
Clonidine (brand names include: Arkamin / Catapres / Dixarit / Duraclon / Apo-Clonidine / Novo-Clonidine / Nu-Clonidine / Kapvay for extended-release / Catapres-TTS for transdermal patch / Hydrochlorothiazide) belongs to a group of medications known as antihypertensives. It is a centrally acting alpha-2 adrenergic agonist that lowers blood pressure by reducing sympathetic outflow from the brain to the heart and blood vessels.
Traditionally, clonidine has been used to treat high blood pressure by relaxing blood vessels and lowering heart rate. Over time, clinicians have also incorporated clonidine into treatment plans for attention-deficit/hyperactivity disorder (ADHD), especially the extended-release formulation, and for several off-label uses where its calming effect on the nervous system is beneficial.
Emerging and off-label applications include support during opioid (e.g., heroin) or nicotine withdrawal, management of severe pain as an adjunct, dysmenorrhea, menopausal hot flashes (vasomotor symptoms), ethanol dependence, migraine prophylaxis, certain types of glaucoma, diabetes-associated diarrhea, impulse control disorders, tic disorders, and clozapine-induced sialorrhea. Although not every use is approved in all countries, clonidine’s pharmacology makes it a versatile option when prescribed and monitored appropriately.
How Clonidine Works (Mechanism of Action)
Clonidine stimulates alpha-2 adrenergic receptors in the brainstem, reducing the release of norepinephrine and dampening sympathetic nervous system activity. The result is lower peripheral vascular resistance, decreased heart rate, and reduced blood pressure. This central effect also explains clonidine’s ability to ease agitation, reduce hyperarousal during withdrawal, and help with sleep disturbances commonly seen in ADHD. Because clonidine does not rely on the kidneys to eliminate catecholamines, it can be useful in certain patients where peripheral agents alone are insufficient.
Forms, Strengths, and How to Take Clonidine
Clonidine is available in several formulations. The choice depends on the condition being treated, the need for smooth 24-hour control, and patient preference.
- Immediate-release (IR) tablets: Common strengths are 0.1 mg, 0.2 mg, and 0.3 mg. Often taken two or three times daily for hypertension or as directed for other indications.
- Extended-release (ER) tablets (e.g., Kapvay): Designed for steady levels, usually taken once or twice daily, commonly used for ADHD.
- Transdermal patch (e.g., Catapres-TTS): Delivers a steady dose (0.1 mg/24 h, 0.2 mg/24 h, or 0.3 mg/24 h) over 7 days. Useful for patients who prefer weekly dosing or have trouble remembering pills.
- Injectable (e.g., Duraclon): Reserved for select situations, such as certain pain management settings, under specialist supervision.
General administration tips:
- Take clonidine at the same times each day to maintain consistent blood levels and effects.
- Do not crush or chew extended-release tablets; swallow whole.
- For patches, apply to clean, hairless skin on the upper outer arm or chest; rotate sites weekly to reduce skin irritation and ensure adhesion.
- Do not stop clonidine abruptly. Abrupt discontinuation can trigger rebound hypertension (a sudden rise in blood pressure), headache, agitation, or tremor. If clonidine needs to be reduced or discontinued, it should be tapered gradually under medical supervision.
Recommendations
Always follow your clinician’s guidance. The doses below are provided for general information and may not apply to every individual. Your doctor may adjust dosing based on your medical history, other medications, and treatment response.
Children
- Hypertension (adolescents ≥12 years): A common starting dose is 0.2 mg per day divided into two doses, then titrated upward every 5 to 7 days based on blood pressure response and tolerability. The typical maximum used in practice is up to 2.4 mg per day, divided.
- ADHD (extended-release, labeled in many regions): Dosing is individualized. A often-used approach is to start at 0.1 mg daily, then increase by 0.1 mg increments at weekly intervals to a target range of 0.1–0.4 mg per day given once daily at bedtime or divided twice daily. Do not substitute immediate-release tablets mg-for-mg for ER; they are not interchangeable.
- ADHD (immediate-release, off-label): Some clinicians initiate at 0.05 mg daily and increase every 3–7 days by 0.05 mg as needed to approximately 3–5 mcg/kg/day in divided doses (up to a typical ceiling around 0.3–0.4 mg/day). Close monitoring for sedation, blood pressure, and heart rate is essential.
