Drug Interactions Are Neglected But Deadly

Drug interactions are one of the most complicated and neglected problems in health care. Physicians, pharmacists and nurses all realize how dangerous it can be to combine certain medications, but they are often too busy to double-check for incompatibilities.
One reader of this column wrote about her hospital experience. She was taking an antidepressant that interacts dangerously with dozens of foods and other medications.
“I always tell everyone I am taking Parnate. The admitting nurse asked if I could take the pain reliever Demerol. I told her I could not and asked her to contact the doctor. She returned and said she would just ask me what I could take, since he did not want to bother gathering that information himself or contacting the physician who had prescribed the Parnate. I later found out I had received Demerol in an injectable form. I was in the hospital for 18 days and was afraid I would not get out alive.”
This woman was indeed lucky to survive her ordeal. The pain reliever Demerol together with Parnate can cause serotonin syndrome, a life-threatening condition characterized by agitation, severe shivering and muscle twitching, confusion, restlessness, elevated temperature, sweating, hypertension and coma.
Even something as simple as cough medicine or a chunk of cheddar cheese can trigger a potentially deadly interaction with Parnate.
Pharmacists are supposed to check for just such complications. But under current conditions that has become difficult, if not impossible. A pharmacist shared a shocking secret:
“For the past 16 years I have been employed as a pharmacist by one of the nation’s largest chains. In my experience the workload my employer requires does not permit me even to read the interaction screen on the computer.
“In many cases prescriptions are entered by pharmacy technicians who have no expertise in drug interactions or who totally ignore the warnings on the screen because of a huge backlog of prescriptions. I am sure that many people are harmed each day because pharmacists don’t have time to consider drug interaction information provided by the computer programs.”
Even when pharmacists are conscientious about checking the computer, interactions may not be detected. One recent study revealed that almost one-third of dangerous drug combinations were not flagged by the computer.
It can take years before interactions are discovered and longer still for them to end up in reference books or computer programs. This leaves the patient holding the bag.
Drugs notorious for hazardous interactions include the anticoagulant Coumadin (warfarin), the heart medicine Lanoxin (digoxin), the impotence drug Viagra (sildenafil) and the asthma medicine theophylline. But thousands of other medications, from atenolol to Zoloft, can cause complications in the wrong combination.
To protect yourself or someone you love from medication misadventures, make sure everyone-physician, pharmacist and nurse-is involved in checking for interactions. In addition, patients need to double-check for incompatibility with food, herbs and even vitamins. To get started, you may wish to consult our Web site (www.peoplespharmacy.org).