Module 2 Study Guide/Module Questions Flashcards
What is the first rule of antimicrobial therapy?
Match the drug to the bug!
Define narrow-spectrum antibiotics? What’s an example?
Agents that act against a single or limited group of microorganisms. Example: Isoniazid works against tuberculosis exclusively. Penicillin.
Define broad-spectrum antibiotics? What is an example? What are you at risk for by using them?
Agents that are effective against a wide variety of microbial species. Example: Tetracycline. Note: Broad-spectrum antibiotics are the most likely to cause superinfection of an organism such as candida infection.
What are some tricks to knowing if a bacteria is Gram positive?
Bacteria starting with staph, strep or Enterococci.
Generally infections above the belly button.
What is the Black Box warning associated with floroquinolones?
Tendon rupture
A patient with a Type I Penicillin reaction has a _______% chance of crossing reacting with _________?
A patient with a Type I Penicillin reaction has a .17-8% chance of crossing reacting with a cephalosporin.
What is a Beta-Lactam?
a ring in the chemical structure of certain antibiotics including PCN, cephalosporins, and related compounds. The beta-lactam antibiotics exert their effect by interfering with the structural crosslinking of peptidoglycans in bacterial cell walls.
What is Beta-Lactamase?
An enzyme that some bacteria have that breaks apart the beta-lactame ring on certain antibiotics to keep them from working.
What antibiotic has many drug-to-drug interactions and what drugs should be avoided while taking?
Clarithromycin (Biaxin) should not be taken with statins or calcium channel blockers (can cause kidney injury)
What patient should NOT be prescribed Fluoroquinolones? What is the risk?
Patients with peripheral atherosclerotic vascular disease, hypertension, Marfan’s syndrome, and the elderly due to the increased risk of aortic aneurysm.
What are some serious side effects of flouroquinolones?
Adverse: Increased risk of tendon rupture in certain patients.
Side effects:
1) decreases in blood sugar
2) anxiety, confusion, and depression
3) non-reversible peripheral neuropathy
4) hepatotoxicity,
5) hematologic disorders
6) seizures,
What serious adverse effect is associated with Trimethoprim-sulfamethoxazole (TMP-SMX)? What concurrent drug increased this risk? What type of patients increases this risk?
Hyperkalemia and sudden cardiac death.
The use of TMP-SMX with angiotensin-converting inhibitors or angiotensin receptor blockers increases the risk. Elderly patients and those with kidney disease are most at risk.
What drug class is most commonly prescribed to pregnant patients?
Antibacterials
What two antibiotic types are second-line treatment in pregnancy if the first line is not effective?
Nitrofurantoins (macrobid) and sulfanomides.
Macrobid is the best choice of these two.
What are the three first-line antibiotics in pregnancy?
PCN, macrolides, cephalosporins
When should sulfonamides be avoided in pregnancy and why?
In the first and third trimesters (unless there is no other option). They inhibit folate metabolism and increase the risk of cardio defects and cleft defects. In the third trimester, they increase the risk of hyperbilirubinemia and kernicterus.
What antibiotic is contraindicated in pregnancy and why?
Tetracyclines (ex docycycline and minocycline) due to fetal tooth defects.
Which antibiotics are considered safe during breastfeeding?
PCN and cephalosporins (some consider macrolides safe)
What is a serious secondary GI infection that is related to antibiotic therapy in general? How do we prevent it?
C. Diff. Match the drug with the bug!
The four antibiotics that are most likely to cause C. diff are imipenem, ceftazidime, clindamycin, and moxifloxacin. Broader the spectrum of the antibiotic, the more likely it is to cause C. diff. This is because broader spectrum agents kill off intestinal flora and allow C. diff to get a head start.
What is the most severe reaction to sulfanomides? What type reaction is this?
The most severe hypersensitivity reaction to sulfonamides is Stevens-Johnson syndrome. Type 4-delayed onset 48-72 hrs. with Morbilliform rash.
What type of reaction is more common with PCN than any other family of drugs? What could cause people to think they are allergic to PCN when they may not be?
Type 1 severe allergic reactions. IgE mediated, Immediate hypersensitivity on the second exposure. Hives are an indication.
They received PCN as a child and had a rash-you can develop a rash with PCN if you have a virus. This is not an allergic reaction.
Which antibiotics in this module prolong Qt interval?
Macrolids: azithromycin, clarithromycin, erythromycin
Ciprofloxacin, levofloxicin, moxifloxacin
chloroquine
flucanazole, pentamadine
What are the four mechanisms microbes have for resisting drugs?
1) Chromosomal mutation
2) Inductive expression of a latent chromosomal gene
3) Exchange of genetic material through transformation (exchange of DNA)
4) Jumping Genes-enter transmissible plasmids or chromosomes.
What is antimicrobial stewardship? Why is it important?