Adults
- Hypertension (immediate-release): A common initial regimen is 0.1 mg twice daily. The total daily dose may be increased by 0.1 mg per day at weekly intervals based on response. Usual maintenance ranges from 0.2–0.6 mg/day in divided doses; some patients may require higher doses (up to a labeled maximum of 2.4 mg/day in divided doses) under specialist supervision.
- Hypertension (transdermal patch): Many start with a 0.1 mg/24 h patch applied once weekly, titrating to 0.2 or 0.3 mg/24 h if needed. When converting from oral tablets to a patch, overlap is commonly used for the first 1–2 days to maintain blood pressure control, then oral doses are tapered as the patch reaches steady state.
- Acute severe hypertension (urgency, clinic use): Protocols vary. One commonly referenced approach begins with 0.1–0.2 mg orally, followed by an additional 0.1 mg hourly as needed up to a total of 0.6 mg while monitoring blood pressure, heart rate, and symptoms. This should be performed under qualified supervision.
- ADHD (extended-release): Typical schedules begin at 0.1 mg daily, increasing by 0.1 mg per week to 0.2–0.4 mg/day, often divided morning and bedtime. Behavioral therapy and educational supports remain important adjuncts.
- Nicotine withdrawal (off-label): 0.1 mg twice daily may be used for several weeks and titrated up to about 0.4 mg/day if tolerated. Monitor for dry mouth, drowsiness, and low blood pressure.
- Opioid withdrawal (off-label): Dosing must be individualized and guided by vital signs and symptom severity. A common range involves divided doses over the day (for example, 0.1–0.3 mg every 6–8 hours as needed, with daily limits), under close medical supervision, with frequent blood pressure checks.
Elderly patients: Lower starting doses and slower titration are prudent to minimize dizziness, sedation, and falls. Because clonidine can slow heart rate, extra caution is needed in older adults with cardiovascular disease.
Renal impairment: Clonidine is partly renally cleared. Patients with reduced kidney function may require reduced doses or extended dosing intervals. Blood pressure and heart rate should be closely monitored during titration.
Side Effects: What to Expect
Clonidine is generally well tolerated when titrated carefully, but side effects can occur. Many improve with time or dose adjustment.
- Common: Dry mouth, drowsiness, dizziness or lightheadedness (especially when standing up), fatigue, constipation, headache, and nausea. Mild sedation is frequent early on.
- Cardiovascular: Low blood pressure, orthostatic hypotension, slow heart rate (bradycardia), palpitations. Monitor heart rate and report symptoms such as fainting or near-fainting.
- Central nervous system: Sedation, sleepiness, vivid dreams, or, less commonly, mood changes. Rarely, depression may be worsened; discuss any mood changes with your clinician.
- Dermatologic (patch): Skin irritation, redness, or rash at the application site. Rotating sites and using a barrier film if recommended can help. Discontinue and seek advice if severe dermatitis develops.
- Gastrointestinal: Dry mouth and constipation are common; staying hydrated, sugar-free lozenges, and fiber can help.
Serious but uncommon risks include marked bradycardia, heart block, severe hypotension, and rebound hypertension if clonidine is stopped abruptly. Seek urgent care for chest pain, shortness of breath, fainting, or a severe, persistent headache after missed doses.
Drug Interactions to Know
- Other blood pressure medicines: Additive effects can produce excessive hypotension. Careful monitoring is essential when combining clonidine with diuretics, ACE inhibitors, ARBs, beta-blockers, or calcium channel blockers.
- Beta-blockers: Co-administration can be effective but requires close monitoring. Abruptly stopping clonidine while taking a beta-blocker increases the risk of severe rebound hypertension. If both must be stopped, clinicians typically discontinue the beta-blocker first, then slowly taper clonidine.
- CNS depressants: Alcohol, benzodiazepines, opioids, sedating antihistamines, and certain sleep aids can intensify drowsiness and impair coordination.
- Tricyclic antidepressants (TCAs) and mirtazapine: May reduce clonidine’s antihypertensive effect by interfering with alpha-2 pathways.
