Most people with diabetic nephropathy need at least one medication to lower their blood pressure. Several medications can be used for this purpose, but a medication known as an angiotensin-converting enzyme inhibitor (abbreviated ACE inhibitor) or a related drug known as an angiotensin receptor blocker (ARB) are used most commonly. ACE inhibitors are generally used first because they have been available longer than ARBs.
ACE inhibitors and ARBs are particularly useful for people with diabetic nephropathy because they decrease the amount of protein in the urine and can prevent or slow the progression of diabetes-related kidney disease. In fact, the kidney benefits of ACE inhibitors and ARBs are so robust that healthcare providers sometimes prescribe them for people with diabetic nephropathy who have normal blood pressure.
Still, despite their kidney-protecting abilities, ACE inhibitors and ARBs do have their downsides. For instance, ACE inhibitors cause a persistent dry cough in 5 to 20 percent of the people who take them. Some people get used to the cough; others find it so disruptive that they cannot continue taking an ACE inhibitor. For them, ARBs are often a good alternative, because ARBs are less likely to cause a cough.
In rare cases, you can have more serious side effects with ACE inhibitors and ARBs. These include a decrease in kidney function or a condition called hyperkalemia, in which too much potassium accumulates in the blood. To monitor for these and other side effects, healthcare providers sometimes run blood tests soon after starting these drugs. In some people, the medications will need to be stopped.
More information on the risks and side effects of ACE inhibitors and ARBs is available.