Amoxicillin belongs to the penicillin family and remains the most commonly prescribed antibiotic in America. This semisynthetic analog of ampicillin treats a wide variety of bacteria. Amoxicillin should not be prescribed for the typical sore throat associated with the common cold.
I’m dr. ken landau thanks for watching let’s talk about amoxicillin amoxicillin is an antibiotic in the penicillin family it’s a semi-synthetic analogue of ampicillin because of its chemical structure it’s sometimes referred to as a beta-lactam antibiotics it was discovered in 1958 in england ii me know penicillin to market here in the united states the first one
Was ampicillin in 1961 then came amoxicillin in 1972 amoxicillin is on the world health organization list of essential medicines it’s a broad-spectrum antibiotic and it was originally described from a fungus it’s one of the most commonly prescribed drugs in the united states and is the most commonly prescribed antibiotic in the united states for the most part it
Is an oral medicine it can be given intramuscularly but if an intravenous form is needed we have to default to ampicillin because there is no iv amoxicillin in the united states but it’s important to realize that the blood levels whether you take it orally intramuscularly or intravenously the blood levels are all the same that seems to be what counts and as with
Any antibiotic it’s not for the common cold it’s not for viral infections it’s okay to take it with food it comes in a variety of forms and comes in capsules and tablets and chewable tablets and it comes as a powder for reconstitution mostly for children it’s a moderate spectrum antibiotic good against both gram positive and the gram negative organisms if you need
A beta-lactam antibiotics it seems to be the drug of choice in the class seems to have better absorption than many of the other beta-lactam antibiotics and the spectrum is a little bit broader than two standard penicillins now since it’s been around for so long bacteria have a chance to become resistant to it but for the most part it still can be used for strep
Infection samatha lewis infections moraxella infections can be used for certain ecoli infections e.coli infections extremely common and it still works against my syria meningitidis the cause of meningitis on the other hand it is not good for bacteroides the cause of intra-abdominal infections and it isn’t very good it doesn’t work for people who have infections
With klebsiella or proteus or pseudomonas which are major infectious organisms that occur especially in people who have kidney disease kidney stones or people who have chronic obstructive lung disease and we’re finding increasing resistance to salmonella shigella to staff and certain other forms of e.coli the way the medicine works works in two fashions one is it
Forms hydroxyl radicals inside the cell and kills the cell and the other thing it does is it prevents the bacteria from making the cell wall bacteria can’t make the cell wall then they leak and they become dehydrated and they die that way well it’s cell cycle dependent of course the cell has to be actively growing it can’t be in the resting phase and the drug is
Bacteria seidel some of the antibiotics for instance the tetracyclines and the sulfa drugs those drugs are bacteriostatic they stop the organism from growing but they don’t kill it so they depend on the body’s immune system to get rid of the organism with amoxicillin it will kill the antibiotic the only difference actually between the amoxicillin and the ampicillin
Is a hydroxyl group on one of the side chains but the activity is basically the same it doesn’t matter whether you take the amoxicillin or the ampicillin but because there’s better absorption with the amoxicillin actually you get two to two and a half times higher blood levels with it that means that there isn’t much use for ampicillin anymore the medicines the
Penicillin family originally discovered in 1928 by alexander fleming discovered it from fungus fungus called penicillium notatum now called penicillium christ’s genome there are five different classes of the penicillin drugs the most common are the natural penicillin that’s penicillin viii penicillin g the penicillin is resistant penicillins that’s methicillin and
Then we have the amino penicillins of which the most common are ampicillin and amoxicillin but since the amoxicillin is in the penicillin family it means if you’re allergic to penicillin you can’t take this what are the side effects if you take the drug side effects or you can develop a rash the rash is probably the most common side effect rascal curve any time
While you’re taking the drug even up to a week or so after you discontinue taking the drug there’s reactions non allergic reactions rather can occur and anywhere between maybe about three and ten percent of people usually they start at least 72 hours after you’ve been taking the medicine it can occur in people who have never taken a penicillin before it usually
Looks like a measles type eruption or a little reddish bump scattering around started off centrally and then spread to the extremities if a person happens to have mononucleosis and takes a drug and you shouldn’t take the drug of the add mononucleosis because mononucleosis not susceptible remember that’s a viral infection but if you do have mononucleosis 80 to 90
