Pain Medicine

Painful joints caused by arthritis is one of the most challenging conditions for professionals to treat, especially when a patient has chronic kidney disease and cannot tolerate the prescribed pain medication. Although controversial, I wanted to provide my perspective on this topic, noting that since there is no correct answer, my goal is to provide you options in terms of what you can do if you suffer from kidney disease and have joint-related pain.

There are many options available to treat arthritic joint pain. Although I'm no expert at treating pain, I frequently get called by primary care providers who do. These physicians need help treating their patients' kidneys that are "being killed" by certain kinds of pain medication.

Let's start with a clinical vignette (that is, case study) to clarify some points. A 65 year old female with a history of osteoarthritis for years with multiple joints involved including the joints in her fingers comes to the kidney doctor for an evaluation. She is overweight, was recently diagnosed with diabetes mellitus type II, has protein in her urine, and high blood pressure. She was started on benazepril at the highest dose (40 milligrams daily). Her kidney function worsened, and her primary care doctor wanted to get nephrology involved to give an opinion. The patient does have severe pain and takes ibuprofen (prescription strength) every day.

What a predicament this poor lady is in. In order to understand this woman's current health issues, we have to learn a few things about the types of pain medicine available to her and the mechanism by which NSAIDS can adversely affect the kidneys.

From a simple country perspective, there are 2 main types of pain medicines: narcotics and non-narcotics:

Narcotics

There are many types of narcotics the physician can choose. The main differences between the options include the strength of the product, the side-effect profile, and the length of time the product works in the body.

Prescription narcotics work in the brain to change the perception an individual has towards pain. Some of my patients describe the affect as follows: "when taking the medicine, I sometimes feel absolutely no pain. And when there is some pain, I don't care that it is there. If the pain becomes bothersome, that means the medicine is not working hard enough to treat my pain, and I ask for more."

Examples of narcotics include: Norco, Lortab, Vicodin, MS Contin, oxycodone, Percocet, Darvocet, and more.

Please note: there is a risk for addiction when using these medicines. There is no anti-inflammatory benefit when a patient uses narcotics to treat pain.

Non-narcotics

Non-steroidal anti-inflammatory drugs (NSAIDS). You can also purchase NSAIDS over the counter. From my perspective, the kidney is affected by all of them. My understanding is that all the NSAIDs are equally effective. That said, if one product doesn't seem to be working in a particular patient, doctors frequently switch to a different brand. When this occurs, there is a very good chance the patient will experience some relief. However, there are price differences among the various NSAID products. Therefore, most of these medicines are initially prescribed based on cost—many 4 dollar lists have NSAIDs as an option. Provided below is a list of prescription non-steroidal anti-inflammatory medications that you may have tried.

• Meloxicam (my personal favorite because it is not as hard on the stomach and is included on several 4 dollar lists.)
• Ibuprofen (Motrin)
• Naproxen
• Fenoprofen
• Ketoprofen
• Indomethacin
• Sulindac
• Etodolac
• Ketorolac
• Piroxicam
• Celecoxib
• Ultram (Also called tramadol. The mechanism of action is not completely known. In many circumstances, this medication is tried before the patient starts taking narcotic medications.)
• Acetaminophen (Tylenol - This medicine works great for pain. The problem is that there is little anti-inflammatory benefit. That means that Tylenol will do nothing to alleviate the swelling associated with arthritic joint pain. Therefore, Tylenol becomes a second-line therapy for arthritic joint discomfort.)

NSAIDS block the formation of prostaglandins from arachidonic acid as shown in the figure above. The enzyme that the NSAIDS block is called cyclooxygenase. For the majority of NSAIDs available on the market today, both COX-1 and COX-2 are not made in the presence of non-steroidal anti-inflammatory drugs. The effect of the interaction is to cause the kidney vessels to constrict and cause kidney injury, especially in the setting of low volume (dehydrated) states. Over time, the temporary kidney injury can become irreversible and lead to chronic kidney disease.

Please note that NSAIDs do more than just treat pain. They also treat inflammation. Inflammation leads to swelling and limited joint mobility. Patients tend to like NSAIDs more than acetaminophen because of the anti-inflammatory benefit seen with NSAID use. This anti-inflammatory benefit is one contributor to the NSAIDs' phenomenal pain control properties.

Bottom line: NSAIDS work pre-kidney by causing constriction and can effect kidney function. In the setting of ACE inhibitor use for hypertension, a patient's kidneys can get real bad, real fast because ACE inhibitors work post kidney by unloading the pressure head on the kidney filters. So we physicians are very careful when we prescribe both medicines at the same time so that we do no harm.

Let's get back to the clinical vignette. I suggested we lower the benazapril to 10 mg orally daily. In addition, we decided to try acetaminophen and Ultram for pain. The patient decided to commit to weight loss, and joined her local Y. Per my recommendation, she signed up for swim aerobics. In addition, she learned the meaning of metabolic equivalents. For severe pain and swelling, she will use the NSAID ibuprofen sparingly. If necessary, her primary care doctor will provide prednisone at a low dose to help with uncontrolled inflammation. If still not able to tolerate her arthritic pain, a narcotic could be prescribed.

We discussed the option of maximizing the dose of the ibuprofen if the above interventions were ineffective. At that point, I would consider stopping the benazepril and managing her expectantly.

The patient and I came up with a plan based on shared decision making. With informed consent, she acknowledged that the need for kidney dialysis may come sooner rather than later, and this therapy may be necessary in the future to avoid unbearable pain.

In conclusion, the decisions that need to be made when patients present to me stating: "my arthritis pain hurts! What can I do without killing my kidneys?" are challenging ones. Kidney specialists help provide options in this setting, and should be used as a resource. We help manage some of the meds that are involved that adversely affect the kidneys. And most importantly, we are there to try to help delay the need for your requiring kidney dialysis. Communication, among the doctors involved in your care, and with you, the patient, is a critical component to a successful, excellent patient experience.