Antibiotics Flashcards
(104 cards)
Sulphonamides consist of many different drugs. Give some examples
Antibiotics: sulfamethoxazole (SMX), sulfadiazine, sulfisoxazole
Nonantibiotic sulfonamides
- Diuretics: thiazides, furosemide, acetazolamide
- Anti-inflammatory drugs: sulfasalazine, celecoxib
- Sulfonylureas
- Probenecid
What are trimethoprim / sulfamethoxazole / cotrimoxazole used for?
Shigella Salmonella Empiric treatment for simple UTI Prophylaxis and treatment of P. jirovecii (PCP) Prophylaxis of toxoplasmosis
What are the risks of daptomycin?
Reversible myopathy
Rhabdomyolysis
Allergic pneumonitis
Hypersensitivity
What is clindamycin used for?
- Anaerobes, such as Clostridium perfringens, Bacteroides spp. (clindamycin is less effective against Bacteroides than other anaerobic species) (aspiration pneumonia, lung abscesses, oral infections)
- Group A streptococcus: especially invasive infections
- Partially effective against gram-positive aerobes e.g. MRSA
- Babesia (together with quinine)
Which Abx are broad spectrum?
Ampicillin
Co-amoxiclav
Piperacillin
3rd, 4th and 5th gen cephalosporins
What are the risks of carbapenems?
Secondary fungal infections CNS toxicity: can lower seizure threshold at high serum concentrations (highest risk: imipenem) (lowest risk: meropenem) Gastrointestinal upset Rash Thrombophlebitis
List 5 penicillins
Penicillin G (benzylpenicillin) Penicillin V (phenoxymethylpenicillin) Oxacillin Nafcillin Methicillin Floxacillin Dicloxacillin Amoxicillin Ampicillin Piperacillin Ticarcillin Mezlocillin Carbenicillin
What is pyrazinamide used for?
TB
What’s rifampin used for?
- TB
- Leprosy
- M.avium-intracellulare
Meningococcal prophylaxis
Hib chemoprophylaxis
What is ethambutol used for?
M. TB
M. avium-intracellulare
What are penicillin G and penicillin V used for?
- Gram-positive aerobes (esp. Streptococcus pyogenes, Streptococcus pneumoniae)
- Gram-negative cocci (esp. Neisseria meningitidis)
- Spirochetes (esp. Treponema pallidum)
- Branching gram-positive anaerobes (especially Actinomyces)
Which Abx are CI in renal failure?
Epoxides Aminoglycosides Tetracyclines Sulfonamides w/ diaminopyrimidines Nitrofurans
Which Abx are CI in hepatic failure?
Tetracyclines Macrolides (azithromycin and clarithromycin) Sulfonamides with diaminopyrimidines Nitrofurans Pyrazinamide
How do fluoroquinolones like ciprofloxacin target bacteria?
DNA gyrase inhibition
What’s given for suspected bacterial meningitis in the community if penicillin allergic?
IV/IM cefotaxime
What is chloramphenicol used for?
Meningitis caused by H. influenzae, N. meningitidis, and/or S. pneumoniae
Rickettsia infections (e.g., Rocky Mountain spotted fever caused by Rickettsia rickettsii)
What are glycopeptide Abx like vancomycin used for?
Is effective against a wide range of gram-positive bacteria only
MRSA
S. epidermidis
Enterococci (if not vancomycin resistant enterococci)
C. difficile (causing pseudomembranous colitis): administered orally
What are the risks and contraindications of aminoglycosides like gentamicin?
Adverse effects
- Nephrotoxicity
- Ototoxicity and vestibulotoxicity (risk of ototoxicity is higher when used concurrently with loop diuretics) resulting in: tinnitus, ataxia, vertigo
- Bc of toxicity risks and narrow therapeutic window, need to measure levels 6-14hrs after first dose
- Neuromuscular blockade
- Teratogenicity
Contraindications Myasthenia gravis Botulism Pregnancy Cautious use in patients with renal dysfunction
SEs of tetracyclines?
Nausea, diarrhoea, vomiting
Photosensitivity
What is co-trimoxazole? Give an example of what it’s used for
Trimethoprim and sulfamethoxazole
Used in PCP
What’s given for suspected bacterial meningitis in the community?
Single dose of IV/IM parenteral benzylpenicillin ASAP
<1yo 300mg
1-9yo 600mg
>9yo 1200mg
Give 3 examples of macrolides
Erythromycin
Clarithromycin
Azithromycin
What are the risk of cephalosporins?
Potential cross-reactivity in patients with penicillin allergies (the rate is low even in patients with allergy to penicillin)
Autoimmune hemolytic anemia (AIHA)
Vitamin K deficiency, which increases the risk of bleeding
Disulfiram-like reaction, especially when consumed with alcohol (flushing, tachycardia, hypotension)
Increases nephrotoxic effect of aminoglycosides when administered together with cephalosporins
Neurotoxicity (can lower seizure threshold)
Side effects and CI of dapsone
Adverse effects Methemoglobinemia Triggers hemolytic anemia in patients with G6PD deficiency Agranulocytosis GI upset Peripheral neuropathy
Contraindications
G6PD deficiency