Term
| What is selective toxicity? |
|
Definition
| The ability of a drug to injure a target cell or target organism without injuring other cells or organisms that are in intimate contact with the target. |
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Term
| Which families of drug weaken the bacterial cell wall and thereby promote cell lysis? |
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Definition
Penicillins
cephalosporins
Imipenem
Vancomycin
Caspofungin |
|
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Term
| Antibiotics that are selectively toxic because they inhibit an enzyme critical to bacterial survival but not to our survival. |
|
Definition
|
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Term
| Which enzyme is effected by sulfonamides that is critical to bacterial survival? |
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Definition
| An enzyme needed to synthesize folic acid from PABA (para-aminobenzoic acid) |
|
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Term
| Which class of antibiotics are active against only a few species of microorganisms? |
|
Definition
| Narrow spectrum antibiotics |
|
|
Term
| Which class of antibiotics are active against a wide variety of microorganisms? |
|
Definition
| Broad spectrum antibiotics |
|
|
Term
| What is the mechanism of action for penicillin? |
|
Definition
| Inhibition of cell wall synthesis |
|
|
Term
| What is the mechanism of action for cephalosporins? |
|
Definition
| Inhibition of cell wall synthesis |
|
|
Term
| What is the mechanism of action for Vancomycin? |
|
Definition
| Inhibition of cell wall synthesis |
|
|
Term
| What is the mechanism of action for Amphotericin? |
|
Definition
| Disruption of the cell membrane |
|
|
Term
| What is the mechanism of action for Daptomycin? |
|
Definition
| Disruption of the cell membrane |
|
|
Term
| What is the mechanism of action for Aminoglycosides? |
|
Definition
| Bactericidal inhibitor of protein synthesis (Lethal - reason for cell death is still unknown) |
|
|
Term
| What is the mechanism of action for Clindamycin? |
|
Definition
| Bacteriostatic inhibitor of protein synthesis (nonlethal - cellular growth is only slowed) |
|
|
Term
| What is the mechanism of action for Erythromycin? |
|
Definition
| Bacteriostatic inhibitor of protein synthesis (nonlethal) |
|
|
Term
| What is the mechanism of action for Linezolid? |
|
Definition
| Bacteriostatic inhibitor of protein synthesis (nonlethal) |
|
|
Term
| What is the mechanism of action for Tetracyclines? |
|
Definition
| Bacteriostatic inhibitor of protein synthesis (nonlethal) |
|
|
Term
| What is the mechanism of action for Fluoroquinolones? |
|
Definition
| Interferes with the synthesis or integrity of bacterial DNA/RNA (bind directly with nucleic acids or interact with enzymes required for nucleic acid synthesis) |
|
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Term
| What is the mechanism of action for Metronidazole? |
|
Definition
| They interfere with the synthesis or integrity of bacterial DNA/RNA (bind directly with nucleic acids or interact with enzymes required for nucleic acid synthesis) |
|
|
Term
| What is the mechanism of action for Rifampin? |
|
Definition
| Interferes with the synthesis or integrity of bacterial DNA/RNA (bind directly with nucleic acids or interact with enzymes required for nucleic acid synthesis) |
|
|
Term
| What is the mechanism of action for Sulfonamides? |
|
Definition
Antimetabolite
(disrupt specific biochemical reactions) |
|
|
Term
| What is the mechanism of action for Flucytosine? |
|
Definition
Antimetabolite
(disrupt specific biochemical reactions) |
|
|
Term
| What is the mechanism of action for Trimethoprim? |
|
Definition
Antimetabolite
(disrupt specific biochemical reactions) |
|
|
Term
| What is the mechanism of action for Acyclovir and Ganciclovir? |
|
Definition
Viral DNA polymerase inhibitor
(suppress viral replication) |
|
|
Term
| What is the mechanism of action for Zidovudine and Lamivudine? |
|
Definition
HIV reverse transcriptase inhibitors
(suppress viral replication) |
|
|
Term
| What is the mechanism of action for Ritonavir and Saquinavir? |
|
Definition
HIV protease inhibitors
(suppress viral replication) |
|
|
Term
| What is the mechanism of action for Enfuvirtide? |
|
Definition
HIV fusion inhibitor
(suppress viral replication) |
|
|
Term
| What is the mechanism of action for Raltegravir? |
|
Definition
HIV integrase inhibitor
(suppress viral replication) |
|
|
Term
| What is the mechanism of action for Maraviroc? |
|
Definition
HIV CCR5 antagonist
(suppress viral replication) |
|
|
Term
| What is the mechanism of action for Oseltamivir and Zanamivir? |
|
Definition
Influenza neuraminidase inhibitor
(suppress viral replication)
|
|
|
Term
| What are the four basic mechanisms for microbe resistance to drugs? |
|
Definition
1. decrease concentration of a drug at its site of action
2. alter the structure of drug target molecules
3. produce a drug antagonist
4. cause drug inactivation |
|
|
Term
| In spontaneous mutation, which type of resistance develops first? |
|
Definition
|
|
Term
| How many drugs does spontaneous resistance confer resistance to? |
|
Definition
|
|
Term
| The process by which extrachromosomal DNA is transferred from one bacterium to another. |
|
Definition
|
|
Term
| Conjugation takes place primarly among which bacteria? |
|
Definition
|
|
Term
| What kind of drug resistance is confered by conjugation? |
|
Definition
| Multiple drug resistance. |
|
|
Term
| Which antibiotic are more likely to promote resistance, narrow or broad spectrum? |
|
Definition
|
|
Term
| What is a suprainfection? |
|
Definition
| A new infection that appears during the course of treatment for a primary infection. |
|
|
Term
| What are the three principal factors that must be considered when choosing an antibiotic? |
|
Definition
1. the identity of the infecting organism
2. drug sensitivity of the infecting organism
3. host factors such as the site of infection ans the status of host defenses |
|
|
Term
What are three conditions that might rule out a first-choice antibiotic agent?
