Atypical, adjuvant and potentiators

Atypical, adjuvant and potentiators (AA&P), also Adjuvants, Atypical Analgesics & Potentiators and similar, is a category of drugs used especially in management of chronic pain but also in other situations which improve the effectiveness of analgesics, usually opioids or opioids+NSAIDS. Many skeletal muscle relaxants, atypical analgesics like nefopam, NSAIDS, anticonvulsants, anticholinergics, antihistamines, ketamine, first generation antidepressants, Cymbalta, centrally-acting depressants and stimulants, drugs with NMDA, dopamine, and sigma receptor activity make up the bulk of this category. Metabolic agents such as cimetidine, which impacts the Cytochrome P-450 II-D-6 liver enzyme pathway and therefore serum levels and metabolic half life of many opioids, especially the codeine-derived semi-synthetics, are also in the potentiator group. Drugs which inhibit or reverse the buildup of tolerance to opioids, such as ketamine and dextromethorphan, also are used.

Nerve pain, cancer pain, and explosive increases in opioid tolerance are the most common reasons for physicians to employ these drugs in the pain management programme for a given patient.

Some opioids have activity similar actions to drugs in the above list, such as the NMDA and sigma action of methadone and ketobemidone and the NMDA, SSRI, SNRI, sigma, and possible anticholinergic action of levorphanol.