Can Irbesartan (Angiotensin II Receptor Antagonist) be used twice daily for the treatment of hypertension?

From the Guidelines

Irbesartan should not be used twice daily for hypertension, as the standard and recommended dosing is once daily, ranging from 150 mg to 300 mg, due to its long half-life of approximately 11-15 hours, as supported by the 2024 ESC guidelines for the management of elevated blood pressure and hypertension 1.

The 2024 ESC guidelines recommend the use of single-pill combinations or monotherapy with one of the four major drug classes, including ARBs like irbesartan, as first-line BP-lowering medications, either alone or in combination, with the goal of achieving better BP control and adherence 1. The guidelines also emphasize the importance of using the lowest effective dose to minimize side effects and improve adherence.

Some key points to consider when using irbesartan for hypertension include:

• The medication's long half-life allows for once-daily dosing, which simplifies the treatment regimen and improves adherence.
• The standard dosing range of 150 mg to 300 mg once daily is typically sufficient for effective blood pressure control.
• If blood pressure is not adequately controlled on a once-daily maximum dose of irbesartan, adding a second antihypertensive medication from a different class may be considered, rather than changing the frequency of irbesartan.
• Irbesartan works by blocking angiotensin II receptors, relaxing blood vessels, and lowering blood pressure gradually and steadily throughout the day, as part of the renin-angiotensin-aldosterone system (RAAS) blockade strategy recommended by the guidelines 1.

It's essential to consult with a healthcare provider to determine the best treatment plan for individual patients, taking into account their specific needs, medical history, and response to treatment, as emphasized by the guidelines 1.

From the FDA Drug Label

The dose-response relationships for effects on systolic and diastolic pressure are shown in Figures 1 and 2. Once-daily administration of therapeutic doses of irbesartan gave peak effects at around 3 to 6 hours and, in one ambulatory blood pressure monitoring study, again around 14 hours. This was seen with both once-daily and twice-daily dosing Trough-to-peak ratios for systolic and diastolic response were generally between 60% to 70%. In a continuous ambulatory blood pressure monitoring study, once-daily dosing with 150 mg gave trough and mean 24-hour responses similar to those observed in patients receiving twice-daily dosing at the same total daily dose.

Irbesartan dosing for hypertension: The FDA drug label does mention that irbesartan can be administered once-daily or twice-daily, but it does not explicitly recommend twice-daily dosing for hypertension. However, it does state that trough-to-peak ratios for systolic and diastolic response were generally between 60% to 70% with both once-daily and twice-daily dosing, suggesting that twice-daily dosing may be effective.

• Key points:
  • Once-daily administration of therapeutic doses of irbesartan gave peak effects at around 3 to 6 hours.
  • Trough-to-peak ratios for systolic and diastolic response were generally between 60% to 70% with both once-daily and twice-daily dosing.
  • In a continuous ambulatory blood pressure monitoring study, once-daily dosing with 150 mg gave trough and mean 24-hour responses similar to those observed in patients receiving twice-daily dosing at the same total daily dose. Based on the information provided, irbesartan can be used twice daily for hypertension, but the FDA drug label does not provide a clear recommendation for twice-daily dosing 2.

From the Research

Irbesartan Dosage for Hypertension

• The standard dosage of irbesartan for hypertension is 150-300 mg once daily 3, 4, 5.
• Studies have shown that once-daily administration of irbesartan provides effective 24-hour blood pressure control 3, 4, 5.
• However, one study compared the efficacy of 75 mg irbesartan twice daily to 75 mg and 150 mg irbesartan once daily, and found that all irbesartan regimens significantly reduced mean 24-hour ambulatory diastolic blood pressure and ambulatory systolic blood pressure 6.

Efficacy of Irbesartan Twice Daily

• The study found that 75 mg irbesartan twice daily had a similar effect to 150 mg irbesartan once daily in reducing blood pressure 6.
• The trough:peak ratio was greater than or equal to 55% with 150 mg irbesartan once daily, indicating a lasting effect over 24 hours 6.
• However, it is not clear if twice-daily administration of irbesartan is necessary or recommended for most patients, as once-daily administration has been shown to be effective in most cases 3, 4, 5.

Safety and Tolerability

• Irbesartan has been shown to be well tolerated, with a side effect profile similar to that of placebo 3, 4, 5.
• The most common adverse events reported with irbesartan include headache, upper-respiratory tract infection, and musculoskeletal pain 3, 4.
• Irbesartan has also been shown to have a lower incidence of cough compared to enalapril, and is not associated with ankle edema or significant drug interactions 4.