Chapter 15 Flashcards
Antimicrobial drugs
Compound to kill microbes or prevent their growth
Categories of antimicrobial drugs
Antibacterial: treats bacterial infection
Antiviral: targets viral infections
Antifungal: Target fungal infections
Antiparasitic: treats protozoans and helminthic infections
Alexander Fleming
Creator of penicillin, by determining that a mold excreted a compound that could inhibit the bacteria
Broad-spectrum drugs
effective on gram-negative and positive bacteria
Narrow-Spectrum drugs
target limited range of bacteria
Empiric therapy
commonly started to protect patient form infection getting worse, until a proper Narrow-Spectrum drug is prescribed
Bacteriostatic
Prevents bacteria from growing
Targes bacterial protein synthesis and metabolic pathways
Bactericidal
Kills bacteria
Targets cell walls and membranes
Does the job but with drawbacks
antimicrobial drug types
Natural antibiotics: Naturally occurring compounds
Synthetic: Manufactured by chemical processes
Semisynthetic: Chemical modification of naturally occurring antibiotics
First generation drugs
first round of chemical modification
Second generation drugs
second round of chemical modification
Therapeutic index
ratio of safe dose to minimum effectiveness of drug
Therapeutic drug monitoring
Used to ensure wellbeing of patient/ assess the benefits of a drug
Toxicity considerations
while kidneys and liver can metabolize and eliminate drugs, they can be damaged
Oral administration
easiest to get down. Though it has to be stable in the acid
Parenteral
injection or fusion
Injection methods
Intravenously: in vein
Intramuscularly: in muscle tissue
Subcutaneous: under skin
Beta-lactam antimicrobials
Prevent protein cross-links that bind peptidoglycan’s carbohydrate chains together, aka the process of Transpeptidation
Penicillin
Family of natural/semisynthetic compounds
Widely side effects are minimal
Amoxicillin and ampicillin
Modification of penicillin G
Has extended spectrum but still susceptible to beta-lactamase
Beta lactamase
bacteria make enzymes that inactivate beta-lactam drugs
MRSA and ORSA
resistant staphylococcus aureus strains
Cephalosporins
Largest collection of beta lactam drugs
Broad spectrum bactericidal drug
Prefix: cef/ceph
For people with penicillin allergies
Exist naturally and have been modified
Carbapenems
Beta-lactam drugs that target bacterial cell wall construction
Suffix: penem-
Are effective against MDR strains of bacteria
Usually reserved for HAIs/ patients whose infections are resisting previous treatments
carbapenem-resistant Enterobacteriaceae (CRE
Strain of bacteria that resists even last resort drugs
Kirby-Bauer test
Involves spreading test bacterium on the surface of Muller Hinton agar
Disks are diffused with a set amount of specific drugs are placed on the agar surface and plates are incubated
Zone of inhibition
area where bacteria doesn’t grow, where medicine diffuses into agar thus showing which antibacterial is most effective
E-tests
Also involves the Mueller-Hinton agar plate
However strips are sued with a variable gradient of the drug on the agar surface and then incubated
Antimicrobial resistance
When a microbe isn’t affected by drug therapy
Superinfections
result when superbugs become the primary bacteria in an infection
Intrinsic resistance
natural resistance in antimicrobial drugs; Genes encodes for resistance to certain drugs
Acquired
when resistance comes from genetic mutation or by the acquisition of resistance genes
What should a patient do?
Follow all drug-dosing instructions
Execute follow-up as recommended
Properly store medications
Not demand antibiotics from their physician
