The best replacement for opioids is opiates.

The best alternatives to opioids are rated as following:
★★★★★  opiates
★★★  narcotics
★  non opioids
★  short acting opioids
★  nsaids
★  no opioids
  barbiturates
  narcotic
  non-opioids
  analgesics

Your alternative for opioids is not listed? Suggest!
Speaking about opioids, one probably shouldn't forget about ceiling effects.

Other search terms related to opioids and their ratings are:
★★★★★ ceiling effects
★★★★★ benzodiazepines
★★ benzos
★ ceiling effect
histamine release
respiratory depression
You have in mind a companion for opioids and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of opioids in all years. Click on graph for more.
opioids
opiates
narcotics