PHM 516: Antimicrobial Agents

This flashcard set covers key antimicrobial agents from the PHM 516 (MOST V) course, including antibacterial, antiviral, antifungal, and antiprotozoal medications. Organized by mechanism of action, drug class, and clinical use, it includes: Core drug names (both brand and generic) Formulation routes (IV, PO, topical, etc.) Spectrum of activity (e.g., MRSA, Pseudomonas, C. diff) Combo-only and TOP 250 designations Special agents for UTIs, infectious diarrhea, COVID-19, and more Perfect for rapid review, board prep, and pharmacology exams.

50s Ribosomal Subunit

Protein synthesis target for macrolides, lincosamides, etc.

Macrolides

Inhibit 50s; used in respiratory and STIs

Erythromycin

PO/IV; GI side effects; older macrolide

Azithromycin (Zithromax)

Long half-life; respiratory, chlamydia

Clarithromycin (Biaxin)

Macrolide; H. pylori and respiratory

Lincosamides

Inhibit 50s; anaerobes and Gram+ coverage

Clindamycin (Cleocin)

Lincosamide; anaerobes, MRSA, risk of C. diff

Streptogramin

Inhibit 50s; used in combo (Synercid)

Quinupristin/Dalfopristin (Synercid)

IV only; Gram+ resistant infections

Oxazolidinone

Inhibit 50s; treat MRSA, VRE

Linezolid (Zyvox)

PO/IV; MRSA, VRE, serotonin syndrome risk

Tedizolid (Sivextro)

Oxazolidinone; once-daily dosing

Pleuromutilin

Inhibit 50s; used for skin infections

Lefamulin (Xenleta)

PO/IV; community-acquired pneumonia

Folate Synthesis

Pathway targeted by TMP/SMX to inhibit bacterial growth

Trimethoprim

PO; UTIs; folate inhibitor

Trimethoprim/Sulfamethoxazole (Bactrim)

PO/IV; broad-spectrum folate inhibitor

Metronidazole (Flagyl)

Anaerobes & protozoa; avoid alcohol

DNA Synthesis

Target for antibiotics like fluoroquinolones

Fluoroquinolones

Inhibit DNA gyrase/topoisomerase

Ciprofloxacin (Cipro)

PO/IV; UTI, Pseudomonas

Levofloxacin (Levaquin)

PO/IV; respiratory infections

Moxifloxacin (Avelox)

PO; respiratory use, not for UTI

Ofloxacin

Older; limited use

Gatifloxacin (Zymaxid, Zymar)

Ophthalmic use

Besifloxacin (Besivance)

Ophthalmic fluoroquinolone

Triazaacenaphthylene

Novel DNA synthesis inhibitor

Gepotidacin (Bluejepa)

Oral UTI and STI agent

RNA Synthesis

Target for Rifampin and Rifaximin

Rifampin

PO/IV; TB treatment; CYP inducer

Topical Agents

Drugs applied to skin or mucous membranes

Bacitracin

Cell wall inhibitor; topical only

Polymyxin B

Cell membrane disruptor; topical

Mupirocin (Bactroban)

Protein synthesis inhibitor; MRSA nasal decolonization

Neomycin

Aminoglycoside; topical; Gram–

Retapamulin (Altabax)

Protein synthesis inhibitor for skin

Ozenoxacin (Xepi)

DNA synthesis inhibitor; impetigo

Urinary Tract Antiseptics

Drugs used for treating UTIs

Fosfomycin

Cell wall inhibitor; one-dose UTI

Nitrofurantoin (Macrobid)

Protein synthesis inhibitor; UTI prevention

Infectious Diarrhea

Category for drugs treating diarrhea from infection

Vancomycin (PO)

Cell wall agent; C. diff only

Fidaxomicin (Dificid)

Protein synthesis inhibitor; C. diff

Rifaximin (Xifaxan)

RNA inhibitor; traveler's diarrhea

Nitazoxanide (Alinia)

