Antibiotics Part 1 PDF

Copyright © 2020 Elsevier Inc. All Rights Reserved. ANTIBIOTICS PART 1 2 Microorganisms are everywhere. Can be harmful or beneficial under normal circumstances MICROBIAL Defenses INFECTION Physical barriers (e.g., intact skin or...

Copyright © 2020 Elsevier Inc. All Rights Reserved. ANTIBIOTICS PART 1 2 Microorganisms are everywhere. Can be harmful or beneficial under normal circumstances MICROBIAL Defenses INFECTION Physical barriers (e.g., intact skin or ciliated respiratory mucosa) Physiologic defenses (e.g., stomach gastric acid, antibodies) Phagocytic cells  3 Copyright © 2020 Elsevier Inc. All Rights Reserved. Gram positive stain purple very thick cell wall, known as peptidoglycan, and they also have a thick outer capsule. Gram negative stain red BACTERIA cell wall structure that is more complex, with a smaller outer capsule and peptidoglycan layer and two cell membranes: an outer and an inner membrane more difficult to treat Categorizing bacteria is on the basis of their response to the Gram stain procedure. 4  5 INFECTIONS Community-associated infections An infection that is acquired by a person who has not been hospitalized or had a medical procedure (e.g., dialysis, surgery, catheterization) within the past year  6 INFECTIONS: SITES OF ORIGIN Health care–associated infections Were not present or incubating in the patient on admission to the facility Occurs more than 48 hours after admission More difficult to treat because causative microorganisms are often drug resistant and the most virulent Methicillin-resistant Staphylococcus aureus (MRSA) is most common. 7 HEALTH CARE–ASSOCIATED INFECTIONS: PREVENTION Handwashing Antiseptics Generally, only inhibits the growth of microorganisms but does not necessarily kill them Applied exclusively to living tissue Static agents Disinfectants Kills organisms Used only on nonliving objects Cidal agent  Medications used to treat bacterial infections 8 ANTIBIOTICS Ideally, before beginning antibiotic therapy, the suspected areas of infection should be cultured to identify the causative organism and potential antibiotic susceptibilities.  ANTIBIOTIC THERAPY 9 Empiric therapy: treatment of an infection before specific culture information has been reported or obtained Definitive therapy: antibiotic therapy tailored to treat organism identified with cultures Prophylactic therapy: treatment with antibiotics to prevent an infection, as in intraabdominal surgery or after trauma  Therapeutic response Decrease in specific signs and symptoms of infection are 10 ANTIBIOTIC noted (fever, elevated white blood cell count, redness, THERAPY inflammation, drainage, pain) (CONT.) Subtherapeutic response Signs and symptoms of infection do not improve.  11 ANTIBIOTIC THERAPY (CONT.) Superinfection C. difficile infection Formerly called pseudomembranous colitis Secondary infection Resistance Food–drug interactions Tetracycline & _____; Quinolones & _____ Host factors age, allergy history, kidney and liver function, pregnancy status, genetic characteristics, site of infection, and host defenses 12 ANTIBIOTIC THERAPY (CONT.) Allergic reactions Most common severe reactions Pregnancy- related host factors  ANTIBIOTIC THERAPY (CONT.) 13 Genetic host factors genetic abnormalities that result in various enzyme deficiencies glucose-6-phosphate dehydrogenase deficiency (sulfonamides, nitrofurantoin, and dapsone - may result in the hemolysis) Slow acetylation-certain drugs to be metabolized more slowly ; leading to toxicity- drug accumulation Anatomic site of the infection 14 ANTIBIOTICS: CLASSES Penicillins Sulfonamides Cephalosporins Macrolides Quinolones Aminoglycosides Tetracyclines  Interference with cell wall synthesis Interference with protein 15 ANTIBIOTIC synthesis THERAPY: MECHANISM Interference with DNA OF ACTION replication Acting as a metabolite to disrupt critical metabolic reactions inside the bacterial cell 16  Bactericidal: kill bacteria 17 ACTIONS OF ANTIBIOTICS Bacteriostatic: inhibit growth of susceptible bacteria rather than killing them immediately; eventually leads to bacterial death  18 ANTIBIOTICS: SULFONAMIDES One of the first groups of antibiotics Often combined with another antibiotic Sulfamethoxazole combined with trimethoprim (a nonsulfonamide antibiotic), known as Bactrim, Septra, or co-trimoxazole and often abbreviated as SMX-TMP, is used commonly in clinical practice.  