Transcript for:
Pharmacology: Antimicrobials Classification

topic 11 for pharmacology is covering uh the classifications or several classifications within the general grouping of antimicrobials uh so each one of the classification we'll be looking at has their own section in the reading so we make use the hyperlinks to go to the text content uh for this material it's important to go back and review some of your antimicrobial terms and just the basics again a pathogen is the microorganism that is causing the disease that's what the um antibiotic or the antimicrobial drug is uh designed to um attack um be aware of some of the testing terms culture and sensitivity the importance of a culture to identify what the organism is and the sensitivity test to identify which micro um microbiotics are going to be most effective uh you'll see U pathogens identified by grham stain Graham stain is going to be a quick way of identifying um characteristics of the pathogen cell wall and that's going to help determine which class of antibiotics is going to be more effective when we talk about uh the number of pathogens a drug can effectively treat we're going to be looking at the issue of broad versus narrow Spectrum so again go back and review those terms be comfortable with what that means super infection are those infections that happen as a secondary unwanted effect of um antibiotic treatment so when we look at um medications that kill off normal bacteria on in our body either in the G tract or on our skin it gives rise to the um potential for uh fungal um organisms that also are normal residents of our body and yeast type organisms to flourish and develop a super infection a secondary infection strictly because our treatment of the initial infection has opened the door for uh these other organisms to flour uh when we're talking about the different drug classes we'll refer to them as bacteriostatic or bacterio cyal so we're we're looking at do they slow the pathogens uh ability to reproduce or do we actually kill the organism with a drug a mechanism of action is how do how does the drug do the do what it does and then again remember drug resistance is a general concept um organisms when they're exposed over time to the same drugs these pathogens can start mutating and the strongest will survive and and the strongest will be ones who have mutated and developed a resistance to the various drugs so when we're providing drug therapy antibiotic or antimicrobial therapy we want to make sure we're being effective that we may Poss use a combination of antimicrobials so we'd lower the um exposure to any specific one we want to make sure that when an antimicrobial is ordered and given that it's given at the appropriate dosing and it's given over the full length of the treatment interference with any of those or interruptions of any of those steps can lead to uh the pathogens developing resistance and we contribute then to uh the multi-drug resistant organism population uh the first class of drugs in the antimicrobials we want to look at it's an antibacterial so it's going to be um effective against bacterium or various bacteria is penicillin so they're going to in their generic names usually end with cin so they're all a related class they are bactericidal they are going to attack the bacterial cell wall and they destroy um weaken the cell wall of the bacteria disable its ability to um rebuild the injured areas and the cell wall eventually fails and the cell dies penicilin is overall the pen classes tend to be a broad spectrum they're going to cover multiple infections uh within this General class though the de development of the various uh subgroupings amus oyin pyin some of the others um May focus them in on specific um pathogens more than others so it maybe a some narrowing uh of their Spectrum but that's by Design some common reactions to the penicillin uh family of drugs is GI um GI upset nause and vomiting some diarrhea uh the potential for C the um fuzzy tongue which would be a yeast infection the candid um candid the the dasis sorry about that um are all those are tied into the fact that it's killing off not just the bacteria we want to treat but it's also killing off normal bacteria in the GI tract which is giving rise to these other pathogens to flourish so these become potential super infections um in terms of the hyperemia has a reaction penicillin contains potassium so as individuals on these penicillin medications for a period of time they're going to be absorbing potassium into their system if they're also on an potassium sparing anti- or potassium sparing diuretic or they're taking pottassium as a supplement we need to be aware of that because we can start increasing the potassium levels and getting into hyperemic issues um it is possible for an individual to develop a sensitivity or hypers sensitivity and Allergy uh normally with any of the antibiotics um the first dose will normally not produce the allergic response but it will begin the process so on the second dose um in particular is where we may see the very rapid anaphylactic response so again if we're producing new antibiotic including the penicillin's first dose we want to watch them carefully for any of those initial immune responses it normally will not progress to an anaphylactic type response but if they do develop and they do develop that sensitivity on the next dose we do see the risk for the anaphylactic type response that's why we want to monitor closely and uh catch it before it becomes a problem so General nursing considerations uh again check for the allergies if they're allergic to Amoxicillin then we assume they're allergic to