Friday, July 25, 2014

Fearlessness in the Mundane: Yet Another Reason Not to Prescribe Antibiotics Indiscriminately

My stunningly attractive and sophisticated wife happens to be a brilliant GI and liver pathologist (yes, I married up). From time to time, she’ll try to educate me by sharing an article from her field with me. Such was the case about a week ago when she handed me an article titled, Hepatic Histological Findings in Suspected Drug-Induced Liver Injury: Systematic Evaluation and Clinical Associations.  Now, this stuff is typically way over my little pediatrician head, so I told her I’d read it… later. But she wouldn’t relent. “Look at Table 1,” she said. “You need to know this.” Boy, did Table 1 get my attention. 
The article was written by members of the Drug-Induced Liver Injury Network (or DILIN) which is an effort involving some of the most prestigious medical centers in the country to better categorize and understand liver injury caused by exposure to drugs. If you had asked me, last week, what drugs are most commonly associated with liver injury, I would have guessed some big-gun, heavy-duty medications such as steroids, immune suppressants such as those used after organ transplantation, chemotherapy drugs, and perhaps some of the anti-fungals. I was only partly right.

Table 1 of the article listed the characteristics of the 249 consecutive patients who were included in the study. The age range of the patients was 7 to 87 years of age. What got my attention were the 8 most common drugs implicated in liver injury.
Turns out I was right only about the steroids. The heading, “Anabolic Agents” was number 6 on the list. They also happened to be the only drug class listed that was not an antibiotic.  Here’s the complete list of the top 8 culprits:

1.      Amoxicillin/clavulanate
2.      Nitrofurantoin
3.      Sulfamethoxazole/trimethoprim
4.      Minocycline
5.      Ciprofloxacin
6.      Anabolic agents
7.      Azithromycin
8.      Levofloxacin

This list should give every physician pause because they are all medications that are prescribed quite frequently. In fact, I suspect that it is the very frequency with which we prescribe them that explains their presence on this list. The likelihood that any one of these medications result in liver injury in an individual patient is extremely low, but when you consider how many courses of antibiotics are prescribed, it’s not surprising that this very small percentage ends up accounting for the majority of incidents. To make an analogy, many more people die in automobile accidents than aviation accidents. Yet more people have a fear of flying than a fear of driving.

Of course, this does not mean we should stop using antibiotics altogether: they are a necessary and useful tool when indications call for their use. But this is yet another warning that the injudicious, indiscriminate use of antibiotics is fraught with danger. No patient should suffer complications from a medication or surgical procedure that was not needed in the first place.