From the Guidelines
The next medication group to be tried in a patient with moderate to severe hypertension on a beta blocker and clonidine should be an ACE inhibitor or an ARB, in combination with a dihydropyridine CCB or a diuretic.
Rationale
- The patient is already on a beta blocker, which is recommended to be combined with other major BP-lowering drug classes when there are other compelling indications for their use 1.
- Clonidine is a centrally acting BP-lowering medication, and the guidelines recommend considering the addition of a RAS blocker (either an ACE inhibitor or an ARB) with a dihydropyridine CCB or diuretic for patients with uncontrolled hypertension 1.
- The combination of a RAS blocker with a dihydropyridine CCB or diuretic is recommended as a first-line treatment for hypertension, and is preferred over monotherapy 1.
- The guidelines also recommend considering the use of single-pill combinations, which can improve adherence and reduce side effects 1.
- Key medication options include:
- ACE inhibitors (e.g. lisinopril, enalapril)
- ARBs (e.g. losartan, valsartan)
- Dihydropyridine CCBs (e.g. amlodipine, felodipine)
- Diuretics (e.g. hydrochlorothiazide, chlorthalidone)
Considerations
- The patient's kidney function and electrolyte levels should be monitored when starting an ACE inhibitor or ARB, as these medications can increase the risk of hyperkalemia and acute kidney injury 1.
- The patient's blood pressure should be closely monitored after starting the new medication, and the dose should be adjusted as needed to achieve optimal blood pressure control 1.
- If the patient's blood pressure is still not controlled after adding the new medication, consideration should be given to adding a third medication, such as spironolactone or a beta blocker, or referring the patient to a specialist for further evaluation 1.
From the FDA Drug Label
Clonidine hydrochloride tablets, USP may be employed alone or concomitantly with other antihypertensive agents. The FDA drug label does not answer the question.
From the Research
Medication Group for Moderate to Severe Hypertension
The patient is currently on a beta blocker and clonidine. Considering the next medication group to try, the following options are available:
- Thiazide diuretics: High-quality evidence shows that first-line low-dose thiazides reduce mortality, total cardiovascular events, stroke, and coronary heart disease 2.
- ACE inhibitors: Low- to moderate-quality evidence shows that first-line ACE inhibitors reduce mortality, stroke, coronary heart disease, and total cardiovascular events 2.
- Calcium channel blockers: Low-quality evidence shows that first-line calcium channel blockers reduce stroke and total cardiovascular events, but not coronary heart disease or mortality 2.
- Triple-combination therapy: Randomised controlled trials have shown that triple combinations of amlodipine/valsartan/hydrochlorothiazide, amlodipine/olmesartan/hydrochlorothiazide, and amlodipine/telmisartan/hydrochlorothiazide produce greater BP reductions, with greater proportions of patients achieving BP control compared with dual therapies 3.
Key Considerations
- The combination of clonidine and a beta-blocker is an effective antihypertensive medication, but patients may be at risk of severe rise of blood pressure and intolerable symptoms of clonidine withdrawal if clonidine is abruptly ceased 4.
- Gradually changing from clonidine to beta-blockers can be successful with few side-effects 4.
- Triple-combination therapy is generally well tolerated with adverse event profiles similar to dual regimens 3.
Potential Next Steps
- Consider adding a thiazide diuretic, ACE inhibitor, or calcium channel blocker to the patient's current medication regimen.
- If the patient's blood pressure remains uncontrolled, consider switching to a triple-combination therapy.
- Monitor the patient's blood pressure and adjust the medication regimen as needed to achieve optimal blood pressure control.