Antibiotics for UTI, CAP, and HAP

Flashcards covering antibiotic classes, dosages, mechanisms of action, and adverse effects for URI, CAP, and HAP treatment.

What is the mechanism of action of Glycopeptides like Vancomycin?

Binds to D-alanine on NAM and NAG to prevent/inhibit transglycosylases from forming glycosidic bonds between subunits to form peptidoglycan strands

Which Gram-positive organisms are covered by Vancomycin?

Staphylo-, Strepto-, and Enterococcus (including MRSA).

What side effect is specifically associated with IV administration of Vancomycin?

Red Man Syndrome.

What are the two specific toxicities associated with Vancomycin use?

Nephrotoxicity and Ototoxicity.

For which condition is oral (PO) Vancomycin exclusively used?

CDAD (Clostridium difficile-associated diarrhea), specifically for intestinal infections.

Which sub-class of antibiotics requires monitoring due to a narrow Therapeutic Level (TL)?

Aminoglycosides (AGs).

What is the primary target of Penicillins in inhibiting the cell wall?

Transpeptidases.

Which narrow-spectrum penicillin covers only Streptococcus spp. (+)?

Penicillin VK.

What is the specific spectrum of activity for Cloxacillin?

Streptococcus spp. (+).

What ingredients are contained in Augmentin?

Amoxicillin and Clavulanic acid (C.acid).

What is the dosing for Augmentin in severe infections?

$1\,g$ BD for $5-7$ days.

What is the treatment duration for Augmentin in cases of pyelonephritis?

$10-14$ days.

Which Gram-negative organisms are covered by Amoxicillin and Augmentin?

H.influenzae, E. coli, and P.mirabilis.

Which antibiotic is described as an 'anti-pseudo' penicillin?

Tazocin (IV).

What are the common GI adverse effects for Penicillins?

$N/V/D$ and abdominal discomfort.

How should probiotics be administered in relation to antibiotics like Augmentin?

Space them $2\,h$ apart.

What is the counseling instruction regarding food for Penicillins?

Take AFTER food.

What is the mild/moderate dose of Augmentin according to Page 2?

$625\,mg$ BD for $5-7$ days.

Which Carbapenem is associated with decreasing the effectiveness of anti-seizure medications like Sodium Valproate?

All affect the effectiveness/efficacy of anti-seizure medications like Sodium Valproate.

Which anaerobe is covered by Imipenem and Meropenem?

Bacteroides fragilis.

Carbapenems are indicated for which type of Gram-negative resistance?

ESBL (Extended-spectrum beta-lactamase).

Which drug-drug interaction is noted for Carbapenems regarding seizure medication?

Sodium Valproate.

Which specific Carbapenem is an exception for treating complicated UTIs?

Ertapenem (Erta).

Which organism does Ertapenem NOT cover compared to other Carbapenems?

P.aeruginosa.

What are the generation 1 (G1) Cephalosporin examples and their routes?

Cefalexin (PO) and Cefazolin (IV).

What is a signature adverse effect for G1 Cephalosporins?

Haemolytic Anemia.

What is the dosing for Cefuroxime (G2 Cephalosporin)?

$250-500\,mg$ BD for $5-7$ days.

What are the examples of Generation 3 (G3) Cephalosporins?

Ceftriaxone (IV) and Ceftazidime (IV).

What does the acronym 'SHEEP' represent for G3 Cephalosporin coverage?

S.pneumoniae (+), H.influenzae, E. coli, P.aeruginosa.

Which toxicities occur in Cephalosporins above the 3rd generation?

Hepatoxicity and Neurotoxicity.

Which antibiotic is a Generation 4 (G4) Cephalosporin administered orally (PO)?

Cefepime.

What is the indication for Ceftaroline (G5 Cephalosporin)?

For MRSA with no alternatives; coverage includes SHEEP + MRSA.

What acronym is used to remember Aminoglycosides?

“America’s Got Talent”.

What is the mechanism of action of Aminoglycosides?

Inhibits $30S$ ribosomal unit (Bacteriostatic).

Which Aminoglycoside is indicated for HA (Hospital-Acquired) UTIs?

Gentamicin.

Aminoglycosides have a synergistic effect when used with which other class?

Beta-Lactams (BLs).

Which class of drugs interacts with Aminoglycosides to increase nephrotoxicity?

NSAIDS.

What is the requirement for spacing eye drops for Tobramycin?

Space each drop $5$ minutes apart.

How long should eye drops be spaced from ointments or suspensions?

$10$ minutes apart.

What is the absorption percentage range for G1 Tetracyclines?

$$75\% - 85\%$.

What is the MOA of Tetracyclines?

Inhibits $30S$ ribosomal unit (Bacteriostatic).

Why do Tetracyclines cause Musculoskeletal (MSK) retardation?

Due to chelation.

What rare hematological ADR is associated with Tetracycline G1?

Blood Dyscrasias (low WBC/RBC/platelet).

How should Tetracycline G1 be taken to avoid esophageal irritation?

With a full glass of water, sitting upright for $30$ minutes, on an empty stomach.

What is the absorption rate of Doxycycline on an empty stomach?

$$95-100\%$.

What is the standard dose for Doxycycline?

$100\,mg$ BD.

What does the acronym 'He Should Call Me Later' for Doxycycline represent?

Atypicals: Chlamydial spp., Mycoplasma spp., Legionella spp.

What acronym is used for Doxycycline indications?

CAS T (CAP, Acne, STIs).

Which Generation 3 Tetracycline is used for A.baumannii infections?

Tigecycline.

