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Which Penicillins are effective against Staphylococcus aureus and Staphlococcus epidermidis producing penicillinase?
Nafcillin and Oxacillin (penicillinase resistant pinicllins)
Which penicllins are most effective against most common streptococci and H influenzae, Proteus, E. coli, Proteus mirabilis, Salmonella and Shigella?
Ampicillin and Amoxicillin (aminopenicillins)
Which penicillins have improved activity against many gram-negative bacillary pathogens (Pseudomonas and Klebsiella)?
Piperacillin and Ticarcillin (expanded spectrum/antipseudomonal)
Which penicillins are used to cover common upper respiratory tract infections due to streptococci or prophylaxis of rheumatic fever or history of cardio valve damage (prior to major or even minor [dental procedures] surgeries)?
Pen G and V
Which penicillins are used to treat systemic infections due to staphylococci?
Nafcillin and Oxacillin (penicillinase resistant)
Which penicillins are used to treat pharyngitis and otitis media which are common upper respiratory tract infections in children due to streptococci or H. influenzae. They also cover some simple urinary tract infections and some serious gastroenteritis due to Salmonella or Shigella?
Ampicillin and Amoxicillin (aminopenacillins)
Which penicillins are reserved for systemic gram-negative bacillary infections?
Piperacillin and Ticarcillin (expanded stectrum)
Name some of the toxicities associated w/ penicillins.
- 1. Hypersensitivity (1-10%)
- 2. Idiopathic skin rash (4-8% with ampicillin
- 3. Diarrhea-typically seen with broader spectrum penicillins especially when given orally 4. Seizures
- 5. Irritating-pain at muscular injection site or phlebitis with IV
- 6. Alterations in platelet function and bleeding problems with some extended spectrum penicillins (e.g., piperacillin)
Which drug should never be mixed w/ penicillins?
Aminoglycosides (exception: can combine antipseudomonal penicillins with aminoglycosides to enhance activity vs. Pseudomonas)
Which cephalosporins are good vs. gram (+) including staphylococci, plus moderate activity vs. gram (-) bacteria (e.g., E. Coli, Proteus mirabilis and Klebsiella)?
Which cephalosporins are more active vs. gram (-) bacteria including some H. influenzae and other enteric gram (-) (e.g., E.coli, Klebsiella), plus adequate gram (+) activity?
Cefuroxime, Loracarbef, Cefaclor
Which cephalosporins are more active vs. enteric gram (-) bacilli (Enterobacter, Proteus, Serratia) and resistant to Β- lactamases, but has less antistaphylococcal activity?
Ceftoxime, Ceftriaxone, Cefixime
Which cephalosporins are effective Gram (-) and expanded activity vs. gram (+) cocci and improved resistance against class I Β- lactamases?
Which cephalosporins are effective against serious Klebsiella or Staphylococcal or streptococcal infections when penicillin is not effective?
Which cephalosporins are active against gram (-) bacteria and may be used for serious gram (-) infections due to Β-lactamase producing organisms, especially respiratory and middle ear infections due to H. influenzae?
Cefuroxime, Loracarbef, Cefaclor
Which cephalosporins are a good alternative for mixed infection caused by hospital-acquired gram (-) or gram (+) bacteria, especially if antibiotic resistance is due to extended spectrum Β-lactamases?
Name the adverse effects of cephalosporins?
- Hypersensitivty -occurs in less than 2%; cross sensitivity with penicillins 3-7% (some estimates up to 16%)
- GI -usually diarrhea, occasionally more severe
- Potential renal damage -especially in elderly or patients with compromised renal function
- Coagulation abnormalities -may lead to severe bleeding
What is unique about Clavulanic Acid, Sulbactam? [Clavulanate + amoxicillin (Augmentin), Clavulanate + ticarcilliin (Timentin), Sulbactam + ampicillin (Unasyn)]
- Inactivates most (but not all) Β-lactamases of Staph aureus and some gram (-) bacteria
- Nonreversible binding at active site of the Β-lactamase
- Does not work against all Β-lactamases (e.g., Pseudomonas, Enterobacter)
- Poor intrinsic antibacterial activity, so these inhibitors are combined with Β-lactam antibiotics
Which drugs fit the following description?
Features: Most gram (+) & gram (-) anaerobes; These drugs are typically reserved for serious nosocomial infections due to suspected (or known) strains of resistant bacteria such as: bacteremias, respiratory tract infections or UTIs caused by resistant pathogens. Adverse Effects: GI reactions include nausea and vomiting; Super infections (diarrhea)
- CARBAPENEMS ==>Imipenem + cilastatin (Carbapenem) and Aztreonam (Azactam)
- Aztreonam differs from other Β-lactams in its antimicrobial activity and looks more like aminoglycosides without activity against gram (+) bacteria or anaerobes and relatively selective against gram (-) (Imipenem only available as combination with “cilastatin” to inhibit renal metabolism and the formation of nephrotoxic metabolites)
Which cell wall synthesis inhibitor is of Bacterial origin, often considered a drug of “last resort” given i.v. for life-threatening resistant gram positive bacteria (e.g., MRSA), especially in situations of penicillin-resistance and serious Β-lactam allergies; Resistance is becoming a problem and is being replaced by carbapenems. Toxcities: (i) painful infusion; (ii) nephrotoxicity and ototoxicity-however, recent studies have been less convincing, suggesting that ________ when used alone and properly is not as likely to affect kidney function and hearing as once thought.
Which bacterial derived antimicrobial is commonly found in OTC topical antibacterial ointments?