Prevent synthesis of folic acid required for Bacteriostatic action synthesis of purines and nucleic acid Do not affect human Only affect organisms cells or certain that synthesize their bacteria; they can use own folic acid preformed folic acid 19 SULFONAMIDES: MECHANISM OF ACTION 20 SULFONAMIDES: INDICATIONS Effective against both gram-positive and gram-negative bacteria Enterobacter spp., Escherichia coli, Klebsiella Treatment of urinary tract infections spp., Proteus mirabilis, Proteus vulgaris, (UTIs) caused by susceptible strains of: Staphylococcus aureus Upper respiratory tract infections SMX-TMP is commonly used for outpatient Staphylococcus infections because of the high rate of community-acquired MRSA infections. 21 SULFONAMIDES: ADVERSE EFFECTS Hemolytic and aplastic Stevens-Johnson anemia, agranulocytosis, Syndrome(watch for rash) thrombocytopenia Urticaria(hives) 22 BETA-LACTAM ANTIBIOTICS Penicillins Cephalosporins Carbapenems Monobactams  23 PENICILLINS First derived from a mold (fungus) often seen on bread or fruit. Natural penicillins Penicillinase-resistant penicillins Aminopenicillins Extended-spectrum penicillins  24 BETA-LACTAMASE INHIBITORS Some bacteria have acquired the capacity to produce enzymes capable of destroying penicillins. These enzymes are called beta-lactamases, and they can inactivate the penicillin molecules by opening the beta-lactam ring. These drugs bind with the beta-lactamase enzyme itself to prevent the enzyme from breaking down the penicillin molecule.  Ampicillin/sulbactam (Unasyn) 25 EXAMPLES OF COMBINATION Amoxicillin/clavulanic AGENTS acid (Augmentin) Piperacillin/tazobactam (Zosyn)  26 Penicillins enter the bacteria via the cell wall. Inside the cell, they bind to penicillin- PENICILLINS: binding protein. MECHANISM Once bound, normal cell wall synthesis is OF ACTION disrupted. Result: Bacteria cells die from cell lysis. Penicillins do not kill other cells in the body.  27 PENICILLINS: INDICATIONS Prevention and treatment of infections caused by susceptible bacteria, such as: Gram-positive bacteria, including Streptococcus spp., Enterococcus spp., Staphylococcus spp.  28 known drug allergy Type of reaction that occurs in patients who state they are allergic to penicillins PENICILLINS: CONTRAINDICATIONS Not all end in “cillin” (e.g., Zosyn, Augmentin) Many medication errors have occurred when a penicillin drug called by its trade name is given to a patient with a penicillin allergy.  Allergic reactions: 0.7% to 4% of treatment 29 courses. Urticaria, pruritus, angioedema PENICILLINS: ADVERSE increased risk of allergy to other beta-lactam EFFECTS antibiotics. History of throat swelling or hives from penicillin should not receive cephalosporins. Common adverse effects Nausea, vomiting, diarrhea, abdominal pain Other adverse effects are less common.  30 PENICILLINS: INTERACTIONS MANY interactions! NSAIDS Oral contraceptives-why is this important? Must teach to use another form of contraceptive Warfarin-enhanced effect Increase bleed risk(high INR)  31 CEPHALOSPORINS Semisynthetic antibiotics Structurally and pharmacologically related to penicillins Bactericidal action Broad spectrum Divided into groups according to their antimicrobial activity 5 generations! 32 CEPHALOSPORINS: FIRST GENERATION Good gram-positive coverage Poor gram-negative coverage Parenteral and oral (PO) forms Examples Cefazolin (Ancef) Cephalexin (Keflex) CEPHALOSPORINS: 33 FIRST GENERATION (CONT.) Used for surgical prophylaxis and for susceptible staphylococcal infections Cefazolin (Ancef and Kefzol): intravenous (IV) or intramuscular (IM) Cephalexin (Keflex): PO 34 CEPHALOSPORINS: ADVERSE EFFECTS Similar to penicillins Potential cross- sensitivity with Mild diarrhea, abdominal cramps, rash, penicillins if allergies pruritus, redness, edema exist 35 MACROLIDES Erythromycin (E- mycin, E.E.S, others) Azithromycin (Zithromax) Fidaxomicin (Dificid, Dificlir)  Prevent protein synthesis within bacterial cells 36 MACROLIDES: Considered bacteriostatic MECHANISM OF ACTION Bacteria will eventually die In high enough concentrations, may also be bactericidal  37 MACROLIDES: Strep infections INDICATIONS Streptococcus pyogenes (group A beta- hemolytic streptococci) Mild to moderate upper and lower respiratory tract infections Haemophilus influenzae Spirochetal infections Syphilis and Lyme disease Gonorrhea, Chlamydia(1 dose), Mycoplasma(pneumonia)(5 day dose) Clostridium Difficile  38 MACROLIDES: GI effects, primarily with ADVERSE EFFECTS erythromycin Nausea, vomiting, diarrhea, hepatotoxicity, flatulence, jaundice, anorexia