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ANTIMICROBIALS
Question | Answer |
---|---|
Folic acid synthesis inhibitors (DNA methylation) | 1. Sulfonamides 2. Trimethroprim |
BLOCK Cell wall synthesis by inhibiting | 1. Peptidoglycan synthesis 2. Peptidoglycan cross-linking |
Peptidoglycan synthesis inhibitors (BLOCK Cell wall synthesis) | Glycopeptides 1. Vancomycin 2. Bacitracin |
Peptidoglycan cross-linking inhibitors (BLOCK Cell wall synthesis) | 1. Penicillinase-sensitive penicillins 2. Penicillinase-resistant penicillins 3. Antipseudomonals 4. Cephalosporins (I-V) 5. Carbapenems (-penem) 6. Monobactams |
DNA Topoisomerases inhibitors | 1. Fluoroquinolones (-xacin) 2. Quinolone (Nalidixic acid) |
Damages DNA | Metronidazole |
BLOCKS mRNA synthesis (RNA polymerase) | Rifampin |
BLOCK protein synthesis at 50S SUBUNIT | 1. Chloramphenicol 2. Clindamycin 3. Linezolid 4. Macrolides (-thromycin) 5. Streptogramins (-pristin) |
BLOCK protein synthesis at 30S SUBUNIT | 1. Aminoglycosides 2. Tetracyclines (-cycline) |
Penicillinase-sensitive penicillins (BLOCK cell wall synthesis) | 1. Penicillin G,V 2. Ampicillin 3. Amoxicillin |
Penicillinase-sensitive penicillins MOA | Bind penicillin-binding proteins (transpeptidases) |
Penicillinase-sensitive penicillins; clinical use | 1. Gram-positive organisms 2. Neisseria meningitidis, Treponema pallidum, and syphilis. |
Penicillinase-sensitive penicillins; TOXICITY | Hypersensitivity reactions, hemolytic anemia. |
Penicillinase-sensitive penicillins RESISTANCE | Penicillinase in bacteria (a type of beta-lactamase) cleaves beta-lactam ring. |
Ampicillin, amoxicillin (aminopenicillins, Penicillinase-sensitive penicillins); CLINICAL USE | HELPSS kill enterococci. 1. Haemophilus influenzae 2. E. coli 3. Listeria monocytogenes 4. Proteus mirabilis 5. Salmonella 6. Shigella |
Ampicillin, amoxicillin (aminopenicillins, Penicillinase-sensitive penicillins); TOXICITY | Hypersensitivity reactions; ampicillin rash; PSEUDOMEMBRANOUS COLITIS. |
PSEUDOMEMBRANOUS COLITIS | Ampicillin, amoxicillin |
Ticarcillin, piperacillin (antipseudomonals); CLINICAL USE | 1. Pseudomonas 2. Gram-negative rods; susceptible to penicillinase; use with clavulanic acid. |
Beta-lactamase inhibitors | CAST (-bactam) 1. Clavulanic Acid 2. Sulbactam 3. Tazobactam |
Often added to penicillin antibiotics to protect the antibiotic from destruction by Beta-lactamase (penicillinase) | Beta-lactamase inhibitors |
Organisms typically not covered by cephalosporins | LAME: 1. Listeria 2. Atypicals (Chlamydia, Mycoplasma) 3. MRSA 4. Enterococci. Exception: ceftaroline covers MRSA. |
Which 5th generation cephalosporin covers MRSA | Ceftaroline |
1st generation (cefazolin, cephalexin); CLINICAL USE | PEcK; gram-positive cocci 1. Proteus mirabilis 2. E. coli, 3. Klebsiella pneumoniae |
1st generation used prior to surgery to prevent S. aureus wound infections | Cefazolin |
2nd generation (cefoxitin, cefaclor, cefuroxime); CLINICAL USE | HEN PEcKS; gram-positive cocci 1. Haemophilus influenzae 2. Enterobacter aerogenes, 3. Neisseria 4. Proteus 5. E. coli 6. Klebsiella 7. Serratia |
3rd generation (ceftriaxone, cefotaxime, ceftazidime); CLINICAL USE | Serious gram-negative infections resistant to other Beta-lactams. |
Ceftriaxone (3rd generation Cephalosporin); CLINICAL USE | Meningitis and Gonorrhea |
Ceftazimide (3rd generation Cephalosporin); CLINICAL USE | Pseudomonas |
