Heart Disease and Chronic Pain

I saw a very pleasant elderly lady in my office today who was doing well from a cardiac perspective but had suffered considerably ever since the Food and Drug Administration (FDA) pulled the pain medication Darvocet from the market.  She has chronic knee and back pain and had remained functional while on Darvocet but had recently descended into near immobility without it.  Her sympathetic doctors tried numerous alternatives but most seem to produce more side effects than real relief.  Now she simply goes without: “I guess I’d rather put up with the pain than the fuzzy head and the nausea.”

Treatment of chronic pain is a challenging topic that all primary care doctors deal with.  The subject is frequently brought up in the cardiologist’s office as well since many of the medications we commonly prescribe can either interact with heart drugs or cause trouble in patients with cardiac problems.  Darvocet is a case in point—the drug, which had a relatively poor track record (a somewhat weak analgesic that has a history of abuse and overdose problems) was actually pulled from the market due to its propensity to trigger dangerous cardiac arrhythmias.  The fairly dramatic move on the part of the FDA caught me by surprise and I confess that I wasn’t even aware that a potential cardiac interaction existed.  We had even included it on our pre-printed order sets as a pain-control option for patients after getting a pacemaker implanted (we obviously wasted no time amending our orders once Darvocet was no longer available).  Looking into this further I’ve learned that the active ingredient propoxyphene can affect the heart muscle in the same way that some of our older antiarrhythmic drugs do, with the associated possibility for malignant rhythm disturbances.

While Darvocet is a good example of the cardiac effects of analgesic drugs it is certainly not the only one.  This is why, as a cardiologist, I am frequently asked by cardiac patients what medications are available to them that won’t mess with their heart.  They read the warning labels on the bottles and find that most painkillers include the caveat “don’t use if you have a history of heart problems.”  Patients become frustrated as drug after drug is nixed from their list of possibilities and are left wondering if there is anything out there that can provide relief without putting their lives at risk.

In order to help with this dilemma I’ll give you my take on the issue.  Here are the major classes of painkillers along with problems that may pertain to cardiac patients:

• Aspirin.  This ancient drug was a mainstay for treating arthritis—particularly the inflammatory rheumatoid arthritis—for years but has now dropped out of favor.  Acetylsalicylic acid, as it is known to people who like to drop big words at cocktail parties, blocks cyclooxygenase (another big word) in a fashion similar to the NSAIDS (see below) and can treat pain, inflammation, and fever.  The problem with aspirin is that you have to take a pretty big dose to get the desired effect, and at that dose you can run into trouble with irritation to the lining of the stomach and bleeding.  These days we use aspirin only for two things:  1. Low dose aspirin blocks platelet function and is useful in preventing heart attack and stroke; 2. it’s useful as a good cliche, i.e. “take two aspirin and call me in the morning.”

• Nonsteroidal antiinflammatory drugs (NSAIDs).  This class includes ibuprofen (Motrin, Advil), naproxyn (Naprosyn, Alleve), and many others.  They are useful for chronic pain, especially musculoskeletal, but their utility is limited by their tendency to irritate the lining of the stomach and small intestine.  To make matters worse, they can also somewhat impair the body’s ability to stanch bleeding (by blocking platelet function similar to aspirin) if a stomach ulcer starts to hemorrhage.  Older patients in particular are prone to gastointestinal side effects.NSAIDs have another set of problems in the world of cardiology.  These drugs can impair kidney function, worsen high blood pressure, mess with the body’s fluid balance, and trigger congestive heart failure in individuals prone to this.  This is the main reason cardiologists and kidney doctors avoid this class of medications.  Still, for patients with no heart failure, good kidneys, and normal blood pressure, I think NSAIDs are a reasonable choice for control of chronic pain.

• COX-2 Inhibitors.  I use the plural for “inhibitor” but should clarify that all but one member of this class has been yanked from the market.  Vioxx (rofecoxib) and Bextra (valdecoxib) were famously discontinued after a spate of hearings and lawsuits about their potential for vascular toxicity.  The only drug left is Celebrex (celecoxib), an NSAID-like medication that has similar pain-controlling properties as ibuprofen and naproxyn but with considerably lower risk of gastrointestinal bleeding.  Like its now discontinued siblings, Celebrex has shown a slightly increased risk of stroke and heart attack among people with cardiovascular disease.  For this reason doctors tend to shy away from it in such patients.My opinion on Celebrex is somehwat more nuanced.  I’ve had enough people tell me how this drug has freed them from the pain of arthritis and allowed them to live a pleasant life that I don’t take a dogmatic stand on its use even among patients with established coronary disease.  I do, however, clarify the potential risks posed by Celebrex but allow the patient to make an educated decision.  I know that if I were debilitated by arthritis and my only hope for a normal life were a medication that slightly increases my risk of heart attack and stroke I’d have no trouble reaching a decision.  In many cases quality of life greatly outweighs longevity.In the end I will approve the use of Celebrex for any patient who has no other good options and who derives great relief from its use.

• Acetaminophen (Tylenol).  This ubiquitous over-the-counter painkiller is moderately effective at controlling pain but can cause liver trouble if taken in high dose.  The current recommendation is no more than 4 grams a day (although there is currently a push to drop this value to 2.6 grams daily), meaning 2 extra strength Tylenols (500 mg each) 3-4 times daily.  My anectodal experience concurs with the less-is-better camp.  When I was in residency we admitted a guy who devoped a sinus infection and unwittingly overdosed on Tylenol.  When he awoke from his coma a few weeks later he was surprised to find himself the owner of a newly transplanted liver.For heart patients Tylenol doesn’t pose much risk when taken in appropriate doses.   Its only downside is that it’s not terribly effective at controlling more severe chronic pain.

• Opioids.  Medications that contain codeine, hydrocodone, and oxycodone are derived from the opium poppy and are used for control of moderate-to-severe pain (the fentanyl that comes in transdermal patch form is a synthetic opioid).  I’ll confess that as a cardiologist I don’t know much about the current clinical applications for this class of medication but I see them frequently used as a therapy for severe pain syndromes (such as spinal stenosis).  The opioids won’t cause any specific problems for cardiac patients and can be used safely in people with coronary disease, heart failure, and arrhythmias.The obvious concern with the use of opioids is dependence and addiction.  My limited reading on the subject suggests that many patients with a real need for pain control tend to undertreat their symptoms out of fear of addiction despite the fact that addiction is rare among patients using these drugs appropriately.

• Others.  There are many medications, such as pregabalin (Lyrica) gabapentin (Neurontin), used for neuropathic pain.  Many of these were originally developed as seizure therapies and don’t cause trouble in cardiac patients.

I can understand the frustration among people who suffer from chronic pain, especially those with concommitant heart or kidney problems.  As you can see, all analgesic drugs are a mixture of benefits and trade-offs—it’s no wonder that the search for a better class of painkillers is big business.  Hopefully we’ll have more to offer in the future than just two aspirin and a phone call in the morning.