Primum no nocere?

This famous motto -- First, do no harm -- attributed to Hipocrates, is thought by many to be a foundation of medical ethics. In fact, if physicians were truly to adopt this principal, the entire medical enterprise would instantly shut down.

Cervantes has been away for a few days dealing with a family emergency. Because my secret identity is not quite as well protected as the truth about George W. Bush's pretzel attack, I can't be too specific. I will speak in general terms.

It's hard to think of a medical intervention that doesn't cause harm as well as good, or carry risk as well as hope of benefit. I'm going to leave aside the question of opportunity cost for now, although it's always there. (That $400,000 for a heart transplant could, if spent for other purposes such as immunizing poor children or providing clean water to a village, save dozens or hundreds of young lives, rather than possibly extending one old one for a few years.)

Human biology, psychology and society are all too complicated for us to understand or to master. Each system is complex beyond our ability to model, and they interact with each other. Put a powerfully biologically active chemical into the system, and it might make one problem better but it's almost certain to make other things worse. Surgery might fix your arthritic knees but it's painful as hell, is gonna cost you some months of work and slowly recovering functioning, and there is a risk of death, brain damage, or serious infection from all surgery. Most of the people who get new knees are old and not necessarily in the best health to begin with, so these are not inconsiderable problems.

Quite a few people have died from liposuction.

If aspirin were a new drug seeking approval today, it might get it, but by prescription only and with strong label warnings.

Some people have allergic reactions to antibiotics, and others mght get their ear infections cured but wind up with very unpleasant opportunistic infections because the symbiotic bacteria in their throats or intestines are killed off.

Medicine is about tradeoffs and, as we said earlier, doctors, researchers and regulators think about these in terms of probabilities. A 2% chance of dying from surgery means one thing before the surgery, and something completely different after you've had it. Any readers who have specific anecdotes or just thoughts to offer about this are invited to comment.