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Pharmacology Exam 2
Antimicrobial and Anticancer Drugs
157
Pharmacology
Professional
02/04/2012

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Cards

Term
Clindmycin and Gentamycin
Definition
Empiric therapy- combination antibiotics
Term
Imipenem
Definition
Single broad-spectrum antibiotic
Term
Cilastatin
Definition
Single broad-spectrum antibiotic
Term
Penicillin family
Definition
Weaken cell wall and promote bacterial lysis
Term
Vancomycin
Definition
Weaken cell wall and promote bacterial lysis
Term
Cephalosporins
Definition
Weaken cell wall and promote bacterial lysis
Term
Sulfonamides
Definition
Inhibit and enzyme that is needed for bacterial production of Folic Acid (from PABA)
Term
Trimethoprim
Definition
Inhibits dihydrofolate release and chokes off the reaction from Dihydrofolic acid to Tetrahydrofolic acid in bacteria
Term
Sulfonamides and Trimethoprim
Definition
Combo drugs given for pneumonia
Term
Rifampin
Definition
Inhibits RNA polymerase
Term
Penicillin G and V
Definition
Narrow spectrum, high specificity
GRAM POSITIVE COCCI, GRAM NEGATIVE BACILLI
Term
Nafcillin
Definition
Penicillanase-resistant penicillin for Gram-positive cocci and gram-negative bacilli
Term
Methicillin
Definition
Penicillanase-resistant penicillin for Gram-positive cocci and gram-negative bacilli
Term
Vancomycin
Definition
Narrow-spectrum antibiotic for Gram-positive cocci and Gram-negative bacilli
Term
Erythromycin
Definition
Narrow-spectrum antibiotic for Gram-positive cocci and Gram-negative bacilli
Term
Clindamycin
Definition
Narrow-spectrum antibiotic for Gram-positive cocci and Gram-negative bacilli
Term
Aminoglycosides-gentamycin
Definition
Narrow-spectrum antibiotic for Gram-negative aerobes
Term
Cephalosporins
Definition
Narrow-spectrum antibiotic for Gram-negative aerobes
Term
Drugs for mycobacterium tuberculosis (RIPE)
Definition
Rifampin, Isoniazid, Pyrazinamide, Ethambutol
Term
Ampicillin
Definition
Broad spectrum for Gram positive and negative microorganisms
Term
Carbenicillin
Definition
Extended-spectrum penicillin for gram positive and negative microorganisms
Term
Sulfamethoxazole
Definition
A sulfonamide- inhibits production of folic acid
Term
Ciproflaxin
Definition
Fluoroquinolone for broad spectrum
Term
Norfloxacin
Definition
Fluoroquinolone for broad spectrum
Term
Levofloxacine
Definition
Doesn't metabolize well- use in urinary tract infections
Term
ABVD Combo
Definition
Doxorubicin, bleomycin, vinblastine, dacarbazine- ANTI CANCER
Term
Verapamil
Definition
Calcium Channel Blocker specific to heart
Term
Dolasetron
Definition
Serotonin-receptor antagonist- drug to treat nausea and vomiting
FIRST LINE
Term
Granisetron
Definition
Serotonin-receptor antagonist- drug to treat nausea and vomiting
FIRST LINE
Term
Ondansetron
Definition
Serotonin-receptor antagonist- drug to treat nausea and vomiting
FIRST LINE
Term
Prochlorperazine
Definition
Antidopaminergic drug for nausea and vomiting
SECOND LINE
Term
Fluphenazine
Definition
Antidopaminergic drug for nausea and vomiting
SECOND LINE
Term
Chlorpromazine
Definition
Antidopaminergic drug for nausea and vomiting
SECOND LINE
Term
Recombinant thrombopoietin
Definition
For cytopenias- reduces need for transfusion due to reduced Hct in chemo patients
Term
What is selective toxicity?
Definition
Trying to target the cell cycle of only cancer drugs while minimizing damage to healthy cells
SELECTIVE KILLING
Term
How do cancer cells invade surrounding tissue?
