UNIT 2 Antiinfective and Chemotherapy PDF

Diploma in Healthcare Please do not reproduce, redistribute or share without the prior express permission of the author. Introduction to Pharmacology 2.1 Antibiotics, antifungal and antiviral drugs Please do not reproduce, redistribute or share without the prior express permission of the author. Top...

Diploma in Healthcare Please do not reproduce, redistribute or share without the prior express permission of the author. Introduction to Pharmacology 2.1 Antibiotics, antifungal and antiviral drugs Please do not reproduce, redistribute or share without the prior express permission of the author. Topic/ Chapter Learning Outcome Describe bacteria and related diseases. Identify types of antibiotics and their uses. Describe fungus and their diseases. Identify types of antifungal drugs available. Define virus and their diseases. Identify types of antiviral and their uses. Define parasite and their diseases. Identify anti-parasites and their uses. Please do not reproduce, redistribute or share without the prior express permission of the author. Pathogens Pathogens are harmful microorganisms to humans. Examples of pathogens are : Bacteria (cholera & tuberculosis) Fungal (candida) Virus (HIV & hepatitis) Parasites Protozoa – (malaria) Helminths – (hook or pin worm infection) Please do not reproduce, redistribute or share without the prior express permission of the author. BACTERIA Unicellular microorganisms. Have many shapes: Spheres, rods, and spirals Bacteria are ubiquitous in every habitat: growing in soil, acidic hot springs, radioactive waste, seawater, and deep in the earth's crust. Please do not reproduce, redistribute or share without the prior express permission of the author. BACTERIA Few pathogenic bacteria cause infectious diseases: cholera, syphilis, leprosy and bubonic plague. In developed countries, antibiotics are used to treat bacterial infections. Please do not reproduce, redistribute or share without the prior express permission of the author. ANTIBIOTIC An antibiotic is a drug that kills or prevents the growth of bacteria. They have no effect against viruses or fungal infections. They are relatively harmless to the host, and therefore can be used to treat infections. Antibiotics can be categorized based on their target specificity: Narrow-spectrum: Affects smaller range of bacteria. Broad-spectrum: Affect a larger range of bacteria. Please do not reproduce, redistribute or share without the prior express permission of the author. Some antibiotics will kill the bacteria (bactericidal) Others may inhibit the growth of the bacteria (bacteriostatic) Antibiotics are administered through: Oral (normal way) Intravenous (more serious cases) Topically (eye drops or ointments) Staphylococcus aureus Antibiotics test plate. Please do not reproduce, redistribute or share without the prior express permission of the author. Antibiotics Groups based on Mode of Action Mode of Action (MOA) Examples Type of Action Inhibit formation of bacterial cell wall Penicillin Cephalosporin Bactericidal Bactericidal Inhibit protein synthesis by bacteria. Tetracycline Aminoglycoside Macrolide Bacteriostatic Bactericidal Bactericidal Inhibit nucleic acid synthesis. Quinalone Bactericidal Inhibit folic acid systhesis. Sulfonamides Bacteriostatic Please do not reproduce, redistribute or share without the prior express permission of the author. Adverse reactions of Antibiotics Hypersensitivity (Allergic) Nephrotoxicity Nausea & vomiting Loss of appetite Fever Please do not reproduce, redistribute or share without the prior express permission of the author. Antibiotic Combination Combination of antibiotic is needed when: Severe infections occur. Bacterium rapidly develops resistance to a single antibiotic. Infections caused by more than one bacterium. Certain combinations shows synergism, that is combination more effective than either drug used separately. Please do not reproduce, redistribute or share without the prior express permission of the author. FUNGUS Multicellular organism. Examples: Yeasts, molds, and mushrooms. Useful Fungi: yeasts are responsible for fermentation of beer & bread, and mushroom farming. Although normally harmless, these fungi sometimes cause local infections of the skin and nails, vagina, mouth or sinuses. Please do not reproduce, redistribute or share without the prior express permission of the author. ANTIFUNGAL An antifungal drug is medication used to treat fungal infections. MOA: Antifungal kills only fungal cells without affecting the host. There are often side-effects to these drugs. Some of these side-effects can be life-threatening. Examples: Fluconazole Itraconazole Amphotericin B Please do not reproduce, redistribute or share without the prior express permission of the author. Adverse reactions of Antifungals Liver toxicity Nausea & vomiting Diarrhea Fever Headache Kidney damage. Please do not reproduce, redistribute or share without the prior express permission of the author. VIRUS A virus is a microscopic particle that can infect the organism. Viruses can replicate themselves only by infecting