Antiinfective Medications Chapter 9 Antiinfective Medications Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Copyright © 2016 by Mosby, an imprint of Elsevier Inc. Overview Pathogen Bacteria Fungi Viruses Parasite Antimicrobials How do synthetic and natural antibiotics differ? When new groups of drugs are refined, purified, and sensitive as a result of long-term testing, they are referred to as generations. How do bactericidal drugs work to treat an infection? List a superinfection patients may acquire when using antibiotics. Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Copyright © 2016 by Mosby, an imprint of Elsevier Inc. Antibiotics Broad-spectrum Narrow-spectrum Adverse reactions Which two antibiotic classifications cause the most allergies? How do bacteriostatic antibiotics differ from bactericidal antibiotics? What body systems are often affected by drug toxicity associated with antibiotic use? Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Copyright © 2016 by Mosby, an imprint of Elsevier Inc. Penicillins Main antibiotic for years Overuse Penicillin-resistant strains Broad-spectrum drug of choice What issues can result from overuse of antibiotics? Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Copyright © 2016 by Mosby, an imprint of Elsevier Inc. Penicillins (cont.) Action and Uses Interferes with creation of the mucopeptide cell wall Used to treat multiple infections Overuse and allergies Are penicillins bacteriostatic or bactericidal? Why are antibiotics prescribed prophylactically? Some penicillins may be useful against organisms used in bioterrorism. Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Copyright © 2016 by Mosby, an imprint of Elsevier Inc. Penicillins (cont.) Adverse Reactions Neuropathy High parenteral doses Skin eruptions GI symptoms Urticaria Laryngeal edema Anaphylaxis Drug Interactions If the health care provider wants the action of penicillin to be prolonged, which drug is used in combination with it? Antacids may decrease absorption of penicillin. Laboratory results may change when penicillin is used. What drugs increase penicillin levels? Ampicillin use may decrease the effectiveness of oral contraceptives, making the woman at increased risk for pregnancy. Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Copyright © 2016 by Mosby, an imprint of Elsevier Inc. Penicillins (cont.) Nursing Implications and Patient Teaching Assessment Signs of infection and allergies Diagnosis Planning 10-day regimen Implementation Route of administration Evaluation Patient Teaching If the patient is treated for syphilis, to what other considerations should the nurse be alert? Why do organisms become resistant to antibiotics? Before administering IM penicillin injections, the nurse should obtain the patient’s blood pressure and pulse. Following administration, the patient should be advised to wait 30 minutes before leaving the clinic. Why? What signs and symptoms would the patient experiencing an allergic reaction to penicillin exhibit? Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Copyright © 2016 by Mosby, an imprint of Elsevier Inc. Tetracyclines Actions and Uses Broad-spectrum antibiotics Adverse Reactions GI upset Drug Interactions Milk, dairy, and calcium Nursing Implications and Patient Teaching Not for pregnant patients or children under 8 Can cause sensitivity to light. Take on empty stomach and avoid dairy within 2 hours of taking drug. For which infections are tetracyclines first-line therapy? Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Copyright © 2016 by Mosby, an imprint of Elsevier Inc. Macrolides Actions and Uses Alternative for penicillin Adverse Reactions GI upset Drug Interactions Increase the action of oral anticoagulants, digoxin, and many other drugs. Nursing Implications and Patient Teaching Check nursing text for drug interactions: there are several! Advise patient to take with food and drink extra fluids. For which infections are tetracyclines first-line therapy? Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Copyright © 2016 by Mosby, an imprint of Elsevier Inc. Aminoglycosides Action and Uses Weaken the bacteria by limiting the production of protein Used in the treatment of serious gram-negative infections Adverse Reactions Nephrotoxicity, ototoxicity, dizziness, ringing in the ears, persistent headache Dosage is calculated on the basis of the patient’s weight and is increased or decreased based on blood levels so an effective level is maintained. Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Aminoglycosides (cont.) Drug Interactions Use with vancomycin increases the risk of nephrotoxicity. Ototoxicity is increased with aspirin, furosemide, ethacrynic acid Nursing Implications and Patient Teaching Poorly absorbed from the GI tract. Patients should have frequent hearing and urine screenings What lab values should be monitored when administering aminoglycosides? Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Copyright © 2016 by Mosby, an imprint of Elsevier Inc. Fluoroquinolones Actions and Uses Bacteriocidal and act by interfering with bacterial DNA synthesis. Effective against gram-negative pathogens. Adverse Reactions Dose must be adjusted with impaired renal function Unpredictable adverse effects including hemolysis, renal failure, hepatoxicity and QT interval prolongation have caused some drugs to be withdrawn from the market. Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Fluoroquinolones (cont.) Drug Interactions Multivitamins and mineral supplements reduce the absorption Increases anticoagulant effects of warfarin Nursing Implications and Patient Teaching Take with food to decrease adverse GI effects Keep older patients well hydrated. Patients may develop excessive nervousness, anxiety or tachycardia if taken with coffee or other caffeine-containing products. Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Copyright © 2016 by Mosby, an imprint of Elsevier Inc. Cephalosporins Action and Uses Bactericidal and weaken the bacteria by interfering with building of the cell wall Broad spectrum activity against gram-negative organisms Adverse Reactions Nausea, vomiting, and diarrhea are frequent Acute hypersensitivity Cephalosporins are used for serious infections, like bacteremia and septicemia and infections of the lower respiratory tract, central nervous system, GU system, joints, and bones. Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Copyright © 2016 by Mosby, an imprint of Elsevier Inc. Cephalosporins Drug Interactions Severe disulfiram reaction resulting in severe flushing, vomiting, and collapse. Nursing Implications and Patient Teaching Must be given IV or IM Patients with a severe reaction to penicillin should not take these products. Probenecid may decrease elimination of the drugs by the kidneys. Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Copyright © 2016 by Mosby, an imprint of Elsevier Inc. Sulfonamides Broad-spectrum antiinfective Bacteriostatic action: inhibits folic acid synthesis in the cell What type of symptoms would a patient exhibit if he or she developed a superinfection while on antibiotics? Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Copyright © 2016 by Mosby, an imprint of Elsevier Inc. Sulfonamides (cont.) Action and Uses Urinary tract infections Effectively treats multiple microorganisms Preoperative and postoperative therapy for bowel surgery If a patient has a urinary tract infection due to Escherichia coli infection, what teaching should the nurse provide? Sulfonamides may be used to treat ulcerative colitis. Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Copyright © 2016 by Mosby, an imprint of Elsevier Inc. Sulfonamides (cont.) Adverse Reactions Minor but irritating problems Drug Interactions Potentiate oral anticoagulants, Methotrexate, sulfonylureas, thiazide diuretics, phenytoin, and uricosuric agents. Decrease effectiveness of penicillins Nursing Implications and Patient Teaching Photosensitivity can occur Should be taken on an empty stomach. What is the rationale for encouraging fluid intake for those patients prescribed sulfonamides? If the patient develops toxemia while taking sulfonamides, what is the cause? A patient complaining of tinnitus reports what type of symptoms? Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Broad-Spectrum Antibiotics Bactericidal or bacteriostatic Is culture and sensitivity testing necessary before drug therapy with a broad-spectrum antibiotic? Which antibiotic is particularly effective for the elderly and for patients with decreased renal function? Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Broad-Spectrum Antibiotics (cont.) Action and Uses Large number of unrelated drugs used to treat infections caused by susceptible organisms Gram-positive or gram-negative organisms Antibiotics are not effective in treating infections caused by viruses, parasites, or fungi. What is a secondary infection? How is an organism determined to be gram-positive or gram-negative? Why is Cipro important in bioterrorism? Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Broad-Spectrum Antibiotics (cont.) Adverse Reactions Superinfections Drug interactions are individualized Food interactions Affected organs: auditory nerves, kidneys, and liver Cross-sensitivity Nursing Implications and Patient Teaching What types of symptoms would the patient with a yeast infection exhibit? Patients receiving aminoglycosides should be monitored for what types of reactions? The nurse should read the manufacturer’s product insert information about specific drug interactions for each drug before administration. Use of tetracyclines during pregnancy and in children under the age of 8 can cause tooth discoloration or inadequate bone or tooth development in the child. Monitoring blood levels for “peak” and “trough” determines therapeutic range levels for those patients receiving aminoglycosides. Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Copyright © 2016 by Mosby, an imprint of Elsevier Inc. Antitubercular Drugs Overview Underdeveloped nations Risks Etiology: Mycobacterium tuberculosis What does the term multiple-drug-resistant (MDR) refer to? What role do the Centers for Disease Control and Prevention (CDC) have in relationship to tuberculosis treatment? Why have states enacted laws related to the treatment of tuberculosis? Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Antitubercular Drugs (cont.) Action and Uses Most antitubercular drugs are bacteriostatic: have intracellular or extracellular effects that prevent the organism from building new cell walls, thus limiting growth and spread Some antitubercular drugs are bactericidal Length of treatment Chemoprophylaxis Box 9-1, High-Priority Candidates for Tuberculosis-Preventive Therapy Chemotherapy refers to taking a drug to treat a disease. Chemoprophylaxis: taking a drug to prevent disease when the patient is at high risk for developing the disease. How are antitubercular drugs classified? What differentiates primary from secondary drugs used in the treatment of tuberculosis? Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Antitubercular Drugs (cont.) Adverse Reactions Common symptoms Toxicity: body sites affected Combination therapy Drug-specific symptoms Why are combination drugs used in the treatment of tuberculosis? What type of side-effect symptoms is common while on antitubercular drugs? Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Antitubercular Drugs (cont.) Drug Interactions Use of other drugs during therapy Nursing Implications and Patient Teaching Assessment Diagnosis History, chest x-ray, labs Additional patient needs Planning Length of treatment Implementation Dose Evaluation Patient and Family Teaching What administration considerations are recommended for the patient on antitubercular therapy? What governmental agency publishes treatment guidelines for tuberculosis? What laboratory test is used to evaluate treatment effectiveness? What treatment is available to the patient with an MDR strain? Family members and close contacts to the patient should be screened for tuberculosis. Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Copyright © 2016 by Mosby, an imprint of Elsevier Inc. Antiparasitic Drugs Amebicides Anthelmintics Antimalarials Parasites affecting humans are a worldwide problem. Patient assessment should include history of recent travel outside the U.S. or Canada. Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Copyright © 2016 by Mosby, an imprint of Elsevier Inc. Amebicides Entamoeba histolytica Relationship to traveling Infection sites in the body Where in the body do amebae invade? Hepatic infection is more difficult to treat than intestinal infection. Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Copyright © 2016 by Mosby, an imprint of Elsevier Inc. Amebicides (cont.) Action and Uses Destroy invading ameba Treatment of intestinal and extraintestinal amebiasis Drug choice depends on location Which drugs are used to treat Trichomonas vaginalis? Chloroquine is also used to treat rheumatoid arthritis. Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Copyright © 2016 by Mosby, an imprint of Elsevier Inc. Amebicides (cont.) Adverse Reactions Common: nausea, vomiting, anorexia, diarrhea, GI distress, hepatic abscess Drug-specific adverse reactions Overdose Symptoms of overdose are seen with all of the antimalarial drugs. To what do the symptoms ataxia and polyuria refer? Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Copyright © 2016 by Mosby, an imprint of Elsevier Inc. Amebicides (cont.) Drug Interactions Alcohol will produce severe headache, flushing, cramps, nausea, and vomiting. Nursing Implications and Patient Teaching No alcohol Teach the patient about the method of infection and review specific methods of personal hygiene. What should patients taking metronidazole be instructed to avoid? What factor does the drug ordered to treat amebiasis depend on? How would dehydration complicate amebicide therapy? What important patient education should the nurse include to prevent reinfection? Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Copyright © 2016 by Mosby, an imprint of Elsevier Inc. Anthelmintics Helminthiasis: infestation by worms Common infestations: Pinworms Roundworms Hookworms Tapeworms Whipworms How is the diagnosis made? Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Copyright © 2016 by Mosby, an imprint of Elsevier Inc. Anthelmintics (cont.) Action and Uses Action is drug-specific Drugs used: Thiabendazole Niclosamide and paromomycin Piperazine and pyrantel pamoate Diethylcarbamazine citrate Mebendazole What is the exact action of diethylcarbamazine citrate? Where would a filarial worm be found within the body? Which drug is used to treat patients who have visited a tropical area and become infected with worms? Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Copyright © 2016 by Mosby, an imprint of Elsevier Inc. Anthelmintics (cont.) Adverse Reactions Drug-specific Allergic reaction due to dead microfilaria What is the relationship among side effect, drug dosage, and treatment length? If the patient complains of myalgia, what symptoms would the patient have? Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Copyright © 2016 by Mosby, an imprint of Elsevier Inc. Anthelmintics (cont.) Drug Interactions Anthelmintic drugs work against each other if they are given together. Interfere with a number of specific drugs and laboratory tests. Nursing Implications and Patient Teaching Assessment Diagnosis Planning Implementation Preventing transmission Evaluation When would the use of anthelmintic drugs be contraindicated? How can the patient prevent transmission to others in the home? The patient receiving drug therapy to treat hookworms may require what type of supplement? What are some foods that are high in iron? Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Copyright © 2016 by Mosby, an imprint of Elsevier Inc. Antimalarials Action Interfere with the life cycle of Plasmodium Uses Prevention and treatment Adverse Reactions Drug-specific: blood dyscrasias, visual and neurologic changes Drug Interactions Drug-specific: dermatologic, ototoxic, or neurologic symptoms How is malaria transmitted? In what regions of the United States is malaria seen? What are the symptoms associated with quinine poisoning? Copyright © 2016 by Mosby, an imprint of Elsevier Inc.

Copyright © 2016 by Mosby, an imprint of Elsevier Inc. Antimalarials (cont.) Nursing Implications and Patient Teaching Assessment Symptoms Diagnosis Planning Treatment is strain-related Implementation Loading dose Prevention Evaluation Laboratory and diagnostic monitoring; eye examination What are the common symptoms of malaria? Caution should be used for patients being treated with quinine who have a history of cardiac dysrhythmias. If a patient develops bruising while on quinine, what should the nurse suspect? Which ethnic backgrounds have an increased risk for blood dyscrasias with antimalarial drug therapy? Copyright © 2016 by Mosby, an imprint of Elsevier Inc.