Is Lorazepam an Opioid?
No, lorazepam is not an opioid—it is a benzodiazepine that works on GABA receptors in the brain, whereas opioids work on mu-opioid receptors. 1, 2
Drug Classification
- Lorazepam is a benzodiazepine that potentiates neural inhibition mediated by gamma-aminobutyric acid (GABA) through GABA-A receptors in the central nervous system 3
- Benzodiazepines do not activate GABA-A receptors directly but require GABA to be present, producing sedation, anxiolysis, amnesia, muscle relaxation, and anticonvulsant effects 3
- Opioids are a completely separate drug class that includes morphine, hydromorphone, fentanyl, and oxycodone, which work through mu-opioid receptors 1
Critical Safety Distinction
While lorazepam is not an opioid, the FDA has issued a black box warning about the profound risks when benzodiazepines like lorazepam are combined with opioids, including respiratory depression, coma, and death 2. This warning exists precisely because these are two different drug classes with synergistic depressant effects:
- Benzodiazepines can cause respiratory depression and hypotension, especially when administered with opioids 1
- The combination increases risk of drug-related mortality compared to opioids alone 2
- If prescribed together, use the lowest effective doses and minimum durations, with close monitoring for respiratory depression 2
Clinical Use Patterns
In clinical practice, lorazepam and opioids are often used together but serve different purposes:
- Opioids are the primary treatment for dyspnea in palliative care, with morphine being the standard 1
- Lorazepam is added when dyspnea is associated with anxiety or when opioids alone provide insufficient relief 1
- The combination of lorazepam with opioids has been shown safe in palliative care when properly monitored, with no significant respiratory depression in studied patients 4
- For acute agitation, combining lorazepam with haloperidol (an antipsychotic, not an opioid) is superior to either agent alone 5
Common Clinical Pitfall
Do not confuse the frequent co-administration of benzodiazepines with opioids as meaning they are the same drug class. They are prescribed together because they address different symptoms (anxiety vs. pain/dyspnea) and have complementary but distinct mechanisms of action 1, 2.