Chapter 20
Alice tilted her head at what I said.
“Pseudomembranous colitis!”
She was sitting at the nurses' station, looking at me quizzically, as if asking what I was talking about when I'd just gotten back.
But what could I do? As soon as my vacation ended, I noticed a case of an illness that hadn't yet been properly identified.
“You mean antibiotics cause pseudomembranous colitis? That's the first I've heard of that.”
As James had mentioned, it was already known in this era that antibiotics could cause diarrhea.
But it seemed the fact that they caused pseudomembranous colitis hadn't yet been properly established. In any case, it wasn't clear.
James was quietly listening beside us. Looks like he had something else to do.
I continued explaining.
“Don't people often develop diarrhea within a few days of taking antibiotics? There are studies on that, too.”
“Wouldn't people usually think it's an allergy or a side effect? Saying it causes pseudomembranous colitis seems like a different matter...”
Alice scratched her head.
Pseudomembranous colitis and diarrhea were different things.
To put it simply, pseudomembranous colitis meant colitis with false membranes.
Scab-like false membranes formed over wounds in the intestines. Usually there were countless of them, and with the intestines in that condition, diarrhea was inevitable.
“They are different.”
“But if we're giving antibiotics, why would a bacterial infection develop? If anything, you'd expect it to happen less.”
The mechanism wasn't that complicated.
“The colon is already full of bacteria, right? Antibiotics don't get rid of all of them.”
“That's true.”
“When you give antibiotics, a lot of the bacteria in the gut die off, allowing unusual bacteria to multiply. Some of them cause pseudomembranous colitis after antibiotic use.”
Alice furrowed her brow briefly.
“That's just a hypothesis.”
“It is.”
As Alice said, research to prove this hadn't yet come out in the 1970s.
It was still an under-researched area, but that also made it a clear opportunity for research. Had I ever been wrong?
“I get what you're saying. But how could we test this hypothesis...?”
The next thing to do was treat the patient's enteritis. The treatment was simple, but since the patient wasn't mine, I couldn't just prescribe medication.
I'd have to ask permission.
It shouldn't be difficult, right?
The attending professor seemed pretty stubborn, though.
***
I looked at the gastroenterology professor.
Henry Harrington.
He was the attending physician for the pseudomembranous colitis patient I'd been looking at earlier. He looked younger than I'd expected for a professor. He furrowed his brow at what I said.
“What kind of crazy nonsense is that?”
It had been a while since I'd encountered resistance.
Professor Harrington was a skeptic.
“I think we should give the patient oral vancomycin to treat the diarrhea.”
“Uh... You said it was antibiotic-induced diarrhea. Your solution is to use even more antibiotics?”
He had a point. It was a complicated problem.
There was a reason the cause and treatment of pseudomembranous colitis hadn't been properly established even in 1970. There was a lot to consider.
I nodded.
“That's right.”
“I know the ward attending is a first-year internal medicine resident, but you know you can't just throw antibiotics around, right? Especially vancomycin.”
“Oral vancomycin is fine.”
Professor Harrington folded his arms this time.
“Why is it fine?”
“Because of vancomycin's bioavailability. Oral vancomycin has 0% bioavailability. Even when taken by mouth, it doesn't enter the bloodstream, so it has little effect on the patient's system.”
He shook his head as if displeased by this, too. Or maybe, rather than displeased, he just enjoyed an academic debate?
Either way, his expression was serious.
“Let's say you're right and oral vancomycin has 0% bioavailability. Why would giving the patient a drug with 0% bioavailability help?”
Bioavailability meant the proportion of a drug that was absorbed into the bloodstream when taken. It varied considerably depending on the drug.
The reason it would help here was simple.
“The bacteria causing pseudomembranous colitis are in the intestines, aren't they? They aren't circulating in the bloodstream.”
Checkmate.
Professor Harrington opened his mouth as if to think of a response, then closed it again.
Because I was right.
“Fine. I get it, so explain why antibiotic-induced diarrhea would be treated with antibiotics.”
“We need to use a drug that kills the bacteria causing pseudomembranous colitis, and there isn't one besides oral vancomycin. Giving it intravenously won't get it into the intestines, so it won't work.”
