Ethambutol, Isoniazid

Indications

Ethambutol, Isoniazid is used for: ETHAMBUTOL
For use, as an adjunct, in the treatment of pulmonary tuberculosis
ISONIAZID
For the treatment of all forms of tuberculosis in which organisms are susceptible

Adult Dose

Child Dose

Renal Dose

Administration

Contra Indications

Precautions

Pregnancy-Lactation

Interactions

Adverse Effects

Side effects of Ethambutol, Isoniazid :

Mechanism of Action

ETHAMBUTOL
Ethambutol inhibits arabinosyl transferases which is involved in cell wall biosynthesis. By inhibiting this enzyme, the bacterial cell wall complex production is inhibited. This leads to an increase in cell wall permeability
ISONIAZID
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 mycobacterium tuberculosis organisms. Specifically isoniazid inhibits inha, the enoyl reductase from mycobacterium tuberculosis, 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