Definition
Secretion of proteolytic enzymes
Term
What is metastasis?
Definition
Spread to secondary sites
Term
From what do cancer cells arise?
Definition
Normal-renewal stem cells (tumor stem cells; ancestral cells)
Term
What part of the life cycle of a cell do cancer cells fail at that normal cells accomplish?
Definition
Differentiation
Term
What are 3 alterations found in cancer cells?
Definition
Cell surface antigens are different;
Enzymes are different
Oncogenes
Term
How can cell alterations in cancer cells be used to our advantage as doctors?
Definition
Immunologic techniques to use the changes as tumor markers for diagnosis and treatment
Term
How do cancer cells produce nutritional deficits and weight loss?
Definition
They have a high metabolic rate
Term
What is the origin of the vast majority of cancer cells?
Definition
Clonal origin- they arise as a consequence of a series of mutations on critical genes
Term
What is the definition of clonogenic as relates to tumor cells?
Definition
Colony-forming capacity- a small subpopulation of cells undergoes repeated cycles of proliferation and can migrate to different sites in the body
Term
What is myelosuppression?
Definition
Chemotherapy that reduces bone marrow
Term
What is chemotherapeutic index?
Definition
A way to describe selective toxicity
The ratio of a drugs toxicity to cancer cells over its toxicity to normal cells
(Toxicity is measured in LD50- the lethal dose for 50% of the cell population)
Term
Name 2 M-phase drug classes:
Definition
Vinca alkyloids; taxanes
Term
What are 3 factors in tumor growth rate?
Definition
-proportion of actively dividing cells (Growth Fraction)
-length of the cell cycle (Doubling Time)
-Rate of cell loss- wear and tear- apoptosis
Term
What shape is the growth curve of tumors and what does signify?
Definition
Sigmoid-shaped- doubling time varies with tumor size
Term
What is a 1-log kill?
Definition
Killing of 90% of tumor cells
Term
What is a 2-log kill?
Definition
Killing of 99% of tumor cells
Term
What is clinical remission?
Definition
When an effective drug kills 99.9% of clonogenic tumor cells
Term
How do we overcome the limited log kill of individual cancer drugs?
Definition
Administer combinations of drugs with different toxicities and mechanisms of action
Term
What is a pharmacologic sanctuary?
Definition
A place, like the CNS or testes, where effective drug concentrations are difficult to achieve
Term
What is required for the use of CCS drugs?
(Cell Cycle Specific)
Definition
The tumor stem cells must be in the sensitive phase of the cell cycle for that drug
Term
In what types of cancer are frequent treatments most effective?
Definition
Leukemia, Hodgkins Disease, Testicular Cancer, Lymphoma- tumor cell kill exceeds regrowth
Term
What are the 3 things that combination chemotherapy accomplishes that single-agent therapy does not?
Definition
-maximum cell kill within the range of drug toxicity
-broader range of coverage of resistant cell lines in a heterogenous tumor
-prevents or slows development of new drug-resistant cell lines
Term
What is an example of a type of tumor that exhibits primary resistance?
Definition
Non-small cell lung cancer; colon cancer
Term
What is primary resistance?
Definition
Absence of response on first exposure
Term
What is acquired resistance?
Definition
Resistance that develops in previously drug-sensitive tumors
Term
What is drug resistance usually based on?
Definition
Change in the genetic apparatus of the tumor with amplification or increased expression of one or more genes
Term
What is usually involved in multi-drug resistance to chemotherapy?
Definition
MDR1 gene has increased expression- codes for P GLYCOPROTEIN
-involved in drug efflux- uses ATP to expel foreign molecules
Term
What is P-glycoprotein?
Definition
A transport molecule responsible for multi-drug resistance in cancer cells
-2 binding sites for ATP- only one is involved in drug transport
Term
What types of drugs can reverse multi-drug resistance experimentally?
Definition
Calcium Channel Blockers- verapamil, quinidine, cyclosporin
Term
What is the consequence of overexpression of MRP?
