Medicines & Supplements A to Z > Misoprostol


Last updated on 15/07/2021.

Overview   |   Dosage   |    Side Effects   |   Precautions  |   Tips  |   Where To Buy  

GENERIC NAME: Misoprostol


BRAND NAME(S) IN HONG KONG: Cytotec, Medabon

DRUG CLASS: Endocrine Drugs

SUB CLASS: Prostaglandin analogue

USED FOR: Gastric ulcer, Duodenal ulcer, Prevention of NSAID associated ulcers, Abortion

AVAILABLE DOSAGE FORMS: 200 mcg (tablets)

What is Misoprostol for?

Misoprostol belongs to the class of endocrine drugs which resembles prostaglandin produced in our body for the purpose of gastric ulcer, duodenal ulcer, the prevention of NSAID associated ulcers and abortion.

How to use it?

Misoprostol is taken orally as tablets. It should be taken with a meal to minimize diarrhea. Magnesium-containing antacids should also be avoided.

Gastric, duodenal and NSAID-associated ulcers
800 mcg daily in 2-4 divided doses for at least 4 weeks up to 8 weeks even if symptoms are relieved sooner. Additional Misoprostol is administered upon relapse.

Prevention of NSAID-associated ulcers
200 mcg daily 2-4 times daily. Dose may be reduced to 100 mcg 4 times daily in case of intolerance.

Termination of intrauterine pregnancy
Day 1 (Oral Misoprostol): 200 mg once
Day 2 or 3 (Buccal Misoprostol): 800 mg
Day 7-14 (Post-treatment exam): 800 mg buccal Misoprostol for those without complete expulsion

What are the side effects of Misoprostol?

Common side effects of Misoprostol include, but not limited to, diarrhea, abdominal pain, headache, constipation, dyspepsia, flatulence, nausea and vomiting.

Who should not take Misoprostol?

– People who are allergic to Misoprostol or any component of the formulation

For those taking Misoprostol to terminate pregnancy:
– Patients with chronic adrenal failure, porphyrias, hemorrhagic disorder, ectopic pregnancy or undiagnosed adnexal mass
– People on anticoagulants or long-term corticosteroids

Pharmacist Tips:

– Even if the ulcer symptoms are relieved sooner than 4 weeks, Misoprostol should continue to be used

For those taking Misoprostol to terminate pregnancy:
– Confirming the pregnancy is not ectopic
– Remove intrauterine device before taking Misoprostol
– Bear in mind that the first drug Mifepristone is taken orally, while the second drug Misoprostol is taken buccally, which is near the cheek
– Provide the physician in charge with your phone number and name for enquiry and emergencies

Common dosing schedule:
For those taking Misoprostol to counter ulcers, it is to be taken 2-4 times daily depending on the severity of the ulcers with meals. For example, if 600 mg of Misoprostol is to be taken, it should be separated into 3 times daily taken along with your breakfast, lunch and dinner.

For those taking Misoprostol to terminate pregnancy, it is to be taken once on Day 2 or 3.

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

Some common medications Misoprostol may interact with:
– Antacids, e.g. Aluminium hydroxide, Calcium carbonate, Magnesium hydroxide
– Carbetocin
– Oxytocin
– Phenylbutazone

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

Where to buy Misoprostol in Hong Kong?

In Hong Kong, Misoprostol is a prescription only medicine, and requires a prescription from a doctor to be purchased in a pharmacy. 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

Need more information?

For detailed information about the use of Misoprostol 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.