Azithromycin and clarithromycin: fewer GI adverse effects, longer duration of action, better efficacy, better tissue penetration  39 TETRACYCLINES Natural and semisynthetic Obtained from cultures of Streptomyces Bacteriostatic: inhibit bacterial growth Inhibit protein synthesis Stop many essential functions of the bacteria Examples Tetracycline Doxycycline (Doryx,Vibramycin) Minocycline (Minocin) Tigecycline (Tygacil)  40 TETRACYCLINES (CONT.) Bind (chelate) to Ca+++ and Mg++ and Al+++ ions to form insoluble complexes Dairy products, antacids, and iron salts reduce oral absorption of tetracyclines. Should not be used in children younger than age 8 years or in pregnant or lactating women because tooth discoloration will occur if the drug binds to the calcium in the teeth  41 TETRACYCLINES: INDICATIONS Wide spectrum Gram-negative and gram- positive organisms, protozoa, Mycoplasma spp., Rickettsia spp., Chlamydia, syphilis, Lyme disease, acne, others 42 TETRACYCLINES: ADVERSE EFFECTS Strong affinity for calcium Discoloration of permanent teeth and tooth enamel in fetuses and children or nursing infants if taken by the mother May retard fetal skeletal development if taken during pregnancy Alteration in intestinal flora may result in: Superinfection (overgrowth of nonsusceptible organisms such as Candida spp. Or yeast) Diarrhea (therefore may give probiotic to prevent) Pseudomembranous colitis (c dif) May also cause: Vaginal candidiasis, Gastric upset, Enterocolitis, Maculopapular rash  Before-Drug allergies; renal, liver, and Assess cardiac function; and other lab studies. Thorough patient health history, 43 NURSING Obtain including immune status. IMPLICATIONS Conditions that may be contraindications Assess to antibiotic use or that may indicate cautious use. Assess Potential drug interactions.  44 NURSING IMPLICATIONS (CONT.) It is essential to obtain cultures from appropriate sites before beginning antibiotic therapy. Instruct patients to take antibiotics exactly as prescribed and for the length of time prescribed; they should not stop taking the medication early because they feel better. Assess for signs and symptoms of superinfection: fever, perineal itching, cough, lethargy, or any unusual discharge.  45 NURSING IMPLICATIONS Sulfonamides Take with 2000 to 3000 mL of fluid/24 hour. Assess red blood cell count before beginning therapy. Take oral doses with food. Penicillins Take oral doses with water (not juices) because acidic fluids may nullify the drug’s antibacterial action. Monitor patients taking penicillin for an allergic reaction for at least 30 minutes after administration.  46 NURSING IMPLICATIONS (CONT.) Macrolides These drugs are highly protein bound and will cause severe interactions with other protein-bound drugs. The absorption of oral erythromycin is enhanced when taken on an empty stomach, but because of the high incidence of GI upset, many drugs are taken after a meal or snack.  47 NURSING IMPLICATIONS (CONT.) Tetracyclines Avoid milk products, iron preparations, antacids, and other dairy products because of the chelation and drug-binding that occur. Take all medications with 6 to 8 oz of fluid, preferably water. Because of photosensitivity, avoid sunlight and tanning beds.  48 NURSING IMPLICATIONS (CONT.) Cephalosporins Assess for penicillin allergy; may have cross-allergy. Give orally administered forms with food to decrease GI upset even though this will delay absorption. Some of these drugs may cause a disulfiram (Antabuse)-like reaction when taken with alcohol.  49 NURSING IMPLICATIONS (CONT.) Monitor for therapeutic effects: Monitor for adverse reactions. Improvement of signs and symptoms of infection Return to normal vital signs Negative culture and sensitivity tests Disappearance of fever, lethargy, drainage, and redness ANTIBIOTICS PART 2  Organisms that are resistant to one or more classes of antimicrobial drugs Methicillin-resistant Staphylococcus aureus (MRSA) 51 MULTIDRUG- RESISTANT Vancomycin-resistant Enterococcus (VRE) ORGANISMS Organisms producing extended- spectrum beta-lactamases (ESBLs) Carbapenem-resistant Enterobacteriaceae (CRE) MULTIDRUG-RESISTANT ORGANISMS (CONT.) 52 MRSA Threat of MRSA becoming resistant to all antibiotics currently available No longer seen just in hospitals; it has spread to the community setting, and approximately 50% of staphylococcal infections contracted in the community involve MRSA VRE usually seen in urinary tract infections (UTIs) Newer antibiotics have been developed to