Definition
Multidrug Resistance Protein- ATP-binding transmembrane transporter
-INCREASES RESISTANCE TO anthracylcines, vinca alkyloids
Term
Can you name six anticancer drugs susceptible to MDR-1 resistance?
Definition
Anthracyclines
Vinca Alkyloids
Paclitaxel (Taxol)
Etoposide
Mitomycin (Mutamycin)
Plicamycin (Mithramycin)
Term
For what types of cancer would you administer endocrine therapy?
Definition
Prostate, breast, endometrium
Term
What is immunotherapy?
Definition
Biologic response modifiers to enhance endogenous immune cell kill;
tumor vaccines
Term
What is important about reproductive gland tumors as far as treatment?
Definition
Reproductive glands are steroid sensitive and their tumors are too
Term
What are some symptoms of low WBC counts as a result of myelosuppression?
Definition
fever, sore throat, cough, SOB, congestion, dysuria, shaking chills, redness and swelling at the site of an injury
Term
What are some symptoms of low RBC counts as a result of myelosuppression?
Definition
Fatigue, dizziness, headaches, irritability, SOB, increase in heart rate and breathing
Term
What are the consequences of low platelet count in chemotherapy?
Definition
Bruising easily, bleeding longer than normal, bleeding gums and nose bleeds, large bruises, petechiae, serious internal bleeding
Term
What are 2 classes of drugs given to treat nausea and vomiting in chemotherapy?
Definition
Serotonin receptor antagonists
Antidopaminergics
Term
In what two regions of the medulla do antiemetics appear to act?
Definition
Chemoreceptor trigger zone (CTZ)
Vestibular Apparatus
Term
What class of drugs is most effective in managing nausea and vomiting associated with chemotherapy or radiotherapy?
Definition
Serotonin-receptor antagonists- FIRST LINE
Term
What are the two important receptors in the chemoreceptor trigger zone?
Definition
D2- dopamine 2 receptors
5HT3- serotonin receptors
Term
How is significant thrombocytopenia managed in cancer patients?
Definition
Transfusion of platelet concentrates
Term
What is the definition of an antibiotic?
Definition
A chemical produced by a microorganism that has the ability to harm other microbes
Term
What is empiric therapy?
Definition
Presumptive- use of antimicrobials before the pathogen for a particular illness is known
Based on experience with a CLINICAL ENTITY
Term
What justifies empirical therapy?
Definition
Risk of death, causes no harm, if disease is contagious, if early intervention works better, for process of elimination
Term
What are the two lines of empiric therapy (drugs)?
Definition
Combo- clinamycin and gentamycin
Single- imipenem or cilastatin
Term
If you give empiric therapy and the culture report is gram positive, what do you do?
Definition
Continue gram positive coverage, discontinue gram negative and anaerobic coverage
Term
If you give empiric therapy and the culture report is gram negative only, what do you do?
Definition
Continue gram negative coverage and discontinue gram positive and anaerobic coverage
Term
If you give empiric therapy and the culture report is mixed, what do you do?
Definition
Continue therapy as initiated
Term
If you give empiric therapy and the culture report is anaerobic only, what do you do?
Definition
Continue anaerobic coverage, discontinue gram positive and gram negative coverage
Term
What is culture and sensitivity?
Definition
A measure of how susceptible or resistant a bug is to a drug
Term
What are 3 ways that selective toxicity is achieved?
Definition
Disrupt bacterial cell wall
Disrupt bacterial protein synthesis (macrolides)
Inhibit an enzyme unique to bacteria
Term
How do cephalosporins and penicillins work on bacteria?
Definition
They weaken the cell wall and promote bacterial lysis
INHIBIT MUREIN SYNTHESIS
Term
How is mammalian folic acid acquired?
Definition
Nutritional/dietary sources
Term
How is bacterial folic acid acquired?
Definition
Synthesized
Term
How do sulfonamides suppress bacterial growth?
