The best replacement for opiate is opioid.

The best alternatives to opiate are rated as following:
★★★★★  opioid
★★★★  narcotic
★★★  benzo
★★  barbiturate
★★  benzo withdrawal
★  benzodiazepine
★  opium
★  nsaid
  analgesic

Your alternative for opiate is not listed? Suggest!
Speaking about opiate, one probably shouldn't forget about benzo.

Other search terms related to opiate and their ratings are:
★★★★★ benzo
You have in mind a companion for opiate and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of opiate in all years. Click on graph for more.
opiate
opioid
narcotic