Is out-of-date doxycycline toxic?an old report of 4gm ingestion of old/decayed drug led to fanconi syndrome, but is it ok to take out of date doxy?

Interesting question: Why do you ask, Dr. R? I had heard about the connection between renal tubular acidosis and expired tetracycline, but rather took it on faith. The case you reference is in the British literature from 1981 where the drug was wet, then dried, then 4 gms were taken, but there are at least three other reported cases, the first from an oncologist in 1960. Dont do it!