What is the recommended dosing for clonidine (antihypertensive/alpha-2 adrenergic agonist) in treating hypertension and Attention Deficit Hyperactivity Disorder (ADHD)?

Clonidine Dosing for Hypertension and ADHD

For hypertension, clonidine should be started at 0.1 mg orally twice daily and titrated up to a maximum of 0.8 mg daily, while for ADHD, the recommended starting dose is 0.05-0.1 mg at bedtime with titration up to 0.4 mg daily divided in 2-3 doses. 1

Clonidine for Hypertension

Dosing Protocol

• Starting dose: 0.1 mg orally twice daily 1
• Dose range: 0.1-0.8 mg daily 1
• Frequency: Typically divided into 2 doses daily 1
• Maximum dose: 0.8 mg daily 1

Clinical Considerations

• Clonidine is generally reserved as a last-line agent for hypertension due to significant CNS adverse effects, especially in older adults 1
• Available in oral tablets (0.1 and 0.2 mg) and transdermal patches (0.1,0.2,0.3 mg/weekly) 2
• Target blood pressure goals should be individualized based on cardiovascular risk:
  • For patients with known CVD or 10-year ASCVD risk ≥10%: <130/80 mmHg 1
  • For patients without additional CVD risk markers: <130/80 mmHg may be reasonable 1

Special Situations

• Hypertensive urgencies: Can use a loading dose protocol of 0.2 mg initially, followed by 0.1 mg hourly until blood pressure is controlled or maximum 0.8 mg is reached 3, 4
• Pregnancy: Starting dose 0.05-0.1 mg at bedtime with target BP 110-135/85 mmHg 2

Precautions

• Never abruptly discontinue clonidine as it may induce hypertensive crisis; must be tapered to avoid rebound hypertension 1
• Monitor for bradycardia, especially when initiating therapy 5
• Common side effects include drowsiness, fatigue, dry mouth, and hypotension 2

Clonidine for ADHD

Dosing Protocol

• Starting dose: 0.05-0.1 mg orally at bedtime 1
• Titration: Increase by 0.1 mg BID-TID based on response and tolerability 1
• Maximum dose: 0.4 mg daily 1
• Frequency: Usually divided into 2-3 doses daily 1

Clinical Considerations

• Clonidine could be considered as an adjunct agent in ADHD treatment following risk-benefit discussion 1
• Drowsiness is common initially but generally resolves within 6-8 weeks of treatment 5
• In clinical trials, doses were flexibly titrated up to 0.6 mg/day with divided dosing 5

Monitoring

• ECG monitoring may be considered, particularly when used in combination with stimulants 5
• Monitor for bradycardia (occurs in approximately 17.5% of patients) 5
• Watch for sedation, especially during initial treatment period 5

Special Populations

Pregnancy

• Limited evidence suggests clonidine is likely not associated with adverse pregnancy outcomes 1, 2
• Consider alternative antihypertensives with more safety data in pregnancy first (methyldopa, labetalol, nifedipine) 2

Breastfeeding

• Clonidine is excreted in human milk (milk-to-plasma ratio ~2, relative infant dose up to 7.1%) 1, 2
• Monitor breastfed infants for drowsiness, hypotonia, and adequate weight gain 1
• One case report noted infant drowsiness, hypotonia, and suspected seizures with maternal dose of 0.15 mg daily 1

Pediatric ADHD

• Safety data supports use in children with appropriate monitoring 5
• Side effects are more common with clonidine (79.4%) compared to non-clonidine treatments (49.2%) but generally don't lead to discontinuation 5

Potential Adverse Effects to Monitor

• Sedation/drowsiness (most common, especially during initiation)
• Bradycardia and hypotension
• Rebound hypertension with abrupt discontinuation
• Rare cases of heart failure with overdose 6