Penicillins
- affect cell wall synthesis
- All have: Thiazolidine ring, beta-lactim ring, variable side chain
- more economical to produce through fermentation than synthetically
-G/V natural forms
- Drug of choice for gram-pos cocci, and some gram-negs
- semi synths (amp, carben, amox) have broader spectra to gram-negs
- meth, naf, clox are ase resistant
- Issues: allergies/resistance
Cepahlosporins
-synth altered b-lactam
- act on cell wall
-broad-spec
-resistant to most ases
- fewer allergies
-4 gens, each broader spec than the last against gram-neg
- each gen has better dosings and fewer side effects
- gen 1: alothin, zolin most gram pos cocci, few gram neg
- gen 2: aclor, onacid, more gram negs
-gen 3: alexin, triaxone - broad spec against enteric w b-lactamases
-gen 4: epime - widest range, gram neg and pos
Carbapenems
Imipenem
- B lactam
- act on cell wall
- broad spec
- aerobic/anaerobic pathogens
- low oral dose
- low side effects
Monobactams
-Aztreonam
- B lactam
- act on cell wall
- narrow spectrum
- for gram neg aerobic bacilli infec
- for penicillin allergic ppl
Vancomycin
- NOT B LACTAM
- act on cell wall
- narrow spec
- mainly staphylococcal infec with pen/meth resistant or allergies
- toxic and hard to administer; restricted use
Bacitracin
- NOT B LACTAM
- cell wall inhib
- narrow spec
- produced by strain of B subtilis
- ointment
Isoniazid (INH)
- NON B LACTAM
- cell wall inhib
- interferes w mycolic acid synthesis
- treat tuberculosis
Polymyxins
- disrupt membrane fxn
- interact w phospholipids
- cause leakage
- gram neg bac
- narrow spec
- unique fatty acid
- drug resistant P aeruginosa and severe UTI
Amphotericin B and nystatin
- disrupt membrane fxn
- form complexes with sterols
-fungal membranes - causes leakage
Chloroquine
- affects nucleic acid synthesis
-binds and cross links double helix
Quinolones
- affect nucleic acid synthesis
- inhibit DNA helicases
Fluoroquinolones
- bind to DNA
- DNA gyrase and topoisomerase IV
- broad spectrum
-concerns about overuse and resistance
Streptomycin and gentamycin
- Block protein synthesis
-aminoglycosides - insert on sites of 30S subunit, cause misreading of mRNA
- composed of 1+ amino sugars and aminocyclitol ring
- products of soil actinomycetes
- broad spec
- especially useful against aerobic gram neg rods and some gram pos
streptomycin - bubonic plague, tularemia, TB
gentamicin - less toxic, gram neg rods
Tetracyclines
- block protein synthesis
- block attachment of tRNA on A acceptor site, stop further synthesis
- broad spec
- treatment for STDs, Rocky Mtn spotted fever, Lyme, typhus, acne, protozoa
- generic is low cost but has side effects
Ethromycin
- macrolide
- large lactone ring w sugars
- attaches to ribo 50S
- broad spectrum, low toxicity
- for mycoplasma pneumonia, legionellosis, chlamydia, pertussis, diphtheria, prophylactic prior to intestine surgery
- for penicillin resistant gonococci, syphilis, and acne
- clarithromycin/azithromycin = new semi synth
Chloramphenicol
- blocks peptide bond formation/ protein synth
- potent
- broad spec
- nitrobenzene structure
- synthetic
- very toxic, irreversible bone marrow dmg
- for typhoid fever, brain abscesses, rickettsial, and chlamydial infections
Sulfonamides
- block enzymes require for tetrahydrofolate synthesis needed for DNA and RNA synth
- block metabolic pathways
-first synthetic antimicrobic
- narrow spec
- sulfisoxazole - shigellosis, UTI, protozoan infec
- silver sulfadiazine - burns and eye infec
- trimethoprim - given in combination for UTI/PCP
Fosfomycin trimethamine
- phosphoric acid effective
- alt treatment for UTI
- inhibit cell wall synthesis
- new
Synercid
- against staphyloccocus and enterococcus that causes endocarditis and surgical infections
- used when bacteria is resistant
- inhibits protein synth
- new
daptomycin
- new
- against gram pos
- disrupts membrane fxn
ketolides - telitromycin (ketek)
new drug
- diff ring structure than ethromycin
- used for macrolide resistant infections
Oxazolidinones - linezolid (zyvox)
- new
- synthetic
- blocks interaction of mRNA and ribosome
- used meth resistant Sa (MRSA) and vancomycin resistant Enterococcus ( VRE )
