Which drug is a fentanyl analogue?

• A. Pentobarbital
• B. Tincture of Opium
• C. Nabilone
• D. Sufentanyl

Answer: (D)

Fentanyl analogues are synthetic opioids that share the same core structure and mechanism as fentanyl, binding strongly to μ-opioid receptors and often having very high potency. Sufentanyl is one of these analogues, chemically related to fentanyl and used clinically as a potent analgesic.

Pentobarbital is a barbiturate, acting on GABA receptors rather than opioid receptors. Tincture of Opium contains natural opiates like morphine and codeine, not a fentanyl-like analogue. Nabilone is a synthetic cannabinoid that acts on cannabinoid receptors, not the opioid system.

So, the fentanyl analogue among the options is Sufentanyl.