What antibiotic should always be added to the empiric treatment with Ceftriaxone of Meningitis in children an immuocompromised | Ampicillin (to cover for Listeria monocytogenes |
4th generation (cefepime); CLINICAL USE | Increased activity against Pseudomonas and gram-positive organisms |
5th generation (ceftaroline);CLINICAL USE | Broad gram-positive and gram-negative , including MRSA |
5th generation (ceftaroline) does NOT cover | Pseudomonas |
Cephalosporins; TOXICITY | -Hypersensitivity reactions -Vitamin K deficiency. -Increased nephrotoxicity of aminoglycosides. |
Which medications increase Cephalosporins nephrotoxicity | Aminoglycosides |
Aztreonam (Monobactam); MOA | Prevents peptidoglycan cross-linking by binding to PBP3. (Cell wall synthesis inhibitor) |
Aztreonam (Monobactam); CLINICAL USE | 1. Gram-negative rods only 2. For penicillin-allergic patients and those with renal insufficiency who cannot tolerate aminoglycosicles. |
Antibiotic used in those patients with renal insufficiency who cannot tolerate aminoglycosicles. | Aztreonam |
Penicillin-allergic patients | Aztreonam |
Carbapenems are always administered with | Cilastatin (inhibitor of renal dehydropeptidase I) to decrease inactivation of drug in renal tubules. |
Carbapenems (lmipenem, meropenem, ertapenem, doripenem); CLINICAL USE | 1. Gram-positive cocci 2. Gram-negative rods 3. Anaerobes |
Which Carbapenem has a reduced risk of seizures and is stable to dehydropeptidase I. | Meropenem |
Carbapenems (lmipenem, meropenem, ertapenem, doripenem); TOXICITY | GI distress, skin rash, and CNS toxicity (seizures) at high plasma levels. |
Vancomycin; MOA | Inhibits cell wall peptidoglycan formation by binding D-ala D-ala portion of cell wall precursors. |
Binds D-ala D-ala portion | Vancomycin |
Vancomycin; CLINICAL USE | 1. Gram positive 2. MRSA 3. Enterococci 4. Clostridium difficile (oral dose for pseudomembranous colitis). |
Clostridium difficile (oral dose for pseudomembranous colitis). | Vancomycin |
Commonly used drugs for MRSA | 1. Vancomycin 2. Daptomycin 3. Linezolid |
Vancomycin; TOXICITY | NOT 1. Nephrotoxicity 2. Ototoxicity 3. Thrombophlebitis, diffuse flushing-¨red man syndrome¨ |
Red Man Syndrome caused by Vancomycin can be largely prevented by pretreatment with | Antihistamines and slow infusion rate |
Vancomycin; RESISTANCE | Occurs with amino acid change of D-ala D-ala to D-ala D-lac |
Protein synthesis inhibitors | Specifically target smaller bacterial ribosome (70S, made of 30S and 50S subunits) |
50S inhibitors | C = Chloramphenicol, Clindamycin E = Erythromycin (macrolides) L = Linezolid |
30S inhibitors | A = Aminoglycosides T = Tetracyclines |
Protein synthesis inhibitors | "Buy AT 30, CCEL (sell) at 50." A = Aminoglycosides T = Tetracyclines C = Chloramphenicol, Clindamycin E = Erythromycin (macrolides) L = Linezolid |
Aminoglycosides (30S inhibitors) | Gentamicin, Neomycin, Amikacin, Tobramycin, Streptomycin |
Aminoglycosides (30S inhibitors); MOA | inhibit formation of initiation complex and cause misreading of mRNA. Also block translocation. |
Require 02 for uptake; therefore ineffective against anaerobes | Aminoglycosides (30S inhibitors) |
Ineffective against anaerobes | Aminoglycosides (30S inhibitors) |
Aminoglycosides (30S inhibitors); CLINICAL USE | Severe gram-negative rod infections |
Used for bowel surgery. | Neomycin (Aminoglycoside; 30S inhibitor) |
Aminoglycosides (30S inhibitors); TOXICITY | 1.Nephrotoxicity (especially when used with cephalosporins) 2.Neuromuscular blockade 3.Ototoxicity (especially when used with loop diuretics) 4.Teratogen |
