Synonyms: 4-Thia-1-azabicyclo[3.2.0]heptane-2-carboxylicacid, 6-(2-ethoxy-1-naphthamido)-3,3-dimethyl-7-oxo-, monosodium salt,monohydrate (8CI);4-Thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid,6-[[(2-ethoxy-1-naphthalenyl)carbonyl]amino]-3,3-dimethyl-7-oxo-, monosodiumsalt, monohydrate, (2S,5R,6R)- (9CI);4-Thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid,6-[[(2-ethoxy-1-naphthalenyl)carbonyl]amino]-3,3-dimethyl-7-oxo-, monosodiumsalt, monohydrate, [2S-(2a,5a,6b)]-;Nafcillin sodium hydrate;Sodium6-(2-ethoxy-1-naphthamido)penicillanate monohydrate;Sodium nafcillinmonohydrate;