Features October 2010 Issue

Pain Killers: When–and How–to Use Them

Not all joint pain is the same. Given the plethora of drugs designed for OA and RA pain relief, it pays to know your treatment options.

 

Many medications are available to decrease the joint pain associated with osteoarthritis (OA) and rheumatoid arthritis (RA), as well as the inflammation associated with RA and other types of inflammatory arthritis.

The upside of having so many options is that it’s very likely that you will find a pain medication that works for you. However,

making the right choice isn’t as simple as you might think. You also need to know about side effects, how the medication interacts with other drugs you may be taking, and how your health status comes into play, says Daniel Mazanec, MD, Associate Director, Cleveland Clinic Center for Spine Health.

 

First steps

First-line pain drugs are different for OA than they are for RA. "With OA, you treat the perception of pain, which occurs mainly in the brain," Dr. Mazanec explains. "That’s why acetaminophen (Tylenol), which affects pain receptors in the brain, is the first choice for OA."

At daily doses of up to 3,000 mg, acetaminophen is safe for the vast majority of people. But at excessive doses—6,000 mg to 8,000 mg or more—it can be toxic to the liver. Liver toxicity has been reported at lower doses, mainly in people at increased risk because of pre-existing liver disease, excess alcohol consumption, and/or dehydration. "The greatest risk is inadvertent overdose," Dr. Mazanec warns. That occurs because acetaminophen is included in a number of prescription drugs, including propoxyphene, oxycodone, tramadol, and other medications routinely prescribed to treat osteoarthritis pain. "If you have OA and are already on one of these drugs for pain, and you take an over-the-counter acetaminophen for additional pain relief, you may easily exceed the 3,000 mg-4,000 mg limit. At that point, you’re at increased risk for liver problems."

For RA, a nonsteroidal anti-inflammatory drug (NSAID) usually is the first choice. "NSAIDs are a tradeoff," Dr. Mazanec says. "Their anti-inflammatory effects can reduce pain and improve function. The tradeoff is that compared with acetaminophen, they’re more hazardous, particularly with respect to the gastrointestinal tract. NSAIDs can cause everything from annoying stomach upset to severe gastric ulceration and bleeding."

The risk of severe gastrointestinal side effects is about 50 percent less for celecoxib (Celebrex) compared with the other NSAIDs. "However, if you take a daily baby aspirin to protect your heart, that advantage is negated," Dr. Mazanec says. "The alternative, which is probably just as good from a GI perspective, is naproxen along with a proton pump inhibitor [PPI] such as omeprazole (Prilosec). That combination is equally gastro-protective as taking celecoxib."

The downside is that recent evidence suggests omeprazole, and probably other drugs in this class, may increase the risk of some types of fractures.

Other options

Before moving on to stronger medication, if your joint pain is "local"—in a specific joint—injections with corticosteroids or viscosupplementation may be tried. Viscosupplementation involves injecting a preparation of hyaluronic acid (a naturally occurring substance found in the synovial fluid that acts as a lubricant) into the painful joint.

Local injections to reduce pain are more common in OA, since in most cases, RA involves multiple joints. "But if joint pain overall is well controlled, and you need treatment for a single painful joint, then you can do the same thing for RA," Dr. Mazanec says.

RA treatment may also include the use of glucocorticoids and disease-modifying antirheumatic drugs (DMARDs) such as infliximab. However, while DMARDs may reduce inflammation, pain may persist even if function is improved. Moreover, both medications are associated with serious side effects, such as high blood pressure, osteoporosis, and increased infection risk.

If these interventions aren’t effective, the next step is an opioid. "Start with a trial of a weaker opioid such as tramadol," Dr. Mazanec suggests.

You may build up tolerance to some of the adverse effects of opioids, such as sleepiness—and that’s a good thing, Dr. Mazanec says. "People tend to abandon the drug too quickly because of sleepiness, whereas if they stayed with it for three or four days, the sleepiness might subside."