successfully treat VRE and MRSA.  53 AMINOGLYCOSIDES Natural and semisynthetic Produced from Streptomyces spp. Poor oral absorption; no oral forms (exception: neomycin) Very potent antibiotics with serious toxicities Bactericidal; prevent protein synthesis Examples Gentamicin Neomycin (Neo-Fradin) 54 AMINOGLYCOSIDES: INDICATIONS Used to kill gram- Often used in negative bacteria, combination with such as Pseudomonas other antibiotics for spp., Escherichia coli, synergistic effects Proteus spp., Klebsiella (beta-lactams or spp., Serratia spp. vancomycin) Exception: neomycin Given orally to decontaminate the Poorly absorbed through GI GI tract before surgical procedures tract and are given Also used as an enema for this parenterally. purpose Used to treat hepatic encephalopathy  55 AMINOGLYCOSIDES: ADVERSE EFFECTS Cause serious toxicities *Nephrotoxicity (renal damage)(BUN, creatinine, GFR, and the peak/trough) *Ototoxicity (auditory impairment and vestibular impairment [eighth cranial nerve]) Superinfections Must monitor drug levels to prevent toxicities Minimum inhibitory concentration (MIC)  AMINOGLYCOSIDES: 56 THERAPEUTIC DRUG MONITORING Serum levels measured to prevent toxicity Serum level needs to be at least eight times higher than the MIC. (minimum inhibitory concentration) lowest concentration of drug needed to kill a certain standard amt of bacteria Time-dependent killing Time-dependent killing the amt of time the drug is above the MIC is critical for maximum bacterial growth Concentration-dependent killing -dependent killing (aminoglycosides) drug plasma concentration that is a certain level above the MIC Peak: highest drug levels for once-daily regimens Trough: lowest to ensure adequate renal clearance of the drug and avoid toxicity  Post-antibiotic effects 57 AMINOGLYCOSIDES: THERAPEUTIC DRUG MONITORING (CONT.) Resistance Drug interactions  58 QUINOLONES Also called fluoroquinolones Excellent oral absorption Absorption reduced by antacids Effective against gram- negative organisms and some gram-positive organisms Examples Ciprofloxacin (Cipro) Below the belt Levofloxacin (Levaquin) Above the belt 59 QUINOLONES: MECHANISM OF ACTION Bactericidal Alter DNA of bacteria, causing death Do not affect human DNA Used to treat S. aureus, Serratia marcescens, and Mycobacterium fortuitum Bacterial resistance 60 QUINOLONES: INDICATIONS Gram-negative bacteria such as Pseudomonas spp. Complicated urinary tract, respiratory, bone and joint, GI, skin, and sexually transmitted infections 61 QUINOLONES: INTERACTIONS Oral quinolones: antacids, calcium, magnesium, iron, zinc preparations, or sucralfate Patients need to take the interacting drugs at least 1 hour before or after taking quinolones. Dairy products Enteral tube feedings Probenecid Nitrofurantoin Oral anticoagulants 62 QUINOLONES: ADVERSE EFFECTS Prolonged QT interval Increased LFT (Liver function studies) *Black box warning: increased risk of tendonitis and tendon rupture 63 MISCELLANEOUS ANTIBIOTICS Clindamycin Linezolid Metronidazole (Cleocin) (Zyvox) (Flagyl) Vancomycin Daptomycin (Vancocin, (Cubicin) Vancoled)  64 MISCELLANEOUS ANTIBIOTICS Vancomycin (Vancocin) Treatment of choice for MRSA and other gram-positive infections Oral vancomycin is indicated for the treatment of antibiotic-induced colitis (C. difficile) and for the treatment of staphylococcal enterocolitis. Must monitor blood levels to ensure therapeutic levels and prevent toxicity May cause ototoxicity and nephrotoxicity  65 MISCELLANEOUS ANTIBIOTICS Vancomycin (Vancocin) Red man syndrome may occur Flushing or itching of head, neck, face, upper trunk Antihistamine may be ordered to reduce these effects. Additive neuromuscular blocking effects in patients receiving neuromuscular blockers Should be infused over 60 minutes Rapid infusions may cause hypotension.  66 NURSING IMPLICATIONS Assess Be Assess Assess Before- drug Obtain a thorough Conditions that Potential drug allergies; hepatic, patient health may be interactions. renal, and cardiac history, including contraindications function; and immune status. to antibiotic use other laboratory or that may study results. indicate cautious use.  