1. AM404, a metabolite of paracetamol, directly blocks pain by inhibiting voltage-gated sodium channels in peripheral sensory neurons.
2. AM404 suppressed channel activity and exhibited analgesic effects in in vivo tests.
3. The study suggests potential for developing targeted pain therapies using AM404 or similar compounds.
4. AM404's action resembles that of local anesthetics such as bupivacaine.

Source: Proc Natl Acad Sci U S A