clonidine vs methyldopa
Side-by-side comparison of clonidine and methyldopa Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.
Catapres
Aldomet
Clonidine (Catapres) is a medicine used to treat high blood pressure. It can be used alone or with other blood pressure medicines.
Methyldopa is a medicine used to treat high blood pressure. It helps to lower your blood pressure.
Clonidine is used to treat high blood pressure. High blood pressure can lead to heart disease, stroke, and kidney problems. This medicine helps to lower your blood pressure to a safer level.
Methyldopa is used to treat hypertension, which is also known as high blood pressure. High blood pressure can strain the heart and blood vessels. Lowering blood pressure can reduce the risk of strokes, heart attacks, and kidney problems.
Clonidine works in the brain to lower blood pressure. It tells your blood vessels to relax and widen. This makes it easier for blood to flow through your body, which lowers blood pressure.
Methyldopa lowers blood pressure by affecting certain chemicals in your brain. These chemicals help to relax blood vessels, which allows blood to flow more easily. This results in lower blood pressure.
- • Dry mouth (occurs in about 40 out of 100 people)
- • Drowsiness (occurs in about 33 out of 100 people)
- • Dizziness (occurs in about 16 out of 100 people)
- • Constipation (occurs in about 10 out of 100 people)
- • Feeling sleepy or sedated (occurs in about 10 out of 100 people)
- • Sedation
- • Headache
- • Weakness
- The medicine is not working 3,869
- Pain 3,038
- Tiredness 2,922
- Feeling sick to your stomach 2,918
- Using the medicine for something it's not approved for 2,853
- Baby exposed to drug during pregnancy 1,261
- Baby born too early 888
- Mother exposed to drug during pregnancy 794
- Exposure to drug during pregnancy 654
- Delivery before term 561
If you suddenly stop taking clonidine, your blood pressure may increase. This can cause serious problems. Talk to your doctor before stopping this medicine.
You should not take methyldopa if you have active liver disease like hepatitis or cirrhosis. Also, do not take it if you have had liver problems caused by methyldopa in the past. Do not take it if you are allergic to any of the ingredients in methyldopa. You should not take this medicine if you are taking a monoamine oxidase (MAO) inhibitor.
Tell your doctor if you are pregnant or plan to become pregnant. It is not known if clonidine will harm your unborn baby. Talk to your doctor if you are breastfeeding.
Tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. Methyldopa can pass into breast milk. Talk to your doctor about the risks and benefits.
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How to Read This clonidine vs methyldopa Comparison
clonidine is classified in the Central Alpha-2 Agonist drug class, while methyldopa sits within the Central Alpha-2 Agonist class. Because both drugs share the same classification, they are often considered interchangeable in theory — but clinical outcomes rarely track that cleanly. Both drugs are prescription-only, so a licensed provider must authorize use.
Adverse event totals above are pulled from the FDA's Adverse Event Reporting System (FAERS). For these top-ranked reactions alone, clonidine has 15,600 submissions while methyldopa has 4,158. Those figures reflect cumulative reporting volume — not per-patient risk — so older, widely dispensed drugs typically look worse on count alone. No direct interaction between these two drugs is listed in our FDA-derived dataset, though co-prescription still warrants pharmacist review. Serious warnings, pregnancy guidance, and contraindications can differ even when indications overlap.
A table cannot substitute for clinical judgment. Effectiveness, tolerability, drug-drug interactions with your other medications, kidney and liver function, pregnancy status, insurance formulary, and price all feed into a decision that only a licensed prescriber can make responsibly. Data here is sourced from FDA Structured Product Labels (SPL) and FAERS, both of which update as manufacturers and clinicians submit new information. This page is for educational purposes only, is not medical advice, and should not be used to self-switch between clonidine and methyldopa — always consult your physician or pharmacist first.
Important: This comparison is for informational purposes only. Drug effects vary between individuals. Always consult your doctor or pharmacist for personalized medical advice.