NURSING MSN 571 - Quiz 2 Study Guide.| VERIFIED GUIDE

NURSING MSN 571 - Quiz 2 Study Guide.| VERIFIED GUIDE Antibiotics Review terminology: 1. Selective Toxicity: The ability of a drug to injure a target cell or target organism without injuring other cells or organisms that are in intimate contact with the target. Refers to the ability of an antibiotic to injure only invading microbes and avoiding injuring the host. 2. Culture and Sensitivity test: Is a test done when trying to treat for infection. Culture is to determine the bacteria or fungus causing the infection . Sensitivity checks for what kind of medicine will work best against the bacteria or fungus. Test used to test drug sensitivity is the disk diffusion test, also known as the kirby-bauer test. 3. Mechanisms of Resistance : decreases concentration of a drug at its site of action; alters the structure of a drug target molecules; produces a drug antagonist; causes drug inactivation. Broad spectrum antibiotics promote the emergence of drug resistance. 4. CYP3A4: inhibitor is Drugs used for erectile dysfunction ; it suppresses the metabolism of sildenafil (viagra), thereby increasing its level. Combination should be used with caution. ● Intraconazole (antifungal) inhibits CYP3A4 5. CYP450: Cytochrome P450 Enzyme 17 inhibitor Abiraterone ( Zytiga) indicated for combined use with prednisone to treat metastatic castration-resistant prostate cancer, if castration has not occured it can inhibit androgen production by the testes. Ketoconazole ( Nizoral) used for fungal infections, can be used off label for prostate ● Azoles( antifungal ) has the ability to inhibit CYP450 6. Disulfiram-like effect: Is an unpleasant effect caused by the medication when ingesting alcohol. Manifest as nause, copious vomiting, flushing , palpitations, headache, sweating , thirst, chest pain, weakness, blurred vision and hypotension. 7. Superinfection: A new infection that appears during a course of treatment for a primary infection. When the body's normal flora is decreased the overgrowth of fungi and yeast can occur, an example is yeast infections after the use of antibiotics. They occur most often with broad spectrum antibiotics 8. Cross-sensitivity: is defined as sensitivity to one substance that renders an individual sensitive to other substances of similar chemical structure. B- lactams and sulfonamides are the most common. 9. Cross-resistance: Resistance to all antibiotics belonging to the same class due to a single mechanism. The more active the drug the lower the level of resistance Review labs: WBC- Purpose of white blood cells can detect hidden infections within your body. - Neutrophil- type of WBC, lead the immune system’s response. Neutrophils are 55-70 % of the wbc. !st cell to arrive on the scene of the infection. NORM COUNT- . Increase with infection, may decrease due to leukemia, vit b12 deficiency cnd chemo. The chemokines attract the neutrophils. It addresses foreign invaders by “eating them” also known as phagocytosis. Lives for 8 hours only. - Lymphocytes- small WBC that actually play an outsized role in defending your body from disease. Role is to fight infections by producing antibodies. Also kill cells in our body that are infected. Moves through the lymphatic system. Uses phagocytosis as well. 2 types- T cells and B cells. T CELLS- continuously scan and monitor your cells for infection and the risk of infection. T stands for thymus (small glands in chest where T cells mature). T cells spot infected cells and proceed to kill the cell. It also remembers the infectious agent so it can attack it quicker if the infection is repeated. Also kills cancer cells. B-CELLS- don’t attack and kill cells, virus or bacteria. It manufactures antibodies that actually stick to the surface of invaders , disabling those invader and spotlighting them for clean up. Also made in the bone marrow. - Basophil- most common for parasites. Involved in producing some of the symptoms caused by allergic reactions (watery eyes, sneezing, runny nose. Made in the bone marrow and developed and differentiated by hematopoiesis. Makes up 0.5% of WBC. Lives for a few days. Are granulocytes- contains small granules inside the, granules store and release enzymes and chemicals, specifically histamine. Does not remember organism, they simply recognize invaders that do not belong and should be destroyed. Triggers production of immunoglobulin E (IgE). - Eosinophil- important against parasitic infections. Phagocytic but less efficient than neutrophils in killing intracellular bacteria. May modulate immediate hypersensitivity reactions by degrading or inactivating mediators released by mast cells, such as histamine, leukotrienes (which may cause vasoconstriction and bronchoconstriction). And lysophospholipids and heparin. Regulated by T cells through secretion of the hematopoietic growth factors granulocyte-macrophage colony-stimulating factor. , interleukin-3 and 5. Il-5 increases eosinophil production. Review drugs (mechanism of action, indication, adverse effects, and which patients to avoid): ● Penicillins : B Lactam ○ Action: Active against a variety of bacteria. Inhibits bacterial cell walls; weakens the cell walls causing the bacteria to take excessive amounts of water and rupture. Inhibition of transpeptidases and activation of autolysins. ○ Indication: used to treat infections caused by sensitive bacteria; bacteria that are undergoing cell growth and division, active against gram + bacteria(narrow spectrum) Gram + & Gram - (broad spectrum). ○ Adverse effects: allergic reactions ( rash, hives, anaphylaxis, Penicillin is considered one of the least toxic and among the safest. ○ Avoid: pt with hx of severe allergic reactions to penicillins, cephalosporins and carbapenems. ● Cephalosporins (differences between generations) : ○ Actions: are B-lactams antibiotics. Bactericidal drugs action similar to penicillins. Bind to PBP (penicillin-binding proteins) causing cell death by lysis. Effective on cells undergoing cell growth and division. ○ Uses: ■ 1st gen. (cefazolin, Keflex) used against Gram + bacteria (surgical prophylaxis) ; ■ 2nd Gen.(ceflacor, cefotetan, ceftin) used for Gram + and - ( otitis, sinusitis, resp. infections); ■ 3rd/ 4th Gen ( cefximine, cefdinir, cefotaximine) used for Gram - ( meningitis, complicated intra abdominal and UTI, HA pneumonia); ■ 5th Gen (ceftaroline) used for Gram + (MRSA). ○ Adverse Effect: allergic reactions (rash, urticaria, hypotension, difficulty breathing) bronchospasms and anaphylaxis are rare. Avoid: hx of allergy to cephalosporins or severe allergy to penicillins ● Tetracycline: Broad spectrum antibiotics- Bacteriostatic inhibitor Action: suppress bacterial growth by inhibition of protein synthesis. Bind to the 30s ribosomal subunit, inhibits transfer of RNA to the messenger RNA- ribosome complex. Enter bacteria by way of an energy dependent transport system. Uses: Treatment of infectious disease; Acne, peptic ulcer disease; Periodontal disease. Adverse Effects: GI irritation, effects on bones and teeth (they bind to calcium in developing teeth causing discoloration); superinfection, hepatotoxicity; renal toxicity. Avoid: Pregnant women, children younger than 8yr. ● Trimethoprim (TMP)/sulfamethoxazole (SMZ): Antimicrobial Action: Inhibiting consecutive steps in the synthesis of tetrahydrofolate; suppresses the ability for the target organism to make nucleic acid. Uses: Gram +/ - bacteria, UTIs, otitis media, bronchitis; pneumonia caused by P. Jirovecci; GI infections; ration 1:20; half life 10h (TPM) 11hr (SMZ). Adverse Effect: Hypersensitivity, blood dyscrasia, kernicterus; renal damage, megaloblastic anemia, hyperkalemia; Birth defects. Avoid: during pregnancy; infants < 2mths. Maintain hydration while taking. Monitor CBC ● Sulfonamides: Bariostatic.- Broad spectrum Action: Structural analogs of para-aminobenzoic acid. Suppress bacterial growth by inhibiting synthesis of tetrahydrofolate. In the absence of tetrahydrofolate, bacteria is unable to synthesize DNA, RNA and proteins. Uses: Nocordiosi, Listeria, P.Jivorecci, C. Trachomaxis, Protozoal infection, Toxoplasmosis, Maralia, Superficial infections of the eye, Burnt patients. Adverse Effects: Hypersensitivity, Blood dyscrasia; Kernicterus (newborns); Hemolytic anemia, Renal Damage. Avoid: Pregnancy; breast feeding. ● Clindamycin: Bacteriostatic Action: active against most anaerobic bacteria. Gram +/ -. Bactericidal if the target is sensitive. Binds to 50S subunit of bacterial ribosomes, inhibits protein synthesis. Uses: as an alternative to penicillins, severe Strep A infection, and gas gangrene. Adverse Effects: C-diff associated diarrhea (CDAD) this condition can be fatal and is treated with Vancomycin. Avoid: during pregnancy ● Fluoroquinolones: Narrow spectrum. Actions: Disruption of DNA replication and cell division, Do not disrupt synthesis of proteins or cell walls. Uses: UTIs. Adverse Effect: Tendinitis, Tendon rupture. Avoid: Pts w/ Myasthenia Gravis, Renal impairment, pts over 60yr. Pts taking glucocorticoids. ● Sulfasalazine: Inhibition of PABA Action: Metabolized by intestinal bacteria, 5-ASA reduces inflammation, sulfapyridine causes adverse effects. Uses: Acute mild to moderate Ulcerative Colitis, Crohn's disease, Anti-inflammatory diseases. Rheumatoid Arthritis (can slow progression of joint deterioration). Adverse Effect: GI reactions, Dermatology reactions; Hematologic; (Bone marrow and Hepatitis are rare). Avoid: during pregnancy and lactation. ● Macrolides: Broad spectrum. Bacteriostatic Action: inhibits bacterial protein synthesis. Get their name due to their size (Big). Erythromycin is the oldest and safest, Azithromycin is the newest. Uses: for Gram + bacteria, Alternative for Penicillin G pts with penicillin allergies, treatment of Corynebacterium diphtheria, chlamydial infections (urethritis and cervicitis) pnemonia (Mycobacterium pneumonie). Adverse Effect: GI effects; QT prolongation and sudden cardiac death. Avoid: