Onyda XR

(clonidine hydrochloride extended-release oral suspension, 0.1 mg/mL)

Onyda XR (clonidine hydrochloride); not controlled

Summary

Onyda XR is extended-release clonidine as an orange-flavoured oral suspension, a central alpha-2 adrenergic agonist approved for ADHD in patients 6 years and older, as monotherapy or added to a stimulant. It is the only clonidine product dosed once daily at bedtime, and the only liquid alpha-2 agonist, which is what recommends it for a child who cannot swallow tablets or who needs a dose the tablet cannot make. Not controlled; brand only, from a single manufacturer.

Forms & Strengths

• Extended-release oral suspension (orange, light beige to tan, viscous): 0.1 mg/mL
• Dose maps to volume: 0.1 mg is 1 mL, 0.2 mg is 2 mL, 0.3 mg is 3 mL, 0.4 mg is 4 mL

Dosing

• Age: 6 y/o and older; not established below 6 years
• Onset: sedation within hours; ADHD benefit over weeks, trial endpoint at 5 weeks
• Duration: once daily; clonidine half-life 12 to 16 hours, up to 41 in severe renal impairment
• Release Profile: clonidine complexed with sodium polystyrene sulfonate; 0.095 mg/mL resin-bound plus 0.005 mg free. Steady-state exposure close to ER tablets twice daily, trough about 26% lower
• Initial Dose: 0.1 mg (1 mL) once daily at bedtime, with or without food
• Titration: 0.1 mg/day every 7 days
• Max Dose: 0.4 mg (4 mL) once daily at bedtime; higher doses were not evaluated
• Considerations: Shake gently at least 10 seconds before every dose and measure only with the supplied dispenser. Do not substitute for any other clonidine product mg-for-mg, and never stop abruptly.

For patients switching from another clonidine product, discontinue that treatment and titrate Onyda XR from 0.1 mg. Do not substitute milligram for milligram; the pharmacokinetic profiles differ.

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: Resin-complexed extended release; median Tmax 7.5 hours (range 4 to 17) against 3 to 5 for immediate release. Steady-state peak 107.9% and exposure 97.7% of ER tablets. Food has no effect.
• Metabolism: About 50% hepatic, 40% to 60% renal unchanged. Half-life 12 to 16 hours, up to 41 hours in severe renal impairment.
• Alcohol and dose dumping: in vitro, 20% alcohol produced faster and more variable release; 5% and 10% did not.
• Class Positioning: Non-selective, more sedating than guanfacine (Intuniv). Same pharmacology as clonidine ER tablets but once daily and measurable to any dose; IR clonidine is not ADHD approved.

Indications

• ADHD, as monotherapy (ICD-10: F90.0, F90.1, F90.2, F90.8, F90.9): patients 6 y/o and older
• ADHD, as adjunctive therapy to CNS stimulants (ICD-10: F90.0, F90.1, F90.2, F90.8, F90.9): patients 6 y/o and older

Off-Label Uses

• Tic disorders and Tourette syndrome (ICD-10: F95.1, F95.2): supported by controlled trials for the class, limited data for this product. (AACAP 2013)
• Sleep-onset insomnia in ADHD (ICD-10: G47.00): limited data. Somnolence is a labeled adverse effect, but this is the only clonidine whose labeled schedule is a single bedtime dose.
• Where the evidence does not support use:
  • Children under 6 (ICD-10: F90.x): insufficient (AHRQ 2018), though the liquid makes dosing a preschooler easy
  • Oppositional defiant disorder and aggression (ICD-10: F91.3): insufficient
  • Anxiety and PTSD (ICD-10: F41.x, F43.1): insufficient

Contraindications & Warnings

• Contraindicated: history of hypersensitivity to clonidine, including generalised rash, urticaria or angioedema
• Use with caution:
  • Hypotension, heart block, bradycardia, cardiovascular or cerebrovascular disease, renal failure; titrate slowly
  • Syncope, orthostatic hypotension, or a tendency to dehydration; avoid dehydration and overheating
  • Conduction abnormality or concurrent sympatholytics; severe bradycardia needing pacing reported
  • Concurrent CNS depressants, because of additive sedation
  • Renal impairment; set the initial dose by degree of impairment
  • Recurrent vomiting illness, named in this label: missed doses raise the rebound hypertension risk
  • Prior sensitisation to the clonidine patch; oral use may cause generalised rash
• Screen before starting:
  • Heart rate and blood pressure, supine and standing; the label makes this mandatory
  • Syncope, palpitations, conduction disease, family history of sudden cardiac death, and all sedating or sympatholytic co-medication
  • Renal function
  • Whether the family can measure a liquid dose reliably and track the discard window

Drug Interactions

• Sinus node and AV nodal agents (digitalis, calcium channel blockers, beta-blockers): additive bradycardia and AV block; label says avoid use. If unavoidable, check vitals each visit
• CNS depressants (alcohol, barbiturates, benzodiazepines, phenothiazines, sedating antihistamines): potentiated sedation; reduce or avoid, and counsel adolescents on alcohol
• Antihypertensives: potentiated hypotension; monitor blood pressure and adjust
• Tricyclic antidepressants: may reduce the hypotensive effect; recheck blood pressure when either is started or stopped
• Amphetamine: clonidine clearance 44% lower, and 11% higher with methylphenidate; titrate more cautiously and watch for sedation and bradycardia

