I stopped taking avelox just after one pill due to the side effects (headache, pain in the wrists and the feet). When are they supposed to disappear?

Avelox. Fluoroquinolones can set off a cascade of adrenal overactivity. In most cases it resolves by itself, however, there are many who require medical intervention.
May be <24 hours. Avelox is about 90% absorbed after ingestion. The half-life of Avelox is about 12 hours and so by 24 hours, only less than 25% of the amount should be left in your system and often this level should not be bothering you much. Your symptoms can be relieved by meds such as motrin/aleve/tylenol etc... If persistent >24 hours, consult doc and inform that you stopped avelox. Good luck.