Treatment of Infectious Diseases

› Drugs used to treat bacterial diseases are grouped into categories based on their modes of action

Treatment of Bacterial Diseases

›Penicillins and cephalosporins

› Interfere with certain layers of the bacteria’s cell wall

› Do not affect the host cells

Treatment of Bacterial Diseases

› Chloramphenicol, Tetracyclines, and Erythromycins

› Bind to bacteria cell ribosomes and inhibits protein synthesis

› May be toxic to human tissue when used in high doses or for prolonged periods of time

Treatment of Bacterial Diseases

›Rifampin› Used to treat

tuberculosis› Inhibits RNA synthesis

Treatment of Bacterial Diseases

›Drugs that effectively inhibit viral infections are highly toxic to host cells because viruses use the host’s metabolic enzymes in reproduction

Treatment of Viral Diseases

› Antiviral drugs target virus-specific enzymes

› Acyclovir Used in treatment of

genital herpes

Treatment of Viral Diseases

› Amantadine› Used to prevent or

moderate influenza (flu) for those at high risk of severe illness

› AZT› Inhibits replication of

HIV genome

Treatment of Viral Diseases

› Development of drugs used treat fungi, protozoan, and helminthic diseases are also highly toxic to mammals

Treatment of Fungal and Parasitic Diseases

› Azol Derivitives › Antifungal› Inhibit sterol synthesis› Sterols are organic

compounds that make up cell walls

Treatment of Fungal and Parasitic Diseases

› Amphotericin B› Antifungal also› Disrupts cell membrane

Treatment of Fungal and Parasitic Diseases

Antimicrobial resistance presents ongoing problems in the fight against infectious diseases

RESISTANCE TO ANTIMICROBIAL AGENTS

› Penicillin resistance noted as early as 1943 by Alexander Fleming (the discover of penicillin)

› He warned that indiscriminate use of penicillin would lead to resistant pathogenic bacteria

Resistance to Antimicrobial Agents

Mycobacterium Tuberculosis (TB)

Some strains are resistant to all of the currently available drugs used for treatment

Resistance to Antimicrobial Agents

› Is a result of changes in genetic information› Resistance mechanism include:› 1. Causes structural changes that inhibit the

drug’s ability to bind to it› 2. Reduces permeability of the cell membrane to

the drug› 3. Actively pumps the drug out of the cell after it

has entered it

Resistance to Antimicrobial Agents