hey everyone this lesson is on the antibiotic amoxicillin and today we're
gonna talk about what are the bacterial targets of amoxicillin what is the
mechanism of action of amoxicillin and then we're also going to talk about some
of the contraindications and the adverse effects of amoxicillin usage so what is
amoxicillin well amoxicillin is actually one of the
amino penicillins and it is a beta lactam antibiotic so like all the
beta-lactam antibiotics it actually has a beta lactam ring now what are some of
the targets of amoxicillin well some of the targets of amoxicillin include the
gram positive cocci which is similar to penicillin G penicillin G is also a beta
lactam antibiotic but amoxicillin has increased effectiveness against
enterococci as opposed to pen G now amoxicillin can also target
gram-negative aerobes such as Salmonella, Shigella, E. coli, Proteus and h influenza
and it can also have some effectiveness against anaerobes similar to penicillin
G as well and amoxicillin can also be used for Listeria monocytogenes
infections as well so how does amoxicillin actually work what is its
mechanism of action well first and foremost amoxicillin is a bacterial
lytic or bactericidal antibiotic and it actually inhibits bacterial cell wall
synthesis so it actually inhibits the bacterial cell wall synthesis by binding
to multiple penicillin binding proteins so the penicillin binding proteins are
important during the transpeptidase steps of peptidoglycan synthesis and in
fact amoxicillin actually inhibits the final transpeptidase and step in
peptidoglycan synthesis so here's a quick schematic of what amoxicillin does
so if you were to look at a bacterial cell wall you'd be able to see these
penicillin binding proteins now again amoxicillin binds to these penicillin
binding proteins and these penicillin binding proteins are critically
important for the cross-linking of peptidoglycan and specifically the final
transpeptidase step so that's why when amoxicillin is in these sites is bound
to penicillin binding proteins the peptidoglycan is unable to cross link
which means that the bacterial cell wall is dysfunctional and in fact the
bacteria would not be able to withstand any changes in osmotic pressure or any
other stressors which would lead to a bacterial lysis or the death of the
bacteria now one of the major problems with the beta-lactam antibiotics is the
development of antibiotic resistance and bacteria have developed an enzyme known
as betalactamase, which can actually break down the antibiotic it'll break
down the beta-lactam ring of the antibiotic making it ineffective so we
can get around this by actually supplementing the antibiotic with
another agent in this case we utilize Clavel innate or clavulanic acid and we
mix this with amoxicillin so you might have heard of a moxie clap and this
increases the effectiveness against a variety of other bacteria as well
including methicillin sensitive Staphylococcus aureus
so the MSSA not mr sa but MSS k it also increases the effectiveness against h
influenza as well it increases effectiveness against Moraxella
catarrhalis so because among Susilo actually gives us an increased
effectiveness against H influenza Moraxella catarrhalis and because
amoxicillin already has some antibiotic properties against strep types of
bacteria moxie cloud can be used and is regularly used during otitis media or
middle ear infection so Titus media if it's a bacterial cause it is most likely
caused by either the three bacteria h influenza Moraxella catarrhalis or
streptococcus so that's why we can use a Moxie class during Ono otitis media
infection so if we have determined that a bacteria is sensitive to amoxicillin
are there any reasons why we wouldn't use amongst a so on so what are some of
the contraindications of amoxicillin use well one of the main reasons why we
wouldn't use amoxicillin is just because the patient has exhibited a previous
history of a serious hypersensitivity to amoxicillin or other beta lactams and
these types of hypersensitivity could include anaphylaxis or stevens-johnson
syndrome so if the patient has presented previously with these types of
hypersensitivity to amoxicillin or other beta-lactam antibiotics we would not use
amoxicillin now what are some of the adverse reactions of amoxicillin use
well monticello news can cause a variety of adverse reactions including
hypersensitivity ng itis it can cause and CNS agitation anxiety confusion
dizziness headache insomnia seizure it can cause rashes your dock area
stevens-johnson syndrome if the patient is allergic to amoxicillin or
beta-lactam antibiotics it can cause dental discoloration like
the tetracyclines but it is extremely rare to do that it can cause diarrhea
nausea vomiting it can cause hematologic issues such as anemia leukopenia
thrombocytopenia or EOC Nephila and increase in OC no fill count and it can
cause hepatitis increase serum alt and ast or cholestatic jaundice and as we
mentioned previously it can cause anaphylaxis but a lot of these adverse
reactions are quite rare and usually are not an issue anyways guys that was a
quick lesson on amoxicillin and its usage I hope you found this video
helpful if you did please like and subscribe for more videos like this one
and as always thank you so much for watching and have a great day