<prompt> Site of action of epidural analgesiaSensory nerve endingsVentral hornSubstantia gelatinosaCoex  <response>: C i.e. Substantia gelatinosa Opoid receptors are maximum in Lamina 2 substantia gelatinosa Lamina 5 of spinal cord. So Epidural Narcotics acts mainly on substantia gelatinosa Common side effects of intraspinal epidural opioids are pruritis itching, nausea - vomiting; urinary retention, sedation, ileus and dose dependent respiratory depression most seriousQ 