Chapter 20

Synthetic drugs Isoniazid – inhibits mycolic acid synthesis. Effective against mycobacterium tuberculosis. Ethambutol – inhibits mycolic acid. Sulfanilamide inhibits folic acid synthesis. PABA - enzyme – folic acid Fluroquinolones inhibits DNA synthesis. Typhoid fever, shigellosis

penicillin Mold – Penicillium notatum – inhibits peptidoglycan synthesis Bacitracin – Bacillus – peptidoglycan – topical applications. Polymyxin – Bacillus – damages plasma membrane – topical treatment. Rifampin – Streptomyces – inhibits RNA synthesis – tuberculosis.

Antifungal drugs Amphotericin B – Streptomyces – damages plasma membrane – systemic mycosis – Histoplasmosis. Nystatin – Streptomyces – damages plasma membrane – Candida infections.

Antiviral drugs Acyclovir – inhibits the synthesis of viral DNA. Effective against herpes virus. Zidovudine – inactivates the reverse transcriptase – can cause anemia in some cases. Used to treat HIV infection.

Antiprotozoan drugs Chloroquine – malaria Metronidazole – inhibits metabolism in an anaerobic environment. Giardiasis, amoebic dysentery.

Antihelminthic drugs Niclosomide – inhibits ATP synthesis in mitochondria – treat tapeworm infestations. Praziquantel – damages plasma membrane – treat fluke infestations. Mebendazole – inhibits microtubule formation – roundworm infestations.

Some bacteria develop resistance. Plasmids – antibiotic resistance. Mutations can result in the overproduction of the enzyme that is being inactivated by the drug.