Aminoglycosides produce Ototoxicity, especially when used with | Loop diuretics |
Aminoglycosides (30S inhibitors); RESISTANCE | Transferase enzymes inactivate drug by acetylation, phosphorylation, or adenylation. |
Tetracyclines (-cycline) | doxycycline, demeclocycline, minocycline. |
Tetracyclines; MOA | bind to 30S and prevent attachment ofaminoacyl-tRNA; limited CNS penetration. |
Tetracycline fecally eliminated and can be used in patients with renal failure | Doxycycline |
Do not take Tetracyclines with | milk, antacids, or iron containing preparations because divalent cations inhibit its absorption in the gut. |
Tetracyclines (30S inhibitors); CLINICAL USE | 1. Borrelia burgdorferi 2. M. pneumnoniae 3. Rickettsia and Chlamydia |
Tetracyclines (30S inhibitors); TOXICITY | 1. Gl distress 2. Discoloration of teeth 3. Inhibition of bone growth in children, 4. Photosensitivity. Contraindicated in pregnancy. |
PHOTOSENSITIVITY | SAT for PHOTO: 1. S= Sulfonamides 2. A= Amiodarone 3. T= Tetracyclines |
Discoloration of teeth and inhibition of bone growth in children | Tetracyclines |
Tetracyclines (30S inhibitors); RESISTANCE | DECREASED uptake into cells or INCREASED efflux out of cell by plasmid-encoded transport pumps. |
Macrolides (50S inhibitors) | Azithromycin, clarithromycin, erythromycin. |
Macrolides (50S inhibitors); MOA | Inhibit protein synthesis by blocking translocation; bind to the 23S rRNA of the 50S ribosomal subunit. |
Bind to the 23S rRNA of the 50S ribosomal subunit | Macrolides |
Macrolides (50S inhibitors); CLINICAL USE | 1. Atypical pneumonias (Mycoplasma, Chlamydia, Legionella) 2. STDs (for Chlamydia) 3. Gram positive cocci (streptococcal infections in patients allergic to penicillin). |
Macrolides (50S inhibitors); TOXICITY | MACRO: 1. M= Motility issues, 2. A= Arrhythmia caused by prolonged QT, 3. C= Cholestatic hepatitis (acute) 4. R= Rash 5. eOsinophilia |
Increases serum concentration oftheophyllines, oral anticoagulants | Macrolides (50S inhibitors) |
Macrolides (50S inhibitors); RESISTANCE | Methylation of 23S rRNA binding site. |
Chloramphenicol; MOA | Blocks peptidyltransferase at 50S ribosomal subunit |
Chloramphenicol (50S inhibitors); CLINICAL USE | 1. Meningitis (Haemophilus influenzae, Neisseria meningitidis, Streptococcus pneumoniae) 2. Rocky Mountain spotted fever (Rickettsia ricketsii) |
Rocky Mountain spotted fever (Rickettsia ricketsii) TREATMENT | Chloramphenicol (50S inhibitors) |
Chloramphenicol (50S inhibitors); TOXICITY | 1. Anemia (dose dependent) 2. Aplastic anemia (dose independent) 3. Gray baby syndrome (in premature infants because they lack liver UDP-glucuronyl transferase). |
50S inhibitor that causes Gray baby syndrome | Chloramphenicol |
50S inhibitor that causes Aplastic anemia (dose independent) | Chloramphenicol |
Chloramphenicol (50S inhibitors); RESISTANCE | Plasmid-encoded acetyltransferase that inactivates drug by acetylation |
Clindamycin; MOA | Blocks peptide transfer (transpeptidation) at 50S ribosomal subunit. |
Clindamycin; CLINICAL USE | 1. Anaerobic infections (e.g., Bacteroides fragilis, Clostridium perfringens) in aspiration pneumonia or lung abscesses. 2. Oral infections with mouth anaerobes. 3. Invasive Group A streptococcal (GAS) infection. |
Treats anaerobes ABOVE the diaphragm | Clindamycin |
Treats anaerobes BELOW the diaphragm | Metronidazole |
