Posted on 09/09/2004 1:14:55 AM PDT by Aracelis
A widely used antibiotic long considered safe dramatically increases the risk of cardiac arrest, particularly when taken with some popular drugs for infections and high blood pressure, a huge study found.
The drug is erythromycin, which has been on the market for 50 years and is prescribed for everything from strep throat to syphilis.
The new study shows the need for continuing research on the safety of older medicines, including how they interact with newer drugs, said researcher Wayne A. Ray, a professor of preventive medicine at Vanderbilt University School of Medicine in Nashville.
In patients taking erythromycin along with other drugs that increase its concentration in the blood, the risk of cardiac death was more than five times greater, Ray and his colleagues found. That translates to six deaths for every 10,000 people taking erythromycin for the typical two weeks while on the other drugs.
"This is an unacceptably high risk," Ray said.
Nobody realized the magnitude of the problem before, said Dr. Muhamed Saric, a cardiologist and director of the electrocardiology laboratory at University of Medicine and Dentistry of New Jersey in Newark. "It was thought that erythromycin is a generally safe drug."
Most heart doctors knew erythromycin alone carried a slight risk because of some individual reports on patient deaths, mostly in people who took the drug intravenously. However, family doctors are less likely to know about it, Saric said.
This study, in Thursday's New England Journal of Medicine, was the first to systematically document the risk. It focused on much more commonly used erythromycin pills, usually sold as a generic, along with certain medicines for infections and calcium channel blockers for high blood pressure.
Ray said the danger seems to come from other drugs slowing the breakdown of erythromycin, which increases its concentration. At high levels it traps salt inside resting heart muscle cells, prolonging the time until the next heartbeat starts, and sometimes triggering an abnormal, potentially fatal, rhythm.
The findings show doctors should choose an alternative antibiotic, Ray said, at least when prescribing the drugs that interact. Amoxicillin, another popular antibiotic, showed no cardiac risk.
"There are other antibiotics that provide the same antimicrobial activity without building up in the blood the way erythromycin does," Ray said.
Ray's team of doctors and nurses spent years studying detailed medical records of 4,404 Medicaid patients from Tennessee who apparently died of cardiac arrest from 1988-93. The team confirmed 1,476 cases of cardiac arrest, then studied Medicaid's records of each patient's medication use.
Only a small number of patients had taken both erythromycin and any of the antibiotics or heart drugs carrying a risk.
Still, three of them died. Statistically, it was extremely unlikely those deaths were due to chance, according to Ray and other experts.
The deaths were in patients taking verapamil or diltiazem, both blood pressure drugs sold as generics and also under various brand names: Verelan and Isoptin for verapamil, Cardizem and Tiazac for diltiazem.
Other drugs posing a risk with erythromycin, Ray said, include the antibiotic clarithromycin, sold under the Biaxin brand; fluconazole, or Diflucan, for vaginal yeast infections; and the antifungal drugs ketoconazole (Nizoral) and itraconazole (Sporanox). Pills and injections of the drugs, but not topical forms, carry the risk.
"People may be taking these medications for years, and they develop a throat infection and someone gives them erythromycin, and that's it," Saric said.
The AIDS drugs called protease inhibitors and grapefruit juice also should be avoided, Ray said, because they, too, can boost blood levels of erythromycin.
Erythromycin, in turn, boosts blood levels of verapamil and diltiazem, which slow heart rate, and thus can worsen abnormal rhythms, said American Heart Association spokeswoman Dr. Nieca Goldberg. The findings show why people should keep a list of medications they take and share them with all their doctors, said Goldberg, chief of women's cardiac care at Lenox Hill Hospital in New York City.
About 340,000 Americans die each year of cardiac arrest, also called sudden cardiac death, according to the heart association. The condition is caused by abnormal heart rhythm, usually when the heart begins beating too rapidly or too chaotically to efficiently pump blood.
Goldberg noted the once-blockbuster nonsedating allergy drug Seldane was taken off the market, in 1998, after reports linking it to sudden cardiac death due to the same types of abnormal heart rhythms.
The study was funded by the Food and Drug Administration, two other federal health agencies and the drug company Janssen Pharmaceutica, which makes Nizoral and Sporanox. Ray and two other researchers have received consulting fees from other pharmaceutical or health products companies.
Erythromycin implicated in cardiac problems.
Speaking of heart attacks - I was very surprised to hear of clinton's urgent heart problems when you know he is checked on a regular basis.
