# Clonidine ### (clonidine hydrochloride, immediate release) **Clonidine** (clonidine hydrochloride, immediate release); not controlled
[**Full Prescribing Information**](https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=a842ab83-3531-44dd-a8a8-64dd89e87026&type=display)[**DailyMed Drug Information**](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=a842ab83-3531-44dd-a8a8-64dd89e87026)
--- ### **Summary** Clonidine immediate-release tablets are a central alpha-2 adrenergic agonist approved for hypertension only, in adults; safety and effectiveness in pediatric patients have not been established. It is short acting and given in divided daily doses. It is not the ADHD product: only extended-release clonidine carries the ADHD indication, and any ADHD use of this tablet is off label, most often a bedtime dose for sleep onset. Not controlled; generic only. --- ### **Forms & Strengths** - **Tablets, immediate release:** 0.05 mg, 0.1 mg, 0.2 mg, 0.3 mg - **Separate labels, not covered here and not interchangeable:** - Clonidine ER tablets 0.1 mg (Kapvay generics): ADHD indicated - Onyda XR, ER oral suspension 0.1 mg/mL: ADHD indicated - Nexiclon XR 0.17 mg: hypertension - Clonidine transdermal system: 0.1, 0.2, 0.3 mg/24 h; hypertension - Javadin oral solution 0.02 mg/mL: adult hypertension - Clonidine injection (Duraclon): epidural analgesia --- ### **Dosing** - **Age:** adults; pediatric safety and effectiveness not established - **Onset:** blood pressure falls in 30 to 60 min, maximum at 2 to 4 hours; ADHD benefit is not an effect of this product - **Duration:** dosed twice daily; half-life 12 to 16 hours - **Initial Dose:** 0.1 mg twice daily, morning and bedtime; lower in elderly or renal impairment - **Titration:** 0.1 mg/day every 7 days to response - **Max Dose:** usual range 0.2 to 0.6 mg/day divided; label maximum effective dose 2.4 mg/day - **Considerations:** This is the hypertension product, not the ADHD product; give the larger share of the daily dose at bedtime to limit dry mouth and drowsiness, and never substitute it milligram-for-milligram for an extended-release clonidine. **Off-label pediatric ADHD dosing:** \[VERIFY\] No FDA-approved pediatric ADHD dosing exists for immediate-release clonidine. Weight-band values published previously are withheld pending a graded pediatric source. For labeled pediatric ADHD dosing use [extended-release clonidine](https://wiki.joshnp.com/link/120) or [Onyda XR](https://wiki.joshnp.com/link/119). --- ### **Pharmacology** - **Mechanism:** Central alpha-2 adrenergic agonist; reduces sympathetic outflow from the locus coeruleus and enhances prefrontal noradrenergic signalling. Not a CNS stimulant; mechanism in ADHD unknown. - **Delivery / Release:** Immediate-release tablet; bioavailability 70% to 80%, peak plasma 1 to 3 hours. - **Metabolism:** About 50% hepatic, 40% to 60% renal unchanged. Half-life 12 to 16 hours, up to 41 in severe renal impairment; haemodialysis removes minimal drug. - **Class Positioning:** Non-selective alpha-2 agonist, more sedating than [guanfacine](https://wiki.joshnp.com/link/5), which is alpha-2A selective. Against [Kapvay](https://wiki.joshnp.com/link/120) and [Onyda XR](https://wiki.joshnp.com/link/119) the difference is kinetic, not pharmacodynamic: same moiety, different release, different indication, no mg-for-mg equivalence. --- ### **Indications** - **Hypertension** (ICD-10: I10): adults, alone or with other antihypertensives. The only approved indication on this label. - **ADHD is not an approved indication for this product.