NAPLEX (North American Pharmacist Licensure Examination) Practice Exam

What is the primary action of centrally acting analgesics such as Tramadol and Tapentadol?

1. Mu-opioid receptor agonists, inhibitors of NE reuptake

2. Selective serotonin reuptake inhibitors

3. NMDA receptor antagonists

4. Alpha-2 adrenergic agonists

The correct answer is: Mu-opioid receptor agonists, inhibitors of NE reuptake

Centrally acting analgesics like Tramadol and Tapentadol primarily exert their analgesic effects by acting as mu-opioid receptor agonists and inhibitors of norepinephrine reuptake. This dual mechanism of action contributes to their pain-relieving properties by enhancing the inhibition of pain pathways in the central nervous system. Options B, C, and D are incorrect: - Selective serotonin reuptake inhibitors (SSRIs) are primarily used as antidepressants and do not have the primary analgesic mechanism of action seen with tramadol and tapentadol. - NMDA receptor antagonists are used for chronic pain conditions like neuropathic pain but are not the primary mechanism of action for centrally acting analgesics like Tramadol and Tapentadol. - Alpha-2 adrenergic agonists, such as clonidine, are used for conditions like hypertension, attention deficit hyperactivity disorder (ADHD), and certain pain conditions like neuropathic pain, but they are not the primary mechanism of action for centrally acting analgesics like Tramadol and Tapentadol.