The accumulation of isoniazid in tissues, and the course of experimental tuberculosis.

In an attempt to find agents enhancing the infiltration of isoniazid into tissues, the authors have investigated the effect of the drug on oedema due to injection of egg white into the rat paw, when it was given alone and in conjunction with histamine, antazoline, carbachol, chlorpromazine, and a pyrogen. Isoniazid increased the oedema. All the substances, except antazoline, increased the rate at which isoniazid disappeared from the blood, and they all favoured accumulation of the drug in tissues. Treatment of experimental tuberculosis with subthreshold doses of isoniazid, in conjunction with the above compounds, gave better results than when isoniazid was used alone.