Penicillins In General

Tx: Work best on actively growing Bac

Ax: Irreversibly inhibit Transpeptidase

Prevent PG cross-linking→lysis or failure to divide

Sx: May expose new Ag to immune system

Allergy: 10% rash & 0.2% Anaphylaxis

Resistance: β-Lactamase, mutated porins, efflux 

Ms: Renal Primary route of Excretion

Penicillin G

Tx: G-:Neisseria Meningitidis, T. Pallidum

G+: Strep pneumo, Anthrax

Ax: See General Pen. card

Mc: IV

Penicillin V

Tx: G+: Strep Pneumo, Anthrax, Strep Pyrogenes

Ax: See Gen. Pen. Card

SE: ↓N. Flora, ↓OCP efficacy, ↓Estrogen

Amoxicillin

Tx: G+: Strep Pneumo, Listeria, Enterococci

G-: Influenzae, Salmonella, E. coli

↓ß-Lactamase Activity

Ax: See Gen. Pen. Card

SE: ↓N. Flora, ↓OCP efficacy, ↓Estrogen

Non-allergy skin rash

Ms: Oral (absorbed better than Ampicillin)

Ampicillin

Tx: G+: Strep Pneumo, Listeria, Enterococci

G-: H. influenzae, Salmonella, E. coli

↓ß-Lactamase Activity

Ax: See Gen. Pen. Card

SE: same as Amoxicillin

Ms: IV or Oral

Nafcillin

Tx: G+: Staph Aureus (MSSA)

Ax: See Gen. Pen. Card

Ms: IV

Piperacillin

Tx: Pseudomonas Spp.

Ax: See Pen. Gen. Card

SE: Inhibits Platelet Aggregation (pot. anticoag Tx)

Ms: IV

Imipenem/Cilastatin

Tx: G+ Cocci, G- Rods, Anarobes

Ax: Broader Spectrum β-Lactam since as

"R" groups - much less susceptible

to β-Lactamase

SE: Severe Colitis, Dizziness, Headaches

Cefazolin

Tx: G+ Cocci (Staph, Strep), G-: E coli, Proteus M.

Ax: 1st Generation Cephalosporin

Two "R" Groups - wider spectrum of activity 

with more stereochemistry

SE: Nephrotoxicity

Cefotaxime

Ceftazidime

Ceftriaxone

Tx: G-: Meningitis, Enterobacter, Serratia, N. Gonorrhoeae, Pseudomonas

Ax: 3rd Generation Cephalosporins

2 "R" Groups

SE: Nephrotoxicity,

Long-term Ceftriaxone→biliary sludging (43%)

Aztreonam

Tx: Only for G- Aerobes

Pts w/ Penicillin Allergy

Ax: "Bare Bones" single B-Lactam Ring (monobactam), Narrow Spectrum B-Lactam

SE: Typical B-Lactam Issues (GI, superinfection, etc.)

Ms: Renal Elimination

Ciprofloxacin

Levofloxacin

Tx: UTIs, GI infxns from G- rods,

Community-Acquired Pneumonia from intracellular Bac. (Legionella, Mycoplasma)

Cipro: Anthrax & Levo: Pen-resist. Strep Pneumo

Ax: Inhib. Topoisomerase G+ TopoIV & G- TopoII

SE: Damages Growing Cartilage (not for kids), Headaches, Prolongs QT Interval, Phototoxicity

Sulfamethoxazole

Tx: UTIs

Ax: Bacteriostatic, Reversibly inhibits DHPS

↓Thymidine Syn. (↓DNA Syn.)

SE: Allergy: "Sulfa Rash," Fever

Hemolytic Anemia in G6PD Pts

Potentiates toxic/anticoag/hemolytic drugs

Not for Preg/nursing infants (bilirubin displaced)

Trimethoprim-Sulfamethoxazole

(TMP-SMX)

Tx: Recurrent UTIs, Septicemia, GI bugs,

Ear Inf., AIDs opportunistic Inf.

Ax: Bactericidal, tougher to get resistance,

inhibits DHPS and DHFR

↓Thymidine and DNA Synth.

SE: Same as Sulfonamide, Megaloblastic anemia (Tx with Leucovorin), Nephrotoxicity

Genmtamicin

Streptomycin

Tobramycin

Neomycin

Tx: Aminoglycosides-Bactericidal, AEROBES only since entry porin req. ATP + O2, use as empiric Tx until ID the bug, TB

Ax: Bind ribosomes and block translation initiation, cause miscoded protiens, block translocation

SE: Ototoxicity, Nephrotoxicity

Ms: Variable renal elimination

Macrolides IN GENERAL

Tx: Bacteriostatic, Generally for G+

Ax: Reversibly bind 50s ribosomal subunit, 

inhibit translocation, accum. in G+ bact. and Human Mitochondria

SE: Diarrhea, N/V, resistance: methylated target ("ribosomal protection")

Biliary excretion (don't give to Pts w/ Liver dis.)

