From the Guidelines
I strongly recommend splitting the amlodipine dose to 5 mg in the morning and 5 mg in the evening to provide better 24-hour blood pressure control. This patient is experiencing early morning hypertension and evening breakthrough hypertension despite taking amlodipine 10 mg in the morning. Amlodipine has a long half-life of 30-50 hours, but individual metabolism varies, and this patient appears to have inadequate coverage during the night and early morning hours. Dividing the dose can help maintain more consistent blood pressure levels throughout the 24-hour period. According to the 2020 international society of hypertension global hypertension practice guidelines 1, it is essential to consider the individual effect of substances on blood pressure, which can be highly variable, especially in the elderly.
The patient's current regimen is not providing adequate blood pressure control, as evidenced by high blood pressure readings in the morning and evening. The 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults 1 emphasizes the importance of periodic blood pressure screening to identify individuals who develop elevated blood pressure over time.
Some key points to consider in this patient's management include:
- Monitoring blood pressure at different times of day, including early morning and evening, to assess the effectiveness of any regimen change
- Considering alternative antihypertensive medications, such as long-acting ACE inhibitors or ARBs, if split dosing is ineffective
- Screening for substances that may increase blood pressure or interfere with the blood pressure-lowering effect of antihypertensive medications, as recommended by the 2020 international society of hypertension global hypertension practice guidelines 1.
By taking a proactive approach to managing this patient's blood pressure, we can reduce the risk of cardiovascular complications and improve overall quality of life.
From the Research
Blood Pressure Control with Amlodipine
- The patient's experience of high blood pressure in the morning before taking amlodipine and the increase in blood pressure after 5:00 PM suggests that the current dosing regimen may not be providing optimal 24-hour blood pressure control 2.
- A study on the effects of dividing amlodipine daily doses on trough drug concentrations and blood pressure control over a 24-hour period found that administering amlodipine in 2 divided doses was not associated with improved BP control over a 24-hour period in patients with essential hypertension 3.
- However, another study demonstrated that amlodipine effectively reduced blood pressure for 24 hours after once-daily dosing and was well tolerated 2.
Combination Therapy for Hypertension
- The European hypertension guidelines recommend combining angiotensin II receptor blockers (ARBs) or angiotensin-converting enzyme inhibitors (ACEIs) with calcium channel blockers (CCBs) and/or thiazide diuretics to improve blood pressure control 4.
- A study on the efficacy of amlodipine in combination with other antihypertensive agents found that adding amlodipine to quinapril or losartan monotherapy reduced blood pressure by 8.1/5.4 mm Hg, compared with a 1.6/0.7 mm Hg decrease with add-on placebo 5.
Amlodipine Efficacy and Safety
- A systematic review and meta-analysis found that amlodipine had a significant effect in reducing stroke and myocardial infarction in hypertensive patients 6.
- Amlodipine has been shown to be safe and effective in various studies, including one that found it to be well tolerated when added to quinapril or losartan monotherapy in patients with hypertension and diabetes 5.