Clonidine

(clonidine)

Forms/Strengths

• Tablets: 0.1 mg, 0.2 mg, 0.3 mg

Dosing

• Age: ≥ 6yr
• Onset: 30-60 min (oral)
• Duration: 6-12 hours
• Considerations: Monitor for bradycardia and hypotension; taper gradually over 2-4 days (or longer based on dose/duration) to avoid rebound hypertension; often dosed BID with larger dose at bedtime for ADHD
• Initial Dose:
  • 27-40 kg: 0.05 mg nightly
  • 40+ kg: 0.1 mg nightly
• Titration: 
  • Increase 0.05mg every 3-7 d taper gradually over 2-4 days to discontinue
• Max Dose:
  • 27-40 kg: 0.2 mg/day 
  • 40+ kg: 0.4 mg/day

Quick Facts

• Central alpha-2 adrenergic agonist that reduces norepinephrine release and sympathetic outflow from the locus coeruleus.
• Improves ADHD symptoms of hyperactivity, impulsivity, and inattention, especially as adjunct to stimulants.
• Particularly useful off-label for ADHD with tics, aggression, or sleep issues.
• Sedation common early and dose-dependent; often improves with time or bedtime dosing.
• Low abuse potential; not a controlled substance.
• Risk of rebound hypertension with abrupt discontinuation.
• Not FDA-approved for ADHD (extended-release form Kapvay is approved).
  

Indications

• Hypertension (ICD-10: I10, I11.0, I11.9)

Off-Label Uses

• ADHD (ICD-10: F90.0, F90.1, F90.2, F90.8, F90.9) – adjunct or monotherapy for hyperactivity/impulsivity.
• Tic disorders/Tourette syndrome (ICD-10: F95.1, F95.2) – reduces tics via noradrenergic modulation.
• Oppositional defiant disorder (ICD-10: F91.3) – decreases aggression when added to stimulants.
• Insomnia/sleep disturbances in ADHD (ICD-10: G47.00) – promotes sleep with bedtime dosing.
  

How to Take

• Take at the same time each day for consistency.
• Can be taken with or without food.
• Swallow whole; do not crush or chew.
• If used for ADHD, often given twice daily, with the larger dose at bedtime to minimize drowsiness.
• Do not suddenly stop taking; tapering may be required to prevent rebound hypertension.
  
• Transdermal patches should be applied to a hairless area on the upper outer arm or chest.

Side Effects

• Common:
  • Sedation/drowsiness (most prominent initially)
  • Dry mouth
  • Dizziness/orthostatic hypotension
  • Constipation
  • Fatigue/headache
• Serious:
  • Bradycardia/hypotension
  • Rebound hypertension (with abrupt stop)
  • Depression, hallucinations (rare)
  • AV block (in cardiac disease)

Monitoring / Labs

• Baseline and periodic blood pressure and heart rate (supine and standing).
• ECG if history of cardiac disease.
• Renal function (dose adjust in impairment).
• Growth parameters in children (long-term use).
  

Education

• When to Call the Doctor:

  • Severe dizziness, fainting, or low blood pressure.
  • Slow or irregular heart rate.
  • Signs of over-sedation, such as excessive drowsiness or difficulty waking.
  • Mood changes, hallucinations, or unusual behavior.
  • Severe headache, blurred vision, or confusion (possible hypertensive rebound if stopped abruptly).

• Safety Tips:

  • Monitor blood pressure and heart rate regularly.
  • Avoid alcohol and sedatives, which may enhance drowsiness.
  • Rise slowly from sitting or lying positions to prevent dizziness.
  • Do not suddenly discontinue, as this may lead to rebound hypertension.
  • Be cautious when driving or operating machinery until individual response is known.

• Parent Tips for Pediatric Patients:

  • May cause daytime drowsiness; consider giving the larger dose at bedtime.
  • Monitor for irritability, behavioral changes, or mood swings.
  • Encourage hydration and salt intake if dizziness occurs.
  • Ensure the child does not engage in high-risk activities (e.g., climbing, swimming unsupervised) if excessively drowsy.
  • Keep in child-proof packaging to prevent accidental overdose.

Additional Information

• Contraindications:

  • Hypersensitivity to clonidine or formulation components.
  • Use with caution in patients with severe heart disease, bradycardia, or hypotension.

• Pregnancy:

  • Category C; use only if benefits outweigh risks.
  • May cause neonatal withdrawal symptoms.

• Lactation:

  • Excreted in breast milk; use with caution due to potential effects on infant blood pressure.

• Drug Interactions:

  • CNS depressants (e.g., alcohol, benzodiazepines) may increase sedation.
  • Beta-blockers may enhance bradycardia; caution if discontinuing either drug.
  • Stimulants (e.g., amphetamines) may counteract clonidine’s effects.
  • Antihypertensive medications may lead to excessive blood pressure lowering.

References

1. Clonidine HCl Tablets Prescribing Information (DailyMed/FDA), 2023, https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=5fe10c92-621a-4d36-b030-34098351a1e2
2. StatPearls: Clonidine, 2024, https://www.ncbi.nlm.nih.gov/books/NBK459124/
3. Safety and Efficacy of Clonidine in Children with ADHD (PMC), 2014, https://pmc.ncbi.nlm.nih.gov/articles/PMC3926778/
4. AACAP Practice Parameters for ADHD (via UpToDate integration), 2022, https://www.uptodate.com/contents/attention-deficit-hyperactivity-disorder-in-children-and-adolescents-treatment-with-nonstimulant-medications