Reviewed on 3/15/2022

What Is Clonidine and How Does It Work?

Clonidine is a prescription medication that is used alone or with other medications to treat high blood pressure, to lower blood pressure to help prevent strokes, heart attacks, and kidney problems.  Clonidine is also used off-label for the treatment of alcohol withdrawal, smoking cessation, restless leg syndrome, Tourette’s syndrome, and opioid withdrawal.

  • Clonidine belongs to a class of drugs (central alpha agonists) that act in the brain to lower blood pressure. It works by relaxing blood vessels so blood can flow more easily.
  • Clonidine is available under the following different brand names: Catapres, Catapres-TTS, Duraclon, Jenloga, and Kapvay.

Dosages of Clonidine

Adult and pediatric dosages

Injectable solution

  • 100 mcg/ml
  • 500 mcg/ml

Patch, extended-release

  • 0.1 mg/day
  • 0.2 mg/day
  • 0.3 mg/day

Tablet, immediate-release

  • 0.1 mg
  • 0.2 mg
  • 0.3 mg

Tablet, extended-release

  • 0.1 mg

Dosage Considerations – Should be Given as Follows:


Immediate-release tablet

  • 0.1 mg orally every 12 hours
  • Range: 0.1-0.2 mg/day every 12 hours, not to exceed 2.4 mg/day

Transdermal Patch

  • Apply 1 patch every 7 days, start with 0.1 mg; increase by 0.1 mg after every 1-2 week interval; usual dose range is 0.1-0.3 mg each week
  • Children older than 12 years

Immediate-release tablets

  • 0.2 mg/day orally divided every 12 hours; increase each week; maintenance dose range, 0.2-0.6 mg/day every 12 hours; not to exceed 2.4 mg/day

Transdermal patch

  • 0.1 mg patch every 7 days initially; may increase by weekly 0.1-mg increments after 1-2 weeks if desired blood pressure reduction not achieved; not to exceed 0.6 mg/week (2 clonidine 0.3 mg patches)

Children under 12 years old

  • Immediate-release tablets and transdermal patch: Safety and efficacy not established


  • immediate-release tablets: 0.1 mg orally at bedtime

Geriatric Dosing considerations

Severe pain in patients with cancer not adequately relieved by opioid analgesics alone


  • 30 mcg/hr, adjust the dose as required for pain relief or presence of side effects
  • Limited data on doses exceeding 40 mcg/hr

Epidural infusion is considered as an adjunct to intraspinal opiate therapy; epidural administration (Duraclon) is indicated in combination with opiates for the treatment of severe pain in patients with cancer not adequately relieved by opioid analgesics alone.

  • More likely to be effective in patients with neuropathic pain than in those with somatic or visceral pain.
  • Pediatric epidural infusion: 0.5 mcg/kg/hr initially; adjust according to clinical response.
  • Epidural administration (Duraclon) is indicated in combination with opiates for the treatment of severe pain in patients with cancer not adequately relieved by opioid analgesics alone. Restrict use to pediatric patients with severe, intractable pain from malignancy that is unresponsive to epidural or spinal opiates or other, more conventional analgesic techniques. More likely to be effective in patients with neuropathic pain than in those with somatic or visceral pain. Safety and effectiveness of epidural administration in this limited indication and clinical population have been established in patients old enough to tolerate placement and management of an epidural catheter; these conclusions are based on evidence from adequate and well-controlled studies in adults and through experience with the use of clonidine in the pediatric age group for other indications.

