From the Guidelines
Clonidine is primarily indicated for treating hypertension, attention deficit hyperactivity disorder (ADHD), and certain pain conditions, with its use as a central alpha-2 agonist providing therapeutic benefits in these areas. The medication works by stimulating alpha-2 adrenergic receptors in the brain stem, which reduces sympathetic outflow and decreases peripheral vascular resistance, heart rate, and blood pressure 1.
Key Indications and Uses
- Hypertension: Clonidine is used to treat high blood pressure, with a typical starting dose of 0.1 mg twice daily, gradually increasing to 0.2-0.6 mg daily in divided doses 1.
- ADHD: It's commonly prescribed for attention deficit hyperactivity disorder (ADHD) in children and adolescents when stimulants are ineffective or contraindicated, often as an adjunct therapy 1.
- Pain Conditions: Clonidine is effective for treating certain pain conditions, particularly neuropathic pain, often as an adjunct therapy.
Administration and Dosage
- The recommended starting dose for hypertension is 0.1 mg twice daily, with gradual increases as needed and tolerated 1.
- For ADHD, clonidine is typically administered in the evening due to its sedative effects, with doses ranging from 0.1 to 0.4 mg/day 1.
Side Effects and Precautions
- Common side effects include sedation, dry mouth, dizziness, and constipation 1.
- Abrupt discontinuation should be avoided as it can cause rebound hypertension; the medication should be tapered gradually over 2-4 days when discontinuing 1.
Clinical Considerations
- Clonidine is generally reserved as a last-line treatment for hypertension due to its significant CNS adverse effects, especially in older adults 1.
- Its use in ADHD and pain management offers an alternative for patients who cannot tolerate first-line treatments or have specific comorbid conditions that make clonidine a preferable option 1.
From the FDA Drug Label
Clonidine hydrochloride tablets, USP are indicated in the treatment of hypertension. Clonidine hydrochloride tablets, USP may be employed alone or concomitantly with other antihypertensive agents. The main indication of clonidine is for the treatment of hypertension. It can be used alone or concomitantly with other antihypertensive agents 2.
From the Research
Clonidine Indications
- Clonidine is indicated for the treatment of hypertension, including all grades of hypertension 3, 4, 5.
- It can be used as monotherapy or in combination with a diuretic to achieve blood pressure control 3, 4.
- Clonidine is effective in patients with renal failure or in hypertensive crisis 3.
- It can also be used in the elderly hypertensive population, with or without a diuretic 4.
- Clonidine has been shown to be effective in reducing blood pressure in patients with asymptomatic severe hypertension, although the response to clonidine can be unpredictable 6.
Clonidine Mechanism of Action
- Clonidine stimulates alpha2-adrenoceptors in the pons-medulla region of the brain, leading to peripheral sympathoinhibition and a reduction in blood pressure 7.
- Clonidine is also considered a mixed agonist that stimulates both alpha2- and I1-receptors, with the latter being another target of centrally acting antihypertensive drugs 7.
Clonidine Efficacy and Safety
- Clonidine has been shown to be effective in reducing blood pressure in various patient populations, including those with essential hypertension, renal failure, and asymptomatic severe hypertension 3, 4, 5, 6.
- The safety profile of clonidine is generally considered favorable, although it can cause side effects such as mental changes, acute kidney injury, and precipitous blood pressure decline 4, 5, 6.