Pharmacological characteristics of D-cycloserine

D-cycloserine is a second-line anti-tuberculosis drug that inhibits the growth of Mycobacterium tuberculosis, but its effect is weaker than that of first-line drugs, and its efficacy against tuberculosis is also low. It can produce drug resistance alone, but drug resistance occurs more than other anti-tuberculosis drugs.

Slow, no cross-resistance with other anti-tuberculosis drugs. Its antibacterial mechanism is to inhibit the synthesis of bacterial cell wall mucin peptides, thereby causing cell wall defects. The main structural component of the bacterial cell wall is the mucoid peptide, which is formed by a repeated alternating association of N-acetylglucosamine (GNAc) and N-acetylmuramic acid (MNAc) linked to the pentapeptide.

The formation of cytosolic internal mucopeptide precursors can be blocked by cycloserine, which blocks the formation of N-acetylmuramic acid pentapeptide by inhibiting the racemase and synthetase of D-alanine. Oral absorption is faster, and the blood concentration in 3-4 hours is widely distributed in body tissues and body fluids. The concentration of the drug in the brain and bone fluid is similar to that in the blood. Most of them are excreted in the urine by the prototype, and about 35% is metabolized. The minimum inhibitory concentration is 25 mg/L.