ACE inhibitors (angiotensin converting enzyme inhibitors) have been shown to be particularly effective in protecting renal function of damaged kidneys, if there is significant proteinuria. They are more effective than other classes of hypotensive drug in the presence of proteinuria. This guidance also covers angiotensin receptor blockers (ARBs).<\/p>\n
Patients who are likely to require particular caution and\/or close supervision include those with:<\/p>\n
You must know Urea, Creatinine, Potassium, Sodium values.<\/p>\n
The major risks from ACE inhibitors are of hyperkalaemia and deterioration of (already) impaired renal function. The risks are greater in individuals with unsuspected renal artery stenosis.<\/p>\n
Captopril is the original agent but is short acting and has some additional side effects. Enalapril may be best administered twice daily. Many newer agents (eg. lisinopril, ramipril) can be given once daily, and may be less likely to cause first-dose hypotension. Benefits seem to be class effects, so choice of agent may be reasonably decided by convenience and cost. In general, the same considerations apply to therapy with angiotensin receptor blockers (ARBs).<\/p>\n
In patients with renal impairment, potassium-sparing diuretics and potassium supplements should usually be discontinued unless there is continuing hypokalaemia. If continued, monitoring for hyperkalaemia should be closer.<\/p>\n
Witholding diuretics for 48h before commencing therapy will reduce the risk of first-dose hypotension. This is not usually necessary in simple hypertension but may be relevant in heart failure or renal failure requiring loop diuretics.<\/p>\n
Non-steroidal anti-inflammatory drugs should be avoided if possible during the initiation phase.<\/p>\n
The effects of ACE inhibition on blood pressure and proteinuria are potentiated by restriction of salt intake and by diuretics.<\/p>\n
Predominantly affects dehydrated patients (eg taking a large dose of diuretics).<\/p>\n
As mentioned, the major risks are of hyperkalaemia and deterioration of renal function. Check effect on blood pressure at the same time as monitoring blood tests.<\/p>\n
LOW RISK PATIENTS<\/span><\/strong> (see above<\/a>) – check creatinine and potassium at about 7 days<\/p>\n MODERATE AND HIGH RISK PATIENTS<\/span><\/strong> (see above<\/a>) – check at 4 and 10 days. Checks should also be sent after dose increases, and if diuretic doses are increased.<\/p>\n For creatinine<\/span><\/strong>, a rise of over 20% is generally considered to be significant, but NICE\/SIGN guidelines allow up to 30% rise (more info). Smaller rises are common and are to be expected in many patients.<\/p>\n For potassium<\/span><\/strong>, we suggest the following:<\/p>\n