Antibiotics Principles Antimicrobial Therapy PDF

Principles of Antimicrobial Therapy and Resistance Study online at https://quizlet.com/_g39ugd Chemicals toxic to microbes, harmless to Selective Toxicity host....

Principles of Antimicrobial Therapy and Resistance Study online at https://quizlet.com/_g39ugd Chemicals toxic to microbes, harmless to Selective Toxicity host. Organisms develop resistance over time Acquired Resistance to drugs. develops when broad-spectrum antibi- otics eliminate a wide range of normal flora organisms, not just those causing Suprainfection infection Eg: C. Diff, Thrush, Vaginal Infection Resistance evolving rapidly in many Antibiotic Resistance species of prokaryotes due to overuse of antibiotics, especially in agriculture. Effective against a wide variety of mi- Broad Spectrum Antibiotics crobes. Effective against only a few microorgan- Narrow Spectrum Antibiotics isms. Bacteria causing severe intestinal infec- C. difficile tion. Antibiotics ending in '-cillin', low toxicity. Penicillins Beta-lactamases Enzymes that inactivate penicillins. Methicillin-Resistant Staphylococcus Au- reus; an infectious disease caused by a MRSA pathogen that is resistant to many antibi- otics Broad-spectrum penicillin, used for vari- Ampicillin ous infections. 1/8  Principles of Antimicrobial Therapy and Resistance Study online at https://quizlet.com/_g39ugd Beta-lactam antibiotics, similar to peni- cillins. Cephalosporins Glycopeptide antibiotic for severe infec- Vancomycin tions. Skin reaction from rapid IV vancomycin Red Man Syndrome infusion. Antibiotics affected by dairy and antacids. Tetracyclines Broad-spectrum antibiotics, inhibit pro- Macrolides tein synthesis. Eg: Erythromycin Combination antibiotic for urinary tract Trimethoprim-Sulfamethoxazole infections. Fluoroquinolone, drug of choice for an- thrax. Ciprofloxacin Peak and Trough Monitoring serum drug levels for toxicity. Prevent infection rather than treat estab- Prophylactic Antibiotics lished infection. Antibiotic treatment before identifying the Empiric Therapy organism. 2/8 Principles of Antimicrobial Therapy and Resistance Study online at https://quizlet.com/_g39ugd Bacteriostatic Stops multiplication of bacteria. Bactericidal Kills bacteria directly. Evaluate for penicillin allergy before ad- Allergy Assessment ministration. Check for interactions affecting antibiotic Drug Interactions efficacy. Observe clinical responses and lab re- Patient Monitoring sults. Lab - Culture and Sensitivity Identify organism CULTURE Drug sensitivity of organism SENSITIV- Selection of Antibiotics: ITY Drug may be ruled out if: Allergy Patient variables: liver/kidneys Antibiotic therapy for patients before Empiric causative organism is positively identi- fied Agents given to prevent infection rather Prophylactic than to treat an established infection enzyme produced by bacteria that deac- penicillinase tivates penicillin Extends antimicrobial spectrum when combined with penicillinase-sensitive an- tibiotics Eg: Penicillin Combinations Ampicillin/sulbactam (Unasyn) Amoxicillin/clavulanic acid (Augmentin) Ticarcillin/clavulanic acid (Timentin) Piperacillin/tazobactam (Zosyn) - ampicillin and amoxicillin Broad Spectrum Penicillins - good oral absorption (amoxicillin = ex- cellent) 3/8  Principles of Antimicrobial Therapy and Resistance Study online at https://quizlet.com/_g39ugd - e.coli, salmonella, shigella, H. Influen- za, H pylori, proteus) -low chance of allergic response -has to do with similar side chains Penicillin and Cephalosporin CROSS -higher chance with 1st generation ALLERGY -important to know their PCN reaction ALLERGIC TO ONE MEANS ALLERGIC TO BOTH water soluble solution for immediate on- set but short duration Potassium Penicillin G Has the least toxicity Has Potassium in it Monitor K+ levels! Inhibits cell wall synthesis Severe infections only Methicillin-resistant Staphylococcus aureus ***Oral dose used for Clostridium diffi- Glycopeptides cile if metronidazole (Flagyl) was tried and found ineffective FLAGYL IS PREFERED TO TREAT C. DIFF Eg: Vancomycin -Structurally and functionally