a host cell. Viruses consist of genetic material contained within a protective protein capsid. Virus are very harmful to the body. Please do not reproduce, redistribute or share without the prior express permission of the author. ANTIVIRUS Antiviral drugs are medication used to treat viral infections. Specific antivirals are used for specific viruses. They are relatively harmless to the host, and therefore can be used to treat viral infections. Most of the antivirals available now are designed to help deal with HIV, herpesvirus, hepatitis B and C viruses. Examples: Amantadine Antiherpes Zidovudine Please do not reproduce, redistribute or share without the prior express permission of the author. PARASITES Parasites are organisms that lives inside or outside the body of other organism (host). It will cause harmful effects or sometimes kills the host. Most common parasitic infections are caused by protozoa and helminth. Please do not reproduce, redistribute or share without the prior express permission of the author. PROTOZOA Microorganism belongs to kingdom Protista (not animals). Most protozoans are too small to be seen with the naked eye. Protozoa such as the malaria parasites, trypanosomes and leishmania cause disease in humans. Please do not reproduce, redistribute or share without the prior express permission of the author. HELMINTHS Worms may also be called helminths. Examples: parasitic worms, roundworms, hookworms, pinworms and tapeworms. They normally infect humans through their eggs. The eggs enter the human body, hatches to release larvae which will then grow into worm. Please do not reproduce, redistribute or share without the prior express permission of the author. Types of Antiparasites Anti-malarial drugs Chloroquine Mefloquine Used to prevent malaria from Plasmodium sp and falciparum malaria. Side effects include: stomach ache itch headache and blurred vision Please do not reproduce, redistribute or share without the prior express permission of the author. Anti-helminthic drugs Mebendazole Piperazine Used to combat pinworms, roundworms and hookworms. MOA: causes slow immobilization and death of the worms. paralysing parasites, which allows the host body to easily remove or expel the invading organism. Please do not reproduce, redistribute or share without the prior express permission of the author. Anti-protozoal drugs Metronidazole Used in the treatment of infections caused protozoa. Responsible for disrupting the DNA structure, thus inhibiting nucleic acid synthesis. Please do not reproduce, redistribute or share without the prior express permission of the author. 2.2 Immunizing & Immunosuppresives Please do not reproduce, redistribute or share without the prior express permission of the author. OBJECTIVES At the end of the lesson, students should be able to: Define Immunity. Describe Active and Passive Immunity. Describe Immunologic agents and their effects. Describe Immunosuppressive agents and their effects. Please do not reproduce, redistribute or share without the prior express permission of the author. Immune System Immunity - ability of the body to identify and resist microorganisms that are potentially harmful. This ability enables the body to fight or prevent infectious disease and inhibit tissue or organ damage. There are two types of immunity: Humoral Immunity Cell-Mediated Immunity Please do not reproduce, redistribute or share without the prior express permission of the author. Humoral Immunity Based on Antigen-Antibody response. B lymphocytes produce antibodies to act against a foreign substances (antigen). Antigen- a protein that stimulates the body to produce antibody. Antibody- a protein produced by B lymphocytes to act against an antigen. Protects body against bacteria and viral infections. Please do not reproduce, redistribute or share without the prior express permission of the author. Cell Mediated Immunity (CMI) Dependent on the action of T lymphocytes. T lymphocytes attack the antigen directly (do not produce antibodies). T lymphocytes defend against viral infections, fungal infections and some bacterial infections. Please do not reproduce, redistribute or share without the prior express permission of the author. Active Immunity Occurs when a person exposed to infectious microorganism. Body will produce antibodies to destroy the microorganism. Takes time to provides immunity to the invading antigen, but lasts for a long time (life long). Two types of active immunity: Natural Active Immunity Artificial Active Immunity Please do not reproduce, redistribute or share without the prior express permission of the author. Natural Active Immunity Occurs when person is experiences the disease and body produces antibodies to provide future defense (life long). Artificial Active Immunity Occurs when individual is given killed or weaken antigens(vaccines) to stimulates the formation of antibodies against antigen (life long). Please do not reproduce, redistribute or share without the prior express permission of the author. Passive Immunity Obtained from the administration of exogenous antibodies. Provide the individual with ready-made antibodies from another human or animal. Examples: Immune globulins Antivenins Provides immediate immunity to the invading antigen, but lasts only for a short time. Please do not reproduce, redistribute or share without the prior express permission of the author. Immunizing Agents Some Immunizing agents stimulate the immune response, thereby create a body protection to a specific disease. Other Immunizing agents supply ready-made antibodies to provide passive immunity. Examples of immunizing agents: 1. 