 minutes and preferably 1 to 2 hours before departure.

Pre-radiation therapy (radiation sickness): In adults, 50 mg to 100 mg of dimenhydrinate may be given as a suppository or injection, 30 to 60 minutes before receiving radiation therapy. This dose may be repeated as needed up to a maximum of 400 mg over a 24-hour period.

Surgery: To control nausea and vomiting following surgery in adults, the usual dose is 50 mg to 100 mg taken by mouth or 50 mg of injection into a muscle before surgery. After surgery, similar doses can be used up to a maximum dose of 400 mg in a 24-hour period.

Children:  Follow the dosing instructions provided to you by your doctor or pharmacist or the ones provided with the product being used. Dimenhydrinate should not be used for children or infants under one year old.

For children 2 to 6 years old, the dose of dimenhydrinate liquid or tablets is 15 mg to 25 mg every 6 to 8 hours as needed to a maximum of 75 mg in a 24-hour period. For the suppositories, the dose in this age group is 12.5 mg to 25 mg. Do not give more than one dose of the suppository form unless recommended by your doctor.

For children 6 to 8 years old, the dose of dimenhydrinate liquid or tablets is 25 mg to 50 mg every 6 to 8 hours as needed to a maximum of 150 mg in a 24-hour period. For the suppositories, the dose in this age group is 12.5 mg to 25 mg every 8 to 12 hours as needed.

For children 8 to 12 years old, the dose of dimenhydrinate liquid or tablets is 25 mg to 50 mg every 6 to 8 hours as needed to a maximum of 150 mg in a 24-hour period. For the suppositories, the dose in this age group is 25 mg to 50 mg every 8 to 12 hours as needed.

For children 12 years of age and older, the dose of dimenhydrinate liquid or tablets is 50 mg every 4 to 6 hours as needed to a maximum of  300 mg in a 24-hours period. For the suppositories, the dose in this age group is 50 mg every 8 to 12 hours as needed.

Chewable tablets and liquid are available for children or adults who are unable to swallow the tablets. When using the liquid, use an oral syringe to measure each dose of the liquid as it gives a more accurate measurement than household teaspoons.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are using the medication without consulting your doctor.

It is important to use Dimenhydrinate exactly as recommended by your doctor or pharmacist.

Store Dimenhydrinate at room temperature and keep it out of the reach of children.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.