What is the recommended use of clonidine (Hypertension (HPB)) in managing hypertension?

From the Guidelines

Clonidine is recommended as a fourth-line or later agent for managing hypertension, rather than as initial therapy, due to its significant CNS adverse effects, especially in older adults 1.

Key Points

• The typical starting dose of clonidine is 0.1 mg twice daily, which can be gradually increased to a maximum of 0.8 mg daily divided into two or three doses 1.
• Clonidine works by stimulating alpha-2 adrenergic receptors in the brain, reducing sympathetic outflow and thereby lowering blood pressure.
• It's particularly useful in patients with renal dysfunction or those who have not responded adequately to first-line agents like thiazide diuretics, ACE inhibitors, ARBs, or calcium channel blockers.
• When prescribing clonidine, it's essential to be aware of potential side effects, including dry mouth, sedation, and fatigue.
• Patients should be cautioned against abrupt discontinuation as this can cause rebound hypertension; the medication should be tapered gradually over several days 1.
• Clonidine is available in immediate-release oral tablets, extended-release oral tablets (Kapvay), and transdermal patches (Catapres-TTS), which are applied once every 7 days and may improve adherence for some patients.

Considerations

• Clonidine should be used with caution in patients with significant CNS adverse effects, especially in older adults 1.
• The 2020 International Society of Hypertension global hypertension practice guidelines recommend considering the addition of clonidine as a fourth-line agent in patients with resistant hypertension 1.
• Other guidelines, such as the 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline, also recommend clonidine as a secondary agent for hypertension management 1.

From the FDA Drug Label

DOSAGE AND ADMINISTRATION Adults The dose of clonidine hydrochloride tablets, USP must be adjusted according to the patient’s individual blood pressure response. INDICATIONS AND USAGE Clonidine hydrochloride tablets, USP are indicated in the treatment of hypertension. The recommended use of clonidine in managing hypertension (HPB) is to adjust the dose according to the patient's individual blood pressure response, with a general guide of:

• Initial Dose: 0.1 mg tablet twice daily (morning and bedtime)
• Maintenance Dose: Further increments of 0.1 mg per day may be made at weekly intervals if necessary until the desired response is achieved
• Therapeutic Doses: Most commonly employed have ranged from 0.2 mg to 0.6 mg per day given in divided doses 2 Clonidine may be employed alone or concomitantly with other antihypertensive agents in the treatment of hypertension 2

From the Research

Clonidine Use in Hypertension (HPB)

• Clonidine is effective in the treatment of all grades of hypertension, including essential hypertension and hypertensive crisis 3.
• The recommended initial oral dose of clonidine for hypertensive emergencies is 0.1 to 0.2 mg, followed by hourly doses of 0.05 or 0.1 mg until goal blood pressure is attained 4.
• Clonidine can be used in combination with other antihypertensive agents, such as diuretics, to achieve better blood pressure control 3.
• Oral clonidine loading and titration is a safe and effective method for controlling severe elevations of blood pressure in hypertensive crisis 4, 5.

Dosage and Administration

• The average dose of clonidine required to achieve a significant reduction in blood pressure is 0.5 mg 5.
• Clonidine can be administered in a "loading" dose of 0.2 mg, followed by 0.1 mg hourly until the blood pressure is substantially reduced 5.
• The use of clonidine in hospitalized older people is common, with a mean number of doses per patient of 1.8 ± 2.0 6.

Safety and Efficacy

• Clonidine has been shown to be effective in reducing blood pressure in patients with hypertensive emergencies, with a response rate of 82.1% 5.
• The use of clonidine is associated with minimal side effects, although potential adverse reactions can occur, including stroke and falls 6.
• Clonidine may have an advantage over other antihypertensive drugs administered parenterally due to its rapid onset and little need for dosing adjustment 5, 6.