2. 3. 4. Vaccines Toxoids Immune globulins Antivenins Active immunity Passive immunity Please do not reproduce, redistribute or share without the prior express permission of the author. 1. Vaccines Vaccines contains an attenuated or killed antigen (microorganisms), to create immunity to certain types disease. Antibody producing tissue cannot differentiate between live antigen, an attenuated or killed antigen. The body starts to produce antibody once they identify an antigen. Although vaccines contain weakened or killed antigen, they do not cause disease. Please do not reproduce, redistribute or share without the prior express permission of the author. 2. Toxoids Toxin is a poisonous substance produced by some bacteria. A toxin is capable of stimulating the body to produce antitoxins (to fight toxin). Toxoid is toxin that is attenuated (weakened) but still capable of stimulating the body to produce antitoxin. Toxoid is used to neutralize toxin. Please do not reproduce, redistribute or share without the prior express permission of the author. Vaccines and Toxoids Both vaccines and toxoids are administered to stimulate the immune response to specific antigen or toxins. These agents must be administered before exposure to the disease. Please do not reproduce, redistribute or share without the prior express permission of the author. Adverse Reaction Vaccines and Toxoids Chills & fever Muscular aches Skin rash Pain and tenderness at injection site Hypersensitivity reactions Please do not reproduce, redistribute or share without the prior express permission of the author. 3. Immune Globulin Immune globulin are solution obtained from human blood containing antibodies to specific antigens. Since Immune globulin contains ready-made antibodies, it is given for passive immunity against disease. Immune globulin are given after infection with a specific disease. Please do not reproduce, redistribute or share without the prior express permission of the author. Adverse Reaction Local tenderness and pain at the injection site Nausea & diarrhea Chills & fever Headache Please do not reproduce, redistribute or share without the prior express permission of the author. 4. Antivenins Venom is a poison released by snakes and spiders. Antivenins is a substance used to neutralize the venom. It is used for passive protection from the toxic effects of spider bites and snakes bites. Most effective response is obtained when the drug is administered within 4 hours after the bite. Please do not reproduce, redistribute or share without the prior express permission of the author. Adverse Reaction Hypersensitivity (most are prepared from horse serum) Itching Edema of face, tongue & throat Vomiting Please do not reproduce, redistribute or share without the prior express permission of the author. Immunosuppressive Agents Agents that suppress the immune system of the body. Causes decreased immune response towards antigen. Immuno-suppression (decreased immune response) can be caused either by Diseases Therapies (treatments) Please do not reproduce, redistribute or share without the prior express permission of the author. Immunosuppressive Diseases Leukemia Lymphoma Cancer HIV infection Please do not reproduce, redistribute or share without the prior express permission of the author. Conditions that need immunosuppression Organ or stem cell transplant Immunity disorders Severe autoimmune diseases Please do not reproduce, redistribute or share without the prior express permission of the author. Immunosuppressive Therapies Alkylating agents Antimetabolites Radiation High dose corticosteroid therapy Please do not reproduce, redistribute or share without the prior express permission of the author. 2.3 Antineoplastic Drugs Please do not reproduce, redistribute or share without the prior express permission of the author. OBJECTIVES At the end of the lesson, students should be able to Define cancer and terms used in cancer. Describe risk factors associated with cancer. Describe types of treatment available for cancer patients. Identify types of drugs used in cancer chemotherapy. Please do not reproduce, redistribute or share without the prior express permission of the author. CANCER Cancer is a class of diseases or disorders characterized by uncontrolled division of cells and the ability of these cells to spread Cancer may affect people at all ages, but risk tends to increase with age. It is one of the principal causes of death in developed countries. Please do not reproduce, redistribute or share without the prior express permission of the author. Early cell changes Normal cervical cells