Clonidine dosage, forms, and strengths

Clonidine (clonidine hydrochloride) is a generic prescription drug used to lower blood pressure or help control the symptoms of ADHD. Healthcare professionals may also use it off-label to treat other conditions, including Tourette syndrome, tic disorders, withdrawal symptoms, menopause symptoms, and others. Most people take clonidine by mouth, but other formulations include skin patches and injections. However, the different formulations are approved for certain conditions and not others.

Clonidine forms and strengths

Clonidine is available in several dosage forms and strengths, including extended-release formulations: 

• Tablet: 0.1, 0.2, 0.3 mg 

• Extended-release tablet: 0.1 mg, 0.17 mg, 0.26 mg

• Extended-release oral suspension: 0.1 mg/mL

• Transdermal patch: 0.1 mg/day, 0.2 mg/day, 0.3 mg/day 

• Epidural injection solution: 100 mcg/ml, 500 mcg/ml 

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Clonidine dosage for high blood pressure

Clonidine is not a first-choice drug for treating high blood pressure because abrupt discontinuation can cause severe rebound hypertension. The American Heart Association advises clinicians to avoid clonidine as a hypertension treatment whenever possible. When prescribed as an antihypertensive agent, patients take immediate-release tablets or use a transdermal patch that provides steady dosing for seven days. Nexiclon XR is a brand-name extended-release clonidine tablet that can be taken once daily for hypertension. Doses are taken at bedtime.

Clonidine dosage for ADHD

While the standard treatment for ADHD involves stimulants, clonidine is one of a handful of nonstimulant drugs used to treat ADHD. When stimulants are not working well in pediatric patients, clinicians may prescribe extended-release clonidine either alone or as an add-on treatment. Two doses are taken daily, one in the morning and one at night. The largest dose should be taken at bedtime.

Clonidine dosage for cancer pain

Clonidine epidural injections are used as an add-on treatment to help relieve moderate to severe cancer pain that is not completely controlled by opioids or other analgesics. Healthcare providers administer the injections as a continuous infusion into the spinal cord area using a pump.

Clonidine dosage for other conditions

Clonidine is widely used for conditions it’s not approved for, that is, “off-label.” For some of these conditions, clonidine is considered a first-line therapy or a top choice for add-on treatment. For other conditions, clonidine is only used when other treatments don’t work. Conditions where clonidine is used as a first-line or adjunct treatment include:

• Tourette syndrome and tic disorders: For tic disorders that impact a patient’s quality of life, the first-line drug treatments are an antipsychotic medication plus an alpha-2 adrenergic agonist like clonidine or guanfacine. Patients will take immediate-release clonidine tablets once or several times a day. The starting dose is smaller than the smallest dosage strength, so patients or caregivers will need to divide the tablet.

• Withdrawal: Clonidine is not a first-line drug for withdrawal. However, it is a second choice, an add-on drug for opiate withdrawal when opioids like methadone aren’t adequately controlling withdrawal symptoms. Some doctors may use clonidine for benzodiazepine withdrawal, alcohol withdrawal, or smoking cessation if first-line medications don’t work.

• Neonatal opioid withdrawal: When babies are born addicted to opioids, the standard drug therapy involves opioids such as methadone to help wean the baby off the dependence. If an opioid is not adequate to control symptoms, clonidine or benzodiazepine injections are the standard second-line add-on drugs used to quiet symptoms.

• Pheochromocytoma: Pheochromocytoma is a rare tumor of the adrenal glands. Doctors use a single dose of clonidine to conduct a test that confirms the diagnosis. 

Personalized dosing considerations

People with renal impairment may be prescribed a lower initial dose, but specific dosage reductions have not been defined. Older adults and people with liver dysfunction do not require dosage reductions.

Clonidine safety info

Clonidine is a relatively safe medication, but because of adverse reactions and the risk of rebound hypertension, it’s not a first choice when treating either high blood pressure or ADHD. The most common side effects of clonidine are drowsiness, fatigue, dizziness, constipation, and dry mouth.

The only clonidine contraindication is any history of allergic reactions to the drug.

To be safe when taking clonidine, tell the prescriber if you have heart problems, kidney problems, blood pressure problems, or a history of fainting (syncope). Older adults should also be cautious when taking clonidine.

The most important safety consideration is that the abrupt discontinuation of clonidine can cause serious rebound hypertension and speed up the heart rate. This is because the sudden removal of the drug causes the body to release a large quantity of a hormone similar to adrenaline. When it’s time to stop, doses must be gradually reduced. There is no set tapering schedule. The process typically takes two to four days for clonidine IR and one to two weeks for clonidine ER.

Clonidine can cause sleepiness and dizziness. Exercise caution when driving or engaging in risky activities.

Women who are pregnant or breastfeeding should ask the prescriber for medical advice before starting this drug. Women who are breastfeeding should be aware that clonidine is excreted in human breast milk. They should monitor the nursing infant for side effects such as sedation or poor muscle toneClonidine has some drug interactions, but no specific drugs are prohibited. Some drugs, like tricyclic antidepressants, may require the clonidine dose to be adjusted. Other drugs, like beta blockers, calcium channel blockers, and digoxin, may cause heart rhythm problems when combined with clonidine. 

The most important drug interactions involve CNS depressants, drugs that make you sleepy or impaired, such as alcohol, barbiturates, sedatives, or similar drugs. Combining these drugs with clonidine will worsen side effects like sleepiness, dizziness, and impairment.