similar to penicillins Most widely used group of antibiotics Cephalosporins Beta-lactam antibiotics Similar to penicillin structure Toxicity is low Eg: Keflex - Increased activity toward staphylococci , but increased covered for streptococci 1st generation Cephalosporin and gram- activity compared to 2nd/3rd generation; covers PEK (proteus gram-, E.coli , Klebisella species gram-) 4/8  Principles of Antimicrobial Therapy and Resistance Study online at https://quizlet.com/_g39ugd - Cefadroxil - Cefazolin (Kefzol) (NO ORAL) - Cephalexin (keflex) -Cefoxitin, cefaclor, cefuroxime -Use: gram-positive cocci, Haemophilus influenzae, Enterobacter aerogenes, 2nd generation cephalosporins Neisseria spp., Proteus mirabilis, E. coli, Klebsiella pneumoniae, Serratia marcescens. -Ceftriaxone, cefotaxime, ceftazidime) -Use: serious gram-negative infec- tions resistant to other beta-lac- 3rd generation cephalosporins tams. Ceftriaxone—meningitis, gonor- rhea, disseminated lyme disease; cef- tazidime—Pseudomonas -Cefepime -Use: gram-negative organisms, with 4th generation cephalosporins activity against Pseudomonas and gram-positive organisms. Use with Aminoglycosides increases risk of nephrotoxicity. Use with anticoagu- lants increases risk of bleeding. Use with alcohol may cause a disulfiram-like reac- tion-very dangerous! Cephalosporin's: Drug Interactions Drugs that promote bleeding ASA, NSAID, Warfarin Interferes with Vitamin K level causing increased anti-coagulation (Vitamin K causes coagulation) What is the preferred C-Diff Drug? Flagyl (metronidazole) nephrotoxicity, ototoxicity, red man syn- Vancomycin Adverse Effects: drome Toxicity to the ears, often drug induced Ototoxicity and manifesting as varying degrees of 5/8  Principles of Antimicrobial Therapy and Resistance Study online at https://quizlet.com/_g39ugd hearing loss that is likely to be perma- nent. damage to the kidneys by a toxic sub- nephrotoxicity stance Hepatotoxic toxic to the liver a rare, benign side effect of taking the an- tiarrhythmic medication amiodarone that Blue Man Syndrome causes blue-gray discoloration of the skin Drug and food interaction Absorption of tetracyclines decreased if given with: Tetracyclines Milk products Calcium supplements Most antacids Bactericidal Inhibitor of Protein Synthe- sis Are NOT Metabolized Most commonly used: Gentamicin, tobramycin, amikacin Aminoglycosides Adverse effects (Peak and trough levels) Nephrotoxicity Ototoxicity Hypersensitivity reactions Neuromuscular blockade Blood dyscrasias Inhibit folic acid synthesis, used for UTIs. Adverse effects Rash - STOP Administration and notify Hypersensitivity reactions: Sulfonamides Stevens-Johnson syndrome Mortality rate of 25% Symptoms: blisters of the skin and mucous membranes Steven Johnson Syndrome (SJS) 6/8  Principles of Antimicrobial Therapy and Resistance Study online at https://quizlet.com/_g39ugd Severe blistering of the skin, with mu- cous membrane involvement and fever Can be fatal Suppresses Bacterial synthesis of DNA Trimethoprim Combined with sulfonamides Uses: urinary tract infections Septra, Bactrim Antibacterial-Sulfon- amide Trimethoprim-Sulfamethoxazole Inhibits sequential steps in bacterial folic acid synthesis Uses: Drug of choice for anthrax Class: Fluoroquinolone Ciproflaxacin USED TO TREAT Infections: respiratory, urinary tract (UTI), GI, bones, joints, skin, and soft tissue Disrupt DNA replication, risk of tendon rupture. Side effects tendon rupture BLACK BOX WARNING FOR PRE- Fluoroquinolones SCRIBERS Usually affects Achilles tendon Inflammation or rupture of Achilles ten- don Eg: Ciproflaxacin Adverse effects Mild GI: nausea/vomiting, diarrhea, abdom- inal pain Ciprofloxacin ADRs Central nervous system (CNS): dizzi- ness, headache, restlessness, confu- sion, rarely seizures Older adult patients: Confusion, lethargy, visual disturbances 7/8  Principles of Antimicrobial Therapy and Resistance Study online at https://quizlet.com/_g39ugd Absorption reduced by: Aluminum antacids Magnesium antacids Drug and food interactions of Cipro: Iron salts Zinc salts Sucralfate Milk and dairy products 8/8