Drug/Small Molecule:

isoniazid

Antibacterial agent used primarily as a tuberculostatic. It remains the treatment of choice for tuberculosis. PubChem (source: Drug Bank)

For the treatment of all forms of tuberculosis in which organisms are susceptible. (source: Drug Bank)

Isoniazid is a prodrug and must be activated by bacterial catalase. Specficially, activation is associated with reduction of the mycobacterial ferric KatG catalase-peroxidase by hydrazine and reaction with oxygen to form an oxyferrous enzyme complex. Once activated, isoniazid inhibits the synthesis of mycoloic acids, an essential component of the bacterial cell wall. At therapeutic levels isoniazid is bacteriocidal against actively growing intracellular and extracellular <i>Mycobacterium tuberculosis</i> organisms. Specifically isoniazid inhibits InhA, the enoyl reductase from <i>Mycobacterium tuberculosis</i>, by forming a covalent adduct with the NAD cofactor. It is the INH-NAD adduct that acts as a slow, tight-binding competitive inhibitor of InhA. (source: Drug Bank)

Isoniazid is a bactericidal agent active against organisms of the genus Mycobacterium, specifically <i>M. tuberculosis</i>, <i>M. bovis</i> and <i>M. kansasii</i>. It is a highly specific agent, ineffective against other microorganisms. Isoniazid is bactericidal to rapidly-dividing mycobacteria, but is bacteriostatic if the mycobacterium is slow-growing. (source: Drug Bank)

Avoid aged foods (cheese, red wine), pickled foods, cured foods (bacon/ham), chocolate, fava beans, beer, unless approved by your physician.
Avoid alcohol.
Do not take calcium, aluminum, magnesium or Iron supplements within 2 hours of taking this medication.
Increase dietary intake of magnesium, folate, vitamin B6, B12, and/or consider taking a multivitamin.
Take on empty stomach: 1 hour before or 2 hours after meals.
Take with a full glass of water. (source: Drug Bank)

Primarily hepatic. Isoniazid is acetylated by N -acetyl transferase to N -acetylisoniazid; it is then biotransformed to isonicotinic acid and monoacetylhydrazine. Monoacetylhydrazine is associated with hepatotoxicity via formation of a reactive intermediate metabolite when N-hydroxylated by the cytochrome P450 mixed oxidase system. The rate of acetylation is genetically determined. Slow acetylators are characterized by a relative lack of hepatic N -acetyltransferase. (source: Drug Bank)

Very low (0-10%) (source: Drug Bank)

Readily absorbed following oral administration; however, may undergo significant first pass metabolism. Absorption and bioavailability are reduced when isoniazid is administered with food. (source: Drug Bank)

LD₅₀ 100 mg/kg (Human, oral). Adverse reactions include rash, abnormal liver function tests, hepatitis, peripheral neuropathy, mild central nervous system (CNS) effects. In vivo, Isoniazid reacts with pyridoxal to form a hydrazone, and thus inhibits generation of pyridoxal phosphate. Isoniazid also combines with pyridoxal phosphate; high doses interfere with the coenzyme function of the latter. (source: Drug Bank)

c1cnccc1C(=O)NN (source: Drug Bank)