Thioacetazone (INN, BAN), also known as amithiozone (USAN), is an oral antibiotic which is used in the treatment of tuberculosis.

[1][2][3][4] It has fallen into almost complete disuse due to toxicity and the introduction of improved anti-tuberculosis drugs like isoniazid.

Use of thioacetazone is declining because it can cause severe (sometimes fatal) skin reactions in HIV positive patients.

[6][7] The biological target of thioacetazone has proven elusive and its mechanism of action remains unknown, although it is thought to interfere with mycolic acid synthesis.

[4] One of the documented adverse effects of thioacetazone is the excessive accumulation of serum (or blood plasma) in the brain.