What is the typical dosage of Clonidine (Catapress) for treating hypertension and ADHD?

Clonidine (Catapres) Dosing for Hypertension and ADHD

Hypertension Dosing

For chronic hypertension management, start clonidine at 0.1 mg twice daily (morning and bedtime), with weekly increases of 0.1 mg/day as needed, typically reaching maintenance doses of 0.2-0.6 mg/day in divided doses, though it should be reserved as a last-line agent due to significant CNS adverse effects. 1

Standard Chronic Hypertension Protocol

• Initial dose: 0.1 mg tablet twice daily (morning and bedtime); elderly patients should start at lower doses 1
• Titration: Increase by 0.1 mg per day at weekly intervals until blood pressure target is achieved 1
• Maintenance range: 0.2-0.6 mg per day in divided doses is most commonly used 1
• Maximum effective dose: 2.4 mg daily, though doses this high are rarely employed 1
• Dosing strategy: Take the larger portion of the daily dose at bedtime to minimize dry mouth and drowsiness 1

Position in Treatment Algorithm

• Clonidine is generally reserved as last-line therapy because of significant CNS adverse effects, especially in older adults 2
• Use clonidine only after first-line agents (ACE inhibitors/ARBs, calcium channel blockers, thiazide diuretics) and spironolactone have failed or are contraindicated 3
• The oral formulation requires twice-daily dosing, while the transdermal patch (0.1-0.3 mg) can be applied once weekly 2

Hypertensive Urgency/Emergency Dosing

For severe hypertension requiring rapid reduction, use oral clonidine loading: 0.2 mg initially, followed by 0.1 mg hourly until blood pressure is controlled or a maximum cumulative dose of 0.7-0.8 mg is reached. 3, 4

• Loading protocol: Initial dose of 0.1-0.2 mg, then 0.05-0.1 mg hourly 4
• Success rate: 93% of patients achieve significant blood pressure reduction with this protocol 4
• Response time: Average 1.8 hours with mean dose of 0.32 mg 5
• Target reduction: Aim for at least 20/10 mmHg decrease, ideally toward 140/90 mmHg 3, 6
• Maximum total dose: 0.7-0.8 mg in the loading protocol 4, 7

Special Populations

• Renal impairment: Start with lower initial doses and monitor carefully; hemodialysis does not remove clonidine significantly, so no supplemental dosing is needed post-dialysis 1

ADHD Dosing

The evidence provided does not contain specific FDA-approved dosing for ADHD. Clonidine is used off-label for ADHD, typically starting at 0.05 mg at bedtime and titrating slowly, with maximum doses generally not exceeding 0.3 mg/day when used for this indication 8. However, this is extrapolated from combination therapy guidance rather than primary ADHD treatment guidelines.

Critical Safety Warnings

Rebound Hypertension Risk

Never abruptly discontinue clonidine—it must be tapered to avoid rebound hypertension and potential hypertensive crisis. 2, 3, 8

• Abrupt cessation can induce severe rebound hypertension 2
• This is the most dangerous pitfall with clonidine therapy 3
• Always taper the medication when discontinuing 8

Common Adverse Effects

• CNS effects: Sedation, drowsiness, and dry mouth are common 3, 1
• Cardiovascular effects: Bradycardia and hypotension, particularly orthostatic hypotension in elderly patients 8
• Monitor blood pressure and heart rate at each visit, especially during dose adjustments 8

Drug Interactions

• When combining with other CNS depressants (e.g., fluoxetine), start with low doses (0.05 mg at bedtime) and never exceed 0.3 mg/day due to additive cardiovascular effects 8
• Both medications can cause bradycardia and hypotension, requiring systematic cardiovascular monitoring 8

Contraindications for Combination Therapy

• History of sudden death, repeated fainting, or arrhythmias in patient or first-degree family members 8
• Pre-existing significant bradycardia or second-degree AV block 8