penicillin sephos sporin are the next class we're going to look at they are closely related to penicillin they use a similar mechanism of action so an allergy to penicillin does not mean automatically there's a allergy to seis sporin but there may be so if we have an allergy to either penicillin or sephos sporin uh we are going to look for some other um other antimicrobial classes to use just to cut down on that potential for an anaphylactic reaction with any of our antimicrobials we want to obtain a culture before the first dose is given again cultures and sensitivities take a period of time to get the results back so generally what we're going to see is based on um the diagnosis uh and what that disease has traditionally responded to uh we're going to go ahead and start out with a generally a broad spectrum um anti antibiotic penicillin would fall in that class and then we're going to adjust that treatment once the sensitivities come back and switch over to another class if it is shown to be more effective than the penicillin product that we're using um we want um the stomach to be diluted down to allow the drug to get through the GI through the stomach in the G track for absorption um so we don't want a lot of acid involvement there so that's why we want to take it on empty stomach where there's not been a trigger to create the hydrochloric acid stimulation not and not taking it with an acidic juice uh if there is some stomach upset we can have the individual take with a small amount of food at the same time just to again facilitate moving it through the stomach with prolonged juice and high doses clotting mechanisms will be effective affected so we're going to be watching INR platelets and the PT levels and again we're treating infection we would just want to monitor our progression of our general signs and symptoms uh or manifestations of infection so monitoring white blood count monitoring temperature again really paying close attention to the cultures and sensitivities to see if we need to make an adjustment the sephos sporin are going to start out with seph cph or CF generally in their beginning of their um generic names they work very similar to penicillin um they are we can consider them a cousin to the penicillin uh they're again they're bactericidal using a similar mechanism of action as the penicillins again tend to be a broad spectrum uh but the Spectrum has been narrowed with different classes um as the specific subsets have been develop so again as the cultures and sensitivities come back it will help fine-tune which of the sephos sporin or another antimicrobial class if needed should be used the reactions um very similar to the penicillins um a little more risk for nephrotoxicity if they already have some renal dysfunctions we want to be watching for that and I've already talked about the issue of along with Penicillin of effect on bleeding um and clotting mechanisms um our our Comming considerations are going to be very common so I just want to point out a few individual ones here again renal impairment is an issue with the seis sporin possibly more so than the penicillin um also um when to be use it with caution with individuals with seizure disorders that may aggravate those situations as well uh the macrolides are a class of drugs that can be used if the penicilin and sephos sporin are uh contraindicated so again if there's an allergy to one or the other um we may see a move to the maites osin and aiyin these are bacterio static um they slow the a reproductive process of the bacteria uh keep the levels down and help allow the body's immune system to um develop and be more effective so again the bacteriostatic drugs are going to slow the disease develop or the bacterial development so immune system can then come in and do the destructive work they do it by invading the bacteria and um interrupting its ability to synthesize RNA so again it's going to uh slow down its reproductive process going to see it used routinely with respiratory infections otitis media the ear infections um going to use it with chlamidia which is sort of a bacteria viral combination type disease organism uh or we'll be seeing seeing it being used when uh the penicilin or seos sporin are not indicated uh still GI upset that's going to be consistent with most the antibiotics uh this um the risk for hypers sensitivity yeah we're leading to an allergic uh response uh over time macroides also um do have a side effect of photosensitivity the skin is going to be more sensitive much easier to burn our eyes are going to be more sensitive to light so if we're on prolonged juice of a macrolide um we want to be aware of um limiting exposure to the sunlight wearing long sleeves sunglasses that type of thing um in this case we're looking at liver function so prolonged juice of the macrolides or if we have any existing liver uh dysfunction we can increase the liver damage uh moving even into a hepatitis type situation as far as developing jaundice okay we're going to monitor the systemic signs of infection as a way of monitoring effectiveness of the drug um if it's a visible sight of infection we're going to be watching that for uh healing uh this drug can be given with or without food it doesn't really matter uh but particularly if they're having any GI upset from it uh taking it with food is encouraged uh the aminoglycosides become a more powerful drug they're bactericidal and they're going to work by inhibiting uh the bacteria's ability to synthesize protein to rebuild its wall so again it's going to lead to cell wall destruction and the death of the bacterium the pathogen again is a heavier Duty or heavier Duty drug