Administration

• Once daily at bedtime, with or without food
• Insert the press-in bottle adapter before first use and leave it in place
• Shake gently up and down at least 10 seconds before every dose; vigorous shaking foams it and spoils the draw
• Measure only with the supplied oral dispenser, never a spoon
• Supplied in 30 mL, 60 mL and 120 mL bottles
• Discard 30 days after opening a 30 mL or 60 mL bottle, 60 days after opening a 120 mL bottle. Store at room temperature, protected from light
• Missed dose: skip it; never exceed the prescribed daily total
• Switching: stop the other product and titrate from 0.1 mg; never convert mg-for-mg from ER tablets or IR clonidine
• Do not stop abruptly; see Discontinuation & Taper

Side Effects

• Common (at least 5% and twice placebo, from the ER tablet trials this label cites):
  • Somnolence, fatigue, irritability, nightmare, insomnia, constipation, dry mouth
  • Somnolence 38% at 0.2 mg/day and 31% at 0.4 mg/day, vs 4% placebo
  • As adjunct: somnolence 19% vs 7%, plus fatigue, decreased appetite, dizziness
• Serious:
  • Rebound hypertension on abrupt discontinuation; this label adds that a vomiting illness causing missed doses raises that risk
  • Dose-related hypotension and bradycardia; hold or reduce and recheck
  • Syncope; stop and check orthostatic vitals before further titration
  • Conduction abnormality or AV block; severe bradycardia has needed pacing. Obtain an ECG and stop
  • Allergic reactions including generalised rash, urticaria and angioedema; discontinue

Monitoring & Labs

• Heart rate and blood pressure: baseline, 1 to 2 weeks after each increment, then every 3 months; hold titration for bradycardia by age
• Orthostatics: lying and standing at baseline, every dose change, and any dizziness visit
• Sedation: ask about morning grogginess at every titration visit and every visit for 3 months
• Rebound hypertension risk: at every refill confirm no missed doses or supply gap, and ask about recent gastroenteritis
• Dosing technique: at first follow-up have the caregiver demonstrate shaking and drawing the dose
• ADHD response: rated scale at 5 to 8 weeks, matching the bridged trial endpoint
• ECG: not routine; baseline if conduction disease, syncope history or concurrent sympatholytics, and promptly for new syncope or bradycardia
• Renal function: baseline and annually
• Laboratory: no routine laboratory monitoring required

Discontinuation & Taper

• Never stop abruptly. Reduce by no more than 0.1 mg (1 mL) every 3 to 7 days; from 0.4 mg that is 12 days to 4 weeks
• Abrupt cessation in adults: headache, tachycardia, nausea, flushing, chest tightness, anxiety
• With immediate-release clonidine: nervousness, agitation, tremor and a rapid rise in blood pressure
• A vomiting illness is de facto abrupt discontinuation, named in this label for children; families should call, and recheck blood pressure afterwards
• Measure blood pressure and heart rate at each taper step and after the last dose
• Drug holidays are not appropriate for this class. Weekend and summer breaks are a rebound hypertension risk here

Pregnancy & Lactation

• Pregnancy: decades of human use show no identified risk of major birth defects, miscarriage or adverse outcomes. Animal resorptions at 10x (rat) and 5x (mouse) the maximum human dose; no rabbit effect to 3x.
• Lactation: relative infant dose 4.1% to 8.4%; milk levels about double maternal serum. Most infants unaffected; one case of sedation, hypotonia and apnoea. Monitor for lethargy, tachypnoea and poor feeding. (LactMed 2024)
• Lactation, milk supply: dose-related oxytocin and prolactin effects, with postpartum galactorrhea reported. Other agents are preferred while nursing a newborn or preterm infant. (LactMed 2024)
• Fertility: animal findings suggest impaired fertility in both sexes
• Exposure Registry: National Pregnancy Registry for Psychiatric Medications, 1-866-961-2388, womensmentalhealth.org

Counseling Points

• Counsel the family on:

  • Shaking gently 10 seconds before every dose, and using only the supplied dispenser; an unshaken bottle underdoses early and overdoses late
  • Writing the opening date on the bottle, because it is discarded at 30 or 60 days whether or not it is empty
  • The bedtime-only schedule; this is not the twice-daily tablet and the dose does not carry across
  • Sleepiness early being expected while the ADHD benefit takes weeks; watch for morning grogginess
  • Never stopping on their own; name rebound high blood pressure in those words, and never doubling a missed dose
  • Calling during any stomach bug that stops the medicine going down
  • Avoiding alcohol in adolescents, for sedation and because alcohol can speed release

• Advise them to call for:

  • Fainting, or dizziness on standing that does not settle
  • A pulse that feels very slow or irregular
  • Morning sleepiness affecting school, or a child hard to wake
  • Severe headache with blurred vision, especially after missed doses
  • New hives, facial or lip swelling, or a widespread rash
  • Any vomiting illness that stops the medicine going down

References

1. DailyMed. Onyda XR (clonidine hydrochloride) extended-release oral suspension prescribing information. NextWave Pharmaceuticals. 2025. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=4a15c850-9da5-4bdc-a34d-7f740a6149b7
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. LactMed. Clonidine. Drugs and Lactation Database, National Institute of Child Health and Human Development. 2024. https://www.ncbi.nlm.nih.gov/books/NBK501628/
4. 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/
5. 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
6. AHRQ. Attention deficit hyperactivity disorder: diagnosis and treatment in children and adolescents. Comparative Effectiveness Review No. 203. 2018. https://www.ncbi.nlm.nih.gov/books/NBK487764/
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