So does aging.
When you figure that presidents probably get gold-plated health checkups, this just shows that modern medicine is all about fixing problems after they have already become crises rather than detecting them early when less invasive measures are still possible.
Additionally, in a retrospective chart review, I'm not sure how significant the "findings" are. Could these people have done this study simply to extract money from the grant money-tree industry?
One good thing it publicizes is that grapefruit juice should be avoided with many, many drugs.
Hindsight is 20/20. It's very easy to talk about detecting health problems early, after it is known that the problem existed. It's another thing entirely to detect a medical problem among innumberable possible health issues when you don't know what you're looking for.
And the fault for detecting health issues before they become crises does not lay squarely on the shoulders of medicine. Many health care consumers ignore the warning signs of illness and don't go to the doctor until and unless they are in a health crisis
6 in 10,000? That doesn't sound too risky to me!
Ping
Erythromycin is not used much anymore, due to side effects (nausea/stomach pain), as well as the fact that other macrolides with less frequent dosing intervals and less side effects are now available (Zithromax and Biaxin).
Now they tell us ...
AQGeier, Oh, boy are you correct. So many today feel it is up to someone else to care for us! Everyone must be pro-active in their health care!
I heard something interesting along these lines on TV yesterday; it seems that Clinton had been taking a statin drug that keeps the artery lining smooth, but stopped abruptly w/o checking with his dr first, because he was loosing weight on a diet. The Dr said this was a big no-no, as the rebound effect causes the artery linings to become very rough, attracting way more plaque than before. It could have been the reason why it became severe very quickly.
BTTT
Erythromycin, Biaxin(clarithromycin), Zithromax(azithromycin), Ketek(telithromycin), and Dynabac(dirithromycin) are members of the macrolide class of antibiotics which work by inhibiting the synthesis of bacterial ribosomes.
They can cause drug - drug interactions and adverse reactions such as sudden cardiac death becuase they are preferentially metabolized by the cytochrome P-450 3A (CYP3A) isozymes, i.e. class of enzymes, such that other drugs accumulate to toxic levels and induce fatal disturbances to the electro-chemically controlled heart rhythm.
If you can join the Vietnam Veterans in Washington DC this Sunday from 2 - 4 PM at Upper Senate Park next to the U.S. Capitol Building, please join us in telling Kerry what we think of him. FRiends are especially welcome.
Thanks!
This is true. But there must be more ways for one to be pro-active. A doctor interviewed in connection with Clinton's heart surgery this week claimed that there can be very few signs of a problem at the same time one's coronary arteries are almost fully blocked.
Ideally there would be a non-invasive test that tells if your arteries are narrowing and by how much. It doesn't make sense to wait for a $100,000 operation if a $100 test could have warned of the developing problem. I know that there is a test called C-reactive protein that can measure arterial inflammation which is often associated with developing arterial problems. I don't know if this would have helped in Clinton's case, but I do know that many doctors do not use this test even though it has been proven to be an excellent diagnostic tool. If more tests like this were used people would get more of a heads-up about problems before they became acute.
The best prevention of arterial blockage is a combination of good health habits and knowledge of one's genetic predisposition for heart disease, not widespread medical screening. Such a test for blockage is nice at first thought. However, the one-size-fits-all approach to preventive medicine that is so prevalent nowadays is really not as helpful as we like to think. Such an approach is imprecise and wasteful at best, and harmful at the worst.
Such medical screenings cost much more than $100. When you consider the price tag of medical diagnostics combined with performing such a test on huge numbers of people, you're looking at a huge expense in terms of money and resources. And it's a huge expense spent in the random search of a health problem that only a small fraction of the patients receiving the screening will ever even have. Not to mention that the test could possibly even have a negative effect on the person receiving the screening. Thankfully, a better knowledge of genetics will enable doctors in the future to better target who should be screened for what disease, thus making diagnosis more efficient and less wasteful.
I'm not trying to be overly contrary. I simply find that many health care consumers don't realize how murky the search for disease really is, and I feel it is important to help people realize that things are not so cut-and-dry, so that their expectations of medicine are not unrealistic.
Now, during a media conference after clinton's surgery the question was asked --how much did this all cost? Dr. answered - $25,000, - media asked - for the hospital - dr. answered - no the whole thing - media asked - surgery and hospital - dr. answered - YES!!!
Or did I hear wrong?
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