Laudanum his "archanum" or "laudanum", may or may not have contained opium. Paracelsus' laudanum was strikingly different from the standard laudanum of the 17th century and beyond, containing crushed pearls, musk, amber, and other substances. One researcher has documented that "Laudanum, as listed in the "London Pharmacopoeia" (1618), was a pill made from opium, saffron, castor, ambergris, musk and nutmeg". Laudanum remained largely unknown until the 1660s when English physician Thomas Sydenham (1624–1689) compounded a proprietary opium tincture that he also named laudanum, although it differed substantially from the laudanum of Paracelsus. In 1676 Sydenham published a seminal work, "Medical Observations
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.