Precancerous cells Please do not reproduce, redistribute or share without the prior express permission of the author. Cancer is a disease of the cell cycle The unregulated growth that characterizes cancer is caused by damage to DNA, resulting in mutations to genes that encode for proteins controlling cell division. Please do not reproduce, redistribute or share without the prior express permission of the author. Please do not reproduce, redistribute or share without the prior express permission of the author. Environmental Risk Factor for Cancer Some environmental agents associated with cancer are: Viruses Tobacco smoke Food Radiation Chemicals Pollution Please do not reproduce, redistribute or share without the prior express permission of the author. Lifestyle Risk Factor for Cancer Tobacco - Cigarette Smoking Electromagnetic fields Alcohol Diet Please do not reproduce, redistribute or share without the prior express permission of the author. Treatments for Cancer Treatment depends on the stage and type of cancer Removal by laser Surgery Radiation therapy Chemotherapy (options include a combination of drugs) Cancer is usually treated with a combination of therapies Please do not reproduce, redistribute or share without the prior express permission of the author. Antineoplastic Drugs Used in the treatment of cancer (to cure, control and relief symptoms). May not always lead to complete cure but often slow the rate of tumour growth and delay metastasis. Metastasis is spreading of the cancer to other sites. Therapy with antineoplastic drugs is known as chemotherapy. Please do not reproduce, redistribute or share without the prior express permission of the author. MOA of Antineoplastic Drugs MOA: Most antineoplastic drugs affect cells that rapidly grow (divide and reproduce). Malignant neoplasm and cancerous tumors usually consist of rapidly growing abnormal cell. These cells are sensitive to antineoplastic drugs. Beside affecting cancerous cells, the antineoplastic drugs also attack the normal cells of the body (bone marrow, hair follicles and lymph tissue). Please do not reproduce, redistribute or share without the prior express permission of the author. Cell Killing Theory Chemotherapy is administered in a series of cycles to allow recovery of normal cells and destroy more malignant cells. According to cell killing theory, a drug regimen is intended to kill 90% of cancer cells during the first course of treatment. Please do not reproduce, redistribute or share without the prior express permission of the author. The second course targets the remaining cancer cells and reduces those cells by 90%. Further courses continue to reduce the number of cancer cells, until all cells are killed. Every malignant cell must be destroyed for the cancer to be cured. Please do not reproduce, redistribute or share without the prior express permission of the author. Cell killing theory by repeated Chemotherapy Please do not reproduce, redistribute or share without the prior express permission of the author. Types of Antineoplastic Drugs Alkylating Drugs Antineoplastic Antibiotics Antimetabolites Hormones Therapeutic Use To treat cancer Please do not reproduce, redistribute or share without the prior express permission of the author. Alkylating Drugs MOA: interfere with the process of cell division of malignant and normal cells. Binds with DNA, causing breaks and preventing DNA replication. Antineoplastic Antibiotic MOA: appear to interfere with DNA and RNA synthesis and therefore delay or inhibit cell division, including the reproducing ability of cancer cells. Please do not reproduce, redistribute or share without the prior express permission of the author. Antimetabolites MOA: interfere with various metabolic functions of cells, thereby disrupting normal cell functions. Inactivates enzymes or alter the structure of DNA, changing the DNA’s ability to replicate. Hormones MOA: appear to counteract the effect of male or female hormones in hormone-dependent tumors. Alter the hormonal environment of the cell. Please do not reproduce, redistribute or share without the prior express permission of the author. Adverse Reactions Affects both cancer cells and rapidly growing normal cells Potentially toxic Bone marrow suppression Nausea Vomiting Diarrhea Hair loss (alopecia) Please do not reproduce, redistribute or share without the prior express permission of the author. REFERENCE Holland, LM and Adams MP. 2007. Core Concepts in Pharmacology. 2nd edition.Pearson. Hitner H and Nagle B. 2002. Basic Pharmacology. 4th edition. McGraw-Hill. Please do not reproduce, redistribute or share without the prior express permission of the author. Q&A Session Please do not reproduce, redistribute or share without the prior express permission of the author. Next Topic Antiinflammatory drugs and autocoids Please do not reproduce, redistribute or share without the prior express permission of the author. Thank you Address Lot 33-40, Blok C, Plaza Juta, KM 7.2 Off Jalan Tuaran, 88400 Likas, Kota Kinabalu, Sabah, Malaysia Telephone +6088 431 025/35 Website kk.cyberjaya.edu.my Email [email protected]