module 4 Flashcards
gram positive bacteria vs gram negative
gram positive - thick peptoglycan layer no outer membrane
gram negative - thin layer and outer membrane
broad spectrum antibiotic
tetracycline
broad spectrum antibiotic
tetracycline
narrow spectrum antibiotic
penicillin g
classification of antibiotics by biochemical pathway
cell wall synthesis inhibitors
DNA synthesis inhibitors
protein synthesis inhibitors
metabolic inhibitors
this antibiotic functions to stop the proper formation of the bacterial cell wall and membrane influencing the structural integrity of the cell
cell wall synthesis inhibitors such as penicillins or cephalosporins
this antibiotic inhibits DNA replication in bacteria, preventing bacterial growth
DNA synthesis inhibitors such as fluoroquinolones
this antibiotic inhibits protein translation within bacteria inhibiting protein synthesis
protein synthesis inhibitors such as tetracyclines and macrolides
this antibiotic blocks the formation of key bacterial metabolic substrates needed for bacteria to survive and reproduce
metabolic inhibitors such as anti folate drugs
cell wall synthesis antibiotics
penicillin g
methicillin
ampicillin and amoxicillin
amoxicillin and cavulanic acid
inhibit bacterial DNA synthesis
fluoroquinolones
inhibit formation of bacterial cell walls by inhibiting transpeptidase
penicillins/ cephalosporins
inhibits protein synthesis by binding to the 30S ribosomal subunits preventing the addition of amino acids to the protein chains
tetracyclines, protein synthesis inhibitor
inhibits protein synthesis by binding to the 50S ribosomal subunits preventing and blocking peptide bond formation
macrolide a protein synthesis inhibitor
block folate metabolism by inhibiting PABA incorporation into dihydropteroic acid
sulfonamides
block folate metabolism by inhibiting dihydrofolic acid reductase
trimethoprim
bacteriostatic
inhibits the growth and reproduction of bacteria
bacteriacidal
directly kills bacteria
macrolides and tetracycline fall under what class of antibiotic
protein synthesis inhibitors
what is the difference between the mechanism of action of tetracyclines and macrolides
tetracyclines bind to the 30S ribosomal subunit of the mRNA ribosome complex and prevents the addition of amino acids to the protein chain
macrolides bind to the 50S ribosomal subunit and blocks the formation of the peptide bond
examples of antifolates a metabolic inhibitor
sulfonamides and trimethoprim
combination antifolates such as sulfamethoxazole or trimethoprime are used for treating what types of infection
UTIs, respiratory and gi tract infections
antimicrobials include
antibiotics anti fungal antivirals and anti parasitic drugs
two major factors associated with the development of antibiotic resistance
evolution of bacteria and clinical and environmental factors such as misuse
causes of antibiotic resistance
over prescription
inappropriate use ( premature discontinuation)
use in agriculture
4 methods that organisms become resistant
uptake - mutations or lack of pores
target - mutation in the target
inactivation - enzyme that deactivate drug
efflux pumps - over expression of transports
anti fungal drugs
echinocandins and amidazoles or azoles
azoles mechanism of action
they inhibit fungal p450 cytochrome thereby inhibiting ergosterol synthesis. ergotsterol is critical for cell wall function and survival. selective toxicity in azoles lies in their higher affinity for fungal p450 than human
a narrow spectrum penicillin that destroys mainly gram positive bacteria. used to treat pneumonia middle ear infections and meningitis
penicillin G
a penicillin that is resistant to attack by penicillinase
methicillin
broad spectrum penicillin useful against a range of infections caused by gram negative bacteria
ampicillin and amoxicillin
a semisynthetic penicillin plus an inhibitor of penicillinase that was introduced into therapy to combat penicillins producing strains of bacteria
amoxicillin and cavulanic acid
which penicillin is resistant to the action of penicillinase
methicillin
co- trimoxazole is a combination of what two drugs?
trimethoprim and sulfamethoxazole
mechanism of action: antifolates
tetrahydrofolic acid a folate, is essential for bacteria to synthesize DNA. if not formed bacteria growth will slow. both sulfonamides and trimethoprim
sulfonamides inhibit PABA incorporation into dihydropteroic acid. they are selectively toxic to bacteria
trimethoprim inhibits the enzyme dihydrofolic acid reductase thus inhibiting tetrahydrofolic acid formation.
selectively toxic to bacteria because it has greater inhibitory actions on the bacterial enzyme than on the human enzyme
potential male contraceptives
androgens
estrogens
progestins and androgen
gossypol
spermatogenisis
hypothalamus release GnRH which stimulates the pituitary gland to release FSH and LH. in males, FSH stimulates the seminiferous tubules in the testes to produce sperm. while LH stimulates leydig cells to produce testosterone. leydig cells are found adjacent to the semininerarous tubules i. the testes testosterone in the hormone responsible for male secondary sex characteristics and the presence of testosterone in the body inhibits the hypothalamus from releasing more GnRH. this prevents over production of testosterone
spermatogenesis mechanism of action
attempts to create male contraceptives by inhibiting the release of gonadotropin release hormone and thus spermatogenesis also decreases testosterone production which leads to the adverse effect of a decrease in sex drive
what benefits would a local injectable non hormonal form of male contraceptives has over hormonal
a non hormonal form of male contraceptives would avoid all the side effects related to administering hormones such as increased aggression, decreased libido or the development of feminine characteristics. additionally an injectable form of contraceptive allows the patient to ensure contraceptive protection before engaging in sexual activity
adverse side effects of male hormonal contraceptives
increased agresssion
decreased libido
development of feminine characteristics
most effective female contraceptive and least
iud both perfect use and typical use
progestin only is the least effective
pros and cons for oral contraceptives
most convenient and least expensive non invasive
variable amount of absorption due to differences in intestinal motility
pros and cons of the shot or depo. contraceptive
patients do not control dosing so it delivers a steady supply for set periods avoids first pass effect
volume of drug is limited and it’s more invasive
the patch pros and cons
convenient delivers steady drug supply for set period and avoids the first pass effect
expensive and causes local irritation
this antiviral is a neuroamidase inhibitor used to treat the flu
oseltamivir
two types of antivirals
acyclover and oseltamivir
this antivirus is activated by the virus and then inhibits viral DNA replication. drug of choice for herpes of vzu
acyclover