Clindamycin;TOXICITY | Pseudomembranous colitis (C. difficile overgrowth), fever, diarrhea. |
Sulfonamides | 1. Sulfamethoxazole (SMX) 2. Sulfisoxazole 3. Sulfadiazine. |
Acne vulgaris (topical antimicrobial) | Tetracyclines (1st line) Erythromycin (2nd line) |
work on Aerobes | Aminoglycosides |
Used in Hepatic Encephalopathy | Neomycin (Aminoglycoside; 30S inhibitor) |
Sulfonamides; MOA | Inhibit Folate synthesis. Para-aminobenzoic acid (PABA) antimetabolites inhibit dihydropteroate synthase. |
Sulfonamides; CLINICAL USE | 1. Gram-positive 2. Gram-negative 3. Nocardia 4. Chlamydia |
simple UTI´s | Triple sulfas or Sulfamethoxazole (SMX) |
Sulfonamides; TOXICITY | 1. Hypersensitivity reactions 2. Hemolysis if G6PD deficient 3. Nephrotoxicity (tubulointerstitial nephritis) 4. Photosensitivity 5. Kernicterus in infants |
Antimicrobial that displaces other drugs from albumin (e.g., warfarin) . | Sulfonamides |
Antimicrobial that produces hemolysis if G6PD deficient | Sulfonamides |
Sulfonamides; RESISTANCE | Altered enzyme (bacterial dihydropteroate synthase), DECREASED uptake, or INCREASED PABA synthesis. |
Inhibit dihydropteroate synthase | Sulfonamides |
Inhibits bacterial dihydrofolate reductase | Trimethoprim |
Trimethoprim; MOA | Inhibits bacterial dihydrofolate reductase |
Trimethoprim-sulfamethoxazole [TMP SMX]; CLINICAL USE | 1. UTI´s 2. Shigella 3. Salmonella 4. Pneumocystis jirovecii pneumonia (treatment and prophylaxis). |
Trimethoprim is used in combination with | Sulfonamides (trimethoprim-sulfamethoxazole [TMP SMX]), causing sequential block of folate synthesis |
Block folate synthesis | Trimethoprim-sulfamethoxazole [TMP SMX] |
Pneumocystis jirovecii pneumonia (treatment and prophylaxis) | Trimethoprim-sulfamethoxazole [TMP SMX] |
UTI´s | Trimethoprim-sulfamethoxazole [TMP SMX] |
Toxoplasmosis prophylaxis | Trimethoprim-sulfamethoxazole [TMP SMX] |
Trimethoprim; TOXICITY | Megaloblastic anemia, leukopenia, granulocytopenia. (May alleviate with supplemental folinic acid [leucovorin rescue].) |
Granulocytopenia caused by Trimethoprim may alleviate with | supplemental folinic acid [leucovorin rescue].) |
Fluoroquinolones; MOA | Inhibit DNA gyrase (Topoisomerase II) and Topoisomerase IV. |
Inhibit DNA gyrase | Fluoroquinolones |
Fluoroquinolones must NOT be taken with | Antacids |
Fluoroquinolones; CLINICAL USE | 1. Gram-negative rods urinary and GI tracts (including Pseudomonas) 2. Neisseria 3. Some gram-positive organisms |
Fluoroquinolones; TOXICITY | 1. GI upset, superinfections, skin rashes, headache, dizziness. 2. Tendonitis, tendon rupture, leg cramps, myalgias. 3. Prolonged QT interval. 4. Tendon rupture in people > 60 years old and in patients taking prednisone. |
Fluoroquinolones contraindicated due possible damage to cartilage. | 1. Pregnant women 2. Nursing mothers 3. Children under 18 |
Tendon rupture in people > 60 years old and in patients taking prednisone. | Fluoroquinolones |
Antimicrobial that prolongs QT interval. | Fluoroquinolones |
Fluoroquinolones; RESISTANCE | Chromosome-encoded mutation in DNA gyrase, plasmid-mediated resistance, efflux pumps. |
Metronidazole; MOA | Forms free radical toxic metabolites in the bacterial cell that damage DNA. |
Bactericidal, antiprotozoal | Metronidazole |
Metronidazole; CLINICAL USE | GET GAP on the Metro with metronidazole! G= Giardia E= Entamoeba T= Trichomonas G= Gardnerella vaginalis A= Anaerobes (Bacteroides, C. difficile). P= H. Pylori. |
Used with a proton pump inhibitor and clarithromycin for "triple therapy" against H. Pylori. | Metronidazole |