Antiprotozoal; Giardia/Cryptosporidium

Bezlotoxumab (Zinplava)

Monoclonal antibody; reduces C. diff recurrence

Antiviral Agents

Drugs that inhibit virus replication

Acyclovir (Zovirax)

DNA polymerase inhibitor; HSV/VZV

Oseltamivir (Tamiflu)

PO; neuraminidase inhibitor

Zanamivir (Relenza)

Inhaled; flu treatment

Peramivir

IV; flu treatment

Baloxavir (Xofluza)

Endonuclease inhibitor; single dose for flu

Nirmatrelvir/ritonavir (Paxlovid)

COVID-19 protease inhibitor

CDI

Clostridioides difficile infection

Traveler’s Diarrhea

Infectious diarrhea during travel

Combo Only

Only available in U.S. as combination

TOP 250 medication

Commonly prescribed (marked with *)

PO

Oral administration

IV

Intravenous administration

IM

Intramuscular administration

Penicillins

Beta-lactams; inhibit cell wall synthesis

Natural Penicillins

Penicillin VK, Penicillin G; Gram+ cocci

Penicillin VK (Veetids)

PO natural penicillin; strep infections

Penicillin G

IV natural penicillin

Penicillin G Benzathine/Procaine

IM long-acting natural penicillin

Anti-Staphylococcal Penicillins

Nafcillin, Oxacillin; MSSA coverage

Nafcillin/Oxacillin

IV anti-staph penicillins

Dicloxacillin

PO anti-staph penicillin

Extended Spectrum Penicillins

Broader Gram–; includes ampicillin, amoxicillin

Ampicillin

IV/PO; Gram– and Enterococcus

Amoxicillin (Amoxil)

PO; otitis media, strep, H. pylori

Pivmecillinam (Pivya)

PO for UTIs

Piperacillin/Tazobactam (Zosyn)

Combo only; anti-pseudomonal coverage

Cephalosporins

Beta-lactams grouped by generations

1st Gen Cephalosporins

Best Gram+; used for skin, surgery

Cefazolin

IV; surgical prophylaxis

Cephalexin (Keflex)

PO; skin, UTI

2nd Gen Cephalosporins

Better Gram–; less Gram+

Cefuroxime (Ceftin)

IV/PO; respiratory infections

Cefoxitin/Cefotetan

Anaerobe coverage; surgical use

3rd Gen Cephalosporins

Broad Gram–; some cross BBB

Ceftriaxone/Cefotaxime

IV; meningitis, pneumonia

Cefdinir (Omnicef)

PO; respiratory infections

4th Gen Cephalosporins

Broadest spectrum cephalosporins

Cefepime

IV; Pseudomonas, neutropenic fever

Cefepime/enmetazobactam (Exbliefp)

Combo with beta-lactamase inhibitor

5th Gen Cephalosporins

MRSA coverage added

Ceftaroline (Teflaro)

MRSA-active cephalosporin

Ceftolozane/Tazobactam (Zerbaxa)

Combo for resistant Gram–

Cefobiprole medocaril (Zevtera)

Broad; approved in Europe

Cephalosporin w/Siderophore

Enhanced Gram– uptake

Cefiderocol (Fetroja)

IV; MDR Gram–, including carbapenemase producers

Carbapenems

Broadest beta-lactams; Gram+/–/anaerobes

Meropenem/Doripenem/Ertapenem

IV broad-spectrum carbapenems

Imipenem/Cilastatin

Cilastatin prevents renal metabolism

Penem/Uricosuric

Beta-lactam + uricosuric for oral use

Sulopenem etzadroxil/probenecid (Orlynhv)

PO; combo only

Monobactam

Gram– only beta-lactam

Aztreonam

IV; used in penicillin-allergic patients

β-lactam/β-lactamase Inhibitor Combinations

Broadens beta-lactam activity against resistant bacteria