Antimicrobials Flashcards
Penicillin
Inhibits Pencillin binding protein (transpeptidase) which prevents cell wall cross linking (cell walls have a D-Ala-D-Ala structure), causing unstable cell walls and cell death
Gram +
N meningitidis
T pallidum
Penicillin V: oral, weaker form
Penicillin G: IV, IM
AA:
o IgE hypersensitivity reaction
o Interstitial nephritis
o Cross reactive with cephalosporins
penicillinase-resistant penicillins
Naficillin, oxacillin, dicloxacillin, methicillin
pennicillinase resistant due to bulky R group
Staph aureus besides MRSA
o Osteomyelitis, myocarditis, soft tissue infections
Amoxicillin, ampicillin
Penicillins with wider spectrum pair with beta-lactamase inhibitors H. influ H. pylori E. coli Listeria Proteus Salmonella Shigella HHELPSS
AA:
rash in CMV
liver
Pipercillin, ticacillin
anti-pseudomonal penicillins
1st gen cephalosporins
cephalexin, cefazolin (flex, fez) PEcK + Proteus E. coli Klebsiella gram positives
2nd gen cephalosporins
cefaclor, cefoxitin, cefuroxime, cefotetan (fake fox fur tea parties) HENS PEcK H. influ Enterobacter Neisseria Serratia
3rd gen cephalosporins
ceftriaxone, cefotaxime, ceftazidime serious gram - infections meningitis psuedomonas (taz covers naz) gonorrhea late stage Lyme
4th gen cephalosporins
cefepime
broad spectrum
meningitis → crosses CSF
pseudomonas
5th gen cephalosporins
ceftaroline
broad spectrum
MRSA
does NOT cover pseudomonas
Carbapenems
-penem
beta-lactamase resistant
used in serious life-threatening side effects
broad spectrum
imipenem → adminster with cilastin to ↑ half life
AA: serious side effects CNS toxic (seizures) GI distress rash
Aztreonam
monobactam
Beta-lactamase resistant
Aerobic gram negative rods
o Treats serious gram negative infections
Sepsis, pneumonia, meningitis
o Pseduomonas
o Penetrates CSF
Vancomycin
Inhibits cell wall synthesis by binding directly to D-Ala-D-Ala polypeptides
Bacterial resistance by changing their cell wall to D-Ala-D-LAC
IV
Treats MRSA and other multi-drug-resistant bacteria
S. epidermidis
C. diff → oral vancomycin
AA o Red man syndrome → flushing during infusion o Thrombophlebitis o Ototoxicity o Nephrotoxicity Excreted through kidneys Monitor plasma levels o DRESS syndrome → eosinophilia and systemic symptoms
Daptomycin
Lipopeptide that disrupts cell membranes
MRSA and VRE
endocarditis
bacteremia
not effective vs pneumonia (surfactant inactivates daptomycin)
AA: rhadomyolysis, myopathy
Tetracycline
doxycycline, minocycline 30S ribosomal binding Tick born pathogens Rickettsia Ehrlichia Francisella Borrelia
Zoonotic diseases
Brucella
Coxiella
Yersinia
chlamydia
acne
MRSA
AA: Contraindicated in pregnancy teeth discoloration inhibits bone growth photosensitivity
macrolides
(-thromycin)
50S ribosomal subunit inhibiting translocation
atypical pneumonia (M. pneumoniae, legionella, chlamydia)
Gram + infections in patients allergic to penicillin
B. pertussis
AA: MACRO Motility (GI) Arrhythmia Cholestatic hepatitis Rash eOsinophilia
P450 inhibitor
Clindamycin
50S ribosomal subunit inhibiting translocation Gram + and anerobes o MRSA o Lung abscesses o Aspiration pneumonia o Bacteroides (oral infections) o Clostridium perfringens o Acne o Gardnerella vaginosis
Clindamycin above the diaphragm
Metronidazole below the diaphragm
paired with gentamicin for broad coverage
AA:
o Diarrhea
o C. difficile infections
Chloramphenicol
Rarely used in the US 50S ribosome, inhibits translation Bacteriostatic Used in meningitis and rocky mountain spotted fever Cheap 3rd world treatment of meningitis
Adverse reaction
o Anemia
o Gray baby syndrome
Accumulation of drug due to lack of liver UDP-glucuronosyltransferase
Linezolid
50S ribosome, bacteriostatic Gram + Staph, strep, enterococcus MRSA and VRE (vancomycin resistant enterococcus) Nosocomial pneumonia (MRSA)
