Chapter 23 deck 3 Flashcards
Oxalodinones name
Nlinezolid
Oxalodinones pharmacodynamics. Action, what is it effective against
Inhibitors of bacterial ribosomal protein synthesis
Most effective against aerobic gram-positive bacteria
Resistance emerging
Oxalodinones pharmacokinetics
Well absorbed orally
Does not use CYP450 enzymes
Oxalodinones ADR
Diarrhea, headache, nausea
Myelosuppression has been reported; resolves with discontinuation of drug
Linezolid (oxalodinone) clincial use
MRSA pneumonia
Uncomplicated skin infections
Use less expensive drugs first
Oxalodinone linezolid can be used in
vancomycin resistant enterocacus.
Vancomycin is
exepensive, but oral form is less expensive than IV
Sulfonamides block
folic acid synthesis
trimethoprim inhibits
dna synthesis
nitrofurantoin may inhibit
acetyl coenzymes
Sulfonamides, trimethoprim, nitrofurantoin and fosfomycin all
inhibit both gram-positive and gram negative bacteria
. coli, S. pyogenes, S. pneumoniae, H. influenzae, and some protozoa
What is an issue with sulfonamides, trimethoprim, nitrofurantoin, and fosfomycin
resistance
Sulfonimide example
bactrim
ADR for Sulfonamides, Trimethoprim, Nitrofurantoin, and Fosfomycin
ADRs: GI – anorexia, n/v, diarrhea, stomatitis; rashes, increased hypersensitivity reactions, photosensitivity; CNS – headache, dizziness, drug interactions
Avoid in glucose-6-phosphate dehydrogenase (G6PD) deficiency
Use cautiously in renal impairment
Clinical use for Sulfonamides, Trimethoprim, Nitrofurantoin, and Fosfomycin
Most commonly used in UTI infections
MRSA is susceptible in some areas
Sulfonamides, Trimethoprim, Nitrofurantoin, and Fosfomycin rational for drug selection
Low-cost alternative in children older than 2 months and in those with PCN allergies
Monitoring for Sulfonamides, Trimethoprim, Nitrofurantoin, and Fosfomycin
Control and status if treating UTI
Long-term use: check complete blood count (CBC)
Chest x-ray in patients who develop a cough when on nitrofurantoin
Chest x-ray in patients who develop a cough when on
nitrofurantoin
Tetracyclines and Doxycycline drug class
Tetracycline
Tetracycline pharmacodynamics
Bind reversibly to the 30S subunit of the bacterial ribosome
What decreases absorbtion with tetracycline
food
especially milk and calcium. Don’t take a multivitamin with it
Precautions and contraindications
Tetracyclines
Do not prescribe to pregnant women (category D), lactating women, or children age less than 8 years.
Drug interactions: many
Tetracyclines
Clinical use and dosing
Doxycycline is considered first-line therapy for C. trachomatis and Ureaplasma urealyticum.
Tetracycline and minocycline are used to treat P. acnes
Tetracyclines
Rational drug selection
Doxycycline and minocycline can be taken with food. still no calcium
Tetracyclines
Patient education
Administration, ADRs, avoiding pregnancy
Glycopeptides name
Vancomycin
Vancomycin pharmacodynamics
Vancomycin, telavancin (Vibativ), dalbavancin (Zeven)
Used for severe gram-positive infections, such as MRSA resistant to first-line antibiotics
Inhibits cell wall synthesis
Pharmacokinetics
Vancomycin
Poor oral absorption, given IV
Vancomycin ADR
Ototoxicity (transient or permanent)
Nephrotocity
“Red Man” syndrome if infused too fast ****
Vancomycin Clinical use and dosing
Serious gram-positive infections resistant to other medications
Oral vancomycin is used to treat C. difficile infection
Vancomycin monitoring
Monitoring Hearing and renal function Patient education Administration ADRs
Mycobacteria
Grow slowly and are relatively resistant to drugs that are largely dependent on how rapidly cells are dividing
Have a lipid-rich cell wall relatively impermeable to many drugs
Are usually intracellular and inaccessible to drugs that do not have good intracellular penetration
Have the ability to go into a dormant state
Easily develop resistance to any single drug
Antimycobacterials
Names
Isoniazid
Rifampin
Ethambutol
Isoniazid action
(INH) and ethambutol inhibit synthesis of mycolic acids.
Rifampin action
binds to the beta subunit of mycobacterial DNA–dependent RNA polymerase and inhibits RNA synthesis.
Ethambutol action
inhibits synthesis of arabinogalactan, an essential component of mycobacteria cell walls.
Pharmacokinetics Antimycobacterials
Well absorbed orally
Metabolism of isoniazid highly variable and dependent on acetylator status
Antimycobacterials ADRS
INH: peripheral neuropathy
INH, rifampin, and pyrazinamide: hepatotoxicity
Ethambutol: optic neuritis
Streptomycin and capreomycin: ototoxicity
Rifabutin: neutropenia and thrombocytopenia
Antimycobacterials Drug Interactions
Many drug interactions
Rifampin: an inducer of CYP450 enzyme
Take home of antimycobacterials
Used to treat a tougher bacteria. ADRs. Well absorbed orally, but genetics can have an impact
Used to treat TB
Antimycobacterials
Clinical use and dosing
Follow Centers for Disease Control and Prevention (CDC) guidelines.
Active TB requires four-drug therapy.
Preventive therapy includes INH.
Antimycobacterials Rational and monitoring
Rational drug selection
Follow CDC guidelines.
Monitoring
Directly observed therapy
