Clonidine Use in Severe Hypertension with Hyperglycemia

Primary Concerns with Clonidine

The American Heart Association/American College of Cardiology guidelines recommend avoiding clonidine in patients with severe hypertension and heart failure, due to increased mortality risk associated with moxonidine, a similar centrally-acting sympatholytic, with a Class III (Harm) recommendation 1, 2, 3
Clonidine should probably be avoided in patients with heart failure because of the class effect observed with moxonidine, despite lack of direct mortality data 1, 2, 3
The American Heart Association/American College of Cardiology guidelines represent a Class III (Harm) recommendation for using clonidine in heart failure patients 2

The American College of Cardiology recommends first assessing for target organ damage to determine if the patient has a hypertensive emergency or urgency, with a comprehensive evaluation including acute kidney injury, encephalopathy, acute coronary syndrome, pulmonary edema, and aortic dissection 4, 5, 6
If target organ damage is present, the American College of Cardiology recommends ICU admission with IV antihypertensives, such as labetalol or nicardipine, to reduce blood pressure by no more than 25% within the first hour 4, 7
The American College of Cardiology recommends reducing blood pressure by no more than 25% within the first hour, then cautiously to 160/100 mmHg over 2-6 hours, in patients with hypertensive emergency 7

The American Heart Association recommends considering alternative agents, such as nicardipine or nitroprusside, for sympathetic hyperreactivity or hypertensive urgency without target organ damage, to avoid the heart failure and glucose concerns of clonidine 4, 5
Phentolamine is specifically useful for sympathetic hyperreactivity states, according to the American Heart Association 4, 5