use caution pts with QT prolongation. ● Metronidazole: Flagyl. Action: Antibacterial. Interacts with DNA causing strand breakage. Uses: Anaerobic organisms only. Treat protozoal infections. Infections of CNS, abdominal organs, bones and joints, skin and soft tissues; GI tract, C-Diff, prophylaxis for colorectal, abdominal and GYN surgeries. Combined w/ Bismuth treats H. Pylori. Adverse Effect: Carcinogenic (unnecessary use should be avoided.) Avoid: hx of Myasthenia Gravis; renal impairment; pt > 60 yr, pt taking Corticosteroids ● Daptomycin: Action:Antibacterial drug. Inserts itself into the bacterial cell membranes and thereby forms channels that permit efflux of intracellular potassium. Depolarizes the cell membrane and inhibits the synthesis of DNA, RNA and proteins. Uses: Cyclic Lipopeptides, can rapidly kill virtually all clinically relevant Gram + bacteria, including MRSA. used for bloodstream infections and complicated skin and skin structure infections. Adverse Effect: constipation, nausea, diarrhea, injection site reaction, headaches, insomnia, rash. Possible muscle injury. Avoid: hx of Myasthenia Gravis; renal impairment; pt > 60 yr, pt taking Corticosteroids ● Vancomycin: Action: inhibits cell wall synthesis, promotes bacterial lysis and death. Does not interact with PBPs. Disrupts cell walls by binding to molecules that serve as precursors for cell wall biosynthesis. Uses: Gram + bacteria. Reserved for serious infections, MRSA, S. epidermidis, sever CDI, alternative for penicillin and cephalosporin allergies. Adverse Effects: Renal toxicity, Nephrotoxicity , C-Diff infections. Avoid: pts with renal impairments, avoid concomitant use of other nephrotic medications (NSAIDs, cyclosporine and aminoglycosides). Rapid infusion causes red man syndrome ● Aminoglycosides: Narrow spectrum antibiotics. Action: Bactericidal inhibitor of protein synthesis. Bind to 30S ribosomal subunit, causes inhibition of protein synthesis , premature termination of protein synthesis and production of abnormal proteins. Uses: Parenteral therapy to treat serious infection due to aerobic Gram - bacilli. Topical therapy to treat ear and eye infections. Used with Penicillins, cephalosporins and vancomycin. Must be administered parenterally. Adverse Effects: toxicity (inner ear and kidneys), can induce neuromuscular transmission causing flaccid paralysis and potential fatal respiratory distress. Avoid: Pregnancy; use caution pts with renal impairment; preexisting hearing impairment, those receiving ototoxic and nephrotoxic drugs. ● Gentamicin: Aminoglycoside. Action: Bactericidal Inhibitors of protein synthesis. Uses: treat serious infections caused by aerobic Gram - bacilli, targets P. aeruginosa and Enterobacteriaceae. Adverse Effects: toxic to ears and Kidneys . Avoid: Pregnancy; use caution pts with renal impairment; preexisting hearing impairment, those receiving ototoxic and nephrotoxic Review diseases (pathophysiology, signs and symptoms, complications, and first-line treatment): 1. Clostridium difficile: ● Patho: Gram + spore forming anaerobic bacillus that infects the bowel; Release of toxins A& B, proceeded by use of antibiotic tx that kills normal flora. ● S/S: 3 or more watery stools; watery diarrhea that leads to pseudomembranous colitis (patches of severe inflammation and pus). ● Complications: Dehydration, electrolytes imbalances, sepsis, toxic megacolon, bowel perforation; renal failure, death. ● Treatment: Stop antibiotics, drug selection based on number of previous episodes and infection severity judged by labs ( WBC and serum creatinine) Most likely used narrow spectrum Microlides. 1. Clostridium difficile: Patho: Gram + spore forming anaerobic bacillus that infects the bowel; Release of toxins A& B, proceeded by use of antibiotic tx that kills normal flora. S/S: 3 or more watery stools; watery diarrhea that leads to pseudomembranous colitis (patches of severe inflammation and pus). Complications: Dehydration, electrolytes imbalances, sepsis, toxic megacolon, bowel perforation; renal failure, death. Treatment: Stop antibiotics, drug selection based on number of previous episodes and infection severity judge by labs ( WBC and serum creatinine) Most likely used narrow spectrum Microlides. 2. Lyme disease: 1. Patho: B. burgdorferi enters the skin at the site of the tick bite. After 3 to 32 days, the organisms migrate locally in the skin around the bite, spread via the lymphatics to cause regional adenopathy or disseminate in blood to organs or other skin sites. Initially, an inflammatory reaction (erythema migrans) occurs before significant antibody response to infection (serologic conversion). 2. S/S 3 stages A. Early Localized: Erythema migrans, the hallmark and best clinical indicator of Lyme disease, is the first sign of the disease. It occurs in at least 75% of patients, beginning as a red macule or papule at the site of the tick bite, usually on the proximal portion of an extremity or the trunk (especially the thigh, buttock,