The B vitamins riboflavin, thiamin, niacin, and pyridoxine dissolve into cooking water at differing rates. Combination drugs with pyridoxine or cyanocobalamin are also marketed. The pyridine ring is part of two B vitamins&colon; niacin and pyridoxine. Patients can be treated with dopamine agonists, MAO inhibitors, and pyridoxine (vitamin B). Past cases of hydrazine exposure have documented success with Pyridoxine (Vitamin B6) treatment. Isoniazid is associated with pyridoxine (vitamin B6) deficiency because of its similar structure. This reaction uses pyridoxine (vitamin B) as a cofactor. "Pichia" is used to produce the amino acid tryptophan and the vitamin pyridoxine. Some sources state that deficiencies of vitamin A or pyridoxine are also linked. Its chemical structure resembles that of pyridoxine, a form of vitamin B. It is used in the combination drug pyridoxine/doxylamine to treat nausea and vomiting of pregnancy. Its chemical structure resembles that of pyridoxine (a type of vitamin B). If treatment is used the combination of doxylamine and pyridoxine is recommended initially. The condensation product of 3-hydroxy-1-aminoacetone phosphate and deoxyxylulose 5-phosphate is pyridoxine 5'-phosphate. With respect to medications, pyridoxine or metoclopramide are preferred.