Inhibition of alcohol metabolism by alcohol dehydrogenase or acetaldehyde metabolism by aldehyde dehydrogenase cause analgesia and prevents nociceptive behaviors.

Figure 2a illustrates changes in threshold over 6 hours in IS infused rats that received ethanol combined with 4-Methyl Pyrazole (4MP blue line). Thresholds are also shown for ethanol alone (black line) from Figure 1a as a comparison. Figure 2b displays change in threshold relative to baseline at 0–2 hours following ethanol +4MP and 4–6 hours following ethanol +4MP. Figure 2c illustrates changes in threshold over time in IS infused rats that received ethanol combined with disulfiram (red line). Thresholds for ethanol alone (black line) are included from Figure 1a as a comparison. Figure 2d displays change in threshold relative to baseline at 0–2 hours following ethanol + disulfiram and 4–6 hours following ethanol + disulfiram.