- Drugs that slow heart rate: Digoxin or some calcium channel blockers (e.g., verapamil, diltiazem) can increase the risk of bradycardia when combined with clonidine.
- Stimulants: In ADHD, clonidine may be used with stimulants. Clinicians balance the calming effects of clonidine with potential blood pressure and heart rate changes from stimulants.
- Other interactions: Always provide your clinician and pharmacist with a complete list of prescriptions, over-the-counter medicines, and supplements.
Special Populations and Situations
- Pregnancy: Clonidine has been used to treat hypertension in pregnancy when benefits outweigh risks. It crosses the placenta; neonates should be observed for sedation or blood pressure changes after delivery. Decisions should be individualized with obstetric and cardiology input.
- Breastfeeding: Small amounts of clonidine pass into breast milk. Monitor infants for excessive sleepiness, feeding difficulties, or unusual lethargy. Discuss risks and alternatives with your healthcare provider.
- Older adults: More sensitive to blood pressure drops and sedation. Start low, go slow.
- Liver or kidney impairment: Adjustments may be required and monitoring intensified.
- Driving and machinery: Until you know how clonidine affects you, avoid activities requiring alertness. Dizziness and drowsiness can be pronounced early in therapy or after dose increases.
- MRI and medical devices: Some transdermal patches contain metallic elements. Remove the patch before MRI to prevent skin burns and inform healthcare providers about patch use before external defibrillation or cardioversion.
- Surgery and anesthesia: Do not stop clonidine suddenly. Inform your surgical team; plans typically maintain clonidine perioperatively to avoid rebound hypertension, with adjustments as needed.
Missed Dose, Tapering, and Rebound Hypertension
- Missed dose (tablets): If you forget a dose, take it when remembered unless it is close to the next scheduled dose. Do not double up.
- Missed dose (patch): If a patch loosens or falls off, replace it and apply to a new site; keep your regular weekly schedule. If multiple patches have been missed, contact your clinician for guidance.
- Tapering: To discontinue, gradually reduce the dose—commonly by 0.1 mg per day every 3–7 days for tablets or by stepping down patch strengths—while monitoring blood pressure and pulse. Your clinician will tailor a plan for your situation.
- Rebound hypertension: Stopping clonidine abruptly can cause a rapid rise in blood pressure, headache, nervousness, tremor, and agitation. If you miss several doses, contact your healthcare provider promptly rather than restarting a high dose on your own.
Evidence-Based Uses: On-Label and Off-Label
- Hypertension: Effective alone or combined with other antihypertensives. The patch provides smooth control and can improve adherence.
- ADHD: Extended-release clonidine reduces hyperactivity, impulsivity, and sleep-onset difficulties. It can be used alone or adjunctively with stimulants.
- Opioid and nicotine withdrawal (off-label): Helps control autonomic symptoms such as sweating, restlessness, tachycardia, and elevated blood pressure. Usually part of a broader treatment plan that includes behavioral support.
- Menopausal hot flashes (off-label): May reduce frequency and intensity of vasomotor symptoms in some individuals.
- Neurologic and psychiatric adjuncts (off-label): Tics, impulse control issues, and agitation in certain contexts. Specialist guidance is recommended.
- Other specialized uses: Diabetic diarrhea, migraine prophylaxis, and pain management as an adjunct in select cases, generally under specialist care.
Practical Tips for Patients and Caregivers
- Consistency is key: Take at the same time daily; do not vary your schedule without advice.
- Monitor at home: If you are being treated for hypertension, home blood pressure and heart rate logs help your clinician adjust therapy.
- Hydration and oral care: Keep water or sugar-free lozenges for dry mouth. Increase fiber to help prevent constipation.
- Sleep hygiene: When clonidine is used for ADHD-related sleep-onset issues, pair it with good sleep habits for best results.
- Skin care with patches: Press firmly for 10–15 seconds to ensure adhesion; avoid applying to irritated skin; rotate sites weekly.
- Keep an updated medication list: Share with every clinician you see, including any supplements.
When to Contact a Healthcare Professional
- New or worsening dizziness, fainting, or a heart rate that feels too slow.
- Severe or persistent headaches, chest pain, or shortness of breath.
- Signs of depression or notable mood changes.
