Antibiotics PowerPoint Presentation PDF

Antimicrobials  Basic Principles of Antimicrobi al Therapy Selective Toxicity  Chemicals toxic to microbes— harmless to host  Disruption of bacterial cell wall  Inhibition of an enzyme unique to bacteria  Disruption of bacterial protein synthesis Acquired Resistanc...

Antimicrobials  Basic Principles of Antimicrobi al Therapy Selective Toxicity  Chemicals toxic to microbes— harmless to host  Disruption of bacterial cell wall  Inhibition of an enzyme unique to bacteria  Disruption of bacterial protein synthesis Acquired Resistance to Antimicrobial Drugs  Over time, some organisms develop resistance  May have been highly responsive and then became less susceptible to one or more drugs  Antibiotic Resistance in Animals and Humans  Antibiotic resistance in animals such as, pigs, chickens, birds (sea gulls) to antibiotics used in humans.  Bacteria in animals develop resistance  Humans develop or are infected by resistant bacteria  Current treatment plans are to use antibiotics from 1960-1970 to treat the infections in humans Antibiotic Use and Drug- Resistant Microbe Emergence  Suprainfection (Superinfection)  Drug resistance  A new infection that appears while the patient is receiving antibiotics for a primary infections  CAUSE: the primary (first) antibiotics eliminated the normal flora allowing an imbalance in the normal flora and a second infection flourishes due to overgrowth.  Broad spectrum antibiotics (effective against a wide variety of microbes) destroy more normal flora than narrow spectrum drug (effective against only a few microorganisms)   Suprainfection A few examples: (Superinfection  C difficile )  Thrush  Vaginal infection Microbial Mechanisms of Drug Resistance Inactivate Drug Drug antagonist Alters molecule Selection of Antibiotics  Lab – Culture and Sensitivity  Identify organism CULTURE  Drug sensitivity of organism SENSITIVITY  Drug may be ruled out if:  Allergy  Patient variables: liver/kidneys Other selection rationale  Empiric: Antibiotic therapy for patients before causative organism is positively identified  Prophylactic: Agents given to prevent infection rather than to treat an established infection Monitoring of Antimicrobial Therapy  Nurse is to monitor clinical responses and laboratory results  Reduction of fever  Reduction or resolution of signs/symptoms of infection of the affected organ/area RED –HOT- SWOLLEN-PAIN- DRAINAGE   Serum drug levels for toxicity Nurse to   Peak and Trough (High/Low) Renal function- know values monitor   BUN Creatine patient  Hepatic function-know values  ALT lab  AST  Infection- know values  WBC values Patient Teaching  Purpose, use, medication specifics, side effects  Women of child-bearing age:  Antibiotics decrease the effectiveness of birth control pills  A second method of birth control should be used until a new pack of pills 21 or 28 days is begun  Check for drug-drug interactions Antibiotic: Types  Drugs that weaken the cell wall  PENICILLLINS  Drug name ends in “-cillin” Penicillins  Active against a variety of bacteria  Direct toxicity: low  Principal adverse effect: allergic reaction  Weakens cell wall, causes bacteria to take up excess water and rupture Bacterial Resistance: Inactivation of Penicillins by Bacterial Enzymes  Beta-lactamases enzymes that can render penicillin inactive  (Ex. Penicillinase)  Bacteria type MRSA  Methicillin resistant staphylococcus aureus Penicillin Combinations  Extends antimicrobial spectrum when combined with penicillinase-sensitive antibiotics  Ampicillin/sulbactam (Unasyn)  Amoxicillin/clavulanic acid (Augmentin) Penicillin Allergy  Development of penicillin allergy  Skin tests for penicillin allergy  Assess for penicillin allergy in each patient who will be receiving penicillin  If history of anaphylaxis, DO NOT administer penicillin or cephalosporin Penicillinand Cephalosporin CROSS ALLERGY  ALLERGIC TO ONE MEANS ALLERGIC TO BOTH Broad- Spectrum  Ampicillin Penicillins  Amoxicillin Potassium penicillin G  Has the least toxicity  Has Potassium in it  Monitor K+ levels! Other Antibiotics That Weaken the Bacterial Cell Wall II: Classification:Cephalosporin ex. Keflex Classification: Glycopeptide ex. Vancomycin Cephalosporins  Most widely used group of antibiotics  Beta-lactam