The effort to measure and improve how antibiotics are prescribed by clinicians and used by patients. Critical to effectively treat infections, protect patients from harm, and combat antibiotic resistance.
How do antivirals work?
Reducing viral shedding and reducing viral count. They block entry into the cells preventing reproduction and shedding
What are the significant concerns with oral antifungals (azole)?
Hepatotoxicity, QT prolongation, drug-to-drug
The main concern with oral antifungals, specifically the azole antifungals, is their inhibition of the CYP450 enzymes which can result in drug-to-drug interactions when other drugs using the CYP450 system are taken concurrently. The statins are contraindicated with many of the azole antifungals.
What is the relationship between the onset of viral illness and antivirals?
most effective if given within the first 48 hours of onset (ex. influenza). These medications can shorten the duration of fever and illness symptoms and may reduce the risk of complications. The medications do not cure but simply reduce the severity of the symptoms.
Who is recommended to get a flu vaccine? how often?
Annual Flu vaccination is recommended for people 6 months old and older who do not have contraindications.
What is PrEP? What are the important teaching considerations when ordering PrEP? What lab monitoring is necessary for PrEP?
Pre-Exposure prophylaxis for HIV (ex. Truveda)
Teaching: The patient must be HIV negative always. Test prior to starting and every three months.
Must take daily. missing doses could increase the risk for drug-resistant HIV.
Labs: HIV testing, other STDs, kidney and liver function, pregnancy test.
Is oral fluconazole (Diflucan) safe in pregnancy and lactation?
In small doses (I.e. 150 mg PO) Diflucan is considered safe. However, higher doses or prolonged exposure are associated with congenital anomalies. Fluconazole is considered compatible with breastfeeding as exposure is less through the breastmilk than those doses considered safe for neonates. When other treatments fail to treat breast candidiasis, oral fluconazole is often prescribed for both mother and baby.
What types of vaccines cannot be given in pregnancy and why?
Only live vaccines have the potential to cause illness. Live vaccines are contraindicated in pregnancy. Because of the potential for viral shedding of the live vaccine, the provider must also consider close contacts and caregivers of patients who may be considering the live vaccine.
Which antifungal/antiviral drugs discussed prolong QT?
Antimalarial: chloroquine
Antifungal: fluconazole, and pentamidine.
When can you give Tdap in pregnancy? Is there an optimal time?
TDAP is recommended in each pregnancy 27-36 weeks or any time if needed.
What immunity are T lymphocytes responsible for? What are they particularly active against?
Cell-mediated immunity. Viruses.
What immunity are B lymphocytes responsible for and what do they produce?
Mediated humoral immunity. Produce antibodies.
What is a live vaccine?
Live, weakened actual infection (best and longest immune response)
What is a toxoid vaccine?
Vaccine against toxins requires sufficient standing antibody titer and needs booster (ex. tetnus)
What is a recombinant vaccine?
Contains only part of the microbe like the protein, sugar, capsid (less effective than whole cell but also less side effects).
What is active immunity?
Formation of antibodies related to direct exposure to antigen. Can be naturally or artificially obtained.
What is Passive Immunity?
Antibodies are passed to a recipient. Can also be obtained passively (ex. through breast milk) or actively (ex. rhogam).
Who cannot receive a live vaccine? How are these patient potentially protected despite not being able to be vaccinated?
Pregnant patients, immunocompromised and patients under 12 months.
Herd Immunity
What are some symptomatic precautions against vaccinations?
Temp greater than 105 within 48 hours, continuous crying greater than 3 hours, convulsions.
What are some true contraindications to vaccines?
Encephalopathy, a true allergy to egg protein, a true allergy to vaccine
CDC guidelines do allow patients with egg allergies to receive the vaccine. Those with severe allergies should be supervised by someone who can intervene if the patient becomes anaphylactic.
MMR: Latex/Gelatin allergy
How should injectable vaccines be spaced (i.e. can live and killed be given together or do they need to be spaced?)
Two or more killed vaccines can be given together or at any interval.
Killed and one live vaccine can be given together or at any time interval.
Two live vaccines can be given together or must be spaced by 4 weeks. Otherwise, the immune system will not respond correctly.
What vaccine has to be restarted if a dose is missed?
Typhoid vaccine
What is the most commonly seen Protozoans? What drug is most commonly used to treat?
Trichomonads (ex. Trich in preganancy) and giardia.
Treated with metronidazole (Flagyl)
What type of drug is Flagyl? What is the oral and vaginal types that we commonly use? Are they safe in pregnancy and breastfeeding?
Both an antibacterial and antiparasitic/antiprotozoal (trich, BV, giardia)
Oral metronidazol for trich, Metronidazol gell 0.75% (MetroGel)-both are considered safe
What vaginal medication can we prescribe in non pregnant patient that do not tolerate metronidazole?
Intravaginal clindamycin cream 2% (Cleocin T, Cleocin Vaginal)
What are the most common drugs used to treat Tuberculosis?