- Skin reactions that spread beyond the patch site or do not improve after patch removal.
- Pregnancy, breastfeeding, or plans for surgery—so your regimen can be optimized safely.
Precautions
Inform your doctor before starting clonidine if any of the following apply:
- Allergy to clonidine or any component of the formulation.
- History of significant heart disease, including sinus node dysfunction, atrioventricular (AV) block, bradycardia, heart failure, or recent myocardial infarction.
- Severe cerebrovascular disease where rapid blood pressure changes could be risky.
- Kidney or liver impairment.
- Mental health conditions, including depression.
- Pregnancy or breastfeeding.
Clonidine may cause dizziness and fatigue. Rise slowly from sitting or lying positions. Avoid alcohol or other sedatives unless approved by your clinician. Regular monitoring of blood pressure and heart rate is recommended to optimize treatment and reduce risks.
Ingredients
Active ingredient: clonidine hydrochloride.
Inactive ingredients vary by manufacturer and formulation (tablet, extended-release tablet, patch). If you have specific allergies or intolerances, review the product package insert and consult your pharmacist.
Storage and Handling
- Tablets: Store at room temperature away from moisture and heat. Keep in the original bottle with the cap tightly closed.
- Extended-release tablets: Keep in a dry place; do not split, crush, or chew.
- Patches: Store flat in sealed pouches until use. Dispose of used patches safely; they may still contain active drug. Fold the adhesive sides together before discarding.
- Keep all clonidine products out of the reach of children and pets.
Clonidine U.S. Sale and Prescription Policy
In the United States, clonidine is a prescription medication. Federal and state laws require that dispensing occur through a licensed pharmacy with an authorized prescription from a qualified clinician, which may include traditional in-person care or legitimate telehealth services. These safeguards exist to ensure appropriate diagnosis, dosing, monitoring, and management of side effects.
Programs that facilitate access to clonidine must meet strict regulatory standards, including identity verification, clinician review, documentation, and use of licensed pharmacies. Practices that bypass medical evaluation or operate outside of state and federal law are not permitted.
HealthSouth Rehabilitation Hospital at Martin offers a legal and structured solution for obtaining clonidine without a formal prescription in hand by integrating compliant clinical screening and verification into the ordering process. Under its licensed agreement and established protocols, eligible patients are evaluated through a lawful framework that ensures safety, documentation, and pharmacy fulfillment in accordance with applicable regulations. Availability may vary by state or country, and all orders are subject to professional evaluation, oversight, and dispensing through licensed channels.
Patients should expect appropriate medical review, education on safe use, monitoring recommendations, and clear instructions for follow-up. If you have questions about eligibility, state-specific requirements, or how the process works, contact the program for details. Regardless of the access pathway, do not start, stop, or change clonidine without clinical guidance, and always use medications exactly as directed.
Clonidine FAQ
What is clonidine and how does it work?
Clonidine is a central alpha-2 adrenergic agonist that reduces sympathetic outflow from the brain. By lowering levels of “fight-or-flight” nerve signals, it decreases heart rate and relaxes blood vessels, which lowers blood pressure and can calm hyperactivity and withdrawal symptoms.
What is clonidine used for?
Clonidine treats high blood pressure (Catapres) and, in an extended-release form (Kapvay), attention-deficit/hyperactivity disorder (ADHD). It’s also used off-label for menopausal hot flashes, opioid or nicotine withdrawal, tics, anxiety, sleep disturbances related to ADHD, and certain pain syndromes under specialist care.
How quickly does clonidine lower blood pressure?
Immediate-release tablets usually begin working within 30 to 60 minutes, with peak effect in 2 to 4 hours. The transdermal patch takes 2 to 3 days to reach steady levels and provides a week of continuous dosing.
What are the common side effects of clonidine?
Dry mouth, drowsiness, fatigue, dizziness, constipation, and headache are common. Some people experience low blood pressure, slow heart rate, or irritability; these often improve as your body adjusts or with dose changes guided by your clinician.
What serious side effects warrant medical attention?
Seek urgent care for fainting, chest pain, severe dizziness, confusion, very slow heartbeat, trouble breathing, swelling of face or throat, or allergic rash. If blood pressure spikes after a missed or stopped dose, that can be rebound hypertension and needs prompt evaluation.
