See under each agent listed on right (anticoagulants, benzocaine, brodifacoum, bromadiolone, caffeine, cannabinoids, cocaine, cocaine (tainted), crospovidone, hydroxyzine, levamisole, paraquat, phenacetin, superwarfarins, talc). An issue as regards self-injected tablets and abused drugs/substances (PMID 18494838, 24509237, 26974713, 28699480). Funduscopy can be of diagnistic help (PMID 23445096)