so it's going to be used for severe infections uh TB some endocarditis stps some uh diseases that have not responded to the um penicilin sephos sporin or the maides some key things to focus on here is um high risk for toxicity effects has a very narrow therapeutic window so the difference between um the Baseline therapeutic level and the level at which it's toxic is not very wide so we have to watch the drug levels in the blood very closely when we get into that toxic level we're going to affect the nephrons so we're going to have some neurological damage uh we're going to affect the the nephrons in the kidneys we're going to affect the uh neurons so again we have kidney damage we have neuro damage uh it's going to have effect on the nerves leading to the ears especially so we have some ototoxicity some uh hearing loss some tenus that type of thing and that can be increased if there're being administered with a loop diuretic such as fosite or Lasix um also the strug will cross over uh the placental barrier barrier or be transferred with uh U milk for breastfed infants and can cause harm so becomes a Extreme Caution or contraindication in those situations so we want to check for allergies again make sure we have a culture before administering as soon as that culture and sensitivity comes back make sure the drug is appropriate injectable we want to put it en llarge muscle otherwise it's going to be extremely painful and damaging to tissue uh we don't want to absorb this drug through our own skin so please use gloves when you're preparing it if you need to prepare it for administration and because of that narrow window I'll be watching for the orders for a peak and trough levels a trough level is going to be ordered um about a half hour 10 hour before the next dose is due so we should get the um levels at their lowest um because the drug should have been metabolized to the as much of an extent as it can be at that point the peak level then is going to be drawn about an hour to an hour and a half after the administration of the drug so we can see what the levels are Peak um uh when it reaches Peak that's going to help us decide are we in the toxic range or not so if we are approaching the toxicity range then either the dose or the frequency is going to be scaled back if we're not um moving up past the therapeutic range or staying in the therapeutic range because we're too low then either the dose will be increased or the frequency of administration will be increased but those are going to be driven by the peak and trough drug levels uh the fluoroquinolones um lefloxin would be an example drug uh these also get inside the bacteria and inhibit their DNA replication they're going to damage cell wall so these are bactericidal drugs going to see them used frequently with certain pneumonias um and more complex infections infections on skin and urinary tract but again complex ones it's not normally um a firstline drug for simple infections again for our pneumonias it does become a first line because it's very effective with um specific ones of that uh carries a blackbox warning again the blackbox warnings are given by the FDA for drugs that have potentially life altering life destroying uh side effects uh the blackbox warning for the FL fluoroquinolones has to do with the potential of affecting the tendons uh and peripheral nerves so we're going to see potential for tendonitis we're going to see the potential of tendons actually rupturing we're going to see some CNS effects possibly um CNS effects may affect the those with myog graphis and increasing that muscle weakness um that's part of their disease again hypers sensitivity and GI upset are going to be a little um issues again photosensitivity again with Flo fluoroquinolones uh can also lead to or contribute to some hypoglycemia and C diff as a uh super infection um or opportunistic infection is a possib um specific things on here make sure they're taking plenty of fluids we want to move it through the system keep them hydrated uh should be administered 2 hours before or after meals or the use of an acids or taking in an iron supplement so we need a um focus on timing so 2 hours before or after the meals and an acids or iron supplements uh when given IV uh you'll notice with your penicillin sephos sporin those are tend to be tend to be given fairly quickly when we give them IV piggy back over 15 to 30 minutes when we get into fluoroquinolones though uh they need to be infused over at least an hour depending on the dose hour to up to an hour and a half uh the pharmacy um will put those instructions on your Mar but make sure you follow those closely otherwise we're going to run into um some toxicity issues the sulfonamides um you're going to hear them commonly the common trade names you'll hear are Baum and um sefta uh They al they're going to inhibit cell growth so they're bacterio static not CIO cyal they're a broadspectrum drug the sulfa type drugs have been around since before the penicillins uh their purpose is some usually going to be using some of the general R quote unquote routine bacteria so urinary tract in infections ear infections can be helpful with um beginning lung infections for people with chronic bronchitis uh also has some effect on traveler's diarrhea or monz Zuma's Revenge Type Thing uh things we're going to look for is the development of hypers sensitivity with use um looking through as it's eliminated through the urine it's going to have require effective uh kidney function and it's going to contribute to some kidney impairment if it already exists so we're going to be looking for some cloudiness or Crystal crystallization