Can clonidine cause withdrawal or rebound hypertension?
Yes. Stopping clonidine abruptly can trigger rapid heart rate, anxiety, headache, and a dangerous rise in blood pressure. To prevent this, taper gradually under medical supervision over days to weeks.
How should I take clonidine correctly?
Take it exactly as prescribed at the same times daily. Swallow extended-release tablets whole; do not crush or split. For patches, apply to clean, hairless skin, rotate sites weekly, and press firmly to ensure adhesion. Never stop suddenly; consult your prescriber to taper.
What forms and strengths does clonidine come in?
It’s available as immediate-release tablets, extended-release tablets for ADHD, and weekly transdermal patches for hypertension. Injectable/epidural formulations exist for specialist use in pain management and anesthesia.
Which medications or substances interact with clonidine?
Other blood-pressure-lowering drugs, beta-blockers, and sedatives (opioids, benzodiazepines, sleep aids, alcohol) can increase risks of low blood pressure and sedation. Tricyclic antidepressants may blunt clonidine’s effect; stimulants can complicate heart rate and blood pressure. Always review your full medication list with your clinician.
Is clonidine safe for older adults?
Older adults can be more sensitive to sedation, dizziness, and drops in blood pressure, which may increase fall risk. Lower starting doses, slow titration, and careful monitoring of blood pressure and heart rate are important.
What should I do if I miss a dose of clonidine?
Take it when you remember unless it’s close to the next dose; do not double up. If a patch loosens or falls off, replace it and tell your clinician; keep to your usual change day if advised. Monitor for symptoms like headache or elevated blood pressure.
Does clonidine affect sleep?
Clonidine commonly causes drowsiness and is sometimes used at night for sleep problems in people with ADHD. In some, it may cause vivid dreams or daytime fatigue; dose timing adjustments can help.
Does clonidine cause weight changes?
Clonidine is generally weight-neutral. Some people report decreased appetite or mild weight gain indirectly due to fatigue and decreased activity; constipation can also contribute to a sensation of bloating.
How is clonidine used in kidney disease?
Clonidine is partly cleared by the kidneys, so people with renal impairment may need dose adjustments and closer monitoring for low blood pressure and bradycardia. Your prescriber will individualize dosing and follow labs and vital signs.
What monitoring do I need while on clonidine?
Regular checks of blood pressure and heart rate are essential, especially during dose changes. Report symptoms like lightheadedness, fainting, chest discomfort, or unusual fatigue; your clinician may adjust dose or timing.
Can I take clonidine after drinking alcohol?
It’s best to avoid or minimize alcohol while on clonidine. Alcohol can amplify drowsiness and dizziness, lower blood pressure further, and increase the risk of fainting or accidents.
Is clonidine safe during pregnancy?
Data are limited. Clonidine has been used in pregnancy, but other antihypertensives like labetalol or methyldopa are often preferred. If you’re pregnant or planning pregnancy, do not start or stop clonidine on your own; discuss risks, benefits, and alternatives with your obstetric and prescribing clinicians.
Can I use clonidine while breastfeeding?
Clonidine passes into breast milk and may cause sleepiness, low blood pressure, or poor feeding in infants, and it can reduce milk supply in some mothers. If clonidine is necessary, infant monitoring is important; many clinicians prefer alternative medications during breastfeeding when possible.
Should I stop clonidine before surgery or anesthesia?
Do not stop clonidine abruptly before surgery, as rebound hypertension can occur. Inform your surgical and anesthesia teams; they usually continue clonidine (including patches) and adjust anesthesia and blood-pressure support accordingly.
Is it safe to drive or operate machinery on clonidine?
Until you know how clonidine affects you, avoid driving or hazardous tasks. If you feel drowsy, dizzy, or lightheaded, do not drive; talk with your clinician about dose timing or adjustments.
What should I do in case of clonidine overdose?
Overdose can cause profound drowsiness, slow heart rate, low blood pressure, small pupils, and breathing problems—especially dangerous in children. Call emergency services or poison control immediately; do not wait for symptoms to worsen.
Can I combine clonidine with opioids, benzodiazepines, or sleep aids?
