Pharmacology of Antibiotics Flashcards
What ADRs are associated with sulfa antibiotics?
Rashes, crystalluria, Steven-Johnson syndrome
The B-lactamase inhibitor clavulanic acid is combined with what drug for effective treatment?
Amoxicillin
What are the common Marcolides?
Azithromycin, Clarithromycin, Erythromycin
How is Moxifloxacin eliminated?
Via the liver
What are the fourth-generation Cephalosporins?
Cefepime, Cefpirome, Cefditoren
When should Daptomycin not be used?
Pneumonia, with combined statin use
Ceftolozane is used in what cases?
Severe pseudomonas infection
True/False. Bacteriostatic antibiotics are less effective in patients without an intact immune system.
True. Bacteriostatic antibiotics only inhibit growth and require a strong immune response to kill and clear bacteria.
What Macrolide is capable of penetrating the biofilm of bacteria?
Clarithromycin
With what drug should calcium not be simultaneously administered?
Ceftriaxone - salt formation and organ damage
C. diff infection is an ADR of this antibiotic due to its concentration in bile.
Clindamycin - should be avoided in elderly & nursing patients
What are the clinical indications for the use of a Carbapenem?
Drug-resistant hospital-acquired infections, polymicrobial infections, G+/G- aerobes/anaerobes, neutropenic patients
What sufla antibiotic combination may be used for the treatment of MRSA?
Trimethoprim/Sulfamethoxazole
What are the most common Generation 3 Cephalosporins?
Cefdinir, Ceftriaxone, Cefixime, Ceftazadime
What is the MOA of sulfa antibiotics?
Blocks folate synthesis
Where is metronidazole metabolized?
Liver
What is the MOA of Nitroimidazoles?
DNA fragmentation
Erythromycin is indicated for use against what bacteria?
G+ aerobes, no effectiveness against G- and anaerobes
What drug is used orally to treat diarrhea associated with C. diff in adults?
Fidaxomycin
What adverse effects are most associated with B-lactams?
Immediate, severe - Anaphylaxis
Delayed, mild - rash & maculopapular rash (children)
What adverse reaction is most associated with piperacillin?
Thrombocytopenia - low platelet count
What antibiotic is contraindicated in patients taking an SSRI due to the potential of serotonin syndrome?
Linezolid
Milk, antacids, and iron should be avoided when taking what class of antibiotics?
Tetracyclines
What adverse effects are associated with vancomycin?
Red man syndrome, nephrotoxicity, ototoxicity
A 5yo child develops a rash after starting amoxicillin to treat strep pharyngitis. The physician decides to switch the patient to another B-lactam drug. What is the most likely candidate?
Cefdinir (Generation 3 Cephalosporin) - broad-spectrum, highly resistant to B-lactamases, effective in children
What is the drug of choice for syphilis treatment?
Penicillin G
What drug classes are protein synthesis inhibitors?
Lincosamides, Macrolides, Tetracyclines, Aminoglycosides
True/False. Aminoglycosides should only be administered via IV.
True, oral forms are ineffective
How is Ceftriaxone metabolized and excreted?
Metabolized in the liver and excreted in bile - drug recommended for renal impaired patients
What categories of antibiotics inhibit cell wall synthesis?
B-lactams & glycopeptides
Why is Cilastatin used in combination with Imipenem?
Prevents Imipenem metabolism into a toxic metabolite by the kidney, decreasing renal clearance and nephrotoxicity
What penicillin drugs may be used to treat MSSA?
Oxacillin
Nafcillin - severe
Dicloxacillin - mild to moderate
What effect will antacids and dairy products have on Levofloxacin?
Decrease bioavailability by reducing absorption
Doxycycline is indicataed for the treatment of…?
CLARA The Stupid CAT
Chlamydia, Lyme Disease, Anthrax, Rickettsia, atypical Pneumonia, Trachomonatis, Staph aureus, Cholera, Acne, Traveler’s Diarrhea
What ADRs are associated with tetracyclines?
Phototoxicity, teeth discoloration, GI discomfort, chelation with Ca2+
What are the common Marcolides?
Azithromycin, Clarithromycin, Erythromycin
What are the two mechanisms of action for bacteriocidal antibiotics?
