Introduction

Chemotherapy: is the use of chemical agents (either synthetic or natural) to destroy infective agents (microorganisms’ i.e bacteria, fungus and viruses, protozoa, and helminthes) and to inhibit the growth of malignant or cancerous cells.

Chemotherapeutic agents: are chemical which are intended to be toxic for parasitic cell but non toxic to the host, such selective toxicity depends on the existence of exploitable biochemical difference between the parasite and the host cell.

Antimicrrobials: are chemical agents (synthetic/natural) used to treat bacterial, fungal and viral infections. Antibiotics: are substances produced by various species of microorganisms (bacteria, fungi, actinomycetes) that suppress the growth of other microorganisms. Antimicrobial drug exhibits selective toxicity. I.e. the drug is harmful to the parasite without being harmful to the host.

Bactericidal versus bacteriostatic action: When antimicrobial agents lead to the death of the susceptible microbe (e.g. bacteria) it is said have bactericidal action but when it merely inhibits the growth and therefore spread of the microbial population it is said to have bacteriostatic action.

Anticancer agents: Drugs or chemicals used to manage neoplastic diseases.

Antiprotozoals: are drugs used to treat malaria, amoebiasis, gardiasis, trichomoniasis, toxoplasmosis, pneumocystis carinii pneumonia, trypanosomiasis and leshmaniasis.

Anthelminthics: are drugs used in the treatment of intestinal and tissue worms.

The classificastion, pharmacokinetics, pharmacodynamics, clinical uses, adverse effects of commonly used antimicrobias, antiprotozoals, antihelimenthics are disscused. Brief introduction is given regading the treatment of cancer.