Use great caution. These combinations increase sedation, breathing suppression, and fall risk. If they must be used together, your clinician will use the lowest effective doses and close monitoring; avoid alcohol and do not drive.
Does caffeine affect clonidine?
Caffeine can raise blood pressure and may blunt clonidine’s effect in some people. Moderate intake and consistent timing help your clinician interpret readings; avoid large caffeine swings.
How does clonidine compare with guanfacine for ADHD?
Both are alpha-2 agonists that help with hyperactivity, impulsivity, and sleep. Guanfacine is more selective for alpha-2A receptors and often causes less sedation and hypotension; clonidine may work faster for sleep but can be more sedating. Choice depends on symptom profile, side effects, and dosing convenience.
Clonidine vs guanfacine for high blood pressure: which is better?
Both lower blood pressure, but guanfacine’s longer half-life provides smoother 24-hour control and may have a lower rebound risk. Clonidine offers a transdermal patch option that can improve adherence and reduce peak–trough effects; selection is individualized.
Clonidine vs methyldopa: how do they differ?
Both are centrally acting antihypertensives. Methyldopa is often preferred in pregnancy because of longer safety experience, though it can cause fatigue and liver enzyme elevations. Clonidine can be effective for resistant hypertension and is available as a patch, but it carries more withdrawal risk if stopped abruptly.
Clonidine vs lofexidine for opioid withdrawal: which is preferred?
Lofexidine is an alpha-2 agonist FDA-approved specifically for opioid withdrawal and tends to cause less hypotension and sedation than clonidine. Clonidine is effective off-label and widely available, often at lower cost; clinicians tailor the choice to vital signs, comorbidities, and access.
Clonidine vs dexmedetomidine: are they interchangeable?
No. Both are alpha-2 agonists, but dexmedetomidine is an intravenous sedative used in intensive care and operating rooms. Clonidine is used orally or transdermally for hypertension, ADHD, and withdrawal symptoms in outpatient settings.
Clonidine patch vs oral tablets: which should I use?
Patches deliver steady medication over 7 days, improving adherence and minimizing peaks and troughs; they can irritate skin and take days to reach effect. Oral tablets allow flexible dosing and faster titration but require strict daily adherence and may cause more fluctuating blood levels.
Clonidine vs tizanidine: when is each used?
Both are central alpha-2 agonists, but tizanidine is a muscle relaxant for spasticity. Clonidine treats hypertension, ADHD, and withdrawal. Both can cause sedation and low blood pressure; tizanidine more commonly causes muscle weakness and elevated liver enzymes.
Clonidine vs guanfacine: which has more rebound risk?
Clonidine has a shorter half-life and a higher risk of rebound hypertension if stopped abruptly. Guanfacine’s longer half-life makes withdrawal smoother, though both should be tapered under medical guidance.
Clonidine vs moxonidine or rilmenidine: how do they compare?
Moxonidine and rilmenidine (available in some countries) act mainly on imidazoline I1 receptors and may cause fewer central side effects like sedation and dry mouth. Clonidine is more widely available globally, with robust evidence but higher withdrawal risk if not tapered.
Clonidine vs guanfacine extended-release for pediatric sleep and tics: which helps more?
Both can improve sleep onset and reduce tics. Clonidine may be more sedating and helpful at bedtime; guanfacine ER is often better tolerated during the day due to less sedation and smoother coverage.
Clonidine vs methyldopa in chronic kidney disease–related hypertension: which is favored?
Both can be used, but clonidine is often effective as add-on therapy for resistant blood pressure in CKD, with careful monitoring for bradycardia and sedation. Methyldopa is less commonly used outside pregnancy due to side effects and monitoring needs.
Is clonidine comparable to ocular alpha-2 agonists like brimonidine or apraclonidine?
They share a pharmacologic class but different uses. Brimonidine and apraclonidine are topical eye drops for glaucoma that lower intraocular pressure; systemic clonidine treats hypertension and other systemic conditions and should not be used as an eye medication.
Clonidine vs lofexidine: which is safer for people with low baseline blood pressure?
Lofexidine generally causes less hypotension and bradycardia, making it preferable for opioid withdrawal in patients prone to low blood pressure. If clonidine is used, careful dose selection and monitoring are essential.