Progress in Analgesic Development: How to Assess its Real Merits?

Background: Assessing analgesic drugs developed over preceding 50 years demonstratedthat very intensive efforts directed at diverse molecular pain targets produced thousands ofPubMed articles and the introduction of more than 50 new analgesics. Nevertheless, these analgesicsdid not have a sufficiently broad spectrum of action and level of effectiveness to demonstrablyaffect the use of opioids or nonsteroidal anti-inflammatory drugs for the treatment of pain. Analgesicsin current are only modestly effective in chronic pain (at least with respect to neuropathicpain), and the widespread application of mu-opioid receptor agonists for this purpose culminated inthe global “opioid crisis”. The introduction of every new drug is regarded as an important success,at least initially. Assessing the merit of a new analgesic is extremely complicated. Objective: The aim of this article is to describe an approach that combines very different categoriesof drug evaluation – multifactorial approach for the assessment of new analgesics. It is based onconclusiveness of clinical trials, novelty of a drug’s molecular target, a drug’s commercial appeal,and the interest in a drug reflected by scientometric indices. Results: This approach was applied to analgesics developed in 1982-2016. It shows that althoughseveral new agents have completely novel mechanisms of action, all newly approved drugs, anddrug candidates, demonstrated the same persistent problems: relatively low therapeutic advantageover previous treatment and narrow spectrum of use in different types of pain, compared to opioidsor NSAIDs. Conclusion: The use of the suggested multifactorial approach to drug assessment may provide abetter view of the whole spectrum of analgesics advantages and disadvantages.