"triple therapy" against H. Pylori. | Proton pump inhibitor + Clarithromycin + Metronidazole |
Metronidazole; TOXICITY | 1. Disulfiram-like reaction (severe flushing, tachycardia, hypotension) with ALCOHOL 2. Headache 3. MetaIIic taste. |
MetaIIic taste | Metronidazole |
Disulfiram-like reaction (severe flushing, tachycardia, hypotension) with ALCOHOL | Metronidazole |
M. tuberculosis; PROPHYLAXIS | Isoniazid |
M. avium-intracellulare; PROPHYLAXIS | Azythromycin, Rifabutin |
M. tuberculosis; TREATMENT | RIPE R= Rifampin I= Isoniazid P= Pyrazinamide E= Ethambutol |
M. avium-intracellulare; TREATMENT | Azithromycin, rifampin, ethambutol, streptomycin |
M. leprae; TREATMENT | Tuberculoid form: dapsone and rifampin Lepromatous form: add clofazimine |
Isoniazid; MOA | Decreases synthesis of mycolic acid. Bacterial catalase-peroxidase (KatG) needed to convert INH to active metabolite. |
ONLY agent used as SOLO prophylaxis against TB | Isoniazid |
Isoniazid; CLINICAL USE | Mycobacterium tuberculosis |
Isoniazid; TOXICITY | 1. Neurotoxicity 2. Hepatotoxicity 3. Lupus |
Can prevent neurotoxicity produced by Isoniazid | Pyridoxine (vitamin B6) |
Rifamycins (Rifampin, rifabutin); MOA | Inhibits DNA-dependent R A  polymerase. |
Rifampin's 4 R's | 1. RNA polymerase inhibitor 2. Ramps up microsomal cytochrome P-450 3. Red/orange body fluids 4. Rapid resistance if used alone |
Used for MONOTHERAPY in Meningococcal prophylaxis | Rifampin |
Red/orange body fluids | Rifampin |
Rifamycins (Rifampin, rifabutin); CLINICAL USE | 1. Mycobacterium tuberculosis 2. Delays resistance to dapsone when used for leprosy. 3. Meningococcal prophylaxis 4. Chemoprophylaxis in contacts of children with Haemophilus influenzae type B. |
Chemoprophylaxis in contacts of children with Haemophilus influenzae type B | Rifamycins (Rifampin, rifabutin) |
Rifamycin prefered in patients with HIV infection due to less cytochrome P-450 stimulation | Rifabutin |
Ethambutol; MOA | Decreases carbohydrate polymerization of mycobacterium cell wall by blocking arabinosyltransferase |
Blocks arabinosyltransferase | Ethambutol |
Ethambutol; CLINICAL USE | M. tuberculosis; RIPE R= Rifampin I= Isoniazid P= Pyrazinamide E= Ethambutol |
Ethambutol; TOXICITY | Optic neuropathy (red-green color blindness) |
Optic neuropathy (red-green color blindness) | Ethambutol |
Endocarditis with surgical or dental procedures; Antimicrobial prophylaxis | Penicillins |
Meningococcal infection; Antimicrobial prophylaxis | Ciprofloxacin (drug of choice), rifampin for children |
Gonorrhea; Antimicrobial prophylaxis | Ceftriaxone (3rd generation Cephalosporin) |
Syphilis; Antimicrobial prophylaxis | Benzathine penicillin G (IV and IM form) |
History of recurrent UTI´s; Antimicrobial prophylaxis | TMP-SMX |
Pregnant woman carrying group B strep; Antimicrobial prophylaxis | Ampicillin |
Prophylaxis of strep pharyngitis in child with prior rheumatic fever | Oral penicillin |
Prevention of postsurgical infection clue to S. aureus | Cefazolin (1st generation Cephalosporin) |
Prevention of gonococcal or chlamydial conjunctivitis in newborn | Erythromycin ointment |
HIV Prophylaxis | 1. CD4 < 200 cells/mm3, Pneumocystis pneumonia: TMP-SMX 2. CD4 < 100 cells/mm3, Pneumocystis pneumonia + Toxoplasmosis: TMP-SMX 3. CD4 < 50 cells/mm3, MAC: Azithromycin |
Treatment of Vancomycin- Resistant Enterococcus (VRE) | Linezolid and Streptogramins (quinupristin/dalfopristin) |