Answer the side-effect intent for hypotone without diagnosing; distinguish common from serious reactions and give safe next-step/reporting guidance.
Source
Clinical statements on this page are taken from the SAHPRA-approved patient information leaflet (approved 01/03/2013) and professional information (approved 01/03/2013) for this product: patient information leaflet, professional information. Retrieved 2026-09-03. Where this page and the approved leaflet differ, the leaflet is correct.
What is Hypotone?
Hypotone contains the active ingredient Anhydrous methyldopa.
- Active ingredient — Anhydrous methyldopa
- Registration number — K/7.1.3/209; K/7.1.3/90
- Registration holder — PHARMACARE LIMITED
It is approved for:
- HY-PO-TONE belongs to a group of medicines called anti-hypertensives, which lower blood pressure
- HY-PO-TONE tablets are used to treat high blood pressure (hypertension)
Common side effects of Hypotone
Not everyone gets side effects. The effects below are those listed in the South African approved leaflet, grouped using the leaflet’s own frequency wording.
About these frequency terms
This leaflet groups effects on the very common/common/uncommon scale.
Reported side effects
- Allergic reactions: inflammation of heart muscle or the sac surrounding the heart, skin rash which may be red and/or scaly, fever
- HY-PO-TONE may alter the numbers and types of your blood cells and cause a rise in urea in the blood. If you notice increased bruising, nosebleeds, sore throat, infections or fever, you should tell your doctor who may want to give you a blood test
- Drowsiness, headache, loss of strength or weakness, tingling or pins and needles, trembling and shuffling walk, partial paralysis of the face, involuntary jerky movements, mental changes including nightmares, confusion, depression, dizziness, lightheadedness, reduced blood flow to the brain
- Slow heart rate and low blood pressure, worsening of existing heart pain, low blood pressure causing dizziness on standing, water retention causing swelling and weight gain
- Blocked/stuffy nose
- Feeling or being sick, bloated stomach, constipation, wind, diarrhoea, inflammation of the large bowel, mild dryness of the mouth, sore or “black” tongue, inflamed salivary glands and inflammation of the pancreas (pancreatitis)
- Tell your doctor immediately if you get very severe abdominal pains
- Liver: abnormal liver function, hepatitis (inflammation of the liver), jaundice (yellowing of the skin and/or whites of the eyes). These would be detected by a blood test
- Skin: eczema (scaly and itchy rashes), hard skin rash (lichenoid), severe rash involving reddening, peeling and swelling of the skin that resembles severe burns (toxic epidermal necrolysis)
- Muscles and bones: joint pain with or without swelling. Muscle pain or cramps
- Reproductive system and breasts: absence of menstrual periods, swelling of breasts in men and women, production of breast milk, failure to ejaculate, decreased sex drive, failure to maintain an erection (impotence). Not all side effects reported for HY-PO-TONE are included in this leaflet. Should your general health worsen or if you experience any untoward effects while taking HY-PO-TONE, please consult your healthcare provider for advice
Serious side effects and warning signs
This leaflet does not set out a separate list of serious side effects. The general warning signs below apply to any medicine.
General warning signs that apply to any medicine
Call for emergency help now if any of these happen
- Difficulty breathing, wheezing, or tightness in the throat or chest
- Swelling of the face, lips, tongue or throat
- A widespread rash with blistering or peeling skin, or sores in the mouth, eyes or genitals
- Fainting, collapse, or a sudden severe drop in alertness
- Chest pain, or sudden weakness or numbness on one side of the body
- A fit (seizure), or confusion that comes on suddenly
In South Africa call 10177 for an ambulance, or 112 from a mobile phone. Go to your nearest emergency department if it is faster. Do not wait to see whether the symptom settles.
How long can side effects last?
How long a side effect lasts depends on the effect, the product, how long it has been used, and the person. Some effects ease within days as the body adjusts. Others continue for as long as the product is used. A few can persist after stopping, and some need review rather than waiting.
- Settling effects — mild effects that ease over the first days or weeks of use
- Ongoing effects — effects that continue while the product is being used and improve after stopping
- Persistent effects — effects that continue after stopping and need medical review
- Delayed effects — effects that appear after weeks or months rather than immediately
Which of these applies to a particular effect is a clinical question. If a side effect is not settling, is getting worse, or is affecting your daily life, that is worth a conversation with a pharmacist or doctor regardless of how long it has been going on.
Evidence required before publish — source the following for Hypotone from the SAHPRA-approved patient information leaflet or professional information, and cite what you actually used.
- Anything the approved information for Hypotone says about how long specific effects last
- Whether the source describes any effect as usually temporary, or as needing review if it persists
- Whether any effect is described as continuing after the product is stopped
Factors that may affect side effects
The approved leaflet identifies the following cautions and factors.
