A person with opioid addiction requires increasingly higher doses to achieve the same pain relief. What causes the decreased opioid effectiveness over time?

💡 Explanation

Tolerance develops to opioids because the body reduces the number of opioid receptors through receptor downregulation to maintain homeostasis in the dopamine reward circuit. Therefore, higher doses are needed to activate the remaining receptors, rather than the body producing more opioid peptides.

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