Infectious Disease Drugs
This large group of drugs are used to stop the growth or kill the microorganisms, bacteria, fungi, and viruses that cause a wide variety of infectious diseases. These drugs attack a target in the microorganism the host cells do not have. Antibiotics are used for the therapy of bacterially induced disease. Bacterial cell wall inhibitors, which include the penicillins, cephalosporins, and vancomycin, prevent some bacteria from making a cell wall, causing a disintegration of the bacterial cell. Protein synthesis inhibitors, such as tetracyclines, chloramphenicol, and clindamycin, interact with the genetic machinery of bacterial cells controlling chemical reactions for making proteins necessary for life. Aminoglycoside antibiotics, including streptomycin, gentamycin, neomycin, and many other drugs with the mycin suffix, interrupt the flow of genetic information necessary for bacterial cells to carry out life-sustaining chemical reactions. Sulfonamides (sulfisoxazole, sulfadiazine) and fluoroquinolones (sparfloxacin, ciprofloxacin) interrupt the ability of bacterial cells to make DNA. Antimycobacterial drugs, used against mycobacteria causing tuberculosis, include isoniazid, ethambutol, and rifampin. They prevent the cells from making a compound known as micolic acid, which the tuberculosis bacterial cells need to live.
Antifungal drugs interrupt cell processes that are special for plants and necessary for the fungal cells to live. Nystatin (mycostatin) and amphotericin B (Fungizone) open up holes in the membrane that surrounds fungal cells, causing the inside of the cell to leak out into the surrounding environment; 5-Fluorocytosine (Flucytosine) interrupts the genetic machinery in fungal cells. Ketoconozole inhibits certain enzymes necessary for chemical reactions in the cells.
Antiviral drugs (acyclovir, gancyclovir, foscarnet) act in different ways to prevent virus replication. A subgroup of the antiviral drugs acts on the HIV virus group, which is responsible for AIDS. Some of these drugs (zidovudine, didanosine) inhibit an enzyme called reverse transcriptase, which is necessary for the normal function of the viral DNA. Newer drugs called protease inhibitors (indinavir, ritonavir, saquinavir) inhibit the actions of the enzyme necessary for the production of the mature infectious viruses.