Do not use it at all if
- Are allergic (hypersensitive) to methyldopa or any of the other ingredients
- Have liver disease, or if your kidneys do not function properly
- Have high blood pressure due to a tumour near the kidney (phaeochromocytoma)
- Suffer from depression
- Suffer from porphyria
- Are taking medicines for depression called monoamine oxidase inhibitors such as moclobemide or selegiline
Use with care, and tell your doctor, if
- Develop and unexplained fever
- Are going to have a blood transfusion
- Are going to have an operation in which you will be given anesthesia
- HY-PO-TONE may cause darkening of the colour of your urine
- Are taking other medicines such as imipramine, monoamine oxidase inhibitors (MAOI’s)
Pregnancy and breastfeeding
- The safety of HY-PO-TONE while pregnant and breastfeeding has not been established
- Always tell your healthcare provider if you are taking any other medicine
- If you are pregnant or breastfeeding your baby, please consult your healthcare provider for advice before taking HY-PO-TONE
- HY-PO-TONE is distributed into breast milk in small amounts
- Driving and using machinery HY-PO-TONE may make you feel drowsy
- Make sure you are not affected before you drive or operate machinery
Interactions and medicines to check
The approved leaflet names these interactions.
- Medicines used to treat high blood pressure
- if you are taking lithium as lithium toxicity may occur
- if you are using hepatotoxic medicines such as halothane; the combination is not advisable
- medicines used to treat depression like tricyclic antidepressants as the blood pressure lowering effect may be diminished. Always tell your healthcare provider if you are taking any other medicine (this includes complementary or traditional medicines)
Bring the actual products to the conversation
A pharmacist can check for interactions much faster from the packaging than from remembered names.
What to do if you experience side effects
If you think you are having a side effect, the response depends on how severe it is. Use the warning signs above first — if any of those apply, treat it as urgent.
If the symptom is severe or frightening
Get medical help immediately. Call 10177 for an ambulance, or 112 from a mobile phone, or go to the nearest emergency department. Take the product and its packaging with you if you can.
If the symptom is mild but bothering you
- Write down what the symptom is, when it started, and how it relates to when you take the product
- Check the leaflet that came with the product to see whether the symptom is listed
- Speak to your pharmacist — for many questions this is the fastest route to a useful answer
- Contact the prescriber if the symptom is affecting your daily life or is not settling
Do not stop a prescribed treatment on your own
Stopping some treatments suddenly causes its own problems, and the condition being treated may get worse. If you want to stop, ask a pharmacist or doctor how to do it safely — they can usually offer an alternative.
You can also report a suspected side effect in South Africa. Reporting does not replace getting medical advice, and you do not need to be certain the product was the cause.
When to seek urgent medical help
Some symptoms need medical attention straight away rather than an appointment in a few days. Do not wait to see whether they settle.
Call for emergency help now if any of these happen
- Difficulty breathing, wheezing, or tightness in the throat or chest
- Swelling of the face, lips, tongue or throat
- A widespread rash with blistering or peeling skin, or sores in the mouth, eyes or genitals
- Fainting, collapse, or a sudden severe drop in alertness
- Chest pain, or sudden weakness or numbness on one side of the body
- A fit (seizure), or confusion that comes on suddenly
In South Africa call 10177 for an ambulance, or 112 from a mobile phone. Go to your nearest emergency department if it is faster. Do not wait to see whether the symptom settles.
Get same-day medical advice if you have
- A high fever, or a rash together with feeling generally unwell
- Yellowing of the eyes or skin, or unusually dark urine
- Unusual bruising or bleeding that you cannot explain
- Severe or persistent vomiting or diarrhoea, especially if you cannot keep fluids down
- A sudden change in mood, or thoughts of harming yourself
- Any symptom that is rapidly getting worse
If you are having thoughts of harming yourself
Help is available in South Africa. The SADAG helpline is 0800 567 567, or you can go to your nearest emergency department. You do not have to wait until it feels like an emergency.
How to report a suspected side effect in South Africa
South Africa has an official system for reporting suspected side effects, run by the South African Health Products Regulatory Authority (SAHPRA). Reports from the public and from healthcare professionals are how safety signals get detected after a product is already in use.
Who can report
Anyone can report — you do not have to be a healthcare professional, and you do not need to prove that the product caused the problem. A suspicion is enough. Patients, caregivers and family members can all submit a report.
What to have ready
- The name of the product, its strength and form, and the batch number if you have it
- Why it was being used, and when it was started and stopped
- What the suspected reaction was, when it began, and how long it lasted
- Any other medicines, supplements or remedies being used at the same time
- Basic details about the person affected — age and sex are usually enough
How to report
SAHPRA accepts adverse reaction reports through its e-Services reporting system and through the Med Safety mobile app. Healthcare professionals can also report through the same routes. Current forms and access points are published on the SAHPRA site.
- SAHPRA Health Products Vigilance — the main vigilance and reporting hub
- SAHPRA e-Services — current adverse reaction reporting access
Reporting is not a substitute for medical care
If someone is unwell now, get medical help first and report afterwards. Urgent symptoms always take precedence over paperwork.
For a fuller walkthrough see how to report an adverse drug reaction.
Related pages
← Back to more medicine side effects.
Report a side effect
If you think you have had a side effect, you can report a suspected side effect in South Africa. Report a suspected side effect through the appropriate SAHPRA pathway where relevant.
Information only
This page gives general medicine-safety information for people in South Africa. It is not a diagnosis and not personalised medical advice. It cannot tell you whether a symptom you are having is caused by a particular product. Speak to a pharmacist or doctor about your own situation, and do not stop or change a prescribed treatment on the basis of a web page.
Editorial status: draft — not for publication
Brief SE-00500 · build rank 500 · Phase 2 · Tier 2. Every evidence slot on this page must be completed from the SAHPRA-approved source and the page signed off by a qualified clinical or pharmacy reviewer before it is published. Target length 1,300–2,000 words.