** Extended-release clonidine ([Kapvay](https://wiki.joshnp.com/link/120)) and [Onyda XR](https://wiki.joshnp.com/link/119) are the ADHD-approved clonidine products, ages 6 to 17. --- ### **Off-Label Uses** - **ADHD** (ICD-10: F90.0-F90.9): the studied agents are ER guanfacine and ER clonidine, effect size about 0.7 versus 1.0 for stimulants; the IR tablet is expert consensus at best. (AAP 2019) - **Tic disorders and Tourette syndrome** (ICD-10: F95.1, F95.2): class option, most useful with comorbid ADHD. Supported by controlled trials for the class; limited data for IR clonidine. (AACAP 2013) - **Sleep-onset insomnia in ADHD** (ICD-10: G47.00): commonest real-world use. Limited data; sedation is a labeled adverse effect, not a demonstrated benefit. - **Where the evidence does not support use:** oppositional defiant disorder and aggression (ICD-10: F91.3); insufficient for IR clonidine. --- ### **Contraindications & Warnings** - **Contraindicated:** known hypersensitivity to clonidine - **Warning, withdrawal:** abrupt cessation causes a rapid rise in blood pressure; rare hypertensive encephalopathy, stroke and death reported - **Use with caution:** - Sinus node dysfunction or AV block; severe bradycardia needing atropine and pacing reported - Concurrent sympatholytics, especially digitalis, calcium channel blockers, beta-blockers - Renal impairment; half-life up to 41 hours, so start lower and monitor - Any child prone to vomiting illness; missed doses are de facto abrupt discontinuation - Contact lens wearers, because of dry eyes - Pheochromocytoma; no therapeutic effect expected - **Screen before starting:** - Blood pressure and heart rate, supine and standing - History of syncope, bradycardia, heart block or conduction disease - Renal function - Sympatholytic and sedating co-medication, including any beta-blocker --- ### **Drug Interactions** - **Beta-blockers:** additive bradycardia and worse withdrawal hypertension; if both stop, withdraw the beta-blocker several days first - **AV nodal agents** (digitalis, calcium channel blockers): monitor heart rate; bradycardia needing pacing reported with diltiazem and verapamil - **Sedatives and alcohol** (barbiturates, benzodiazepines, antihistamines): potentiated CNS depression; ask at every visit - **Tricyclic antidepressants:** reduce the hypotensive effect; recheck blood pressure when either is started or stopped - **Neuroleptics:** worsen orthostatic hypotension; check orthostatic vitals after adding either agent - **Other antihypertensives:** additive lowering; adjust and recheck --- ### **Administration** - Same times daily, with or without food; food does not affect kinetics - Give the larger share of the daily dose at bedtime - The 0.1, 0.2 and 0.3 mg tablets are scored and may be bisected - The 0.05 mg tablet is listed by a single labeler; confirm stock with the pharmacy - **Do not substitute mg-for-mg** for [Kapvay](https://wiki.joshnp.com/link/120), [Onyda XR](https://wiki.joshnp.com/link/119) or the transdermal system - Do not stop abruptly; see Discontinuation & Taper - Continue to within 4 hours of surgery, resume promptly, monitor blood pressure perioperatively - Store locked; as little as 0.1 mg has produced toxicity in a small child --- ### **Side Effects** - **Common** (adult label rates, dose related, diminish over time): dry mouth 40%, drowsiness 33%, dizziness 16%, constipation 10%, sedation 10% - **Serious:** - Withdrawal with rebound hypertension, rarely hypertensive encephalopathy, stroke, death; never stop abruptly - Bradycardia, sinus arrest, high-degree AV block; stop and obtain an ECG for syncope or slow, irregular pulse - Orthostatic hypotension and syncope; recheck standing vitals, reduce or hold - Hallucinations, delirium, depression; discontinue and reassess - Raynaud phenomenon, hepatitis, thrombocytopenia, colonic pseudo-obstruction - Angioedema, urticaria, generalised rash, especially after prior transdermal sensitisation --- ### **Monitoring & Labs** - **Heart rate and blood pressure:** baseline, after each increase, then every 3 months - **Orthostatics:** lying and standing at baseline, at every dose change, and at any dizziness visit - **Sedation:** ask at every titration visit and every visit for 3 months; commonest reason for stopping - **Rebound risk:** at every refill confirm no missed doses and restate that the drug is never stopped abruptly - **ECG:** not routine; baseline if conduction disease, syncope history or concurrent sympatholytics, and promptly for new syncope or bradycardia - **Renal function:** baseline, annually, and after any illness that could impair it - **Mood and perception:** ask about depression and hallucinations each visit; neither is volunteered - **Laboratory:** no other routine monitoring required --- ### **Discontinuation & Taper** - **Never stop abruptly.