(2S)-amino(phenyl)acetic acid and derivatives as α

1. A method of treating neuropathic pain, in a mammal using a ligand of the α 2 δ voltage-gated calcium channel, wherein the ligand is a compound of formula (I)

or a pharmaceutically acceptable salt, amide, or ester, thereof, wherein R 1 is hydrogen or alkyl.

2. A method of claim 1 , comprising administering to the mammal a compound of formula (I) in combination with an opioid.

3. A method of claim 2 , wherein the opioid is morphine.

4. A method according to claims 1 or 2 wherein the compound of formula (I) is (2S)-amino(phenyl)acetic acid or pharmaceutically acceptable salt thereof.