Medicines & Supplements A to Z > Methyldopa


Last updated on 12/07/2021.

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

GENERIC NAME: Methyldopa



DRUG CLASS: Antihypertensives

SUB CLASS: Alpha-2 agonists

USED FOR: High blood pressure

AVAILABLE DOSAGE FORMS: 125 mg, 250 mg (tablets)

What is Methyldopa for?

Methyldopa belongs to a class of medications called alpha-2 agonists. It is used to treat high blood pressure.

How to use it?

Methyldopa can be taken by mouth, with or without food.

High blood pressure
Initially 250 mg 2-3 times daily. Dose should be increased gradually at intervals of at least 2 days. Maximum dosage is 3 g per day.
Initially 125 mg twice daily. Dose should be increased gradually. Maximum dosage is 2 g per day.

What are the side effects of Methyldopa?

Common side effects of Methyldopa include constipation, diarrhoea, nausea and vomiting, sore tongue, black discoloration of tongue, arthralgia, asthenia, headache, anxiety, depression, amenorrhoea, impotence, nasal congestion, and fever.

Who should not take Methyldopa?

– People allergic to Methyldopa or any component of the formulation.
– People who are taking or took monoamine oxidase inhibitors (MAOIs) within the past 14 days.
– Patients with liver diseases.
– Patients with depression.

Pharmacist Tips:

– This medication can make you dizzy. Avoid driving or operating machinery until you know how you respond to Methyldopa.
– Report any signs and symptoms of adverse cardiac effects such as angina or arrhythmia to your doctor immediately.
– Do not stop the medication abruptly.

Common dosing schedule:
Take Methyldopa at around the same time everyday.

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

Some common medications Methyldopa may interact with:
– Diuretics, e.g. Furosemide, Hydrochlorothiazide
– Sympathomimetics, e.g. Epinephrine, Norepinephrine, Pseudoephedrine
– Tricyclic antidepressants, e.g. Amitriptyline, Doxepin
– Antipsychotics, e.g. Aripiprazole, Risperidone, Olanzapine

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

Where to buy Methyldopa in Hong Kong?

In Hong Kong, Methyldopa 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 Methyldopa 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.