Inhibit cell wall & DNA synthesis
What ADRs are associated with Macrolides?
Liver enzyme inhibitor, QT prolongation
Neurotoxicity is an adverse drug reaction associated with what B-lactam drug?
Cefepime (4th generation Cephalosporin)
What are the clinical indications for use of a Third Generation Cephalosporin?
Multi drug-resistant G- infection & hospital-acquired infections
Metronidazole & Tinidazole can be used against what pathogens?
Anaerobic bacteria & protozoa (except malaria)
Ceftazadime may only be delivered via IV. What bacterial infection is it usually used to treat?
Pseudomonas
Antibiotics with what MOA are indicated in immunocompromised patients?
Bacteriocidal - inhibit cell wall & DNA synthesis
What adverse effects are associated with Moxifloxacin?
Chondrotoxicity, aneurysm, QT prolongation, glycemic fluctuations, phototoxicity
What ribosome subunit is targetted by Lincosamides & Macrolides?
50S
How are most 3rd generation Cephalosporins administered?
IV
What are the most common Generation 1 Cephalosporins?
Cephalexin & Cefazolin
What is the MOA of Daptomycin?
Cell membrane inhibitor
What Macrolide is contraindicated in pregnant women?
Erythromycin
How does the MOA of glycopeptides differ from B-lactams?
Inhibit transglycosylation in cell wall synthesis instead of binding to the transpeptidase
What are the contraindications for the use of tetracyclines?
Pregnancy, women who are nursing, infants, children,
Fourth-generation Cephalosporins are reserved for use when?
Multi-drug resistant infections, pseudomonas, G- bacteria, immunocompromised patients
Metronidazole use is contraindicated in what patients?
Alcoholics, patients on lithium or warfarin, patients in their first trimester of pregnancy
How are most B-lactams excreted?
Kidney
Penicillin VK is the drug of choice for what disease?
Strep pharyngitis
What third generation Cephalosporin may be used against respiratory infections, UTIs, & gonorrhea?
Cefixime
What are the commonly used Carbapenems?
Imipenem, Meropenem, Ertapenem
What B-lactamase inhibitor is combined with piperacillin for effective treatment?
Tazobactam
What are the common aminoglycosides?
Gentamycin, amikacin, tobramycin, streptomycin
What adverse effects are associated with metronidazole?
Metallic taste, brown-red urine, nausea, psychosis, disulfiram-like reaction
What Monobactam is used as a first-aid ointment against G+ cocci?
Bacitracin
Imipenem is not used in children. Why is this?
Can cause seizures in children
What is the penicillin drug of choice to treat Pseudomonas?
Piperacillin with tazobactam
What penicillin drugs may be used to treat MSSA?
Oxacillin
Nafcillin - severe
Dicloxacillin - mild to moderate
What Fluoroquinolone is not indicated for use in renal or urinary infections?
Moxifloxacin - indicated for anaerobes
What is a common adverse effect of Ceftriaxone use?
Bile stones & induration after injection
What are the clinical indications for Ciprofloxacin use?
Pseudomonas, anthrax, complicated UTIs & STIs
How are the uses of Generation 2 Cephalosporins differentiated?
Cefuroxime generally treats severe infections above the waist, while Cefoxitin treats infections below the waist
What B-lactam drug is indicated in patients with a B-lactam allergy infected with a G- aerobe?
Aztreonam (Monobactam)
What classes of drugs are B-lactams?
Penicillins, Cephalosporins, Carbapenems, Monobactams
What penicillin antibiotic is safe for use during pregnancy and breast feeding?
Ampicillin
What is a major contraindication for the use of a sulfa antibiotic?
Allergy, pregnancy
What Carbapenem is most effective against Enterobacteriaceae?
Meropenem
True/False. The effectiveness of Cephalosporins against G+ bacteria increases with each generation.
False. Generation 1 Cephalosporins are very effective against G+ bacteria, but this decreases with each generation as effectiveness against G- bacteria increases
What is the most common side effect of erythromycin?
GI disturbances due to increased peristalsis
Moxifloxacin has good activity against what type of bacteria?
Anaerobes
What is the MOA of Fluroquinolones?
Binds to the bacterial topoisomerase to inhibit DNA synthesis
What adverse reaction is most associated with piperacillin?
