Clonidine Dosing Parameters for Hypertension
For antihypertensive therapy, start clonidine at 0.1 mg twice daily (morning and bedtime), with weekly increments of 0.1 mg/day as needed, targeting a typical maintenance range of 0.2-0.6 mg/day in divided doses. 1
Initial Dosing
- Begin with 0.1 mg twice daily (morning and bedtime administration) 1
- Elderly patients should receive a lower initial dose due to increased risk of CNS side effects 1, 2
- Patients with renal impairment require a lower starting dose with careful monitoring 1
Dose Titration
- Increase by 0.1 mg per day at weekly intervals until desired blood pressure response is achieved 1
- Taking the larger portion of the daily dose at bedtime minimizes transient side effects of dry mouth and drowsiness 1
- Dividing doses into twice-daily administration maintains steady blood levels 2
Maintenance Dosing
- Therapeutic range: 0.2-0.6 mg/day in divided doses (most commonly employed) 1
- Maximum effective daily dose is 2.4 mg, though doses this high are rarely used 1
- Steady-state plasma concentrations are typically reached by day 4 of therapy 3
Hypertensive Urgencies/Emergencies (Rapid Titration Protocol)
- Initial dose: 0.1-0.2 mg orally 4
- Follow with 0.05-0.1 mg hourly until goal blood pressure achieved or maximum total dose of 0.7-0.8 mg given 5, 4
- This achieves significant blood pressure reduction in 93% of patients 4
- Mean response time is approximately 1.8 hours with mean effective dose of 0.32 mg 5
Alternative Formulations
- Transdermal patches deliver 0.1-0.3 mg weekly, with maximum blood pressure reduction occurring 2-3 days after initial application and maintained for 7 days 3
- Intramuscular administration (150 mcg) produces effect within 5 minutes, maximal at 75 minutes, persisting 5 hours—useful when oral therapy cannot be tolerated 6
Critical Safety Considerations
- Never abruptly discontinue clonidine—must be tapered to avoid rebound hypertensive crisis 2, 7, 1
- Monitor blood pressure regularly throughout therapy 2
- Common side effects include dry mouth, drowsiness, dizziness, and sedation, which correlate significantly with plasma concentrations 8, 2
- Peak plasma concentration occurs approximately 2 hours after oral administration with elimination half-life of 7.5-7.7 hours 8
Special Populations
- Renal impairment: Lower initial doses required; hemodialysis does not significantly remove clonidine, so no supplemental dosing needed post-dialysis 1
- Elderly: Start with lower doses due to increased CNS adverse effects 1, 2
- Pregnancy: Use only after careful risk-benefit assessment 2