Laudanum of opium tincture prevails today only because opium tincture was sold prior to the Federal Food, Drug & Cosmetic Act of 1938. Its "grandfathered" status protects opium tincture from being required to undergo strict FDA drug reviews and subsequent approval processes. However, the FDA closely monitors the labeling of opium tincture. Bottles of opium tincture are required by the FDA to bear a bright red "POISON" label given the potency of the drug and the potential for overdose (see discussion about confusion with Paregoric below). Despite opium tincture being an "unapproved drug" as discussed above, a search of FDA's website
Drug eruption there is a complex interplay between a patient's inherited genetics, the pharmacotoxicology of the drug and the immune response that ultimately give rise to the manifestation of a drug eruption. Because the manifestation of a drug eruption is complex and highly individual, there are many subfields in medicine that are studying this phenomenon. For example, the field of pharmacogenomics aims to prevent the occurrence of severe adverse drug reactions by analyzing a person's inherited genetic risk. As such, there are clinical examples of inherited genetic alleles that are known to predict drug hypersensitivities and for which diagnostic testing is available.