Isoniazid (INH and rifampin (rifadin)
What are the side effects we must consider with Isoniazid (INH)? What is the Black Box Warning for it? What lb monitoring is required?
Side effects: risk for symptomatic vitamin B6 deficiency (supplement with vitamin B6)
Black Box: Possibility of severe hepatitis.
Lab: LFTs required while taking
What important to consider with a patient taking Rifampin when prescribing new medications?
Rifamin is a powerful CYP450 inducer (speeds up metabolism). Make sure to check interactions and use backup contraception!
What coverage (Gr+ Gr-, broad, atypical) does Penicillin (Pen VK) provide?
Gr+
What coverage (Gr+ Gr-, broad, atypical) does Penicillin (Augmentin) extended coverage provide?
Gr + and Gr- and beta lactamase
What coverage (Gr+ Gr-, broad, atypical) does the Cephalosporins Keflex provide?
Gr+
What coverage (Gr+ Gr-, broad, atypical) does Florouquinolone Ciprofloxicin provide?
weak Gr+ Gr– and pseudomonas
What coverage (Gr+ Gr-, broad, atypical) does Macrolid Erythromycin provide? What generation is it?
Gr+, atypicals. Early generation.
What coverage (Gr+ Gr-, broad, atypical) do Sulfonamides provide? Give example of name.
Bactrim. Gr-, MRSA
What coverage (Gr+ Gr-, broad, atypical) do Tetracyclines (Doxycycline) provide?
Doxycycline: Gr-, Broad, atypical, MRSA.
What antibiotics should not be used in pregnancy/lactation?
Tetracyclines (doxycycline, inocycline) and fluoroquinolones
There is conflicting information on tetracyclines with BF
What is the Black Box Warning for Metronidazole/Flagyl?
It has shown to be carcinogenic in mice and rats
What coverage does Cephalasporin Ceftin give?
Gr+ Gr-
What coverage does Cephalasporin Rocephin give?
Gr+, Gr –, B lactamase
What coverage does Fluroquinalone Levaquin provide?
Gr+, Gr-, B lactamase, DRSP, Anaerobes, pseudomona
What coverage does Fluroquinaline Avelox provide?
Gr+, Gr-, atypical, B lactamase, DRSP MRSA, anaerobes, Pseudomonas
What coverage does Macrolid Azithromycin provide? (Gr+, GR-, atypical, broad?) What generation is it?
Later Generations. Gr+, Gr-, atypicals, broad
What are examples of broad spectrum antibiotics?
azithromycin, amoxicillin, tetracycline, and quinolones
Define the term selective toxicity
The ability of a drug to injure or target an organism without injuring other cells or organisms that are in intimate contact with the target.
Define and apply the term superinfection
A new infection that appears during treatment for another infection.
What circumstances would lead you to believe that your patient is more likely to have a resistant microbe
Daycare, smoker, long term antibiotic use.
How do antibiotics promote resistance? Which antibiotics promote resistance? Are any more likely than others to promote resistance? Why?
They kill of some, which reduce competition or makes the remaining ones immune to that antibiotic.
Broad spectrum are the most as they kill more competing bacteria.
What is drug susceptibility? And how do we determine susceptibility?
Drug susceptibility is what drug is going to work on the said organism.
Can do disk diffusion, serial dilution, and gradient diffusion.
What are the indications for using antibiotic combinations?
Initial therapy of a severe infection, especially of unknown etiology.
TB therapy is better and reduces resistance with two drugs.
What are the disadvantages of using antibiotic combinations?
Increased risk for toxic and allergic reactions.
possible antoginsm of antimicrobial effects.
increased risk for superinfection.
Selection of drug-resistant bacteria.
Increased cost.
What are the indications for prophylactic use of antimicrobials?
Surgery
Bacterial endocarditis (dental work)
Neutropenia
UTI, STD, chronic pneumonia.
Can you name five misuses of antimicrobial drugs?
Attempted treatment of viral infection.
Treatment of fever of unknown origin.
Improper dosage.
Tx in the absence of adequate bacteriologic information
Omission of surgical drainage (can prevent effectiveness, need clean wound!)
Do you understand factors in the selection of the best antimicrobial? Tip: Consider the most likely pathogen at the site, coverage needed, and tissue penetration of the selected drug.
Infecting organism, site of infection, the status of host defense, pharmacokinetics, the status of renal and liver function, clinical evaluation of effectiveness.
What does the generation of antibiotics mean? Is there a difference in microbe coverage as the generations progress?
The further generation, the more coverage you get.
List some Beta-lactamase inhibitors.
clavulanic acid, sulbactam, tazobactam
Which three drugs require lab monitoring (according to prof)?
Truveda-HIV
Antifungals-LFTs
Gentamycin-Troph
What drug in this lecture does not need to be avoided in warfarin?
PCN, flouroquinolones
