ANTI-INFECTIVE AGENTS Roselyn A. Naranjo

Anti-infective Agent - are drugs capable of acting against infection, by inhibiting the spread or by killing the infectious agent. - is a general term that encompasses antibacterials, antibiotics, antifungals, antiprotozoans and antivirals.

CHEMOTHERAPHY - is the use of chemical substances to treat disease. In its modern-day use, it refers to cytotoxic drugs used to treat cancer or the combination of these drugs into a standardized treatment regimen.cytotoxiccancerstandardized treatment regimen -is the use of medicines (or drugs) to treat disease. - can destroy cancer cells that have metastasized, or spread to parts of the body far away from the primary (original) tumor. -is the study and use of chemical agents that are selectively more toxic to the invading organism. - it is the cure of an infectious disease without injury to the host.

Cytotoxic Cells - a cytotoxic T cell (also known as TC, CTL, T- Killer cell or killer T cell) belongs to a sub-group of T lymphocytes (a type of white blood cell) which are capable of inducing the death of infected or somatic tumor cells. - they kill cells that are infected with viruses (or other pathogens ), or are otherwise damaged or dysfunctional.

Selective toxicity - is the property of certain chemicals to destroy one form of life without harming another. - the cornerstone of modern antimicrobial chemotherapy. Paul Ehrlich - discovered the antibacterial dyes and parasitic activity of organic arsenical.

Classification of chemotherapeutic Agents 1. Chemical Type 2. Biological Properties 3. Therapeutic indicators Types of Anti-infective agent according to source: 1. Antibiotics – derived from natural source or semi- synthetically prepared. 2. Antimicrobials – produced from synthetic substances.

Classification of Local Anti-infective Agents 1. Antiseptic - are compounds that kill or prevent the growth of microorganism when applied to living tissue. Criteria of an ideal Antiseptic * exerts rapid and sustained lethal action against microorganism (narrow and broad spectrum) * retain activity in the presence of body fus including pus * non-irritating to tissues * non-allergenic * lack systemic toxicity when applied to skin or mucous membrane * does not interfere with healing

2. Disinfectant - is an agent that prevents infection by the destruction of pathogenic microorganisms when applied to inanimate objects Criteria of an ideal disinfectant * exerts a rapid lethal action against all potentially pathogenic microorganisms and spores. * has good penetrating power into organic matter * compatible with organic compounds (especially soap) * not inactivated by living tissues * non-corrosive * esthetically desirable (non-staining and odorless) Classification of Local Anti-infective Agents

ALCOHOLS AND RELATED COMPOUNDS - also known as ethanol, wine spirit, Cologne spirit. - has burning taste and flammable. - miscible with water and other organic solvents. - fermentation product from grain and other carbohydrates. - most widely abused of all recreational drugs. - metabolized in the liver to aldehyde then to acetic acid and finally to carbon dioxide and water. A. Alcohol

Classification of Local Anti-infective Agents The antibacterial action of alcohol is due to the denaturing effect on proteins. 100% ethyl alcohol 70% ethyl alcohol coagulates A. Alcohol

Uses: - antiseptic, preservative, mild counter-irritant or solvent of pharmaceutical preparations including spirits, tinctures and fluidextracts. - rubbing alcohol is used as astringent, rubefacient, refrigerant and mild local anesthetic. - alleviate pain of neuralgia by injecting alcohol to nerve and ganglia. - used internally in diluted forms as a mild sedative, as a weak vasodilator, as carminative and as source of energy.

Denatured alcohol - is ethanol that has been rendered unfit for use in intoxicating beverages by the addition of other substance. Completely denatured alcohol Specially denatured alcohol - is ethanol treated with one or more substances so that its use may be permitted for specialized purposes. Examples are methanol for plant extracts Iodine in alcohol for tincture of iodine - contains added wood alcohol and benzene and is unsuitable for either external or internal use. Types of alcohol

ALCOHOLS AND RELATED COMPOUNDS B. Dehydrated Ethanol - also known as absolute alcohol - it contains not less than 99% by weight of C 2 H 5 OH. - it is prepared by azeotropic distillation of an ethanol and benzene mixture. - it has a very high affinity of water and must be stored in tightly sealed containers. - it is use primarily as chemical agent, but it has also been injected for the local relief of pain in carcinoma and neuralgia.

ALCOHOLS AND RELATED COMPOUNDS C. Isopropyl alcohol, USP - it is a clear, colorless liquid having a characteristic odor and slightly bitter taste. It is considered a suitable substitute for ethyl alcohol for most external uses, but it must not be taken internally. - it is prepared commercially by the sulfuric acid-catalyzed hydration of propylene.

Uses:  - it is rapidly bactericidal in the concentration range of 50% to 95%. - 40% concentration is considered equal in antiseptic power to a 60% ethanol concentration. - Azeotropic isopropyl alcohol, USP is used by diabetics

To be continued…