How to take clonidine

Clonidine should only be taken when and how it is prescribed by a healthcare provider to minimize the risk of adverse effects. Oral clonidine can be taken with or without food.

• How to take immediate-release and extended-release clonidine tablets:

  • Take the initial single daily dose at bedtime.

  • When the healthcare provider splits the dose, take one in the morning and the second at bedtime.

  • For clonidine ER, the second dose should be the largest of the two doses.

  • Swallow the tablet whole with a drink of water. Do not crush, break, or chew.

  • Store clonidine tablets at room temperature.

• How to take Nexiclon XR tablets:

  • Take one dose daily.

  • Take the tablet at night before bedtime.

  • Swallow the tablet whole with a drink of water. Do not crush, break, or chew.

  • Store Nexiclon XR tablets at room temperature.

• How to take clonidine oral suspension (Onyda XR):

  • Shake the bottle before measuring a dose.

  • Only use the calibrated oral syringe that comes with the medicine to measure a dose.

  • Store Onyda XR at room temperature in its original bottle in an upright position. Protect from light.

• How to use clonidine patches:

  • Apply patches to clean, undamaged, and hairless skin. Do not shave the skin before applying the patch.

  • Remove the patch from the pouch.

  • Remove the protective backing and place the patch sticky side down on the skin.

  • Remove the patch after one week and replace it with a new one.

  • Use a different area of the skin when replacing patches.

  • Apply new patches on the same day of the week at the same time of day as the last patch.

  • If a patch comes loose, apply the adhesive cover to keep it firmly attached to the skin.

  • When disposing of a patch, fold it in half so that the sticky side is covered. Place it in a place that children can’t reach.

  • Store clonidine patches in their original pouch at room temperature.

• Do not stop taking doses until talking to the prescriber. 

Clonidine dosage FAQs

Clonidine vs. clonidine ER: What’s the difference in doses?

Immediate-release clonidine is FDA-approved only to treat high blood pressure. Clonidine ER is FDA-approved only to treat ADHD in pediatric patients. There’s one exception: Nexiclon XR is an extended-release clonidine tablet FDA-approved to treat hypertension. Doses are different because Nexiclon XR uses a different chemical version of clonidine.

How long does it take clonidine to work?

Oral clonidine takes about 30 minutes to start lowering blood pressure. It reaches its peak effects one to two hours after a dose is taken. Clonidine patches typically take two or three days before the antihypertensive effects are noticeable. For ADHD or tic disorders, it may take weeks or months to notice symptom improvement.

How long does clonidine stay in your system?

With an elimination half-life of 12 to 16 hours, it can take two to three days to completely clear a dose from the body. It may take as long as a week for people with kidney impairment. 

What happens if I miss a dose of clonidine?

Ask the prescriber how to handle a missed dose of clonidine. Whether to skip or take a missed dose will depend on several factors. No matter what, never double up the next dose to make up for a missed dose.

Can you overdose on clonidine?

Yes. A clonidine overdose can cause serious problems, including hypotension, slow heart rate (bradycardia), heart rhythm problems, seizures, and coma. Symptoms usually appear within 30 minutes and include a weak pulse, low blood pressure, slowed breathing, somnolence, and small pupils. Call a poison control center or get emergency medical care.

How do I stop taking clonidine?

Clonidine should not be abruptly stopped. Stopping this medication suddenly may result in very high blood pressure and withdrawal symptoms. The dose should be slowly reduced before the medication is stopped.

What is the dosage of clonidine for dogs/cats?

Clonidine is not generally a veterinarian’s first choice for treating pets. Instead, it’s used as a second-line or adjunctive therapy when other drugs won’t work. When they do use it, they primarily use it in dogs to treat anxiety, phobias, or similar behavioral issues. They may also use it to control diarrhea and diagnose pheochromocytoma. They give it to cats as an anti-diarrhea medication. Doses are not standardized, but expect to give a pet two to 20 micrograms per pound of body weight two to three times a day. 

Sources

• 2025 AHA/ACC/AANP/AAPA/ABC/ACCP/ACPM/AGS/AMA/ASPC/NMA/PCNA/SGIM guideline for the prevention, detection, evaluation and management of high blood pressure in adults: a report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines, Circulation

• Catapres drug summary, Prescriber’s Digital Reference (PDR)

• Clinical practice guideline for the diagnosis, evaluation, and treatment of attention-deficit/hyperactivity disorder in children and adolescents, Pediatrics

• Clonidine, StatPearls 

• Clonidine extended-release patch prescribing information, DailyMed (NIH National Library of Medicine)

• Clonidine injection prescribing information, DailyMed (NIH National Library of Medicine)

• Clonidine hydrochloride extended-release tablet prescribing information, DailyMed (NIH National Library of Medicine)

• Clonidine hydrochloride tablet prescribing information, DailyMed (NIH National Library of Medicine)

• Neonatal opioid withdrawal, Pediatrics

• Nexiclon XR clonidine extended-release tablet prescribing information, DailyMed (NIH National Library of Medicine)

• Plumb’s Veterinary Drug Handbook, 7th ed

• Onyda XR clonidine hydrochloride extended-release suspension prescribing information, DailyMed (NIH National Library of Medicine)

• Tourette syndrome and other tic disorders, StatPearls

• Withdrawal management, Clinical Guidelines for Withdrawal Management and Treatment of Drug Dependence in Closed Settings