clonidine
Brand names: Catapres
Clonidine (Catapres) is a medicine used to treat high blood pressure. It can be used alone or with other blood pressure medicines.
Drug Pricing (NADAC)
Generic Price
$5.80/unit
Generic Available
Yes (20 manufacturers)
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
What it does
Clonidine is used to treat high blood pressure.
Common side effects
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)
Key warnings
If you suddenly stop taking clonidine, your blood pressure may increase.
How It Works
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.
How to Take It
Take clonidine exactly as your doctor tells you. The starting dose is usually 0.1 mg twice a day, once in the morning and once at bedtime. Your doctor may increase your dose by 0.1 mg each week until your blood pressure is controlled. You can take it with or without food.
Pregnancy & Breastfeeding
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.
Missed Dose
If you miss a dose, take it as soon as you remember. If it is close to your next dose, skip the missed dose and continue with your regular schedule.
Storage
Store clonidine at room temperature (between 59° to 86°F) in a tightly closed container, away from light.
Side Effects (from patient reports)
Based on 27,604 FDA adverse event reports.
FDA Adverse Event Report Analysis
Detailed analysis of 49,370 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2004–2025.
Total Reports
49,370
Death-Related Reports
5,854
Hospitalization Reports
17,724
Top Indication
Product Used For Unknown Indication
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 1 | DRUG INEFFECTIVE | 3,866 |
| 2 | PAIN | 3,038 |
| 3 | FATIGUE | 2,925 |
| 4 | NAUSEA | 2,920 |
| 5 | OFF LABEL USE | 2,852 |
| 6 | HEADACHE | 2,798 |
| 7 | HYPERTENSION | 2,595 |
| 8 | DYSPNOEA | 2,296 |
| 9 | DIARRHOEA | 2,201 |
| 10 | CHRONIC KIDNEY DISEASE | 2,113 |
| 11 | VOMITING | 2,031 |
| 12 | RENAL FAILURE | 1,916 |
| 13 | DIZZINESS | 1,876 |
| 14 | ACUTE KIDNEY INJURY | 1,818 |
| 15 | BLOOD PRESSURE INCREASED | 1,691 |
Reactions in Death Reports
Reactions in Hospitalization Reports
Source: FDA FAERS (Adverse Event Reporting System) FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation
Serious Warnings
If you suddenly stop taking clonidine, your blood pressure may increase. This can cause serious problems. Talk to your doctor before stopping this medicine.
Known Drug Interactions
( 7.1 , 7.5 ) Hypotensive agents (e.g., reserpine, MAO inhibitors, clonidine) may increase the risk of hypotension and/or severe bradycardia. Concomitant administration of clonidine with a β-blocker may cause hypotension and bradycardia. When concomitant treatment with a β-blocker and clonidine is to be terminated, the β-blocker should be discontinued first.
Mechanism: Both drugs lower blood pressure and slow down the heart rate. Taking them together can make these effects too strong, causing a dangerously slow heart or very low blood pressure.
What to do: Your doctor should monitor your heart rate and blood pressure. If you need to stop these medicines, follow your doctor's specific order to stop the beta-blocker first.
( 7.3 ) Concomitant use of glycosides, clonidine, and diltiazem and verapamil with beta-blockers can increase the risk of bradycardia. ( 7.4 ) Beta-blockers including metoprolol, may exacerbate the rebound hypertension that can follow the withdrawal of clonidine. 7.4 Negative Chronotropes Digitalis glycosides, clonidine, diltiazem and verapamil slow atrioventricular conduction and decrease heart rate.
Mechanism: Both drugs work to slow down your heart rate, which can cause your heart to beat too slowly when taken together. Additionally, stopping one of these drugs suddenly can cause a dangerous rise in blood pressure.
What to do: Your doctor should monitor your heart rate and blood pressure regularly. Do not stop taking either medication without first consulting your healthcare provider.
Examples: beta-blockers, clonidine, guanethidine, and reserpine Clopidogrel : Avoid concomitant use; if used concomitantly initiate at 0.5 mg before each meal and limit total daily dose to 4 mg (7) Cyclosporine : Limit daily dose of repaglinide to 6 mg and increase frequency of glucose monitoring when co-administered (7) CYP2C8 and CYP3A4 Inhibitors and Drugs That May Increase the Risk of Hypoglycemia : Co-administration may require repaglinide dose reductions and increased frequency of glucose monitoring (7) CYP2C8 and CYP3A4 Inducers and Drugs That May Decrease the Blood Glucose Lowering ...