Copyright © 2020 Elsevier Inc. All Rights Reserved. It is essential to obtain Instruct patients to take cultures from antibiotics exactly as appropriate sites prescribed and for the before beginning length of time prescribed antibiotic therapy. Assess for signs and symptoms of superinfection: fever, perineal itching, cough, lethargy, or any unusual discharge 67 NURSING IMPLICATIONS (CONT.) 68 NURSING IMPLICATIONS Monitor for Monitor for therapeutic adverse reactions. effects: Improvement of Disappearance of Negative culture signs and Return to normal fever, lethargy, and sensitivity symptoms of vital signs drainage, and tests infection redness Antiviral Drugs  Viral replication A virus cannot replicate on its own. It must attach to and General enter a host cell. Principles It then uses the host of Virology cell’s energy to synthesize protein, DNA, and RNA. 70  Viruses enter the body through at least four routes: Inhalation Ingestion Transplacentally 71 General Inocculation Principles Viruses are difficult to kill of because they live inside the Virology cells. (Cont.) Any drug that kills a virus may also kill cells.  Smallpox (poxviruses) Sore throat Conjunctivitis (adenoviruses)(pink eye) Warts (papovaviruses) Influenza (orthomyxoviruses) 72 Viral Respiratory infections (coronaviruses, rhinoviruses) Illnesses Gastroenteritis (rotaviruses, Norwalk-like viruses) Human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS) (retroviruses) Herpes (herpesviruses) Hepatitis (hepadnaviruses) Most viral illnesses are bothersome but survivable. Effective vaccines have prevented some illnesses. 73 Viral Illnesses (Cont.) Effective drug therapy is available for a small number of viral infections.  Antiviral Drugs Antiviral drugs kill or suppress the virus by destroying virions or inhibiting the ability of viruses to replicate; controlled by current antiviral therapy. Immunoglobulins are concentrated antibodies that can attack and destroy viruses. 74  Viruses controlled by current antiviral therapy Cytomegalovirus (CMV) Hepatitis viruses 75 Antiviral Herpesviruses Drugs HIV (Cont.) Influenza viruses (the “flu”) Respiratory syncytial virus (RSV)  Key characteristics of antiviral drugs Able to enter the cells infected with virus Interfere with viral nucleic acid synthesis, regulation, or 76 Antiviral both Drugs Some drugs interfere with (Cont.) ability of virus to bind to cells. Some drugs stimulate the body’s immune system.  Antiviral drugs Used to treat infections caused by viruses other than HIV 77 Antiviral Antiretroviral drugs Drugs Used to treat infections (Cont.) caused by HIV, the virus that causes AIDS  Best responses to antiviral drugs are in patients with competent immune systems. 78 Antiviral Drugs A healthy immune (Cont.) system works synergistically with the drug to eliminate or suppress viral activity. 79 Antiviral Opportunistic infections Drugs Occur in immunocompromised patients Con’t. Would not normally harm an immunocompetent person Require long-term prophylaxis and antiinfective drug therapy Can be other viruses, fungi, bacteria, or protozoa   Herpesviridae  HSV-1 (oral herpes) 80 Herpes  HSV-2 (genital herpes) Simplex  Chickenpox and shingles (HHV-3 or VZV) and  Epstein-Barr (HHV-4) Varicella-  CMV (HHV-5) Zoster  Human herpesviruses 6 and 7 are not especially clinically significant; Virus immunocompromised patients Infections  Kaposi’s sarcoma (HHV-8)  Herpesviridae (cont.) Shingles (HHV-3 or VZV) Painful: opioids for pain control Postherpetic neuralgias Acyclovir may speed 81 Herpes recovery; best results are Simplex generally seen when the and antiviral drug is started within 72 hours of symptom onset. Varicella- Zoster Zostavax Virus Infections (Cont.)  Hepatitis B Mild, without symptoms or chronic hepatitis or liver failure and death Transmission of hepatitis B virus occurs through blood and body fluid exposure. Transmission to infants Hepatitis B vaccine Antiviral drug therapy for hepatitis B: lamivudine, tenofovir, and telbivudine, and alfa-interferon (we don’t need to know these medications) 82  Hepatitis C Leading cause of liver failure leading to liver transplantation Symptoms Transmission: infected blood and sexual contact Alcoholic disease can lead to development of hepatitis C. Treatment: interferon, ribavirin, simeprevir, and sofosbuvir (do not need to know medications) 83 84  Mechanism of action Most of the current antiviral drugs work by blocking the activity of a polymerase enzyme that normally stimulates the synthesis of new viral genomes. 85 Antiviral Drugs Used to treat non-HIV viral infections (Non- HIV) Influenza viruses HSV, VZV CMV Hepatitis  Adverse effects Vary with each drug Healthy cells are often killed 86 Antiviral also, resulting in serious Drugs toxicities. (Non- Interactions HIV) (Cont.)  