What is the time frame for amlodipine (calcium channel blocker) to reduce hypertension?

From the Guidelines

Amlodipine typically takes at least 2 weeks to effectively lower blood pressure, as patients are reassessed after this period to determine the medication's effectiveness. This is based on the most recent evidence from the study published in the British Journal of Cancer in 2019 1. The study recommends initiating antihypertensive treatment with 5 mg amlodipine daily in antihypertensive-naive patients and reassessing them after at least 2 weeks.

Key Points to Consider

• Amlodipine is considered a safe and efficient treatment for hypertension, and its effectiveness is assessed after a period of consistent use.
• The standard starting dose of amlodipine is usually 5 mg once daily, which may be increased to 10 mg daily if needed after 1-2 weeks.
• Patients should take amlodipine at the same time each day to maintain consistent blood levels, and it is essential to continue taking the medication even if symptoms improve, as hypertension is often symptomless.
• Blood pressure should be monitored regularly during the initial treatment period to assess the medication's effectiveness, and adjustments to the treatment plan can be made as needed.

Additional Considerations

• The study published in Circulation Research in 2021 1 provides an update on guideline-driven management of hypertension, emphasizing the importance of agreeing on blood pressure targets, using fixed-dose combinations, and substituting long-acting chlorthalidone for hydrochlorothiazide.
• However, the primary focus of this study is on the overall management of hypertension, and the specific details about amlodipine's onset of action are not directly addressed.
• Therefore, the recommendation to reassess patients after at least 2 weeks of amlodipine treatment, as stated in the 2019 study 1, remains the most relevant and evidence-based approach.

From the FDA Drug Label

After oral administration of therapeutic doses of amlodipine, absorption produces peak plasma concentrations between 6 and 12 hours. Steady-state plasma levels of amlodipine are reached after 7 to 8 days of consecutive daily dosing.

The time it takes for amlodipine to lower blood pressure is not directly stated, but steady-state plasma levels are reached after 7 to 8 days of consecutive daily dosing, which may be related to its effectiveness in lowering blood pressure 2.

From the Research

Amlodipine and Blood Pressure Reduction

• Amlodipine is a calcium antagonist that has been shown to effectively reduce blood pressure in hypertensive patients 3, 4, 5, 6, 7.
• The medication has a long plasma half-life, allowing for steady state blood levels to be achieved with a once-daily dose regimen 3.
• Studies have demonstrated that amlodipine can reduce blood pressure throughout a 24-hour period, with significant reductions in both daytime and nighttime blood pressure 3, 5, 7.

Timeframe for Blood Pressure Reduction

• One study found that mean supine blood pressure was reduced from 168/103 mmHg to 153/95 mmHg after 2 weeks of treatment with amlodipine 5 mg once daily 3.
• Another study showed that amlodipine 5/10 mg/day therapy provided significant reductions in both office BP and ambulatory BP over 8 weeks 6.
• A 4-week study found that patients receiving amlodipine had significantly lower blood pressure compared with placebo 24 hours after the last dose 7.

Key Findings

• Amlodipine has been shown to be effective in reducing blood pressure in patients with mild-to-moderate essential hypertension 3, 4, 5, 6, 7.
• The medication can be used as monotherapy or as add-on therapy to other antihypertensive agents 6.
• Amlodipine is well tolerated, with minimal adverse effects reported in clinical studies 3, 5, 6.