From the Guidelines
No washout period is required when transitioning from an Angiotensin-Converting Enzyme (ACE) inhibitor to an Angiotensin Receptor Blocker (ARB). Patients can typically switch directly from one medication to the other on the next scheduled dose. For example, if a patient is taking lisinopril (an ACE inhibitor) 20 mg daily in the morning, they can take their last dose of lisinopril one day and start their prescribed ARB (such as losartan 50 mg or valsartan 80 mg) the following day. This direct transition is safe because while both medication classes affect the renin-angiotensin-aldosterone system, they do so through different mechanisms. ACE inhibitors block the conversion of angiotensin I to angiotensin II, while ARBs block the binding of angiotensin II to its receptors. Since there is no competitive binding at the same receptor site, there is no need for a washout period, as stated in the 2018 guideline for the prevention, detection, evaluation, and management of high blood pressure in adults 1. However, patients should be monitored for blood pressure changes, kidney function, and potassium levels after the transition, as individual responses may vary. It's also important to note that the same precautions apply to both medication classes, including avoiding their combination and monitoring for side effects like hyperkalemia.
Some key points to consider when transitioning from an ACE inhibitor to an ARB include:
- Monitoring for blood pressure changes, as the patient may experience a change in blood pressure control
- Monitoring kidney function, as both ACE inhibitors and ARBs can affect renal function, especially in patients with pre-existing kidney disease
- Monitoring potassium levels, as both medication classes can increase the risk of hyperkalemia, especially in patients with kidney disease or those taking potassium-sparing diuretics
- Avoiding the combination of ACE inhibitors and ARBs, as this can increase the risk of adverse effects such as hyperkalemia and acute kidney injury, as noted in the guideline 1.
It's worth noting that the European Society of Cardiology guidelines for the diagnosis and treatment of acute and chronic heart failure also provide guidance on the use of ACE inhibitors and ARBs, including the monitoring of kidney function and potassium levels 1. However, the most recent and highest quality study, the 2018 guideline for the prevention, detection, evaluation, and management of high blood pressure in adults, does not recommend a washout period when transitioning from an ACE inhibitor to an ARB 1.
From the Research
Transitioning from ACE to ARB
- The need for a washout period when transitioning from an Angiotensin-Converting Enzyme (ACE) inhibitor to an Angiotensin Receptor Blocker (ARB) is not explicitly stated in the provided studies as a requirement for all patients.
- A study 2 investigated the adherence to a 36-hour washout period when switching from ACEi to ARNI (angiotensin receptor/neprilysin inhibitor) and found that 67% of patients received the full washout period, with no significant differences in hospital readmissions or adverse effects between the groups.
- However, the studies provided do not directly address the necessity of a washout period when transitioning from ACE to ARB.
- The CORD trials 3 demonstrated that switching from an ACEI to an ARB (losartan) is safe and effective, with no significant increase in adverse events, but do not mention a washout period.
- Other studies 4, 5, 6 discuss the efficacy and safety of ACEIs and ARBs in various patient populations, but do not provide information on the need for a washout period when transitioning between these medications.