Indeed. He also was supposedly epileptic and at that time Digoxin was a form of treatment epilepsy. A side effect of to much Digoxin is Xanthopsia. It causes a yellow-green tinge to your vision. He also suffered from tertiary syphilis.
YOu are talking of Gauguin, right? He had syphilis.
I have not read that of Van Gogh.
Too much Digoxin causes death by cardiac arhythmia. And I have not heard of Digoxin as a treatment for seizures.