Penicillin- Penicillin G (IV and IM form)- Penicillin V (oral) Mechanism: D-Ala-D-Ala structural analog- Bind penicillin-binding proteins (transpeptidases)- Block transpeptidase cross-linking of peptidoglycan in ...
Penicillinase-sensitive penicillinsAmoxicillin, ampicillin; aminopenicillins Mechanism: same as penicillin, wider spectrum.- Combine with clavulanic acid to protect against β-lactamase.- Amoxicillin has greater oral bioavailability than ...
Penicillinase-resistant penicillinsDicloxacillin, nafcillin, oxacillin Mechanism: Same as penicillin. Narrow spectrum; penicillinase resistant because bulky R group blocks access of β-lactamase to β-lactam ring. Clinical use: S. aureus ...
β-lactamase inhibitorsOften added to penicillin antibiotics to protect from destruction by β-lactamase (penicillase). CAST- Clavulanic acid- Avibactam- Sulbactam- Tazobactam
Cephalosporins (generations I-V)Mechanism: β-lactam drugs that inhibit cell wall synthesis but are less susceptible to penicillinases. Bactericidal.Organisms typically not covered by cephalosporins are LAME (Listeria, atypicals, MRSA, ...
CarbapenemsImipenem, meropenem, doripenem, ertapenem Mechanism: broad-spectrum, β-lactamase-resistant carbapenem.- Always administered with cilastatin (inhibitor of renal dehydropeptidase I) to ↓ inactivation ...
VancomycinInhibits cell wall peptidoglycan formation by binding to D-ala-D-ala portion of cell wall precursors.- Bactericidal against most bacteria (bacteriostatic against C difficile).- Not susceptible to β-lactamases. ...
AminoglycosidesGentamicin, Neomycin, Amikacin, Streptomycin, Tobramycin(Not daptomycin; interferes with membrane integrity.) Mechanism: Bactericidal- Irreversible inhibition of initiation complex through binding of ...
TetracyclinesTetracycline, doxycycline, minocycline Mechanism: Bacteriostatic- Bind to 30S and prevent attachment of aminoacyl-tRNA- Limited CNS penetration.- Doxycycline is fecally eliminated and can be used in patients ...
ChloramphenicolMechanism: Blocks peptidyltransferase at 50S ribosomal subunit. Bacteriostatic. Clinical use: Meningitis (H influenzae, N meningitidis, S pneumonia) and Rocky Mountain spotted fever (Rickettsia rickettsii).- ...
ClindamycinMechanism: Blocks peptide transfer (translocation) at 50S subunit. Bacteriostatic. Clinical use: Anaerobic infections (eg Bacteriodes spp, Clostridium perfringes) in aspiration pneumonia, lung abscesses, ...
OxazolidinonesLinezolid Mechanism: Inhibit protein synthesis by binding to 50S subunit preventing formation of initiation complex. Clinical use: Gram ⊕ species including MRSA and VRE Adverse effects: Bone marrow ...
MacrolidesErythromycin, azithromycin, clarithromycin Mechanism: Block translocation by binding to the 23S rRNA of the 50S ribosomal subunit. Bacteriostatic. Clinical use: Atypical pneumonias (Mycoplasma, Chlamydia, ...
DapsoneMechanism: Similar to sulfonamides (inhibits dihydropteroate synthase), but structurally distinct agent. Clinical use: Leprosy (lepromatous and tuberculoid), Pneumocystis jirovecii prophylaxis. Adverse ...
TrimethoprimMechanism: Inhibits bacterial dihydrofolate reductase (vs SMX, inhibits dihydrofolate synthase). Bacteriostatic. Clinical use: Used in combination with sulfonamides (trimethoprim-sulfamethoxazole [TMP-SMX]), ...
FluoroquinoloneCiprofloxacin, Enoxacin, Norfloxacin, OfloxacinRespiratory fluoroquinolones – Levofloxacin, Gemifloxacin, Moxifloxacin Mechanism: Inhibit DNA gyrase (topoisomerase II) and topoisomerase IV. Bactericidal. ...
DaptomycinMechanism: Lipopeptide that disrupts cell membrane of gram ⊕ cocci by creating transmembrane channels. Clinical use: S aureus skin infections (especially MRSA), VRE, bacteremia, endocarditis. - Not ...
MetronidazoleMechanism: Forms toxic free radical metabolites in the bacterial cell that damage DNA. Bactericidal, antiprotozoal. Clinical use: Giardia, Entamoeba, Trichomonas, Gardnerella vaginalis, anaerobes (Bacteroides, ...
Antimycobacterial drugsM. tuberculosis: Rifampicin, Isoniazid, Pyrazinamide, Ethambutol M. avium: Azithromycin or clarithromycin + ethambutol- Can add rifabutin or ciprofloxacin M. leprae: Long-term treatment with dapsone ...
RifamycinsRifampin, rifabutin Mechanism: Inhibit DNA-dependent RNA polymerase Clinical use:- Mycobacterium tuberculosis- Delay resistance to dapsone when used for leprosy. - Meningococcal prophylaxis and chemoprophylaxis ...
