> Western Medicines > Dimenhydrinate


Used for: Vomiting, Vertigo, Nausea, Treatment and prevention of motion sickness
Chinese name:

What is Dimenhydrinate for?

Dimenhydrinate is a sedating (first generation) antihistamine that can be used to treat nausea and vomiting caused by motion sickness.

How to use it?

Dimenhydrinate can be taken by mouth as tablets and syrup or inserted into the rectum as suppositories.


The adult dose is 50-100 mg 3-4 times daily and the maximum daily dose is 400 mg. If you are taking it for prevention of motion sickness, you should take it at least 30 minutes before your trip.


The dose for children between 2 and 5 years old is 12.5-25 mg every 6-8 hours and the maximum daily dose is 75 mg; whereas that for children between 6 and 12 years old is 25-50 mg every 6-8 hours and the maximum daily dose is 150 mg.


For suppositories, you should remove the wrapper, and insert suppository into the rectum.

What are the side effects of Dimenhydrinate?

Common side effects of Dimenhydrinate include drowsiness and dizziness, dry mouth, blurred vision, and constipation. Avoid driving or operating machinery until you know how you respond to Dimenhydrinate.

Who should not take Dimenhydrinate?

  • People with an allergy to Dimenhydrinate or any component of the formulation
  • Children under the age of 2
  • Patients on monoamine oxidase inhibitors (MAOI) or use of MAOIs within the past 14 days

Pharmacist Tips:

  • Dimenhydrinate can cause drowsiness. If affected, do not perform tasks that require mental alertness, such as driving or using machinery.
  • Skin rash is rare. Stop taking Dimenhydrinate if this occurs and report it to your doctor or pharmacist.
  • Avoid taking Dimenhydrinate if you are 65 years and older as you are at higher risk of side effects, such as confusion, dry mouth and constipation.
  • Remove the outer aluminium wrapper of the suppository before use.

Common dosing schedule:
You can take Dimenhydrinate tablets with or without food.

Avoid alcohol while taking this drug.


This schedule is for reference only, adjustments may be made according to individual needs.


Some common medications Dimenhydrinate may interact:

Please notify your doctor or pharmacist if you are taking the above medication, dosage adjustments might be needed.

Where to buy Dimenhydrinate in Hong Kong?

In Hong Kong, Dimenhydrinate is an over-the-counter medicine which can be purchased without a prescription from any retail outlet in Hong Kong. This includes grocery stores, convenience stores, medicine shops, and pharmacies. It can also be obtained from doctors. To find a pharmacy near you, refer to the list of pharmacies (“Authorized Sellers of Poisons”) from the Hong Kong Department of Health.


For more information about drug names and ingredients, you can visit Hong Kong’s Drug Office at https://www.drugoffice.gov.hk

Need more information?

For detailed information about the use of Dimenhydrinate in children, pregnancy and breastfeeding, and for questions about drug interactions, please check with your pharmacist or doctor.

Disclaimer: our goal is to provide you with the most relevant drug information and common dosage for Hong Kong. This information does not constitute medical advice. For specific treatment recommendations and advice, always discuss with your doctor or pharmacist, and follow the instructions included with your specific medicine.

Brands in Hong Kong
Available dosage
  • 15mg/5ml (Syrup)
  • 50mg (Tablets)
  • 50mg (Suppositories)
Drug class
Sub class
Antihistamines (First Generation)
Other drugs in same class
Used for: Hay fever, Asthma, Allergic rhinitis
Chinese name:
Used for: Motion sickness, Vertigo, Peripheral circulatory disorders
Chinese name:
Used for: Urticaria, Upper respiratory allergies
Chinese name:
Chinese name: