ATI Pharmacology Infection Notes PDF

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ATI Pharmacology – Infection Notes

Types of Organisms 

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Bacteria Shapes and Cell Walls o Bacteria shapes  Round – cocci  Rod – bacilli o Cell wall surrounding bacteria  Gram positive – thin  Staphylococcus, streptococcus, diphtheria, listeria  Gram negative – thick  Neisseria meningitides, Neisseria gonorrhea, Escherichia coli, salmonella Mycobacterium o Waxy cell wall (hard to kill) o Most common mycobacterium o Tuberculosis Viruses o Invade cells of host (intracellular parasite) o Reproduce inside cell o Efforts to kill viruses tend to kill host cells o New drugs target virus-specific process o Antibiotics ineffective Fungi o Plant-like organisms o Live in damp, dark places o “Eat” dead tissue o May infect through opportunistic opening in the skin o Common skin infections are:  Tinea pedis (athletes foot)  Tinea corporis (ringworm) o Antibiotics ineffective Parasites o Live in blood cells, organs, structures (intestines, vagina) o Malaria: travels to liver  Proliferates, infects red blood cells  Helminths: worms in intestines  Trichomonas: reproductive tracts Aerobic o Require oxygen to survive o Mouth, GI tract, and lungs o Staphylococcus aureus (skin infections) and Pseudomonas aeruginosa (lung disease)

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Anaerobic o Do not require oxygen to survive o Produces abscesses and tissue necrosis o Clostridium perfringens (gangrene) and Actinomyces (abdominal/pelvic infections)

Type of Antibiotics Bactericidal  Kills bacteria directly  Weaken cell wall (lysis)  Bind to ribosomes, decrease protein synthesis  Interfere with enzymes  Eventually destroys all bacteria o Bacteriostatic  Kills bacteria indirectly  Bind to ribosomes, decrease protein synthesis  Decreases the number of bacteria  Body’s immune system kills remaining bacteria o Broad spectrum  Effective against a broad range of bacteria  Exerts action on a structure that has similar characteristics between several different types of bacteria o Narrow spectrum  Effective against a narrow range of bacteria  Exerts action on a characteristic that is specific to only one or a few types of bacteria Sensitivity o Determine the type of bacteria o Obtain sample – view under microscope o Grow a sample over 24 to 48 hours o Expose to various antibiotics Resistance o Grow in culture o Expose to various antibiotics o Broad-spectrum antibiotics create more resistant strains of bacteria o

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Goal of Drug Therapy for Infections 

Kill bacteria through: o Interrupt cell-wall synthesis o Inhibit protein synthesis o Inhibit DNA replication/cell division

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o Inhibit folic-acid synthesis Kill viruses, parasites, fungi

 Antibacterial – Drugs that interfere with cell wall synthesis o

Penicillins  Treats broad-spectrum infections (ear and throat, urinary tract)  Amoxicillin: treats gonorrhea  Addition of clavulanic acid increases spectrum of disorders (allows amoxicillin to kill bacteria  Prototype Drug:  Amoxicillin (Amoxil)  Amoxicillin and clavulanic acid (Augmentin)  Other Drugs:  Nafcillin (Unipen)  Methicillin  Ticarcillin-clavulanate (Timentin)  Piperacillin (Zosyn)  Pharmacologic Action:  Weakens and destroys cell wall o Inhibits enzyme necessary for cell-wall formation (transpeptidase) o Activates enzyme that opens cell wall during replication (autolysin) o No effect on human cells, no cell wall  Bactericidal o Many aerobic gram positive o Some aerobic gram negative  Penicillin G is active constituent  Side/Adverse Effects:  GI symptoms o Diarrhea o Nausea o Vomiting  Rare, but may cause pseudomembranous colitis due to superinfection o More frequent with other penicillins than amoxicillin  Superinfection with Candida albicans  Allergy to penicillin o Rash o Hives  Anaphylactic reaction o Swelling of the airway o Wheezing

o Difficulty breathing Interventions:  Monitor for GI symptoms  Report bloody stools or long periods of watery diarrhea  Monitor for and report Candida infections of mouth or vagina  Expect to treat Candida infections with an antifungal agent  Monitor for allergy manifestations and notify provider  Administration:  Patients should not crush or chew extended-release form  Chew chewable forms before swallowing  For infants or young children, place drops directly on tongue or mix with small amount of juice or formula – assure that child takes full dose  Give a the beginning of meals to decrease GI symptoms and increase absorption  Give amoxicillin with probenecid, if prescribed, to increase therapeutic activity of amoxicillin  Patient Education:  Report watery or bloody diarrhea to provider  Take drug at the start of meals  Report mouth pain or inability to eat  Report vaginal burning, itching or discharge  Stop drug and notify provider for possible allergic reactions  Call 911 for severe symptoms – difficulty breathing  Contraindications:  Allergy to penicillins  Infectious mononucleosis  Sever liver disease (Augmentin)  Precautions:  History of allergies, hay fever, and asthma  History of allergy to cephalosporins or carbapenem antibiotics  Colitis or diarrhea  Liver disease (amoxicillin)  Renal failure or dialysis (amoxicillin)  Diabetes mellitus  Interactions:  Probenecid increases penicillin blood levels  Tetracyclines may decrease therapeutic effects Cephalosporins  Cephalexin, a first-generation cephalosporin, treats infections that gram positive cocci cause  Subsequent generations of cephalosporins (2nd, 3rd, and 4th generations) become:  More active against gram negative bacteria  More resistant to beta-lactamase (gram positive) bacteria  More able to penetrate CSF to treat infections, such as meningitis 

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Prototype Drug:  Cephalexin (Keflex) Other Drugs:  1st generation o Cephradine (Anspor, Velosef) nd  2 generation o Cefaclor (Ceclor), cefotetan (Cefotan)  3rd generation o Ceftriaxone (Rocephin), ceftotaxime (Claforan)  4th generation o Cefepime (Maxipime) Pharmacologic Action:  Weaken and destroy cell wall Inhibits enzyme necessary for cell-wall formation (transpeptidase) o Activates enzyme that opens cell wall during replication (autolysin) o No effect on human cells, no cell wall Bactericidal o Many aerobic gram positive o Latter generations more effective against aerobic gram negative and anaerobic o

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Side/Adverse Effects:  GI symptoms o Diarrhea o Nausea o Vomiting  Rare pseudomembranous colitis  Possible cross-allergy to penicillin allergy (especially for patient with a history of severe penicillin allergy)  Risk for hemorrhage with cefotetan (Cefotan) only  Thrombophlebitis (for cephalosporins infused via IV only)  Potential for disulfiram-like reaction if taken with alcohol Interventions:  Monitor and report bloody stools or watery diarrhea  Inquire about cephalosporin allergy or penicillin allergy  Prepare to treat a severe allergic reaction or anaphylaxis  Monitor PT/INR and PTT  Expect to administer Vitamin K if bleeding occurs  Monitor for thrombophlebitis o Stop infusion o Change IV site

Follow recommendations when diluting IV cephalosporins – infuse slowly  Monitor renal function tests – expect to reduce dose with renal insufficiency  Inform patient about potential for disulfiram-like reaction if cefotetan is taken with alcohol  Administration:  Cephalexin is only available as capsules, tablets, or oral suspension  Other cephalosporins may be available for oral, IM, or IV use  Be careful to differentiate between cephalosporin prescriptions – generic names may be similar  Patient Education:  Take with food to decrease GI symptoms  Report watery or bloody diarrhea to provider  Inform provider of rash or hives – STOP drug  Difficulty breathing, wheezing, or swelling to the airway – CALL 911  Report unusual bruising or bleeding to the provider  Inform about the potential for nausea, vomiting, severe headache, and hypotension if taken with alcohol  Report IV site burning, pain, or swelling during cephalosporin infusion  Contraindications:  Allergy to cephalosporin antibiotics  Viral infections  Cefiditoren (Spectracef) carnitine or milk protein allergy  Cefotetan (Cefotan) any alcohol use causes a disulfiram-like reaction  Precautions:  Allergy to penicillin (possible cross sensitivity)  Renal failure  Liver of GI disease  Interactions:  Probenecid causes prolonged effect of most cephalosporins  Alcohol or any drug that promotes bleeding – cefotetan (Cefotan) only  IV calcium and ceftriaxone (Rocephin) only Monobactams  Narrow-spectrum antibiotic  Fights infections that gram negative bacteria cause  Lower respiratory infections  UTIs  Abdominal and GYN infections  Prototype Drug:  Aztreonam (Azactam)  Pharmacologic Action: 

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Weaken and destroy cell wall

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Bactericidal o Effective against aerobic gram negative o Not effective against anaerobic o Not effective against gram positive  Side/Adverse Effects:  Thrombophlebitis or inflammation at IV site  Superinfection with Candida albicans  Interventions:  Monitor IV site o Redness, swelling, and pain o Inflammation: changes sites  Vaginal Candida infections o Miconazole (Monistat)  Oral Candida infections o Nystatin (Mycostatin)  Administration:  Aztreonam is available in IM and IV forms  It also is available in a powder for inhalation  Administer IM injections into large muscle and rotate sites  IV – can give as slow IV bolus or infusion – follow recommendations for dilution and rate  Patient Education:  Report pain, redness, or swelling at IV sites  Report mouth pain and ability to eat  Report vaginal burning, itching, or discharge  Take inhaled three times per day for 28 days  Contraindications:  Viral infection  Lactation  Precautions:  History of allergy to penicillin, cephalosporins (although aztreonam has little cross-sensitivity to these antibiotics)  A decrease in liver or renal function  Older adults  Interactions:  Incompatible in IV solution with other multiple drugs  Probenecid can increase blood levels of aztreonam  Some other antibiotics (imipenem, cefoxitin) can decrease the effectiveness of aztreonam Carbapenems 

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Inhibits enzyme necessary for cell-wall formation (transpeptidase) Activates enzyme that opens cell wall during replication (autolysin)

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Treats serious infections and those that multiple types of organisms cause Prototype Drug:  Imipenem and cilastatin (Primaxin) Other Drugs:  Meropenem (Merrem IV) Pharmacologic Action:  Beta-lactam antibiotics  Weaken and destroy cell wall o Inhibits enzyme necessary for cell-wall formation (transpeptidase) o Activates enzyme that opens cell wall during replication (autolysin)  Bactericidal against: o Gram positive cocci o Gram negative cocci and bacilli o Anaerobic bacteria  Resist beta-lactamase and better than penicillins, cephalosporins Side/Adverse Effects:  GI symptoms o Nausea o Vomiting o May occur with IV infusion that is too rapid  Thrombophlebitis at IV site  Possible cross-sensitivity with other antibiotics with beta lactam ring (penicillins, cephalosporins)  Superinfection Interventions:  Follow recommended rate when infusing IV carbapenem  Monitor for nausea during infusion o Treat with anti-emetic  Monitor IV site for infiltration prior to infusion o Redness o Swelling during infusion  Assess for and report antibiotic allergy prior to infusing imipenem  Monitor for secondary infections, such as oral candidiasis Administration:  Carbapenems are only available for IM or IV use  IM and IV forms are not interchangeable – assure and use correct form for prescription  Follow recommendations for rate and dilution when infusing IV doses Patient Education:  Report nausea, especially when it occurs during IV infusion  Report pain, swelling, or redness at the IV site  Report mouth pain, difficulty chewing, and swallowing  Report vaginal irritation or discharge

Contraindications:  Allergy to carbapenems  Allergy to penicillin  Precautions:  Allergy to cephalosproins  Seizures and other CNS disorders  Renal impairment  Interactions:  Monobactam, penicillin, and cephalosporin antibiotics may decrease the effects of imipenem Vancomycin  Severe infections  MRSA infections  Pseudomembranous colitis caused by ABX therapy  Infections in patients with a penicillin allergy  Prototype Drug:  Vancomycin (Vancocin)  Pharmacologic Action:  Weaken and destroy cell wall o Inhibits enzyme necessary for cell-wall formation (transpeptidase) o Activates enzyme that opens cell wall during replication (autolysin)  Bactericidal o Effective against gram positive bacteria o Effective against MRSA o Effective against Clostridium difficile  Side/Adverse Effects:  Hypotension and flushing of the face and trunk (red-person syndrome) with rapid IV infusion  Hearing loss due to ototoxicity (usually reversible, but not always)  Kidney damage secondary to nephrotoxicity  Thrombophlebitis at IV site and tissue damage with IV infiltration  Interventions:  Administer IV infusion for at least 1 hour and follow recommendations for dilution  Monitor vital signs during infusion  Monitor vancomycin blood levels  Determine baseline hearing acuity and monitor for hearing loss during treatment  Monitor for redness and swelling  Assure that IV is patent prior to and during infusion  Administration:  Give orally for colitis  Give IV for all other infections 

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Administer slowly and follow recommendations for dilution Infuse separately if possible (incompatible in solution with many other IV drugs) Patient Education:  Report o Facial flushing o Feelings of faintness o Hearing loss o Pain, swelling, redness at IV site  Ototoxicity Contraindications:  Allergy to vancomycin  Allergy to corn products Precautions:  Renal insufficiency (reduce dosage)  Hearing impairment  Colitis and inflammatory disorders of the colon Interactions:  Metformin may increase the risk for lactic acidosis  Drug that are toxic to hearing or the kidneys increase the risk for ototoxicity or nephrotoxicity  Incompatible in solution with multiple other IV drugs  

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 Antibacterial – drugs that inhibit protein synthesis o

Tetracyclines (Bacteriostatic)  First choice ABX for:  Chlamydia infections  Mycoplasmal infections  Rickettsial infections o Typhus o Rocky Mountain Fever  Syphilis and gram negative infections in patients with a penicillin allergy  Gram positive infections (Tetanus) o Cholera o Anthrax  Treats acne vulgaris (topical and oral forms)  Prototype Drug:  Tetracycline  Other Drugs:  Doxycycline (Vibramycin)  Minocycline (Minocin)  Pharmacologic Action:  Inhibits protein synthesis o Inhibits transfer of RNA from binding with messenger RNA at the ribosomal acceptor site

Prevents amino acids from adding themselves to the peptide chain o Blocks bacterial protein synthesis  Bacteriostatic o Effective against gram-positive and negative bacteria (if no development of resistance) o Atypical organisms such as parasites  Prevents malaria in quinine-resistant parasites  Promotes growth in cattle Side/Adverse Effects:  GI symptoms o Nausea o Vomiting o Diarrhea o Abdominal pain  Liver toxicity  Superinfections o Pseudomembranous colitis o Candida infections  Photosensitivity o Severe sun-burn type reaction  Teeth Interventions:  Give with non-dairy foods if GI symptoms occur  Monitor and report GI symptoms o A decrease in dose may be necessary  Determine if patient is pregnant before giving her the drug  Monitor LFTs  Monitor for symptoms of liver damage  Monitor for signs of superinfection  Monitor for photosensitivity reactions Administration:  Oral form o Best on empty stomach o 1 hour before or 2 hour after meals o Do not give right before bedtime o Give with a non-dairy food o Doxycycline (Vibramycin) with food  Safer for patients with renal failure  Topical form o Acne vulgaris  IM and IV forms only if patient cannot tolerate oral form  Liquid form: shake solution before measuring dose  Avoid giving the out-of-date drug (kidney dysfunction) o

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Patient Education:  Take with non-dairy foods if GI upset occurs (report severe symptoms) o 1 hour before or 2 hours after meals  Report pregnancy  Avoid giving to infants and children under 8  Report signs of liver damage o Jaundice o Abdominal pain o Fatigue  Symptoms of superinfection o Mouth pain, difficulty chewing and swallowing (oral yeast infection) o Vaginal irritation and discharge (vaginal yeast infection) o Watery or bloody stool (pseudomembranous colitis)  Wear protective clothing and sunscreen  Keep drug in light-protected container  Contraindications:  Women who are pregnant  Children less than 8 years old  Allergic  Exposure to UV light  Serious renal or liver failure  Precautions:  History of allergies (hay fever)  History of liver of kidney disorder  Myasthenia gravis  Interactions:  Calcium-containing foods  Antacids containing calcium, magnesium, aluminum  Decreases absorption of tetracyclines o Anti-diarrheal containing kaolin o Dairy products o Supplements with iron or zinc  Tetracyclines decrease effectiveness of oral contraceptives Macrolides (Bacteriostatic)  First line treatment for:  Legionnaires’ disease  Whooping cough  Acute diphtheria  Patients who carry diphtheria  Some Chlamydia infections  Certain pneumonias  Treats common infections for patient who have a penicillin allergy  Use ophthalmic ointment to prevent eye infection in neonates  Prototype Drug: 

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 erythromycin Other Drugs:  Azithromycin (Zithromax) Pharmacologic Action:  Inhibits protein synthesis o Inhibits transfer RNA from binding with messenger RNA at the ribosomal acceptor site o Prevents amino acids from adding themselves to the peptide chain o Blocks bacterial protein synthesis  Bacteriostatic o Effective against gram positive bacteria o Effective against SOME gram negative bacteria Side/Adverse Effects:  GI symptoms o Nausea o Vomiting o Abdominal pain o Diarrhea  Cardiac symptoms o Ventricular dysrhythmias  Caused by prolonged QT on ECG  Ototoxicity o Hearing loss o Vertigo o Tinnitus o Reversible when treatment ends  Superinfection o Pseudomembranous colitis o Candidiasis Interventions:  Monitor for and report GI reactions o A decrease in the dose may stop symptoms  Evaluate all drugs the patient is taking o Concurrent use of other drugs can increase erythromycin blood levels  Monitor for and report signs of ototoxicity  Question a patient about history of a prolong in QT intervals  Monitor for and report superinfection Administration:  Available in 4 forms: o Erythromycin base  Tablets  Capsules

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 Topical  Ophthalmic ointment o Erythromycin stearate  Tablets o Erythromycin ethylsuccinate (EES)  Tablets o Erythromycin lactobionate  IV form  Give erythromycin base and erythromycin stearate on an empty stomach o 1 hour before or 2 hours after a meal for best absorption o Give with 8 oz of water  If GI symptoms occur – give with food  Give EES enteric-coated forms of erythromycin with or without meals  For IV form, follow recommendations for dilution and rate to prevent thrombophlebitis  Patient Education:  Take with food if GI symptoms occur  Report continuing symptoms to provider  Report palpitations, fainting spells, or history of QT prolongation on ECG to provider  Report hearing loss, vertigo, or tinnitus to provider  Report bloody or watery diarrhea  Report mouth pain or vaginal discomfort or discharge  Contraindications:  Allergy to erythromycin and other macrolide antibiotic  History of prolonged QT on ECG  Prec...