Clonidine Dosing for Hypertension
For chronic hypertension management, start with 0.1 mg twice daily (morning and bedtime), which can be increased by 0.1 mg per day at weekly intervals up to a usual maintenance range of 0.2-0.6 mg daily in divided doses, with a maximum effective dose of 2.4 mg daily. 1
Standard Dosing Algorithm
Initial Dosing
- Start with 0.1 mg twice daily (morning and bedtime) for most adults 1
- Elderly or frail patients should start at 0.05 mg twice daily to minimize adverse effects 1, 2
- Consider taking the larger portion at bedtime to minimize dry mouth and drowsiness 1
Dose Titration
- Increase by 0.1 mg per day at weekly intervals until blood pressure control is achieved 1
- Therapeutic range: 0.2-0.6 mg daily in divided doses 3, 1
- Maximum effective dose: 2.4 mg daily, though doses this high are rarely needed 1
Critical Safety Parameters
When to Hold Clonidine
- Hold if systolic BP <90 mmHg, diastolic BP <60 mmHg, or heart rate <50 bpm to prevent cardiovascular compromise 4
- Hold if orthostatic hypotension is present, particularly in elderly patients 4
Monitoring Requirements
- Check BP and heart rate before each dose 4
- Monthly follow-up until BP control achieved, with target achievement within 3 months 4
- Target BP reduction: at least 20/10 mmHg from baseline 4, 5
- Goal BP: <140/90 mmHg for general population, or <130/80 mmHg for patients with CVD or 10-year ASCVD risk ≥10% 4
Clinical Context and Positioning
Role in Hypertension Management
- Clonidine is a last-line agent, reserved for resistant hypertension after failure of ACE inhibitors/ARBs, calcium channel blockers, thiazide diuretics, and spironolactone 3, 4, 6
- Not first-line therapy due to significant CNS adverse effects, especially in older adults 3, 4
- Consider as add-on therapy when spironolactone is not tolerated or contraindicated 3
Acute/Urgent Situations
Rapid Titration Protocol (Hypertensive Urgencies)
- Initial dose: 0.1-0.2 mg orally 7, 8, 9, 10
- Follow with 0.05-0.1 mg hourly until goal BP achieved or maximum 0.7-0.8 mg total dose given 7, 8, 9
- 93% of patients respond with mean dose of 0.26-0.5 mg and response time of 1.8-2 hours 7, 8, 9, 10
- Note: Immediate-release nifedipine is preferred over clonidine for hypertensive urgencies due to faster onset 5, 6
Critical Warnings
Discontinuation
- Never abruptly discontinue clonidine - this can induce severe hypertensive crisis 3, 4
- Always taper gradually when discontinuing 3, 4
Special Populations
- Renal impairment: Use lower initial doses and monitor carefully 1
- No supplemental dosing needed after hemodialysis as minimal clonidine is removed 1
- Elderly patients: Start at 0.05 mg twice daily and titrate cautiously 1, 2
Common Pitfalls to Avoid
- Do not use as monotherapy initially - clonidine should only be added after optimizing first-line agents 3, 6
- Avoid excessive or rapid BP reduction which can cause organ hypoperfusion 4, 5
- Do not discharge patients on intensified regimens without clear follow-up plans 5
- Watch for CNS side effects (drowsiness, dry mouth) which are common but usually manageable 7, 8, 9, 10