On call

Discolored respiratory mucus

Q. Every time I get a flow of green mucus from my nose after a cold, I call my doctor and get a prescription for antibiotics. But when I called last week, my doctor was on vacation, and the young covering M.D. would not call in an antibiotic. I was very upset. What can I do to get an antibiotic if this happens again?

A. The short answer is to memorize your doctor's vacation schedule. But the real answer may not be any more welcome than the jest, since the covering doctor is probably right.