Percent of the time you will develop a rash when you take the amoxicillin the medicine also can cause some nausea vomiting and can cause some diarrhea the diarrhea can be relatively mild it’s less common than with ampicillin but sometimes it could be a very severe diarrhea it could be a severe diarrhea where you have watery bloody stools sometimes associated with
Cramps or fever even colitis overgrowth of an organism known as clostridium difficile that can be very important and can occur while you’re taking the drug or even up to a couple months after you stop the drug bacterial overgrowth on the tongue can lead to a black tongue you have to remember that if there is an allergy to penicillin or amoxicillin chances are
There’s going to be a fair chance of some kind of an allergy to cephalosporin but fortunately most people who think they’re allergic to penicillin really are not we can get a super infection if kill off the so-called good bugs then you can have some overgrowth of yeast or you can have overgrowth of some other bacteria that cause kind of problems some of the rare
Side effects are lightheadedness or insomnia some people get confused or become anxious or sensitive to light and sound you can’t have an allergic reaction to the medicine especially if you happen to have either asthma or hay fever or air to carry hives history of any of those allergic reactions can come on quite suddenly to start off oftentimes with some nausea
Vomiting and then a rash but the rash with the allergies oftentimes begins around the fingertips or the groin and then spreads very rapidly sometimes with a fever and a changed mental state the skin rash can become quite severe you can develop redness of the entire skin you can have altered liver functions you can become anemic you can have other sorts of problems
And at some times it may be a fatal reaction you can take the medicine if you happen to have kidney disorders but if you have deteriorated kidney function you might have to lower the dose it’s okay if you happen to be pregnant to take the drug doesn’t seem to cause any harm to the fetus doesn’t cause any impairment of fertility if you’re breastfeeding it’s still
Okay to take the medicine some will get into the breast milk but we use medicine and children in the pediatric age group especially in the newborns or the very young infants then we have a situation where the kidneys aren’t fully mature so you can’t fully eliminate the drug so we’re a little bit cautious with the dose and neonates are in young children geriatric
Population pretty much the same thing as the kidneys become less functional with aids and we might want to decrease the dose somewhat the common infections for which we use amoxicillin well there the ear nose and throat infections middle ear infections or strep throat or maybe certain forms of bacterial sinusitis person might have strep pneumoniae and certain
Kinds of sensitive staph or sensitive hamas luis influenza infection for genital urinary infection sometimes it’s used for acute cystitis although with increasing resistance of the e.coli that might not be as good a choice sometimes it’s used for asymptomatic bacteriuria in pregnancy it’s used in skin disease for cellulitis or impetigo and it’s sometimes used for
Lyme disease or for people have community acquired pneumonia at times previously it was used for gonorrhea that’s another form of neisseria neisseria meningitidis caused the meningitis well this is my syria gonorrhea that causes the genital infection now it’s pretty much resistant in many areas of the world the hamas fluid i’m sorry the h pylori the gila go back
To pylori the organism that causes the stomach ulcer that may go on and perhaps lead to ulcers or in some cases gastric cancer well that was once upon a time commonly treated with what we call triple therapy amoxicillin and clarithromycin and proton pump inhibitor but now it seems that there’s a lot of resistance to that so that’s sort of out and then formerly
It was used for a lot of gastrointestinal infections gastrointestinal infection with salmonella and should go on but now we have increased resistance now there’s some interactions so we have to be a little bit careful as i mentioned a moment ago with some of the antibiotics antibiotics like the soft drugs or the rifra meissen drugs or tetracycline drugs cory and
Finical those are all bacteriostatic drugs so they wound the organism they prevent it from dividing but the penicillin needs the organism to be dividing so it sort of defeats the purpose there is another medicine known as probenecid preventative very commonly used to treat the gout well in addition what it does is it prevents the excretion or delays the excretion
Of amoxicillin from the body so it increases the time the amoxicillin is going to be present and increases the concentration of the amoxicillin which might be a good thing you have to be a little careful if you’re taking warfarin the blood thinner if you happen to be taking methotrexate if you happen to be taking our pure and all the dose of the medicine well you
