Watch out for Your Kidneys When You Use Medicines for Pain

August 12, 2014, 10:06am EDT

Medicines For PainWhat do you do if you have a headache, fever, or muscle pain? Chances are you go to the local drug store to pick up an over–the–counter (nonprescription) pain medicine. These drugs are the medicines most often used by Americans. Pain medicines, also called analgesics, help relieve pain, fever, and even inflammation. These medicines may help with arthritis, colds, headache (including migraine), muscle aches, menstrual cramps, sinusitis and toothache.

These drugs are effective and usually safe. However, it is important to realize that no medicine is completely without risk. They should be used carefully. When used improperly, pain medicines can cause problems in the body, including the kidneys. According to the National Kidney Foundation, as many as 3 percent to 5 percent of new cases of chronic kidney failure each year may be caused by the overuse of these painkillers. Once kidney disease occurs, continued use of the problem drug makes it worse.

Nonprescription pain medicines should not be used without your doctor’s permission if you know you have low kidney function. Also, even if your kidney function is good, long–term use with high doses of these pain drugs may harm the kidneys. Kidney damage happens because high doses of the drugs have a harmful effect on kidney tissue and structures. These drugs can also reduce the blood flow to the kidney. If you are older, your kidneys may have a stronger reaction to these medicines and you may need a smaller dose.

Kidney disease from pain medicines is often preventable. You can change your risk by how you take medicines. To avoid kidney problems, it is important to follow the instructions on the label. You should tell your health care team how often you use these drugs and how many of pills you take. You should drink plenty of fluids and avoid becoming dehydrated when you use these medicines. If you have special risks, your doctor may be able to recommend a safer alternative and can order regular tests to monitor kidney function.

Even with normal kidney function, you should use pain medicines:

  • Exactly as prescribed or as on the label
  • At the lowest dose possible
  • For the shortest period of time.

What are analgesics?

Analgesics are medicines that help to control pain and reduce fever, and some types also decrease inflammation. These are commonly used analgesics:

Acetaminophen. Although aspirin was most common analgesic for decades, today, the most commonly used over–the–counter pain medicine is acetaminophen. This drug is available under the brand name Tylenol® and as a generic (no brand name) with the word “acetaminophen” on the package. It is often effective for mild to moderate pain. Its safety depends on how it is used. People who take too much or take it too often risk side effects or worse. Acetaminophen is also found in combination with other ingredients in many cold, sinus, and cough medications. If you take these drugs together, the dose can add up.

Aspirin. This is one of the drugs grouped together under the name “nonsteroidal anti–inflammatory drugs” or NSAIDs. Nonsteroidal anti–inflammatory drugs (NSAIDs) are a specific group of pain relievers. Some NSAIDs are available over the counter. This includes different brands of aspirin, ibuprofen, naproxen sodium and ketoprofen. Prescription strength NSAIDs are also available.

  • Ibuprofen (common brand names are Advil® or Motrin®) is an NSAID. Like other NSAIDs, ibuprofen relieves inflammation, which causes pain, or blocks pain signals going to the brain.
  • Some analgesics contain a combination of painkilling ingredients in one pill––such as aspirin, acetaminophen and caffeine.

What analgesics are safe for people who have kidney disease?

Acetaminophen is the drug often recommended for occasional use in patients with kidney disease. But everyone with kidney disease should rely on their doctor or other health care professional for a personal recommendation. It is important to know that any drug can be harmful if used at high doses or very frequently. People with kidney disease should also be sure to avoid drinking alcohol while taking pain medicines.

Are NSAIDs safe to take if you have kidney disease?

NSAIDs are usually safe for occasional use when taken as directed. However, if your doctor has told you that you have low kidney function, NSAIDs might not be right for you. These medications should only be used under a doctor's care by patients with kidney disease. Also, they might not be the best choice for people with heart disease, high blood pressure or liver disease. Some of these drugs affect blood pressure control. High doses over a long period of time can also lead to chronic kidney disease and even progress to kidney failure.

For people without kidney disease, the recommended dose of aspirin can be safe if you read the label and follow the directions. When taken as directed, regular use of aspirin does not seem to increase the risk of kidney disease in people who have normal kidney function. However, taking doses that are too large (usually more than six or eight tablets a day) may temporarily and possibly permanently reduce kidney function. In people with kidney disease, aspirin may increase the tendency to bleed.

My doctor recommended that I take an aspirin in low doses every day to prevent heart attacks. Will this hurt my kidneys?

It’s not likely. There is no evidence of risk regarding the regular use of aspirin in the small doses recommended for prevention of heart attacks. Use of a “baby aspirin” is fine, even with reduced kidney function.

I have arthritis and I need pain medicines frequently. What pain relievers can I take that won’t hurt my kidneys?

You should speak to your doctor about the best choice for you. In addition, if you have a medical condition, you should only use NSAIDs under your doctor's supervision.

How do I know if analgesics have affected my kidneys?

Your doctor can check your kidneys by doing a simple blood test called a serum creatinine test. The results of the serum creatinine test can be used to estimate your glomerular filtration rate (GFR). Your GFR number tells your doctor how much kidney function you have.

A urine test for the presence of protein may also be done. Persistent protein in the urine may be an early indication of kidney damage.

If I need pain medicines, what can I do to keep my kidneys healthy?

Kidney disease caused by pain relievers is often preventable. Here are some things you can do to help keep your kidneys healthy.

How you take these medicines makes a difference:

  • Make sure you read the warning label before using any over–the–counter analgesics.
  • Do not use over–the–counter pain relievers more than 10 days for pain or more than three days for fever. If you have pain or fever for a longer time, you should see your doctor.
  • Avoid using pain medicines that contain a combination of ingredients, like aspirin, acetaminophen and caffeine mixed together in one pill.
  • If you are taking pain medicines, increase the amount of fluid you drink to six to eight glasses a day.
  • If you are taking pain medicines, avoid drinking alcohol.

Talking with your doctor about pain medicines can also make a difference:

  • If you have kidney disease, ask your doctor before taking a pain medicine, particularly NSAIDs and higher dose aspirin.
  • If you have high blood pressure or heart disease, make sure you only take NSAIDs under your doctor’s supervision. This is especially important if you take diuretic medications or are over 65 years of age.
  • Make sure your doctor knows about all medicines you are taking, even over-the-counter medicines.

Other safety tips:

  • If you have pain medicines in your house, make sure children cannot reach them.
  • To avoid serious interactions with prescription medicines, check with your pharmacist or doctor before using analgesics, if you take other drugs on a regular basis.
  • And, throw away any unused pain medicines after the expiration date.