Hi. My son took Clarithromycin for 10 days. At around 6 days, he started having severe panic attacks (which he d never had before in his life!). He stopped taking it two days ago but his panic has not subsided. I should note, he is a regular nicotine and cannabis user and the panic attacks seem to be intensified after using cannabis. How long will it take for the Clarithromycin to work its way completely out of my son s system? Is there anything homeopathic he can do to survive the panic attacks until then? Thank you.