AUTHOR: Donna Cosgrove PhD MPSI
Donna graduated with a BSc in Pharmacy from the Royal College of Surgeons in Ireland. She then returned to university to complete a MSc in Neuropharmacology. This led to a PhD investigating the genetics of schizophrenia, followed by a postdoctoral research position in the same area. Currently Donna works as a pharmacist in Galway, and as a clinical writer.
60 Second Summary
The 2020 pain definition is: “An unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage.” Pain signals are sent from nociceptors to the cerebral cortex via the spinal cord. The motor cortex then elicits a physical response if necessary. Specialised receptors on primary afferent nerves signal the sensations of pressure (compression), inflammation (prostaglandins, nerve growth factors, cytokines, interleukins), and temperature, amongst others. Pain management is one of the most common reasons for people to seek advice in the community pharmacy with 47% of EU consumers having used an overthecounter (OTC) analgesic once per week in the last month. “Acute pain” (pain lasting <12 weeks) results from inflammation and swelling, and can significantly impact functional ability and quality of life. Non-steroidal anti-inflammatory drugs work through mediation of prostaglandin and thromboxane A2 production through reversible inhibition of the enzyme cyclooxygenase (COX). Prostaglandins mediate many physiological functions including inflammatory and nociceptive processes; also maintaining the gastric mucosal barrier, regulating renal blood flow and endothelial tone. The mechanism of action of paracetamol was elusive for a long time. It appears to inhibit COX 1 and COX 2, although it does not inhibit COX in peripheral tissues. It is for this reason that paracetamol has no peripheral anti-inflammatory effects like traditional NSAIDs. Understanding the definition of, and mechanisms behind, pain can aid with pain assessment. When evidence-based recommendations of OTC analgesics are made while taking into consideration individual patient characteristics, this can make a significant positive impact on patient outcomes.