antibiotics  Similar to penicillin structure  Toxicity is low Cephalosporins  Mechanism of action  Bind to penicillin-binding proteins (PBPs), disrupt cell wall synthesis, and cause cell lysis  Resistance  Beta-lactamases (cephalosporinase)  Bacteria can produce a large variety of these enzymes specific for cephalosporin (and other beta- lactam antibiotics) Cephalosporin's: Drug Interactions  Drugs that promote bleeding ASA, NSAID, Warfarin Interferes with Vitamin K level causing increased anti-coagulation (Vitamin K causes coagulation)  Adverse effects  Allergy  Bleeding  Thrombophlebitis Glycopeptide: Vancomycin  Action  Inhibits cell wall synthesis  Uses  Severe infections only  Methicillin-resistant Staphylococcus aureus  ***Oral dose used for Clostridium difficile if metronidazole (Flagyl) was tried and found ineffective  FLAGYL IS PREFERED TO TREAT C. DIFF Vancomycin  Adverse Effects:  Ototoxicity (reversible or permanent)  Red man syndrome - IV Administration  Rapid systemic release of histamine that causes the skin to turn red on neck and chest  Avoid by infusing over 60 – 90 minutes  Renal Toxicity – check labs BUN and Creatine Bacteriostatic Inhibitors of Protein Synthesis  Bacteriostatic: stops multiplication of bacteria  Tetracyclines  Macrolides Tetracyclines  Drug and food interaction  Absorption of tetracyclines decreased if given with:  Milk products  Calcium supplements  Most antacids Tetracyclines  Summary of major precautions  Tetracycline eliminated primarily in urine and will accumulate in patients with kidney disease  Discoloration of deciduous and permanent teeth  Diarrhea may indicate a potentially life-threatening suprainfection of the bowel - C. Diff  Photosensitivity – use sun screen Macrolides (Erythromycin)  Broad-spectrum antibiotic  Inhibition of bacteria protein synthesis  Use if allergic to penicillin Bacteriostatic: Macrolides (Erythromycin) Therapeutic Adverse effects uses Gastrointestinal Whooping cough, Dysrhythmias diphtheria, Superinfection pneumonia Bactericidal Inhibitors of Protein Synthesis: Aminoglycosides Bactericidal: Kills bacteria Aminoglycosides  Most commonly used:  Gentamicin, tobramycin, amikacin  Adverse effects (Peak and trough levels)  Nephrotoxicity  Ototoxicity  Hypersensitivity reactions  Neuromuscular blockade  Blood dyscrasias Aminoglycosides Are NOT Metabolized  Aminoglycosides are excreted unchanged in the urine, with 80–90% of administered drug recoverable from the urine.  Released into the environment – i.e. Lake Sulfonamides Inhibit synthesis of folic acid Bacteria need folic acid to replicate Primary use: Urinary tract infections Sulfonamides  Adverse effects  Rash – STOP Administration and notify  Hypersensitivity reactions: Stevens- Johnson syndrome  Mortality rate of 25%  Symptoms: blisters of the skin and mucous membranes Trimethoprim Suppresses Bacterial synthesis of DNA Combined with sulfonamides urinary tract Uses infections Trimethoprim- Sulfamethoxazole  Trimethoprim-sulfamethoxazole (TMP-SMZ) combination  Trade names: Bactrim and Septra  Inhibits sequential steps in bacterial folic acid synthesis  Therapeutic uses  Urinary tract infection Antibacterial Drugs: Fluoroquinolone and Metronidazole Fluoroquinolones  Disrupt DNA replication and cell division  Side effects tendon rupture  BLACK BOX WARNING FOR PRESCRIBERS  Usually affects Achilles tendon  Inflammation or rupture of Achilles tendon Fluoroquinolones: Ciprofloxacin (Cipro)  Ciprofloxacin (Cipro)  Uses:  Drug of choice for anthrax  USED TO TREAT Infections: respiratory, urinary tract (UTI), GI, bones, joints, skin, and soft tissue Fluoroquinolones: Ciprofloxacin (Cipro)  Adverse effects  Mild GI: nausea/vomiting, diarrhea, abdominal pain Central nervous system (CNS): dizziness, headache, restlessness, confusion, rarely seizures  Older adult patients Confusion, lethargy, visual disturbances Fluoroquinolones: Ciprofloxacin (Cipro)  Drug and food interactions  Absorption reduced by:  Aluminum antacids  Magnesium antacids  Iron salts  Zinc salts  Sucralfate  Milk and dairy products  Metronidazole (Flagyl)  Inhibits nucleic synthesis  Used to treat Clostridium Difficile (C. Diff)  C. Diff Treatment:  Stop antibiotic (precipitating cause)  Hand sanitizers ineffective  Do not give anti-diarrheal Questions?