Acute Hypertension (Off-label)

  • 0.1-0.2 mg orally, may follow with additional doses of 0.1 mg every hour as needed to maximum 0.6 mg total dose

ETOH Withdrawal (Off-label)

  • 0.3-0.6 mg orally every 6 hours

Smoking Cessation (Off-label)

Oral administration

  • 0.1 mg each day; increase by 0.1 mg/day to 0.15-0.75 mg/day if required

Transdermal administration

  • 100-200 mcg/day patch every 7 days
  • 0.3-0.6 mg orally every 6 hours

Restless Legs Syndrome (Off-label)

  • 100-300 mcg orally every 2 hours before bedtime, up to 900 mcg/day

Tourette's Syndrome (Off-label)

  • 0.0025-0.015 mg/kg/day orally for 6 weeks to 3 months

Cyclosporine Nephrotoxicity (Off-label)

  • 100-200 mcg/day transdermal patch; change every 7 days

Menopausal Flushing (Off-label)

  • Apply 100 mcg/day patch; change every 7 days, OR
  • 50 mcg orally every 12 hours initially; may increase up to 400 mcg every 12 hours

Dysmenorrhea (Off-label)

Oral administration

Opioid Withdrawal (Off-label)

Oral administration

  • 0.1-0.3 mg every 4-6 hours, increase by 0.1 mg/day to 0.15-0.75 mg/day if required; do not exceed 2.4 mg/day

Transdermal administration

  • 100-200 mcg/day patch every 7 days initiate 0.1-0.3 mg orally every 4-6 hours for first 2 days to allow for adequate drug levels

Postherpetic Neuralgia (Off-label)

Oral administration

  • 0.1 mg every 12 hours

Psychosis (Off-label)

Oral administration

  • 0.4-1.4 mg/day in divided doses

Pheochromocytoma Diagnosis (Off-label)

Clonidine suppression testing

  • 0.3 mg orally for 60-80 kg patient; obtain blood sample 3 hours after administration to the supine patient

Dosing Considerations

  • The extended-release is not to be used interchangeably with immediate-release tablets.
  • Conversion from oral to transdermal
  • Day 1: Place Catapres-TTS-1; administer 100% of an oral dose
  • Day 2: Administer 50% of an oral dose
  • Day 3: Administer 25% of an oral dose
  • Day 4: Patch remains, no further oral supplement is needed

ADHD, Pediatric

  • Children under 6 years old: Not established
  • Children 6 years or older: (extended-release tablets, Kapvay): 0.1 mg orally at bedtime initially; may adjust dose by increments of 0.1 mg/day at weekly intervals until desired response; not to exceed 0.4 mg/day.
  • When discontinuing, taper gradually by decrements not to exceed 0.1 mg every 3-7 days.

Dosing considerations

  • May be given as monotherapy or as adjunctive therapy with stimulants. The extended-release is not interchangeable with the immediate-release product.
  • Doses 0.2 mg/day or greater should be divided twice a day, with either an equal or higher split dosage being given at bedtime. Swallow tablet whole; do not crush, chew, or split.

Dosing Modifications

  • Renal Impairment
  • Impact of renal impairment not assessed
  • The initial dose should be based on the amount of renal impairment
  • Monitor carefully for low blood pressure and lower heart rate.
  • Removed minimally during hemodialysis; no need to re-dose the following dialysis

Geriatric: immediate release: Lower initial doses than for non-geriatric adult dosing, as well as gradual adjustments, are recommended.

Extended-release: May require a lower initial dose than for non-geriatric adult dosing.


How to Lower Blood Pressure: Exercise Tips See Slideshow

What Are Side Effects Associated with Using Clonidine?

Common side effects include:

  • skin reactions (patch)
  • dry mouth
  • sleepiness
  • headache
  • fatigue
  • drowsiness
  • dizziness
  • low blood pressure, epidural
  • postural low blood pressure, epidural
  • anxiety
  • constipation
  • sedation
  • nausea/vomiting
  • feeling unwell (malaise)
  • low blood pressure when standing up
  • loss of appetite
  • abnormal liver function values
  • rash
  • weight gain

Side effects of Clonidine in children with ADHD include:

  • upper respiratory tract infection
  • irritability
  • throat pain
  • nightmares
  • insomnia
  • emotional disorder
  • constipation
  • nasal congestion

Postmarketing side effects of Clonidine reported include:

What Other Drugs Interact with Clonidine?

