Chronic Renal Disease and Hypertension.

A 45-year-old woman with type 1 diabetes mellitus is reviewed in the diabetes clinic. Three months ago her blood tests were as followed:
K+ 4.5 mmol/l , Creatinine 116 μmol/l , eGFR 47 ml/min

At the time she was started on lisinopril to treat both the hypertension and act as a renoprotective agent. Lisinopril had been titrated up to treatment dose. Her current bloods are as follows:
K+ 4.9 mmol/l , Creatinine 123 μmol/l ,  eGFR 44 ml/min

Of the following options, what is the most appropriate course of action?
A. Stop lisinopril and arrange investigations to exclude renal artery stenosis
B. Switch to a angiotensin 2 receptor blocker
C. Switch to a different ACE inhibitor
D. No action
E. Reduce dose of lisinopril

Answer:
D. No action

Discussion: The small change in both the creatinine and eGFR are acceptable and below the threshold where ACE inhibitors should be stopped.

Chronic kidney disease And Hypertension.
The majority of patients with chronic kidney disease (CKD) will require more than two drugs to treat hypertension. ACE inhibitors are first line and are particularly helpful in proteinuric renal disease (e.g. diabetic nephropathy). As these drugs tend to reduce filtration pressure a small fall in glomerular filtration pressure (GFR) and rise in creatinine can be expected. NICE suggest that a decrease in eGFR of up to 25% or a rise in creatinine of up to 30% is acceptable, although any rise should prompt careful monitoring and exclusion of other causes (e.g. NSAIDs). A rise greater than this may indicate underlying renovascular disease.
Furosemide is useful as a anti-hypertensive in patients with CKD, particularly when the GFR falls to below 45 ml/min. It has the added benefit of lowering serum potassium. High doses are usually required. If the patient becomes at risk of dehydration (e.g. Gastroenteritis) then consideration should be given to temporarily stopping the drug