Pill with imprint 559 is Blue & White, Capsule-shape and has been identified as Nitrofurantoin (Macrocrystals) 50 mg. It is supplied by Zydus Pharmaceuticals (USA) Inc.

Nitrofurantoin is used in the treatment of Urinary Tract Infection; Prevention of Bladder infection; Bladder Infection and belongs to the drug class urinary anti-infectives. There is no proven risk in humans during pregnancy. Nitrofurantoin 50 mg is not a controlled substance under the Controlled Substances Act (CSA).