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.