Adverse reactions o Thrombocytenia o Optic neuropathy o Peripheral neuropathy (glove and stocking) o Serotonin syndrome
Aminoglycosides
gentamicin, neomycin, streptomycin, tobramycin, amikacin
30S ribosome, misreading mRNA causing cell death → bacteriocidal
Gram – bacilli, aerobes only
Coupled with beta lactams or vancomycins to help them get through cell wall
IV
Neomycin → bowel surgery prep
Streptomycin → tularemia, Y. pestis
Gentamicin and Tobramycin → severe, drug-resistant gram – rods
Amikacin → new, expensive, effective vs drug resistant
Adverse effects
o Nephrotoxicity
o Ototoxicity
o Neuromuscular blockade (myasthenia gravis is contraindication)
o Teratogen (contraindicated in pregnancy)
Tuberculosis drugs
rifampin, isoniazid, pyrazinamide, ethambutol
4 drugs for 2 months, then 2 drugs for 4 months
Isoniazid
Only agent that can be used by itself, iso → isolated
Latent TB
↓ mycolic acids in cell wall
Adverse effects
INH → injures neurons and hepatocytes
Drug induced SLE
Vit B6 deficiency → administer with Vit B6
Siezures
P450 inhibition → ↑concentration of drugs
Rifampin
Inhibits RNA synthesis
P450 stimulation → ↓concentration of drugs
Prophylactic monotherapy to close contacts of patients infected with H. influenzae or N. meningitidis
Adverse effects
Orange body fluids
Hepatotoxicity
Ethambutol
↓ carb polymerization of cell walls by blocking arabinosyltransferase
Adverse reactions
Optic neuropathy → red-green color blindness
Pyrazinamide
Adverse effects
Hyperuricemia → gout
Hepatotoxicity → hepatic necrosis
Mycobacterium avium treatment
- Azithromycin or clarithromycin
- Ethambutol
- Rifabutin → less potent stimulator of P450
Mycobacterium leprae treatment
Tuberculoid form
o Dapsone
o Rifampin
•
Lepromatous form
o Dapsone
o Rifampin
o Clofazimine
Sulfonamides
Inhibits folate synthesis (dihydopteroate synthase)
Adverse reactions o Allergic drug reactions (Rash, fever, urticaria) o G6PD deficiency patients → hemolysis o Stevens-Johnson syndrome o Interstitial nephritis o Kernicterus in infants o Displace drugs from albumin (such as warfarin) o P450 inhibition
Trimethoprim
Inhibits folate synthesis (dihydrofolate reductase)
Trimethoprim + sulfamethoxazole = bactrim
o 1st line treatment for UTI
o Shigella
o Nocardia
o Pneumocystis jirovecii
o Toxoplasma ghandii prophylaxis
Fluorquinolones
-floxacins
Inhibits DNA gyrase and topoisomerase, bacteriocidal
gram - rods of UTI and GI
o Complicated UTI’s (bactrim is first line)
Some gram +
Bacillus anthracis
Otitis externa
Divalent and trivalent metals decrease absorption
Adverse effects
o GI
o Teratogenic
o Tendonitis or tendon rupture
Metronidazole
Forms free radicals that disrupt bacterial DNA Anaerobes below the diaphragm (clindamycin → above the diphragm) o C. diff o Clostridium Giardia Entamoeba Trichamonas Gardnerella
Adverse reactions
o When taken with alcohol → flushing, tachycardia, hypotenstion
o Metallic taste
Amphotericin
Antifungal
Binds to ergosterol, forms (TEARS) pores which leak electrolytes
Serious, life threatening fungal infections
o Mycoses
o Mucor
o Fungal meningitis
Adverse reactions
o Nephrotoxicity (almost always occurs)
o Fever, chills, hypotension
o Thrombophlebitis
Nystatin
- Same as amphotericin
* Topical use for candidiasis
Flucytosine
- Conversion of uracil to 5-fluoruracil inhibiting DNA and RNA synthesis
- Systemic fungal infections
- Cryptococcus
Azoles
Inhibits ergosterol synthesis (lanosterol → ergosterol) by inhibiting P450
Antifungal
Voriconazole
o Aspergillosis
o Candida
Fluconazole
o Candida
o Cryptococcal meningitis
Itraconazole
o Dimorphic mycoses (2 Iterations)
Clotrimazole and miconazole
o Topical fungal infections (tinea)
Adverse effects
o Inhibits testosterone synthesis
Gynecomastia
o Inhibits P450
Terbinafine
inhibits squalene epoxidase
used for dermatophytoses