Thrombocytopenia - low platelet count
The kidney excretes most B-lactams. What are the exceptions to this?
Nafcillin - bile excretion
Moxifloxacin - liver excretion
What are the clinical indications for Vancomycin use?
Severe G+ infection, MRSA, B-lactam allergy, prophylaxis
What tetracycline should be administered via IV?
Tigecycline
What are the 4 MOA for antibiotics?
Inhibit cell wall synthesis
Inhibit DNA/RNA synthesis
Inhibit folate synthesis
Inhibit protein synthesis
What are the most common glycopeptides?
Vancomycin, Telavancin, Bacitracin
What ADRs are associated with aminoglycosides?
Renal toxicity & ototoxicity
Amoxicillin is used for the treatment of what?
Strep pharyngitis (in children) & acute otitis media
Clindamycin is recommended for treatment of infections caused by what types of bacteria?
G+ cocci & anaerobes, generally infections above the diagphragm
What B-lactamase inhibitor is combined with ampicillin for effective treatment?
Sulbactam
Clindamycin belongs to what drug class?
Lincosamides
What are the most common Generation 2 Cephalosporins?
Cefuroxime, Cefoxitin
What is the MOA of Fidaxomycin?
Binds to the RNA polymerase to inhibit RNA synthesis
What is the effect of Probenecid on B-lactams?
The half-life of B-lactams is prolonged and the dose must be reduced
What is the only B-lactam antibiotic with coverage against MRSA?
Ceftaroline (5th generation Cephalosporin)
Describe the PK of B-lactams.
Short half-life with good tissue distribution, kidney elimination
What is the MOA of B-lactam antibiotics?
Bind to transpeptidase (PBP) to prevent cross-linkage of the peptidoglycan wall
Aminoglycosides are indicated for the treatment of infections by what bacteria?
G- aerobes
What antibiotic is associated with the ADR gray baby syndrome?
Chloramphenicol
What penicillin can be administered only via IV or IM?
Penicillin G. Only Penicillin VK can be administered PO
What classes of drugs are DNA synthesis inhibitors?
Nitroimidazoles - Metronidazole, Tinidazole
Fluoroquinolones - Ciprofloxacin, Levoflaoxacin, Moxifloxacin
How is Clindamycin metabolized?
By the liver and excreted in feces
What antibiotics are often used for surgical prophylaxis?
Generation 1 Cephalosporins - Cephalexin & Cefazolin
What ribosome subunit is targetting by Tetracyclines & Amingoglycosides?
30S
A patient is diagnosed with a mycoplasma infection. What antibiotic is relatively cheap and extremely effective for treatment?
Azithromycin
What are the contraindications for the use of tetracyclines?
Pregnancy, women who are nursing, infants, children
Cephalexin & Cefazolin are most effective against what types of bacteria?
Staph & strep, skin infections, aerobes (NO anaerobic coverage)
A patient is prescribed a Cephalosporin to treat meningitis. Soon after, they develop eosinophilia, decreased Hb, nausea, and vomiting. What Cephalosporin were they likely prescribed?
Cefuroxime (Generation 2)
Methicillin-sensitive staph infections may be treated with what penicillin drugs?
Nafcillin, oxacillin, dicloxacillin
Nafcillin, oxacillin, and dicloxacillin are most commonly used to treat…?
Mild to moderate staph infections that are methicillin-sensitive (systemic staph, osteomyelitis, endocarditis)
Sepsis, pseudomonas, and hospital-acquired pneumonia can all be treated with what penicillin drugs?
Ticarcillin & Piperacillin
Steven-Johnson Syndrome is associated with what drug class?
Aminopenicillins
Amoxicillin is most commonly used to treat…?
Strep pharyngitis, acute otitis media, lyme disease, sinusitis, H. pylori
What is the only Cephlasporin effective against Mrs.A?
Ceftaroline
What is the empiric treatment of gonorrhea?
Ceftriaxone, IM administration
What Cephlasporin is the empiric treatment for meningitis?
Ceftriaxone
What Cephalosporin is used as surgical prophylaxis?
Cefazoline, Cephalexin
What antibiotic classes bind the 30S ribosomal subunit?
Tetracyclines & aminoglycosides