If nerves are what transmit pain, why do some medications work only on neuropathic pain (gabapentin) and some work on muscle related? (tylenol)

The cause matters.: Targeting the genesis of the pain problem more effectively treats it with less meds and associated side effects. Neuropathic pain is notoriously poorly treated with nsaids, tylenol (acetaminophen) and even narcotics , which is why targeting it with nerve meds is best. True muscle pain is best treated with heat or cold, stretching exercises as tolerated and nsaids. Tylenol is a general analgesic, nonspecific.

It is complex: Although Gabapentin and other similar medications are used primarily for neuropathic pain, they can also be used for somatic (including muscle) pain. The mechanism of action of the medication and the underlying cause of the patient's pain are the primary determinants of what class of medication is used.

Different reasons: "neuropathic pain" generally refers to pains that are either generated by, or result from, disordered nerves involved in the transmission of pain. "normal" pains, such as aches from strained muscles, suggest tissue injury; that's the function of a normal pain reporting system of nerves. Anti-neuropathic pain medications work best on disordered nervous systems, common analgesics best on normal ones.

Awesome question: I am no expert on medications and their transmitter pathways, but your question is terrific and should be researched more thoroughly. I would consult a pharmacist or a pharmacology school for answers, which I am sure are quite extensive and technical.