Abstract
The acetylation of isoniazid by pigeon liver extracts is inhibited by various aromatic amino, amido, and hydrazino compounds. p-Aminosalicylic acid, given in conjunction with isoniazid to rabbits, produced a marked increase in the plasma level of free isoniazid. A similar effect was obtained with sulfanilamide. A colorimetric method for the determination of free isoniazid in the presence of aromatic amines is described.