Definition
Inhibit the synthesis of folic acid from PABA
Term
What enzyme do sulphonamides inhibit and how?
Definition
Dihydropteroate synthase, by competing with PABA
Term
What inhibits Diydrofolate reductase and what does it accomplish?
Definition
Trimethoprim- chokes off the synthesis of tetrahydrofolic acid
Term
What class of drugs inhibits DNA gyrase?
Definition
Fluoroquinolones
Term
What is MIC?
Definition
Minimum Inhibitory Concentration- an antimicrobial should be present in concentrations such that it can either inhibit growth or kill the organism (minimum bactericidal concentration, MBC)
Term
What happens if there is a mutation in bacterial porin?
Definition
The drug can get to, but not INTO the microbe
Term
What are 3 factors determining resistance or limited susceptibility?
Definition
Failure of a drug to reach its target, drug inactivation, target alteration
Term
What is important about the outer membrane of gram negative bacteria?
Definition
It is a barrier that excludes large polar molecules from entering the cell
Term
How do small polar molecules enter gram negative bacteria?
Definition
Porins- protein channels
Term
How do bacteria become resistant to Gentamicin?
Definition
A deficiency in transport of the drug by mutating the pathway that maintains the electrochemical gradient required to move it into the cell
Term
How is the electrochemical gradient generated that is required for the transport of Gentamicin and other drugs into the bacterial cell?
Definition
Specific enzymes couple electron transfer and oxidative phosphorylation
Term
What are 5 drugs for which resistance can be established by bacterial expressing efflux pumps to transport them out of the cell?
Definition
Tetracyclines, chloramphenicol, fluoroquinolones, macrolides, beta lactam antibiotics
Term
What do the MDR gene make?
Definition
The efflux pump that aids in bacterial drug resistance
Term
Why is levofloxacine used in UTIs?
Definition
It doesn't metabolize well so winds up intact in the urinary tract
Term
How is resistance to aminoglycosides and Beta lactam antibiotics established?
Definition
Bacterial production of enzymes that modify or destroy the antibiotic
Term
What is unique about resistance of TB against Isoniazid?
Definition
Typically, TB converts isoniazid from a prodrug to its active form. If it loses this ability, resistance develops
Term
What type of drug most promotes resistance?
Definition
Broad spectrum antibiotics
Term
What is superinfection and how is it defined?
Definition
A new infection that appears during the course of treatment for a primary infection
-antibiotic use limits the inhibitory influence of normal flora, allowing a second bug to flourish
Term
What type of drugs are most likely to cause superinfection?
Definition
Broad spectrum antibiotics
Term
What are the 3 principle factors in selecting antibiotics?
Definition
Identity of organism
Drug sensitivity of organism
Host factors (site of infection, status of host defenses)
Term
What characterizes a "drug of choice" in antibiotic administration?
Definition
Greater efficacy, lower toxicity, very narrow spectrum (rifle)
Term
What happens if sulfonamides are given to newborns?
Definition
Kernicterus, a neurological disorder caused by displacement of bilirubin from plasma proteins
Term
What causes kernicterus in newborns?
Definition
Sulfonamides
Term
What do tetracyclines do to developing teeth?
Definition
Cause discoloration
Term
What causes discoloration in developing teeth?
Definition
Tetracyclines; too many oreos
Term
What is an additive response?
Definition
The antimicrobial effect of a combination is equal to the sum of the effects of the drugs alone
Term
What is a potentiative/synergistic interaction?
Definition
The effect of the combination of drugs is GREATER than the sum of the individual drugs- one drug must show at least a 4fold increase in antibacterial activity
Term
What is the synergistic action of Trimethoprim and sulfamethoxazole?
Definition
Blockade of sequential steps in metabolic sequence of folic acid
Term
What is the synergistic action of beta-lactams and beta-lactamase inhibitors?
Definition
Kill, and promote enzymatic inactivation of the killer
Term
How do penicillins synergize with aminoglycosides?
Definition
They enhance the uptake of aminoglycosides in staphylococci and enterococci
Term
What is an antagonistic response?
