Q: Simultaneous use of which commonly used drugs during intubation may exacerbate etomidate-related adrenal insufficiency?

Answer:  Opioids and benzodiazepines.

Simultaneous use of etomidate with opioids and/or benzodiazepines has shown tendency to exacerbate etomidate-related adrenal insufficiency, at least in 2 studies.

References:

1. Daniell, Harry (2008). "Opioid and benzodiazepine contributions to etomidate-associated adrenal insufficiency". Intensive Care Medicine 34 (11): 2117–8.

2. Daniell, HW (2008). "Opioid contribution to decreased cortisol levels in critical care patients". Arch Surg 143 (12): 1147–1148.