NSAIDs and Chronic kidney disease. A great post at the Renal Fellow Network

One of the standard pieces of advice I give patients regarding chronic kidney disease is to avoid NSAIDs. However, not infrequently, patients have co-morbidities that demand NSAIDs. This usually triggers a conversation with my patients where I describe how ibuprofen can cause acute renal failure (I just took care of a new patient who developed RIFLE stage: Failure from a couple of doses of Mobic on top of stepped up ibuprofen use). I then explain that we extrapolate from the acute renal failure that NSAIDs are probably not beneficial in CKD and are likely harmful.

Lisa J Cohen at The Renal Fellow Network has a nice post on the lack of hard data implicating NSAIDs in the progression of CKD:

What about chronic renal dysfunction following long-term NSAID intake? In today’s medical environment, the evidence is weak. Prospective cohort studies in the Physicians’ Health Study (Rexrode et al, JAMA 2001) and the Nurses’ Health Study (Curhan et al, Arch Int Med 2004) failed to show an association between even high levels of cumulative lifetime NSAID intake and decrease in renal function.

My concern about these studies is the effect, we physicians have on the outcomes. Telling kidney patients to avoid ibuprofen and other NSAIDs is standard fare in CKD care. I’m sure these patients tend to use less ibuprofen and more acetaminophen, just as liver patients probably do the opposite. So educated patients with CKD will avoid NSAIDs but regardless of NSAID intake they will have a much higher progression to kidney related endpoints than their peers without a diagnosis of CKD. The epidemiologist sees a large cohort of acetaminophen users (my CKD patients) ending up with renal failure and sees that people with CKD use very little ibuprofen and may infere that acetaminophen causes kidney failure and ibuprofen is protective.

These are the type of questions that CRIC should be able to answer.

Patient information: over-the-counter medications

What over the counter medications should I be careful about with my kidney disease?

All over-the-counter medications have the potential to be harmful and so they should only be taken according to the labels and if you have any questions you should call you doctor. However, there are a few over-the-counters that are particularly problematic for patients with weak kidneys. Here they are:

  1. Ibuprofen (Advil, Motrin), Naproxen (Naprosyn)
  2. Sodium phosphorous solutions (Fleets enemas or fleets oral cathartics)
  3. Magnsesium citrate (MagCitrate)
  4. Pseudophedrine

Ibuprofen (Advil, Motrin), Naproxen (Naprosyn). Both of these medications are non-steroidal anti-inflammatory drugs or NSAIDs. There are a number of other NSAIDs that are prescription only including indomethacin, Celebrex and others. The problems with NSAIDs goes for all of these agents, not just the over-the-counter ones. NSAIDs block the production of prostaglandins that trigger inflammation in the body. Unfortunately, in the kidneys, prostaglandins help maintain blood flow. Blocking prostaglandins can decrease the blood flow to the kidney and cause the kidney to shut down. This is more common when patients are also taking diuretics (water pills) and blood pressure medicines called ACE inhibitors or ARBs. (Common ACE inhibitors include Vasotec, Zestril benazapril, Altace or any drug which ends with –pril. Common ARBs include Cozaar, Diovan, and Atacand or any drug which ends with –sartan.)

NSAIDs can also interfere with blood pressure medicines and cause patients to retain fluid.

Sodium phosphorous cathartics. Fleets enemas and oral solutions are used to treat constipation or prepare patients for surgery or colonoscopy. Recently we have learned that these medications can cause severe permanent kidney damage. Little is known about how often this occurs and appears to be rare but people with normal kidney function have developed severe renal failure requiring dialysis or transplant following exposure to these medications. Unfortunately not all doctors are aware of this complication and are still prescribing these medications. A clear picture of who is at risk for this complication has not emerged but experts agree on the following risk factors:

  1. Advanced age
  2. Chronic kidney disease
  3. Use of diuretics (water pills)
  4. Use of ACE inhibitors or ARBs

In addition to the risk of damaging the kidneys with sodium phosphorous, patients on dialysis who take these drugs are at risk of severe elevations in phosphorous that may kill them.

Magnesium citrate is sold under the brand names Citro-mag and Citroma. Magnesium citrate is used to treat constipation and to cleanse the bowels before surgery. In patients with severe kidney disease (CKD stage 4 and 5 and dialysis) it can cause harmful levels of magnesium.

Pseudoephedrine is the active ingredient in some cold medicines (Actifed, Sudafed) that are now kept behind the counter due to the fact that pseudoephedrine is one of the ingredients needed to manufacture methamphetamine (crystal meth). Pseudoephedrine raises the blood pressure by about one point and the heart rate by about 2 beats per minute in patients with normal blood pressure or people with well-controlled high blood pressure. This should not cause any problems. However, in patients with poorly controlled or untreated hypertension, pseudoephedrine may cause larger changes in blood pressure and should only be used after speaking with your doctor.