If your doctor has directed you to use this medication, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

  • Clonidine has no known severe interactions with any drugs.
  • Clonidine has serious interactions with at least 30 different drugs.
  • Clonidine has moderate interactions with at least 82 different drugs.
  • Clonidine has mild interactions with at least 38 different drugs.

This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist. Check with your physician if you have health questions or concerns.

What Are Warnings and Precautions for Clonidine?


  • Epidural clonidine is not recommended for obstetric postpartum or perioperative pain management because the risk of hemodynamic instability (low blood pressure or low heart rate) may be unacceptable in this population
  • Dilute product with strength of 500 mcg/ml prior to use
  • This medication contains clonidine
  • Do not take Catapres, Catapres-TTS, Duraclon, Jenloga, Kapvay, or Nexiclon XR if you are allergic to clonidine or any ingredients contained in this drug
  • Keep out of reach of children. In case of overdose, get medical help or contact a Poison Control Center immediately.


  • Hypersensitivity


  • Concurrent use of anticoagulants, hemorrhage
  • Presence of injection site infections
  • Administration above C4 dermatome, due to lack of adequate safety data
  • Obstetric/perioperative pain

Effects of Drug Abuse

  • May impair ability to perform hazardous tasks.

Short-Term Effects

  • May impair ability to perform hazardous tasks. Epidural clonidine is not recommended for obstetric postpartum or perioperative pain management because the risk of hemodynamic instability (low blood pressure or low heart rate)
  • See "What Are Side Effects Associated with Using Clonidine?"

Long-Term Effects

  • Clonidine use is only recommended for short periods, 2-3 weeks
  • See "What Are Side Effects Associated with Using Clonidine?"


  • Epidural: Hemodynamically unstable patients (risk of severe low blood pressure)
  • Do not discontinue suddenly (risk of rebound high blood pressure)
  • Patch: May need to remove if severe erythema and/or localized vesicle formation develop at application site or generalized rash; consult with a physician
  • Use caution in patients with:
  • May impair ability to perform hazardous tasks
  • Remove patch before MRI (may cause burns)
  • Low blood pressure may occur; usually responsive to IV fluids and, if necessary, appropriate parenterally administered pressor agents
  • Cardiac conduction abnormalities: Sympatholytic action may worsen sinus node dysfunction and atrioventricular (AV) block, especially if coadministered with other sympatholytic drugs
  • Adjust dosing slowly and monitor vital signs frequently in patients at risk for hypotension, heart block, low heart rate, fainting, cardiovascular disease, vascular disease, cerebrovascular disease or chronic renal failure; measure heart rate and blood pressure prior to initiation of therapy, following dose increases, and periodically while on therapy; avoid concomitant use of drugs with additive effects unless clinically indicated; advise patients to avoid becoming dehydrated or overheated
  • Epidural administration may result in mild respiratory depression (usually with higher than recommended dose)
  • Use with caution in cerebrovascular disease
  • Avoid as first line antihypertensive in the elderly due to high risk for adverse side effects
  • Children may be particularly susceptible to hypertensive episodes when experiencing GI illnesses that lead to vomiting
  • Discontinue oral immediate release formulations within 4 hours of surgery; restart as soon as possible following surgery
  • Due to different pharmacokinetic profiles, oral formulations are not interchangeable with extended release on an mg-mg basis due to different pharmacokinetic profiles

Pregnancy and Lactation

  • Use clonidine with caution in pregnancy if the benefits outweigh risks
  • Animal studies show risk and human studies are not available, or neither animal nor human studies were done
  • Clonidine is distributed in breast milk; caution is advised if lactating. Consult with your physician


Salt and sodium are the same. See Answer
Medscape. Clonidine.

Health Solutions From Our Sponsors