__________ each attach to the 30s subunit blocking the attachment of the amino-acyl tRNA.
Tetracyclines (doxycyline, minocycline, tetracycline)
________ attaches to the 50s subunit blocking transpeptidation and chain elongation.
________ attach to the 50s subunit blocking translocation of the peptide-bearing tRNA from A to P.
__________ are effective against a wide variety of gram-positive and gram-negative bacteria plus Rickettsia, Mycoplasma Chlamydia, Legionella and spirochetes, but their use is largely restricted due to increasing bacterial resistance and availability of other drugs with lower toxicity and/or less potential for causing superinfections. One of ______ main uses is to treat pneumonia caused by pathogens not readily treated with other drugs (Chlamydia, Mycoplasma, Legionella).
Tetracycline (doxycycline, minocycline, tetracycline)
What are the adverse effects of tetracyclines?
GI, photosensitivity, hepatotoxicity, vestibular, superinfections, Renal (doxy is preferred to mino because it lacks mino’s significant vestibular toxicities)
____________ is the safest for renal impaired patients.
________ is very similar to doxycycline, but it is broader spectrum. It is to be conserved to decrease development of resistance.
________ is a broad-spectrum antibiotic much like that of tetracyclines but it is not used for any but the most severe infections because of its toxicities. Because of its toxicities, it is almost exclusively used as a backup to other antimicrobial drugs.
What are the adverse effects of Chloramphenicol?
Myelosuppression, aplastic anemia (can be fatal), Gray baby syndrome, superinfections, blurred vision, and more.
_______ has low GI toxicity, but is a strong CYP3A4 inhibitor resulting in many drug interactions. It also crosses the placenta and enters breast milk.
________ is similar to erythromycin, but it doesn’t have the GI toxicity or inhibit CYP3A4. It also has expanded antimicrobial activity.
__________ is similar to azithromycin, but it is more active against gram + bacteria, and less active against gram – bacteria. It also inhibits CYP3A4 and can prolong QT interval (can cause fatal arrhythmias)
What are the side effects associated w/ tetracyclines?
- Bone discoloration
What is the mechanism of action for tetracyclines?
TCs are bacteriostatic; they inhibit protein synthesis by attaching to the 30s ribosome subunit and blocking the binding of amino-acyl-tRNA to the mRNA-ribosome complex.
What is the mechanism of action of chloramphenicol?
CA is primarily bacteriostatic but might be bactericidal against highly susceptible strains (H. influenzae, N. meningitidis, or S. pneumonia). It inhibits protein synthesis by binding to the 50s ribosomal subunit at the peptidyltransferase site and blocking transpeptidation and peptide chain elongation. CA’s binding site is near that of clindamycin and the macrolides with the result that these antibiotics would interfere with that of CA.
What is the mechanism of action of macrolides?
The macrolides are bacteriostatic and inhibit protein synthesis by binding to the 50s ribosomal subunit. MACs block the translocation of the tRNA with the growing peptide chain to an adjacent location on the ribosome which frees up the site where the next amino-acyl-tRNA will bind.
Name the drug.
Binds 30s & 50s but is O2 dependent for transport into cells.
Primarily gram -, pseudomonas (synergistic G+ w/ B-lactams)
Increasing the dosing interval is necessary w/ renal insufficiency
Renal and Oto toxicity
- Gentamicin, tobramycin, streptomycin amakacin
Name the drug.
Target: 50s (same location as erythromycin)
Effective against G- & G+ anaerobes (a. fragilis)
exhibits cross resistance w/ macrolides
Unchanged drug in feces => c. dificile => diarrhea & pseudomembranous colitis
Name the drug
G+ anaerobes, G+, atypical pneumonias and E. faceum
effective against MRSA (nosocomial infections)
Name the drug.
50s (unique 23s binding site)
G+ anaerobes, G+ (no cross resistance)
100% oral distribution
can cause mild myelosuppression
Effective against MRSA, resistant staphs and streps, Vancomycin resistant enterococci
Which Ig is associated with histamine release?
What are the effects of histamine on H1 receptors?
vasodilation, increased capillary permeability, smooth muscle contraction,
Are drowsiness, anti-cholinergic effects, and CNS effects characteristic of 1st or 2nd generation antihistamines?
1st (diphenhydramine--Benadryl, and dimenhydrinate--Dramamine)
What are the key 2nd generation antihistamines and what is different about them than 1st generation?
- Fexofenadine (allegra)
- Loratadine (Claritin, CYP3A4 inhibitor)
- Desloratadine (clarinex)
- Cetirizine (zyrtec, can cause drowsiness)
Generally they are similar to 1st gen. w/out the side effects. NOT effective in treating asthma
Which antihistamines are not subject to drug interactions? (not metabolized by CYP)
Name the antitussive.
NMDA receptor antagonist
Can cause drowsiness, dizziness, resp. depression, nausea/vomiting, cramping
Not good for kids
should not be taken w/ MAOIs, SSRIs, SSNRis, TCAs, opiates, or CNS depressants
Which cough medicine should not be taken by patients with renal dysfunction?
Name the decongestant.
Many adverse effects: CV, CNS stimulation, metabolic acidosis, muscle weakness, decreased renal output, respiratory depression
Should not be taken by Pts w/: diabetes, CV dz, hypertension, prostatic hypertrophy, hyperthyroidism, glaucoma, pregnancy, anxiety, bipolar disorder,
Name the decongestant.
post-synaptic alpha-adrenergic effects
vasoconstriction (decreased cardiac output)
Adverse effects: upset stomach, trouble sleeping, dizziness, headache, nervousness, shaking, tachycardia, arrythmia
Pt's that should not take: blood vessel problems, high BP, diabetes, glaucoma, heart dz, mental/mood disorders, hyperthyroidism
Less CNS stimulation than psuedophedrine
What is the drug in nasal sprays?
oxymetazoline (should not be taken for more than 3 days)