Heat is a factor in all chemical reactions. Hotter is almost always faster. Drug degradation and alteration is designed to be minimized by keeping the majority of them between 68-77°F (optimal) or 59-86°F (maximal).
As we cope with another southern summer aboard, we have been assessing the best way to keep our medicine chest (boxes and bags actually) cool when the AC is not in use. The good news is we have never encountered temps outside this range in the Bahamas during cruising season. The bad news is we can’t leave the medicines aboard the boat with the AC off during hurricane season travels — air and water temps are near 90°F. Hot car trunks are a non-starter. It gets over 135°F in there. As we were working our way through this, we came upon the article below which is worth reading.