From the Guidelines
It is generally acceptable to start certain antihypertensive medications before obtaining renal function labs in patients with uncomplicated hypertension. Thiazide diuretics (like hydrochlorothiazide 12.5-25mg daily or chlorthalidone 12.5-25mg daily), calcium channel blockers (such as amlodipine 5-10mg daily), or ACE inhibitors/ARBs (like lisinopril 10mg daily or losartan 50mg daily) are reasonable first-line options 1. However, baseline labs should be obtained as soon as possible, ideally within 1-2 weeks of starting therapy. This is particularly important for ACE inhibitors and ARBs, which can affect renal function, especially in patients with underlying kidney disease, bilateral renal artery stenosis, or volume depletion.
In patients with risk factors for kidney disease (diabetes, older age, known cardiovascular disease), it's preferable to check renal function before starting these medications 1. If starting treatment before labs, ensure close follow-up and consider using agents with less impact on renal function like calcium channel blockers initially. The benefit of promptly treating significantly elevated blood pressure often outweighs the risk of delaying treatment while waiting for lab results in otherwise healthy individuals.
Some key considerations include:
- Monitoring renal function and serum potassium levels when initiating RAAS inhibitors in patients with heart failure and moderate chronic kidney disease (CKD) 1
- Using caution when initiating antihypertensive pharmacotherapy with 2 drugs in older patients due to the risk of hypotension or orthostatic hypotension 1
- Considering the potential impact of antihypertensive medications on renal function, particularly in patients with underlying kidney disease or risk factors for kidney disease 1
Overall, the decision to initiate antihypertensive medication before assessing renal function should be made on a case-by-case basis, taking into account the individual patient's risk factors and medical history. The most recent and highest quality study, published in 2018, supports the use of antihypertensive medications in patients with uncomplicated hypertension, with careful monitoring of renal function and serum potassium levels 1.
From the Research
Assessment of Renal Function Before Initiating Antihypertensive Medication
- The provided studies do not directly address whether it is appropriate to initiate antihypertensive medication before assessing renal function through laboratory tests 2, 3, 4, 5, 6.
- However, the studies emphasize the importance of monitoring renal function during antihypertensive therapy, particularly when using certain classes of medications such as angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) 2, 3, 4.
- The study by 2 highlights the need for close surveillance of renal function and blood pressure during therapy with ACE inhibitors and ARBs, even in patients with relatively preserved renal function.
- Another study 4 discusses the treatment of elevated blood pressure in patients with peripheral artery disease and recommends the use of renin-angiotensin-system (RAS) inhibitors to reduce cardiovascular risk, but does not specifically address the assessment of renal function before initiating antihypertensive medication.
- The remaining studies 3, 5, 6 focus on the effectiveness and safety of various antihypertensive medications, as well as patient adherence to medication regimens, but do not provide direct evidence regarding the assessment of renal function before initiating antihypertensive therapy.