Antiviral Drugs (Non-HIV) (Cont.) Acyclovir (Zovirax) Synthetic nucleoside analogue Used to suppress replication of HSV-1, HSV-2, VZV Drug of choice for treatment of initial and recurrent episodes of these infections Oral, topical, parenteral forms 87  Antiviral Drugs (Non-HIV): Neuraminidase Inhibitors Oseltamivir (Tamiflu) and zanamivir (Relenza) Active against influenza types A and B Reduce duration of illness Oseltamivir: causes nausea and vomiting Zanamivir: causes diarrhea, nausea, sinusitis Treatment should begin within 2 days of influenza symptom onset. 88  New cases of HIV have decreased by 19% since between 2005 and 2014. Retrovirus Transmitted by sexual activity, intravenous drug use, perinatally from mother to HIV and child 89 AIDS The risk for transmission to health care workers via percutaneous (needlestick) injuries is currently calculated at approximately 0.3%. Prophylactic therapy for accidental exposure  Stage 1: asymptomatic infection Stage 2: early, general symptoms of disease Stage 3: moderate 90 Four symptoms Stages of HIV Stage 4: severe symptoms, Infection* often leading to death *World Health Organization model 91 Opportunistic Infections Protozoal Fungal Toxoplasmosis of the Candidiasis of the lungs, brain, others esophagus, trachea Pneumocystis jiroveci pneumonia, others Viral Bacterial CMV disease, HSV Various mycobacterial infection, others infections, others Extrapulmonary TB Opportunistic HIV wasting neoplasias syndrome Kaposi’s sarcoma, others Major weight loss, Copyright © 2020 Elsevier Inc. All Rights Reserved. chronic diarrhea, chronic fever  Highly active antiretroviral therapy Includes at least three 92 Antiretroviral medications Drugs These medications work in different ways to reduce the viral load.  Numerous and vary with each drug Drug therapy may need to be modified because of adverse effects. 93 Antiretroviral Goal is to find the regimen Drugs: that will best control the Adverse Effects infection with a tolerable adverse effect profile Medication regimens change during the course of the illness.  Before beginning therapy, assess underlying disease and medical history, including allergies. Assess baseline vital signs 94 Nursing and nutritional status. Implications Assess for contraindications, conditions that may indicate cautious use, and potential drug interactions.  95 Nursing Implications (Cont.) Teach Emphasize Instruct proper application Handwashing before Patients to wear a glove technique for ointments, and after administration or finger cot when aerosol powders, and so of medications to applying ointments or on. prevent site solutions to affected contamination and areas. spread of infection.  Instruct Emphasize Inform Instruct Emphasize the Inform patients patients to importance of that antiviral consult their good hygiene. drugs are not prescribers cures but do before taking help to any other manage medication, symptoms. including over- the-counter medications. 96 Nursing Implications (Cont.) 97 Nursing Implications (Cont.) Instruct patients on the importance of taking these medications exactly as prescribed and for the full course of treatment. Instruct patients to start therapy with antiviral drugs at the earliest sign of recurrent episodes of genital herpes or herpes zoster.  Monitor for adverse effects: Effects are varied and specific to each drug. Monitor for therapeutic effects: 98 Nursing Effects vary depending on the type of Implications viral infection. con’t Effects range from delayed progression of AIDS and other viruses to a decrease in flulike symptoms, decrease in frequency of herpes-like flare-ups, or crusting over of herpetic lesions. ANTITUBERCULAR DRUGS  ANTITUBERCULAR DRUGS TUBERCULOSIS (TB) CAUSED BY MYCOBACTERIUM TUBERCULOSIS ANTITUBERCULAR DRUGS TREAT ALL FORMS OF MYCOBACTERIUM (MTB). TB IS MOST COMMONLY CHARACTERIZED BY GRANULOMAS IN THE LUNGS: NODULAR ACCUMULATIONS OF INFLAMMATORY CELLS (E.G., MACROPHAGES, LYMPHOCYTES) THAT ARE DELIMITED (“WALLED OFF” WITH CLEAR BOUNDARIES) AND HAVE A CENTER THAT HAS A CHEESY OR CASEATED CONSISTENCY. 100  MYCOBACTERIUM (MTB) INFECTIONS COMMON INFECTION SITES LUNG (PRIMARY SITE) BRAIN (CEREBRAL CORTEX) BONE (GROWING END) LIVER KIDNEY GENITOURINARY TRACT 101  MYCOBACTERIUM (MTB) INFECTIONS (CONT.) AEROBIC BACILLUS PASSED FROM INFECTED: HUMANS (DROPLET) COWS (BOVINE) AND BIRDS (AVIAN) MUCH LESS COMMON 102  MYCOBACTERIUM (MTB) INFECTIONS (CONT.) TUBERCLE BACILLI ARE CONVEYED BY DROPLETS. DROPLETS ARE EXPELLED BY COUGHING OR SNEEZING, AND THEY THEN GAIN ENTRY INTO THE BODY BY INHALATION. TUBERCLE BACILLI THEN SPREAD TO OTHER BODY ORGANS VIA BLOOD AND LYMPHATIC SYSTEMS. TUBERCLE BACILLI MAY BECOME DORMANT, OR WALLED OFF BY CALCIFIED OR FIBROUS TISSUE. 