Take it every eight hours or every 12 hours depending on the situation that’s at hand we know that it readily absorbs from the gastrointestinal tract gets into the tissues very quickly gets into the body tissues even penetrates into the central nervous system especially if you happen to have some inflammation of the meninges the onset is within about half an hour
The half-life of the medicine mahler’s i mentioned in children about 3 to 4 hours if we look at adults it’s only about one to two hours only 20% of the medicine is bound that means 80% is unbound and it’s the unbound fraction of the medicine that’s active in the system so that’s good 60% goes out in the urine and six to eight hours so we have high concentration
In the kidneys high concentration in the bladder and as a matter of fact there’s what we call an intro a patek circulation so it gets into the intestine and then it’s reabsorbed then goes into the liver and it travels back out into the intestine so that means we have a significant increase in the concentration in the bile and in the stool overdose well that’s not
Really an issue if you take too much of antibiotic it might crystallize out so we make sure that you’re hydrated the dose is anywhere between 250 milligrams and 2 grams or 2,000 milligrams either twice a day or three times a day for adults and children over 90 pounds depending on the severity of the infection for children under 90 pounds it’s toast on the basis of
The body weight now that means for common your nose and throat infections skin infections genital urinary infections of moderate mild intensity but those could be 500 milligrams every 12 hours or 250 milligrams every eight hours if the person has severe infection then we boost the dose we go up to about eight hundred seventy five milligrams every 12 hours were 500
Milligrams three times a day you have to think about 80 percent of the dose in order for it to be fully effective and in order to prevent resistance or to reduce the likelihood of resistant organisms now there’s an issue with people taking the medicine has a prophylactic drug when they see the dentist because they’re worried about bacterial endocarditis now the
Rules have sort of been tightened so if you happen to have a prosthetic valve if you happen to have prosthetic material used to repair your valve if you have a past history of endocarditis or if you have certain forms of congenital heart disease or if you had a heart transplant then it might be wise to take the drug prior to the time you have a dental procedure
Where there’s going to be manipulation of the gingival tissues or the periapical tissue the region around the top of the tooth or there’s gonna be perforation of the oral mucosa it’s not used for just common cleaning of the teeth it also can be used for people are going to have procedures performed on the respiratory tract or on infected skin or infected tissue
Underneath the surface of the skin but there’s no specific link no reason to take prophylaxis if you’re going to have a gastrointestinal procedure or even a genital urinary tract procedure because the bacteria that tend to cause mischief in the heart are different so we’re worried more about the upper respiratory or sometimes the skin the dose would be single dose
30 to 60 minutes before your procedure amoxicillin at a dose of two grams one time only or it could be clindamycin 600 milligrams one time only or maybe cefalexin two grams taken once only now as i mentioned for he’ll go back to pylori for the stomach infection used to be that we would use clarithromycin and amoxicillin and a proton pump inhibitor for two weeks
That’s sort of obsolete and as of 2017 the official recommendation of the american college gastroenterology is that you take the clarithromycin in the amoxicillin and metronidazole combine those three drugs with proton pump inhibitor for two weeks but if you’ve ever taken clarithromycin in your entire life then the helical factor are going to be resistant to the
Clarithromycin and then the appropriate for drug treatment would be bismuth and tetracycline and the metronidazole in the proton pump inhibitor and forget the clarithromycin and forget the amoxicillin the likelihood of eradication with any of those regimens 70 80 % too likely to be reinfected most people are infected with helical factor pylori in their childhood
The likelihood of being reinfected in adulthood less than 1% a year the good news about amoxicillin is it’s very inexpensive you can get a month’s worth i’m sorry you can get a course worth of therapy for cash about twenty dollars and if you have a coupon in some place like good rx well you could get it for about ten dollars now you can’t get the amoxil brand they
Stopped making it because it’s now so inexpensive so you have amoxicillin it’s a very good antibiotic but remember it’s only good for certain bacterial infections bacterial infections with sensitive organisms it’s not good for the common cold so it’s still good even though it’s been around for a long time and that’s the story thanks for watching if you enjoyed the
Show that subscribe maybe tell a friend about us anyway i’m dr. ken landa
Transcribed from video
Amoxicillin By wellnowdoctor