ASK DR. BAUGHAN                                             February 24, 2000

THE PROPULSID ALERT

The latest drug to be implicated in previously unknown complications is Propulsid (generic: cisapride).  Propulsid is a drug used for gastroesophageal reflux (GERD), irritable bowel syndrome, diabetic gastroparesis, and other bowel spasm or irregularity type problems.  Given how common GERD is, there are many people taking Propulsid.  Over a six year period, from 1993-1999, 270 reports of serious cardiac arrhythmias (irregular heartbeats) were reported, including 70 deaths.  Of these 270, 225 were in people with risk factors for irregular heartbeats.  So on the one hand, 270 out of thousands and thousands is not a lot.  On the other hand, not all cardiac arrhythmias get reported if someone happens to be on Propulsid.

Why should a drug for stomach and bowel problems cause heart trouble?  The way Propulsid works is to decrease the tendency for strong contractions in the smooth muscle of the gut.  In GERD, it works to increase the tone of the gastroesophageal sphincter, the muscle that connects the esophagus (food pipe) to the stomach.  This helps prevent stomach acid from splashing back up into the esophagus, causing heartburn.  So it is intended to work on muscle tissue.  Although the heart is a different type of muscle tissue, it is not far-fetched that it might influence the contraction pattern of heart muscle.  When the medicine is digested, it does not know to avoid the heart and only go to the gut.

Who is particularly at risk?  Those who already have irregular heartbeats should check with their health providers.  Those with other heart problems such as angina, congestive heart failure, or heart attacks should also be wary.  Patients with conditions that cause their electrolytes (sodium, potassium, or magnesium) to become low are also at risk.  Electrolyte problems are often caused by other medicines, but may occur in conditions that cause vomiting or diarrhea, kidney failure, malnutrition or dehydration.

Certain medicines have been implicated in increasing the risk with Propulsid.  These include antibiotics in the family that includes erythromycin, Biaxin, and Zithromax; medicines for fungal infections (Sporonox, Lamisil, Nizoral); medicines for nausea and vomiting (Phenergan or Compazine); certain heart medicines (quinidine, procainamide, sotalol), tricyclic antidepressants (which are the older ones like amitryptiline, Elavil, nortryptiline, Pamelor, or imipramine, Tofranil - not the SSRIs like Prozac, Paxil, Zoloft, Celexa); diuretic medicines that may lower potassium such as furosemide (Lasix) or hydrochlorothiazide (HCTZ, Hydrodiuril).  Grapefruit juice also seems to increase the risk.  Fortunately, most people with GERD probably don’t drink much grapefruit juice.

If someone has GERD, Propulsid can be very helpful, so I doubt it will be taking off the market.  If a patient is not doing all they can with diet and exercise to manage GERD (avoid cigarettes, alcohol, caffeine, chocolate and mint, weight reduction), then re-doubling effects in that direction would be valuable.  An EKG can give a clue if the person is at risk for Propulsid-associated cardiac arrhythmias, and the electrolytes should be checked periodically.  There is also an alternative drug called Reglan.

As with other drug alerts, it is important to keep perspective.  People have not been dropping like flies from Propulsid, but in keeping with the prime directive of medicine to “Do No Harm,” a careful re-appraisal of the need for Propulsid is appropriate.