Azithromycin

Tx: Chlamydia, Neisseria Gon., 

Ax: reversibly bind 50s

SE: ↓peak serum levels with Al3+/Mg2+ antacids

↓ absorption with food

Clarithromycin

Tx: Myobacterium avium complex (AIDs Pts)

Ax: reversibly binds 50s

SE:↓ Serum levels with rifabutin or rifampin

Ms: Potent CYP3A4 inhibitor

Erythromycin

Tx: Otitis Media (w/ sulfa)

Ax: reversibly binds 50s

SE: Cardiotoxicity/Arrhythmia (do not give with drugs that prolong QT interval)

Ms: Potent CYP3A4 inhibitor

Clindamycin

Tx: Bacteriostatic, typically ANAEROBES (G-rods)

Acne treatment

Ax: Similar to macrolides, irreversibly binds 50s ribosomal subunit, inhibits translocation, stops toxin produced by strep and staph

SE: Diarrhea (10-30%), Abx-associated Colitis (C. difficile is naturally resistant)

Blocks absorption of antidiarrheal drugs

distributes in tissues/bone, but not CNS

Doxycycline

Tx: Broad Spectrum Bacteriostatic,

Rickettsia (typus, rocky mount. spotty fever)

Spirochetes (Lyme, syphilis)

Ax: Tetracycline - binds 30s r. subunit, blocks tRNA binding, pumped into Bac.

SE: Binds Bones + Teeth (not for preg. or Kids)

GI distress, Photosensitivity

Ms: Very Lipophilic, overtime covers to toxic form → Kidney damage (toss expired pills) 

Chloramphenicol

Bacteriostatic

Tx: CNS abcesses (Bacteroides Fragilis, Strep)

Ax: Binds 50s r. subunit, inhibits translocation, strongly affects mitochondria→toxic→NOT 1st line

SE: BM Suppression, Gray Baby Synd. → newborns can not metabolize → cardiovascular collapse

Optic neuritis, peripheral neuritis (esp. long term use)

Ms: Accumulate in CNS

Not for Preg. (unless topical)

Vancomycin

Drug to Tx Bac. Resistance

Tx: Only G+, MRSA, Penicillin resist. Strep

Ax: Bactericidal in dividing Bac, binds D-ala-D-ala terminus of cell wall precursor, inhibits cell wall synthesis

SE: adds to oto/nephrotoxicity, allergies, rash, anaphylaxis, "Red man Syndrome" w/ rapid IV infusion (histamine release→severe flushing)

Ms: IV (dist. to CSF), poor oral (except for colitis)

Not given given IM (histamine)

Polymyxin B & E

Tx: resistant G-, B: ear, eye, & topical, 

E: ear, "nuke bomb" (last resort oral/IV for Acinetobacter or Pseudomonas)

Ax: Bactericidal, detergent-like→disrupts cell membranes, also toxic to our membranes

SE: Non-selectively toxic, oral/IV very neurotoxic & nephrotoxic

Ms: Topical, oral, IV & renal eliminated

Metronidazole

Tx: ANAEROBES: Bacteroides, Helicobacter,

C. difficile

Ax: Anaerobe reductive metabolism→free radicals

free radicals damage bac. DNA + proteins

SE: mild: headache, GI/nausea dry mouth

metal taste, red-brown urine (harmless)

Ms: safe in kids, good dist. (incl. CNS)

Met: Liver and Renal

Isoniazid/INH

Tx: selective for Mycobacterium, TB combo Tx

Ax: inhibits mycolic acid synth (TB cell wall)

Bactericidal in growing and bacteriostatic if resting

SE: Hepatotoxic, rash, periph. neuritis (Tx w/

Vit B6) hemolysis in G6PD pts

Ms: oral or IV

Met: Liver acetylases (genetic polymorphism)

Rifampin

Tx: TB/Leprosy combo Tx, many G+ & G- bac, meningitis prophylaxis

Ax: inhibits bac. RNA poly, blocks transcription

SE: minor liver hepatotoxicity in patient with prior liver problems

Ms: Generally well tolerated

Dapsone

Tx: Daily Tx for Leprosy for 1yr (combo w/ rifampin)

Ax: Antifolate (inhibits DHPS) similar to sufonamides

SE: Similar to sulfa drugs