IsoniazidMechanism: ↓ synthesis of mycolic acids. Bacterial catalase-peroxidase (encoded by KatG) needed to convert INH to active metabolite. Clinical use: Mycobacterium tuberculosis. The only agent used as ...
PyrazinamideMechanism: Uncertain. Pyrazinamide is a prodrug that is converted to active compound pyrazinoic acid. Works best at acidic pH (eg, in host phagolysosomes). Clinical use: Mycobacterium tuberculosis Adverse ...
Ethambutol↓ carbohydrate polymerization of mycobacterium cell wall by blocking arabinosyltransferase. Clinical use: Mycobacterium tuberculosis Adverse effects: Optic neuropathy (red-green color blindness).
StreptomycinMechanism: Interferes with 30S component of ribosome Clinical use: Mycobacterium tuberculosis (2nd line) Adverse effects: Tinnitus, vertigo, ataxia, nephrotoxicity
Antimicrobial prophylaxisHigh risk for endocarditis and surgical/dental procedures – Amoxicillin Exposure to gonorrhea – Ceftriaxone History of recurrent UTIs – TMP-SMX Prevention of gonococcal conjunctivitis in newborn ...
Amphotericin BMechanism: Binds ergosterol (unique to fungi); forms membrane pores, allowing leakage of electrolytes. Clinical use: Serious, systemic mycosis. Cryptococcus (amphotericin B with/without flucytosine ...
NystatinMechanism: Same as amphotericin B (binds ergosterol and forms membrane pores). - Topical use only as too toxic for systemic use. Clinical use: - "Swish and swallow" for oral candidiasis (thrush)- Topical ...
FlucytosineMechanism: Inhibits DNA and RNA biosythesis by conversion to 5-fluorouracil by cytosine deaminase. Clinical use: Systemic fungal infections (especially meningitis caused by Cryptococcus) in combination ...
AzolesClotrimazole, fluconazole, isavuconazole, itraconazole, ketoconazole, miconazole, voriconazole Mechanism: Inhibit fungal sterol (ergosterol) synthesis by inhibiting the cytochrome P-450 enzyme that converts ...
TerbinafineMechanism: Inhibits the fungal enzyme squalene epoxidase. Clinical use: Dermatophytoses (especially onychomycosis – fungal infection of finger or toe nails) Adverse effects: GI upset, headaches, hepatotoxicity, ...
ChloroquineMechanism: Blocks detoxification of heme into hemozoin. Heme accumulates and is toxic to plasmodia. Clinical use: Treatment of plasmodial species other than P falciparum (frequency of resistance in P ...
Oseltamivir, zanamivirMechanism: Inhibit influenza neuraminidase → ↓ release of progeny virus. Clinical use: Treatment and prevention of both influenza A and B. - Beginning therapy within 48 hours of symptom onset may ...
Acyclovir, valacyclovir, famciclovirMechanism: Guanosine analogs. Monophosphorylated by HSV/VZV thymidine kinase and not phosphorylated in uninfected cells. Triphosphate formed by cellular enzymes. Preferentially inhibit viral DNA polymerase ...
GanciclovirMechanism: Guanosine analog. 5'-monophosphate formed by a CMV viral kinase. Triphosphate formed by cellular kinases. Preferentially inhibits viral DNA polymerase. Clinical use: CMV, especially in immunocompromised ...
FoscarnetMechanism: Viral DNA/RNA polymerase inhibitor and HIV reverse transcriptase inhibitor. Binds to pyrophosphate-binding site of enzyme. Does not require any kinase activation. Clinical use: CMV retinitis ...
NNRTIsDelavirdine, Nevirapine, Efavirenz Bind to reverse transcriptase at site different from NRTIs.- Do not require phosphorylation to be active or compete with nucleotides. Adverse effects:- Rash and hepatotoxicity ...
Protease inhibitorsAtazanavir, Darunavir, Fosamprenavir, Indinavir, Lopinavir, Ritonavir, Saquinavir- All protease inhibitors end in -navir. Assembly of virions depends on HIV-1 protease (pol gene), which cleaves the ...
Hepatitis C therapyChronic HCV infection is treated with different combinations of the following drugs; none is approved as monotherapy. Ribavarin also used to treat RSV (palivizumab preferred in children). Ledipasvir: ...
MonobactamsAztreonam Mechanism: Same as penicillin/cephalosporins. Prevents peptidoglycan cross-linking by binding to penicillin-binding protein 3.- Resistant to β-lactamases- Synergistic with aminoglycosides- ...
Antimicrobials to avoid in pregnancy- Aminoglycosides (Ototoxicity)- Fluoroquinolones (Cartilage damage)- Sulfonamides (Kernicterus)- Tetracyclines (Discolored teeth, inhibition of bone growth)- Clarithromycin (Embryotoxic)- Ribavarin (Teratogenic)- ...