** Reduce the dose gradually over 2 to 4 days - Abrupt cessation: nervousness, agitation, headache, tremor, then rapid blood pressure rise; rarely hypertensive encephalopathy, stroke, death - Risk rises with higher doses and continued beta-blockade; **withdraw the beta-blocker several days first,** then taper clonidine - An excessive post-discontinuation rise reverses with oral clonidine or IV phentolamine - A vomiting illness in a child is de facto abrupt discontinuation; families should call rather than let doses lapse - Drug holidays are not appropriate for this class --- ### **Pregnancy & Lactation** - **Pregnancy:** no adequate controlled human studies; clonidine crosses the placenta. Rats showed increased resorptions, rabbits no teratogenicity. Use only if clearly needed; ER labels note decades of human use without an identified defect risk. - **Lactation:** milk levels about double maternal serum; relative infant dose 4.1% to 8.4%. One infant had drowsiness, hypotonia, suspected seizures and apnoea. Monitor for sedation, lethargy, tachypnoea, poor feeding. (LactMed 2024) - **Lactation, milk supply:** dose-related oxytocin and prolactin effects; postpartum galactorrhea and hyperprolactinaemia with gynecomastia reported. Other antihypertensives preferred while nursing a newborn. (LactMed 2024) --- ### **Counseling Points** - **Counsel the family on:** - Why this tablet is not the ADHD-approved product, and why the box says hypertension - Never stopping on their own, even for a few days; name rebound high blood pressure as the reason - Calling if the child cannot keep the medicine down, because missed doses and withdrawal are the same thing - Dry mouth and drowsiness peaking early, dose related, easing with time - Standing up slowly, and calling rather than pushing through dizziness - Keeping the bottle locked; one 0.1 mg tablet can seriously harm a small child - Avoiding alcohol and sedating medicines, including over-the-counter antihistamines - **Advise them to call for:** - Fainting, or dizziness on standing that does not settle in a minute or two - A pulse that feels very slow or irregular - Drowsiness so heavy the child is hard to wake - Severe headache with blurred vision or confusion, especially after missed doses - Seeing or hearing things that are not there, or a marked mood change - Numbness or colour change in the fingers or toes - Any vomiting illness that stops the medicine going down --- ### **References** 1. DailyMed. Clonidine hydrochloride tablets, USP prescribing information. Actavis Pharma, Inc. 2022. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=a842ab83-3531-44dd-a8a8-64dd89e87026 2. DailyMed. Clonidine hydrochloride extended-release tablets prescribing information. Actavis Pharma, Inc. 2023. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=0100c70d-7fde-46a1-8374-940550a27e43 3. DailyMed. Catapres-TTS (clonidine transdermal system) prescribing information. Boehringer Ingelheim. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=39e1d35e-533c-4647-8649-8168a6e92dfa 4. LactMed. Clonidine. Drugs and Lactation Database, National Institute of Child Health and Human Development. 2024. https://www.ncbi.nlm.nih.gov/books/NBK501628/ 5. American Academy of Pediatrics. Clinical practice guideline for the diagnosis, evaluation, and treatment of attention-deficit/hyperactivity disorder in children and adolescents. Pediatrics. 2019. https://publications.aap.org/pediatrics/article/144/4/e20192528/81590/ 6. AACAP. Practice parameter for the assessment and treatment of children and adolescents with tic disorders. Journal of the American Academy of Child and Adolescent Psychiatry. 2013. https://www.jaacap.org/article/S0890-8567(13)00695-3/fulltext 7. FDA. openFDA National Drug Code Directory, clonidine, queried by generic name across all labelers. 2026. https://api.fda.gov/drug/ndc.json?search=generic\_name:%22clonidine%22&limit=1000