|
|
Definition
1. allergy to the drug of choice
2. inability of the drug of choice to penetrate to the site of infection
3. heightened susceptibility of the patient to toxicity of the first choice drug |
|
|
Term
| If it is necessary to start therapy without laboratory data, what must be done before treatment to prevent misidentification of the infective microbe? |
|
Definition
| Get samples of exudates and body fluids for culture |
|
|
Term
| What is the first rule of antimicrobial therapy? |
|
Definition
| Match the drug to the bug |
|
|
Term
| What are the most useful samples for a gram-stained preparation? |
|
Definition
| direct aspirates from the site of infection |
|
|
Term
| Which organism identification method can detect very low titers of bacteria and viruses? |
|
Definition
| polymerase chain reaction test (PCR) or nucleic acid amplification test |
|
|
Term
| Which test is more specific and sensitive, PCR tests or gram staining? |
|
Definition
|
|
Term
| What is another name for the disk-diffusion test? |
|
Definition
|
|
Term
| What is the lowest concentration of antibiotic that produces complete inhibition of bacterial growth but does NOT kill bacteria? |
|
Definition
| The minimum inhibitory concentration (MIC) |
|
|
Term
| What is the lowest concentration of drug that produces 99.9% decline in the number of bacterial colonies, indicating bacterial kill? |
|
Definition
| The minimum bacteriocidal concentration (MBC) |
|
|
Term
| What are the body's host defenses? |
|
Definition
| Immune system and phagocytic cells |
|
|
Term
| What determines optimum dosage sizes for antibiotics? |
|
Definition
Drug concentrations should be equal to or greater than the minimum inhibitory concentration (MIC) for the infection being treated.
Drug levels 4 to 8 times the MIC are often desirable |
|
|
Term
| What are the hazards of early discontinuation of antibiotic therapy? |
|
Definition
1. reinfection
2. increased resistance in the microbe, making subsequent treatment more difficult |
|
|
Term
| Which effect of antibiotic combinations is equal to the sum of the effects of the two involved antibiotics? |
|
Definition
|
|
Term
| Which effect of antibiotic combinations is greater than the sum of teh effects of the individual agents? |
|
Definition
| potentiative or synergistic reaction |
|
|
Term
| Which effect of antibiotic combinations is less effective than one of the agents by itself? |
|
Definition
|
|
Term
| What is the most common indication for using multiple antibiotics? |
|
Definition
| Initial therapy of severe infection of unknown etiology, especially in the neutropenic host. |
|
|
Term
| What are the disadvantages of antibiotic combinations? |
|
Definition
1. increased risk of toxic and allergic reactions
2. possible antagonism of antimicrobial effects
3. increased risk of suprainfection
4. selection of drug-resistant bacteria
5. increased cost |
|
|
Term
| Why should antibiotics NOT be used to treat fever of unknown origin? |
|
Definition
1. if the fever is not due to an infection, antibiotic use may expose the patient to unnecessary toxicity and delay correct diagnosis of the fever's cause
2. if the fever is caused by infection antibiotics could delay later attempts to identify the infecting organism |
|
|
Term
| What are some common illnesses that antibiotics are prescribed for, but have no effect on? |
|
Definition
| The common cold, bronchitis, sore throat, sinusitis |
|
|
Term
| In antimicrobial therapy, what is meant by the term selective toxicity? |
|
Definition
| the ability of a drug to injure invading microbes without injuring the cells of the host |
|
|
Term
| What are some of the mechanisms of resistance to antibiotic therapy? |
|
Definition
1. drug efflux
2. altered drug targets
3. enzymatic inactivation of drugs |
|
|
Term
| What is special about NDM-1 gene carrying bacteria? |
|
Definition
| They are resistant to nearly all available antibiotics |
|
|
Term
| In the hospital, what are four ways the emergence of antibiotic resistence can be delayed? |
|
Definition
1. prevention of infection
2. diagnosing and treating infection effectively
3. using antimicrobial drugs wisely
4. preventing patient-to-patient transmission |
|
|
Term
| When are combination antibiotics appropriate to use? |
|
Definition
1. initial treatment of severe infection
2. infection with more than one organism
3. treatment of tuberculosis
4. treatment of an infection in which combination therapy can greatly enhance antibacterial effects |
|
|
Term
| What are some appropriate indications for prophylactic antimicrobial therapy? |
|
Definition
1. certain surgeries
2. neutropenia
3. recurrent urinary tract infections
4. patients at risk for bacterial endocarditis |
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