103  MTB: very slow-growing organism More difficult to treat than most other bacterial infections MYCOBACTERIUM First infectious episode: primary TB infection (MTB) INFECTIONS (CONT.) Reinfection: chronic form of the disease Dormancy: may test positive for exposure but are not necessarily infectious because of this dormancy process 104  Diagnosis of tuberculosis Step 1 Tuberculin skin test (Mantoux test) Step 2 If skin test results are positive, then chest x-ray DIAGNOSIS Step 3 If chest x-ray shows signs of tuberculosis, then culture of sputum* or stomach secretions *The acid-fast bacillus smear test is performed on sputum as a quick method of determining whether tuberculosis treatment and precautions are needed until a more definite diagnosis is made. 105  MULTIDRUG-RESISTANT TUBERCULOSIS (MDR-TB) TB INFECTS ONE THIRD OF THE WORLD’S POPULATION. MDR-TB THAT IS RESISTANT TO BOTH ISONIAZID (INH) AND RIFAMPIN EXTENSIVELY DRUG-RESISTANT TUBERCULOSIS (XDR-TB): RELATIVELY RARE TYPE OF MDR-TB, RESISTANT TO ALMOST ALL DRUGS USED TO TREAT TB, INCLUDING THE TWO BEST FIRST-LINE DRUGS, INH AND RIFAMPIN, AS WELL AS TO THE BEST SECOND-LINE MEDICATIONS XDR-TB IS OF SPECIAL CONCERN FOR PATIENTS WHO HAVE AIDS OR ARE OTHERWISE IMMUNOCOMPROMISED. USE OF MULTIPLE MEDICATIONS TO TREAT TB DUE TO INCREASING PRESENCE OF RESISTANCE 106  ANTITUBERCULAR DRUGS FIRST-LINE DRUGS : INH: PRIMARY DRUG USED RIFAMPIN STREPTOMYCIN 107  Major effects of drug therapy: reduction of cough and, therefore, reduction of the infectiousness of the patient Normally occurs within 2 weeks of the initiation of drug therapy if TB strain is ANTITUBERCULAR drug sensitive DRUG THERAPY CONSIDERATIONS Most cases of TB can be cured. Successful treatment: several antibiotic drugs for at least 6 months and sometimes for as long as 12 months Copyright © 2020 Elsevier Inc. All Rights Reserved. 108  ANTITUBERCULAR DRUG THERAPY CONSIDERATIONS (CONT.) Perform drug-susceptibility testing on the first Mycobacterium spp. that is isolated from a patient specimen to prevent the development of MDR-TB. Even before the results of susceptibility tests are known, begin a regimen with multiple antitubercular drugs (to reduce the chances of development of resistance). 109  Adjust drug regimen after the results of susceptibility testing are known. Monitor patient compliance closely ANTITUBERCULAR during therapy. DRUG THERAPY CONSIDERATIONS Problems with successful therapy occur because of patient nonadherence to drug therapy and the increased incidence of drug-resistant organisms. 110  MECHANISM OF ACTION THREE GROUPS: PROTEIN WALL SYNTHESIS INHIBITORS: STREPTOMYCIN, RIFAMPIN, RIFABUTIN CELL WALL SYNTHESIS INHIBITORS: CYCLOSERINE, ETHIONAMIDE, INH 111  Effectiveness depends on: Type of infection Adequate dosing Sufficient duration of treatment Adherence to drug regimen ANTITUBERCULAR Selection of an effective drug THERAPY combination Problems: Drug-resistant organisms Drug toxicity Patient nonadherence 112 Drug of choice for TB Resistant strains of Mycobacterium emerging Metabolized in the liver through acetylation—watch for “slow acetylators”(toxicity) Used alone or in combination with other drugs Contraindicated with liver disease ISONIAZID (INH) 113 Rifamycin antibiotic Also used to treat infections caused by non-TB mycobacterial species Adverse effects: turns urine, feces, saliva, skin, sputum, sweat, and tears a red-orange-brown color Oral use only RIFABUTIN , RIFAMPIN, AND RIFAPENTINE 114  NURSING IMPLICATIONS Perform liver function studies in patients Assess for contraindications to Obtain a thorough medical who are to receive INH or the various drugs, conditions for history and assessment. rifampin cautious use, and potential drug (especially in older patients and interactions. those who use alcohol daily). Take medications exactly as Strict adherence to regimen for Therapy may last for up to 24 ordered at the same time every improvement of condition or months. day. cure. 115  NURSING IMPLICATIONS Remind patients that they are contagious during the initial period of their illness—instruct in proper hygiene and prevention of the spread of infected droplets. Teach patients to take care of themselves, including getting adequate nutrition and rest. Copyright © 2020 Elsevier Inc. All Rights Reserved. 