What enzyme can inactivate Macrolides?

Esterases.

What is the MOA of Azithromycin according to the transcript?

binds to P-site of the 50S ribosomal subunit to prevent ribosome formation and prevent t-RNA from forming peptide bonds to form peptide chains which fold into proteins eventually

Which anaerobe is mentioned under Macrolide coverage?

Peptostreptoccocus.

What unique sensory side effect is caused by Macrolides?

Dysguesia (metallic taste/lack of taste).

Which cardiac abnormality is caused by both Macrolides and Fluoroquinolones?

QTc Prolongation.

Which Macrolide is a stronger CYP3A4 inhibitor?

Clarithromycin.

What is the half-life of Azithromycin compared to Clarithromycin?

Azithromycin has a longer $t_{1/2}$.

What is the dose and duration of Clarithromycin for CAP?

$500\,mg$ BD for $7$ days.

Which Macrolide undergoes the first-pass (FP) effect?

Clarithromycin.

What is the non-antibiotic use for Erythromycin?

Prokinetics for GI management.

What is the mechanism of action of Clindamycin?

Inhibits $50S$ ribosomal unit.

Clindamycin is indicated for which types of infections?

Gram +ve SSTIs, Infective Endocarditis, Osteomyelitis, and Intra-abdominal infections (anaerobes).

What is the MOA of Fusidic Acid (Fusicidic Acid) in the eye?

Inhibits the “E” site of the $50S$ subunit.

What local adverse effects can Fusidic Acid cause?

Temporary eye irritation, burning, and erythema.

Where should Chloramphenicol be stored and when should it be discarded?

Stored in the fridge at $2-8$ degrees and discarded after $4$ weeks of opening.

What is the MOA of Chloramphenicol?

Inhibits the “P” site of the $50S$ subunit to prevent peptide bond formation.

Which deficiency contraindicates the use of Chloramphenicol?

G6PD deficiency.

What is the MOA of Linezolid?

Interferes with $23S$ in the $50S$ ribosomal unit and disrupts DNA translation.

What is a major hematological concern with Linezolid use?

Thrombocytopenia.

Linezolid can cause Optic Neuritis if used for longer than how many weeks?

$4$ weeks.

Which psychiatric-related syndrome is a risk when taking Linezolid?

Serotonin Syndrome.

What is the MOA of Sulfonamides (S) and Trimethoprim (T)?

S: Acts on dihydropteroate synthase; T: Acts on dihydrofolate reductase.

What renal adverse effect is associated with Sulfonamides?

Crystalluria.

What is the dose of Bactrim (Trimethoprim/Sulfonamide) for UTI?

$960\,mg$ BD for $3-7$ days.

What is the duration of Bactrim treatment for pyelonephritis?

$14$ days.

What can be used to overcome the folate blockage caused by Sulfonamides?

Leucovorin.

Sulfonamides taken with ACE inhibitors can lead to which electrolyte disturbance?

Hyper Na+ (Hypernatremia).

What birth defects are associated with Sulfonamides?

Neural tube defects, CV malformations, and UT defects.

Why do Sulfonamides not affect human folate pathways?

Due to other existing folate pathways in humans.

What is the mechanism of action for Metronidazole?

DNA strand breakage through reduction of $NO_2$ to free radicals, halting transcription and translation.

Metronidazole is the treatment of choice for which anaerobe and amoebas?

Clostridium difficile, H. pylori, Entamoeba Histolytica, and Trichomonas vaginalis.

What side effect is shared by Metronidazole and Macrolides?

Dysguesia (metallic taste).

What effect does Metronidazole have on urine?

Causes dark urine.

What drug-drug interaction must be avoided with Metronidazole?

Alcohol (due to Disulfiram-like reaction).

How should Metronidazole be taken in relation to food?

Take AFTER food.

What is the MOA of Fluoroquinolones?

Inhibit DNA gyrase, causing supercoiled DNA stress and truncated transcription/translation.

What is the name of the Generation 1 Fluoroquinolone?

Nalidixic Acid.

What are the common skeletal and CNS side effects of Fluoroquinolones?

Arthralgia (joint pain), Tendonitis, Dizziness, and Headache.

What is the dose for Ciprofloxacin (Gen 2 Fluoroquinolone)?

$250\,mg$ BD.

What is the duration of Ciprofloxacin for pyelonephritis?

$7$ days ($3$ days for simple UTI).

Which Gen 3 Fluoroquinolone covers Mycobacterium TB and Bacteroides fragilis?

Levofloxacin.

What is the dose and duration of Levofloxacin?

$750\,mg$ OD for $7$ days.

What is the dosing for Nitrofurantoin?

$50-100\,mg$ TDS/QDS for $3-5$ days.

In which trimester is Nitrofurantoin contraindicated?

The 3rd trimester.

Why is Nitrofurantoin not used for pyelonephritis?

Due to inadequate MIC (Minimum Inhibitory Concentration).

What is the single-dose treatment for UTI using Fosfomycin?

$3\,g$ OD.

What is the MOA of Fosfomycin?

Inhibits the enzyme that forms NAM in bacterial cell wall peptidoglycan.

Why is a single dose of Fosfomycin sufficient for UTI?

The drug stays above the MIC for $2-4$ days.

Which drug is mentioned as the only one that can treat ESBL in the urinary antiseptic section?

Fosfomycin.

How should Fosfomycin be taken in relation to food?

Taken on an empty stomach ($1\,h$ before or $2\,h$ after food).

What is the primary indication for G4 Cefepime according to the transcript?

SSTI/HAP + Sepsis.