Naloxone is effective in reversing the effects of which of the following medications?

Naloxone is an opioid antagonist, primarily used to counteract the effects of opioids. It is effective in reversing the effects of medications that produce their effects through opioid receptors. Butorphanol is classified as an opioid analgesic which means it acts on these receptors to provide pain relief. Therefore, when naloxone is administered, it competes for the same binding sites at the opioid receptors, effectively reversing the sedative and analgesic effects of butorphanol.

In contrast, acepromazine is a tranquilizer that works through dopaminergic and adrenergic receptors, making it unaffected by naloxone. Gabapentin primarily interacts with calcium channels rather than opioid receptors, and likewise, tramadol, although it has a dual mechanism involving opioid receptors, also presents additional pathways that naloxone does not target as effectively. Thus, naloxone is specifically effective for reversing the effects of butorphanol due to its nature as an opioid medication.