116  Should not consume Alcohol NURSING IMPLICATIONS (CONT.) Rifampin causes oral contraceptives to become ineffective; another form of birth control is needed. 117  Patients who are taking rifampin should be told that their urine, stool, saliva, sputum, sweat, or tears may become reddish orange; even contact lenses may be stained. NURSING Pyridoxine may be needed to IMPLICATIONS combat neurologic adverse (CONT.) effects associated with INH therapy. Oral preparations may be given with meals to reduce gastrointestinal upset even though recommendations are to take Copyright © 2020 Elsevier them Inc. All Rights 1 hour before or Reserved. 118 2 hours after meals.  Monitor for adverse effects. Instruct patients on the adverse effects that should be reported to the prescriber immediately. These include fatigue, nausea, vomiting, numbness and tingling of the extremities, NURSING fever, loss of appetite, depression, and IMPLICATIONS jaundice (liver failure). (CONT.) Monitor for therapeutic effects. Decrease in symptoms of TB, such as cough and fever Laboratory study results (culture and sensitivity tests) and chest radiographs should confirm clinical. findings. 119 Watch for lack of clinical response to therapy, indicating possible drug resistance. Copyright © 2020 Elsevier Inc. All Rights Reserved. 120 Antifungal Drugs  Fourgeneral types:  Cutaneous  Subcutaneous Mycotic  Superficial  Systemic (fungal)  Can be life threatening Infections  Usually occur in immunocomprom ised host 122  Mycotic Infections (Cont.) Candida albicans  May follow antibiotic therapy, antineoplastics, or immunosuppressants (corticosteroids)  May result in overgrowth and systemic infections  Growth in the mouth is called thrush or oral candidiasis.  Common in newborn infants and immunocompromised patients Vaginal candidiasis  Yeast infection  Pregnancy, women with diabetes mellitus, women taking oral contraceptives 123  Antifungal Drugs Drugs used to treat infections caused by fungi Systemic  Amphotericin B, fluconazole, griseofulvin, nystatin, Topical  nystatin Ophthalmic: natamycin 124  Mechanism of Action (Cont.) Polyenes  amphotericin B and nystatin  Bind to sterols in cell membrane lining  Result: fungal cell death  Do not bind to human cell membranes or kill human cells 125  Mechanism of Action (Cont.) Imidazoles and triazoles  ketoconazole, fluconazole  Inhibit fungal cell cytochrome P-450 enzymes, resulting in cell membrane leaking  Result: altered cellular metabolism and fungal cell death 126  Indications Systemic and topical fungal infections Drug of choice for the treatment of many severe systemic fungal infections is amphotericin B. Choice of drug depends on type and location of infection Fluconazole: passes into the cerebrospinal fluid and inhibit the growth of cryptococcal fungi, effective in the treatment of cryptococcal meningitis 127  Contraindication allergy, liver failure, kidney failure Adverse Effects Fluconazole Antifungal Drugs: Nausea, vomiting, diarrhea, Contraindications/ stomach pain Adverse Effects Increased liver enzymes Use with caution in patients with renal and liver dysfunction Nystatin Nausea, vomiting, anorexia, diarrhea, rash 128  Antifungal Drugs: Interactions Many antifungal drugs are metabolized by the cytochrome P-450 enzyme system. Co-administration of two drugs that are metabolized by this system may result in competition for these enzymes and thus higher levels of one of the drugs. 129  Assess Before-hypersensitivity, possible contraindications, and conditions that require cautious use. Obtain Nursing Baseline vital signs, complete Implications blood count, liver and renal function studies, and electrocardiography. Assess Other medications used (prescribed and over the counter) to avoid drug interactions. 130  Follow manufacturer’s directions carefully for reconstitution and administration. Monitor Nursing Implications vital signs of patients (Cont.) receiving intravenous (IV) infusions every 15 to 30 minutes. Monitor Monitor input and output to identify adverse effects, during IV infusion 131 Nursing Implications Nystatin given as an oral lozenge or troche should be slowly and completely dissolved in the mouth (not chewed or swallowed whole). Nystatin suspension should be swished thoroughly in the mouth as long as possible before swallowing. 132  Monitor for therapeutic effects. Easing of symptoms of Nursing infection Implications Improved energy levels (Cont.) Normal vital signs, including temperature Monitor carefully for adverse effects. 133