Professor Harrington fell into thought at my words. He seemed to be coming around.
Vancomycin was about the only drug that killed Clostridium difficile. The problem was that injecting it into a vein didn't work.
It could only be taken by mouth. Medicine was sometimes pointlessly complicated like that.
“It's a little strange to say that there's a separate bacterium causing pseudomembranous colitis... Isn't it just a kind of drug side effect?”
No.
How should I put this?
“No. Based on this patient's blood tests, this is probably a type of bacterial enteritis involving neutrophils, not eosinophils.”
“That does make some sense.”
I shrugged.
“Let's keep it simple, Professor. We suspect bacterial enteritis, so we take an antibiotic that kills bacteria. If we choose one with low bioavailability, so less of the drug enters the bloodstream...”
“Then it's oral vancomycin again.”
This time, I nodded triumphantly. That should have convinced him, right?
“Yes.”
Professor Harrington raised both hands as if admitting defeat.
“You've even come up with a workaround to justify treating your ridiculous hypothesis. Where do you come up with these ideas?”
“I gave it a lot of thought.”
“Fine... What's so hard about taking some vancomycin? Give it a week and monitor the patient.”
“Thank you.”
I bowed to the professor.
I'd gotten permission to use the medication.
Still, I wondered if Professor Harrington would start researching this topic.
I'd spoon-fed him an explanation that covered everything from the mechanism to the pharmacological properties.
Harrington would probably get the hint and start researching once he saw the results.
***
When oral vancomycin was used, symptoms usually began improving within about a day.
Of course, the patient's symptoms were severe enough that they wouldn't recover right away, but I was still expecting an almost immediate response.
It was Professor Harrington's rounds now.
I followed Professor Harrington.
The patient in question was lying quietly in bed, still looking sick. They seemed a little better than yesterday, though?
“Hello, how are you feeling?”
“Hello.”
“How's the diarrhea?”
“Uh... Much better than yesterday. My stomach still hurts a little, but I think I'm a lot better than yesterday.”
Professor Harrington nodded.
“That's good. How are you recovering from your gallbladder surgery?”
“I don't know. I guess it's all right.”
“All right. Get some rest.”
The patient turned over again, and we drew the curtain before leaving the bedside. Professor Harrington began speaking in the hallway.
***
I listened closely.
“You were right. I thought it over.”
Sometimes it was like that. Diseases didn't always behave according to doctors' logic.
Contrary to the common belief that antibiotics killed bacteria, some bacteria could thrive because antibiotics killed off their competitors. And depending on the tissue, a drug given intravenously might not work at all.
As you can see.
But what could you do when illnesses were complicated?
“Really?”
“I didn't believe it at all. Just as Dr. Parks said, there really were no eosinophils. And after we started oral vancomycin, the fever went down a lot.”
Just as I'd expected.
“I'm glad it worked.”
“Oral vancomycin works. If what you say is true, that means there's a separate bacterium that causes pseudomembranous colitis. One that's killed by oral vancomycin.”
“Clostridium difficile.”
“That makes...”
Professor Harrington stopped himself. Whether it made sense or not wasn't the point. We had to determine whether it was medically sound.
“Hmm. Tell me why you think it's Clostridium difficile. Have you been reading a textbook on internal medicine from the future?”
How did he know?
Maybe he was more perceptive than I thought.
Specifically, toxins produced by the bacteria attack the intestinal wall and cause diarrhea.
Because there were so many bacteria in the gut, it hadn't been properly figured out even by the 1970s.
I thought about how to explain it.
“It's right there in the name: difficile. It means it's a difficult bacterium to culture, doesn't it? Among known bacteria, if it's not a normal gut bacterium and has intrinsic antibiotic resistance, there aren't many possibilities.”
The professor furrowed his brow again.
“Hey, do you think medicine is theoretical physics? You can't just sit at a desk and think hard enough to deduce something like this...”
But I was probably right.
Should I suggest a bet?
“The test will show it. In an anaerobic culture, Clostridium difficile will grow, and we won't see many other bacteria.”
“Fine. We'll see.”
Professor Harrington let out a dry chuckle.
He wouldn't be able to resist checking, anyway.