Mechanism: Clonidine can hide the warning signs of low blood sugar and may also cause blood sugar to drop further when taken with repaglinide.
What to do: Your doctor may need to lower your repaglinide dose and you should check your blood sugar levels more often.
7.6 Clonidine Concomitant use with sotalol increases the risk of bradycardia and AV block. Because beta-blockers may potentiate the rebound hypertension sometimes observed after clonidine discontinuation, withdraw sotalol several days before the gradual withdrawal of clonidine to reduce the risk of rebound hypertension.
Mechanism: Both of these medicines slow down your heart rate, which can cause your heart to beat too slowly. Additionally, taking them together can cause a dangerous spike in blood pressure if the clonidine is stopped suddenly.
What to do: If you need to stop these drugs, your doctor should have you stop sotalol several days before you slowly lower your clonidine dose. Monitor your heart rate and blood pressure closely.
Amitriptyline in combination with clonidine enhances the manifestation of corneal lesions in rats (see Toxicology ). In combination with amitriptyline, clonidine hydrochloride administration led to the development of corneal lesions in rats within 5 days.
Mechanism: These drugs may work together to cause damage to the clear front part of the eye.
What to do: Tell your doctor if you notice any eye pain or changes in your vision while taking these medicines.
Common Questions
Can I drink alcohol while taking clonidine?
Will clonidine make me sleepy?
How long does it take for clonidine to start working?
Can I drive while taking clonidine?
What should I do if I feel dizzy while taking clonidine?
Can I take clonidine with other medicines?
What if I have kidney problems?
Can clonidine cause dry eyes?
Is it okay to stop taking this medication if I feel better?
What number can I call if I have questions about this medication?
What are the common side effects of clonidine?
Does clonidine interact with other medications?
What drug class is clonidine?
Is clonidine safe during pregnancy?
Related Medications in Central Alpha-2 Agonist
Other drugs grouped near clonidine — same-class peers and common alternatives.
acebutolol
Sectral
Acebutolol is a medicine that helps lower blood pressure and control irregular heartbeats.
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aliskiren
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Tekturna is a medicine used to treat high blood pressure.
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amiloride
Midamor
Amiloride is a water pill that helps your body hold onto potassium.
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amlodipine
Norvasc
Amlodipine (Norvasc) is a drug that lowers blood pressure and treats chest pain.
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amlodipine/benazepril
Lotrel
Lotrel is a combination medicine that contains amlodipine and benazepril.
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Medication Guides
Understanding Drug Interactions
How CYP450 enzymes, inhibitors, and inducers affect your medications
Generic vs Brand Name Drugs
FDA requirements, cost savings, and when the difference matters
Narrow Therapeutic Index Drugs
Why some drugs demand precise dosing and monitoring
Common Drug Interactions
Dangerous medication combinations and how to protect yourself
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What the FDA Data Shows for clonidine
The FDA label for clonidine (sold under brand names such as Catapres) classifies it as a prescription-only medication in the Central Alpha-2 Agonist class. Clonidine is used to treat high blood pressure. Official labeling lists 5 commonly reported side effects, including 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).
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 27,604 voluntary reports. The database also lists 29 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated moderate severity. NADAC pricing from CMS shows a generic unit cost of $5.80.
Report counts do not establish causation — a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history, and patent information further shape supply and switching decisions. This page summarizes public FDA data for educational purposes only and is not a substitute for professional medical advice — always consult a licensed healthcare provider before starting, stopping, or changing any medication.
Data Sources
Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC).
FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. Always consult a healthcare professional before making medication decisions.
Last updated: May 22, 2025
Read our methodology — how this data is sourced, computed, and verified.
All federal data sources used on this page
- FDA Orange Book — approved drug products with therapeutic equivalence. accessdata.fda.gov/cder/ob
- FDA DailyMed — NIH-hosted drug labeling for FDA-approved meds. dailymed.nlm.nih.gov
- FDA Adverse Event Reporting System (FAERS) — post-marketing safety surveillance. fda.gov/drugs/faers
- NLM RxNorm — standardized clinical drug nomenclature. nlm.nih.gov/research/umls/rxnorm
- CMS Medicare Part B Drug Average Sales Price Files — federal drug pricing data. cms.gov/medicare/part-b-drugs/asp
- FDA Drug Shortages Database — current and resolved drug shortage tracking. accessdata.fda.gov/drugshortages