What are the uses and dosages of Clonidine (clonidine)?

Clonidine: Clinical Uses and Dosing

Primary Indications

Clonidine is FDA-approved primarily for hypertension, with off-label uses including ADHD (particularly as a second-line non-stimulant option), anxiety disorders, PTSD-associated nightmares, and opioid withdrawal management. 1

Hypertension (FDA-Approved)

For hypertension, start with 0.1 mg twice daily (morning and bedtime), with weekly increases of 0.1 mg/day as needed until blood pressure is controlled. 1

• Therapeutic doses typically range from 0.2-0.6 mg/day in divided doses 1
• Maximum effective daily dose is 2.4 mg, though doses this high are rarely needed 1
• Elderly patients should start at lower initial doses 1
• Taking the larger portion at bedtime minimizes dry mouth and drowsiness 1

For hypertensive urgencies/emergencies, oral clonidine loading can achieve rapid blood pressure control: start with 0.1-0.2 mg, followed by 0.05-0.1 mg hourly until goal blood pressure is reached or a total of 0.7-0.8 mg is given. 2, 3 This achieves successful blood pressure reduction in 93% of patients within 1-2 hours. 3

ADHD (Off-Label, Second-Line)

Clonidine functions as a non-stimulant option for ADHD through alpha-2 adrenergic receptor agonism, providing "around-the-clock" effects but with smaller effect sizes compared to stimulants. 4

• Particularly useful as first-line when comorbid sleep disorders, substance use disorders, disruptive behavior disorders, or tic/Tourette's disorder are present 4
• Requires 2-4 weeks until therapeutic effects are observed 4
• Twice-daily dosing is necessary for immediate-release formulations 4
• Transdermal patches are available for more consistent delivery 4
• Can be used to augment stimulant treatment 4

Anxiety and PTSD

For anxiety, initiate at 0.05-0.1 mg at bedtime to minimize side effects, gradually increasing to 0.1 mg 2-3 times daily, with a maximum of 0.4 mg/day. 5

• For PTSD-associated nightmares specifically, doses of 0.2-0.6 mg in divided doses have demonstrated efficacy 5
• Clonidine acts as a central alpha-2 agonist that suppresses sympathetic nervous system outflow, producing anxiolytic effects 5

Opioid Withdrawal

Clonidine helps manage withdrawal symptoms during opioid tapering, though specific dosing protocols are not clearly established in guidelines. 5

Formulations and Bioequivalence

• Oral tablets: 0.1-0.8 mg daily, typically divided into two doses 6
• Transdermal patches: Provide steady-state plasma concentrations by day 4, with maximum blood pressure reduction occurring 2-3 days after application and maintained for 7 days 7
• The transdermal system releases drug proportional to surface area, with the smallest system being 3.5 cm² 7

Critical Safety Monitoring

Never discontinue clonidine abruptly—this can precipitate hypertensive crisis with rebound hypertension; always taper the medication. 5, 8

• Monitor pulse and blood pressure regularly 4, 5, 8
• Common side effects include orthostatic hypotension, drowsiness, dry mouth, and sedation 5, 8
• Clonidine is generally reserved as a last-line antihypertensive agent in older adults due to significant CNS adverse effects 5, 8
• In ADHD treatment, monitor for somnolence/sedation (evening administration is preferable) 4
• For ADHD in children, also monitor suicidality and clinical worsening 4

Special Populations

Patients with renal impairment should start at lower doses with careful monitoring, though hemodialysis does not require supplemental dosing. 1

Clonidine is primarily metabolized via CYP2D6, which may affect dosing in patients with genetic polymorphisms or drug interactions. 6