developing um with our type 2 diabetic patients we're going to use the sodomize very cautiously uh because we may see a drop in blood sugar so we need to make sure we're monitoring glucose levels um frequently and carefully it also can um increase the actions of our anti-coagulant such as warin uh Tetra cyclan uh is another class of antibiotics they are going to again get inside the cell inhibit their ability to synthesize protein um main effect is damaging the cell wall again so the cell wall fails the cell the bacterial cell dies uh Tetra cleans are broad spectrum so we're going to see them used from several different types of um organisms uh things we want to watch for again the GI upset photosensitivity CI and um the candidasis um again we're looking at yeast or as um opportunistic or super infection potentials here because we're going to wipe out a lot of good bacteria in the GI tract it's going to allow the C diff or the yeast um fungal organisms that normally live in our GEOS system to uh proliferate with children um as they're getting their permanent teeth in tetracyclines can cause permanent teeth discoloration so it's not um normally given or it's should not be given to those under 8 years old that's also going to fact fact some bone mass uh development as well uh can have some impact on the central nervous system in terms of circulation to the central nervous system so we might see some intracranial hypertension so we're going watch for any of those kind of symptoms of CNS involvement it also decreases the effectiveness of oral contraceptive so individuals who are taking site tetracycline uh will need to have um probably a dual approach to contraception becomes really important because as we get into uh the adverse reaction um it's very important um that an individual not take this drug if they're pregnant so we want to make sure that they're on very effective probably two two levels of protection for oral Contra for contraception oral plus um other approaches uh to decrease or eliminates a chance of developing a pregnancy so pregnancy testing before starting is also going to be important so let's try and think some things that stand out on this one this is a drug that as it ages it does not age well so if we use an outdated or a drug that has deteriorated it's going to um increase the potential for nerve damage nephrotoxicity diet and food interactions it should not be taken with dairy products and acids or the iron products because it's going to be reduced uh in its Effectiveness we want to schedule it an hour or two hour before meals and two hour 2 hours after meals in at least an hour before bedtime again we're going to avoid using children under eight um for the because of the discoloration of the teeth and it also is going to U bone growth and again in pregnancy uh needs to be avoided because because um it is very damaging to fetal development the last two slides just want to talk in real general terms about antivirals so these all the drugs up until now have been primarily antibacterials a couple of them were also good with chlamidia which is a bacteria viral type combination pathogen both for straight viruses uh the antibacterials will not tend to work because virus does not have the same cell structure as bacteria so those mechanisms of actions will not be effective on viruses that's why if we're looking at someone having a respiratory um symptoms that are most likely viral in nature we should not be seeing antibiotics ordered for that unless there's been a culturing sensitivity obtained that shows that it is truly a bacterial infection our antivirals I'm just going to talk in some real general terms because it's very specific to each virus on how the drug is going to work and what the effect is going to be in terms of the drugs themselves anytime you see a generic name uh that ends in vir you're are most likely looking at an antiviral and again what it's being used for is going to be specific to the virus involved uh the actions of antivirals is not to cure they don't um directly kill the virus what they do is impede or inhibit its ability to reproduce or release new viruses into the surrounding area um and how it does that is going to be very focused on the nature of the specific virus each antiviral is going to be developed specifically specifically for that class or subass of the virus so the purpose again is not to cure or kill the virus but to reduce the effects of the viral infection so that our body's normal immune systems can take over and um destroy the virus uh some general reaction with antivirals just be aware that they are uh toxic to can be toxic to the neuros system uh the level of toxic is going to vary by class so just need to look specifically at each one um as you're preparing to administer a drug we need to make sure that we're dosing it properly and administration compliance we're being compliant uh with our antivirals for influenza they need to be given and it's similar with Co um they need to be given within a specific window of time from the onset of symptoms or their effectiveness is going to be very uh very low uh we want to make sure there's good kidney function so we want to monitor that and with each grouping um it's going to be important to look over the documentation that comes with it for adverse effects to be monitoring so again antivirals um just in general um not going to kill the virus um merely going to slow its progression so the body can take over and do its job through the immune system um Effectiveness or how it works it's going to be specific to the specific viruses or viral class um that concludes the information then uh for topic 11