Boy! I remember that drug, even though I read the book in grade school 30+ years ago. IIRC, it was kanamycin.
I was terribly disappointed any time it was mentioned in grad school or medical school - which wasn’t often. It’s just an antibiotic (specifically, an aminoglycoside).
It is sometimes used in serious infections, but it is toxic – mostly kidney damage, ototoxicity (damage to the inner ear causing hearing loss or balance problems) and sometimes muscle weakness, especially in parkinson’s or Myathenia gravis. There are other issues that make it less commonly used than other drugs of the same class–e.g. it can be inactivated by penicillin-like drugs, especially in cases where the kidney is already compromised, so it can’t be used in one-two knockout combos like ampicillin/gentamycin (which is very effective and widely used in a hospital along with measurements of serum levels through the day to limit the risk of toxic effects).
The imaginary version of kanamycin Crichton described seems to be a combination of several real antibiotics that were “hot” when he was in medical school. Doxycycline was usedas part of certain chemoptherapy cocktails at the time (I’m not an oncologist, though its derivatives are still used in chemo cocktails, AFAIK, doxycycline itself is used in few if any current chemo regimens)
I don’t specifically recall him mentioning a problem with going off the drug, but it would fit with something doctors worried about then (bacterial overgrowth and imbalance, especially in the colon, after the use of “super-powerful” antibiotics). There turned out to be some limited validity to this (e.g. a bacterial condition called pseudomembranous colitis, which has the unique property of being a known side effect of all the drugs used to treat it!) The principle is sound, and I believe it may be a more important notion someday, but it isn’t today. I wish I could say more (the role of commensal and other “normal” bacterial flora has always been a particular interest of mine) But I’ve been exhausted all day, and I’m tired enough now that I probably shouldn’t be posting.
So, like, none of this is medical advice, dig?
Crichton was one of my favorite authors when I was growing up. I also read his nonfiction books on medicine, like Five Patients, but I have to say that I had to unlearn a lot of the details I learned from him (e.g. his description of how daily rounds were or should be ideally conducted may have reflected the practice at Mass General when he was there, and does indeed highlight a few points that would be useful insights for laymen, but it only got me in trouble as a med student, until I realized why I mistakenly thought I should be presenting cases that way and changed. He hated medical school, and tried to drop out at the end of each year, but was talked into staying (per his autobiography). I hate to say it, but I think it shows in his medical writing.