Definition
The combo of two agents is less effective than one of the agents by themselves
Term
Chloramphenicol and penicillin together are examples of ...
Definition
Antagonistic agents in the treatment of pneumococcal meningitis
Term
Tetracycline is________ to penicillin
Definition
Antagonistic
Term
Where are mixed infections most common?
Definition
Brain abscesses, pelvic infections, and perforation of abdominal organs
Term
What is the main disease in which combinations are always employed?
Definition
Tuberculosis
Term
What is the mechanism of action of penicillins?
Definition
Binding to penicillin binding proteins
Term
What is the mechanism of action of tetracyclines?
Definition
Attack bacterial 30S ribosome
Term
What is the mechanism of action of aminoglycosides?
Definition
Affect protein synthesis
Term
What is the mechanism of action of quinolones?
Definition
Inhibit DNA gyrase
Term
What is the mechanism of action of cephalosporins?
Definition
Affect protein synthesis
Term
What is the mechanism of action of macrolides?
Definition
Attack bacterial 50S ribosome
Term
What is the most commonly used method to test susceptibility to antibiotics?
Definition
Disk diffusion
Term
What antibiotics inhibit cell wall synthesis?
Definition
Penicillins, cephalosporins, imipenem, vancomycin
Term
What antibiotics disrupt cell wall membranes?
Definition
Amphotericin B, ketoconazole
Term
What antibiotics are bacteriostatic inhibitors of protein synthesis?
Definition
Clindamycin, erythromycin, tetracyclines
Term
What antibiotics interfere with bacterial DNA or RNA synthesis?
Definition
Fluoroquinolones, rifampin
Term
What antibiotic inhibits mycolic acid synthesis?
Definition
Isoniazid
Term
What is a bacteriostatic drug?
Definition
It inhibits bacterial GROWTH (does not kill)
Term
What is the cause of staphylococcal resistance to methicillin?
Definition
Production of low-affinity variant of penicillin binding proteins (PBPs)
Term
How is resistance transmitted horizonatally between individual bacteria?
Definition
Plasmid exchange
Term
By what mechanism can multiple resistance genes be transferred in a single event?
Definition
Direct transfer of resitant genes by cell to cell contact through a sex pilus or bridge (CONJUGATION_
Term
What is conjugation, and in what type of bugs is it most common?
Definition
Direct transfer of resitant genes by cell to cell contact through a sex pilus or bridge
-gram negatives
Term
What two DNA segments constitute the resistance factor (R factor)?
Definition
One that codes for the mechanism of resistance
One that codes for the sexual apparatus needed to transfer the DNA
Term
Resistance to fluoroquinolone is seen in....
Definition
E. coli
Term
Resistance to penicillin is seen in...
Definition
S. pneumoniae
Term
Resistance to vancomycin is seen in...
Definition
S. aureus
Term
What type of antimicrobials are best in an immunocompromised host?
Definition
Rapidly bactericidal
Term
Why is endocarditis hard to treat?
Definition
Bacterial vegetations in the heart are difficult to penetrate
Term
Why are infected abscesses hard to target/treat?
Definition
Poor vascularity and the presence of pus and other material
Term
At what speed do neonates eliminate drugs and why?
Definition
Slowly due to poorly developed kidney and liver functions
Term
What is the main adverse reaction to using gentamycin during pregnancy?
Definition
Hearing loss
Term
What are the consequences of using tetracyclines during pregnancy?
Definition
Hepatic necrosis, pancreatitis, renal damage
Term
What are 3 antibiotics associated with a high incidence of allergic response?
Definition
Sulfonamides, trimethoprim, erythromycin
Term
What happens if patients whose RBCs are deficient in G6PD take sulfonamides?
Definition
Hemolysis
Term
What two gram-positive bacteria transfer antibiotic resistance via conjugation?
Definition
Staph and Enterococci
Term
What two gram-positive bacteria transfer antibiotic resistance via conjugation?
Definition
Staph and Enterococci
Term
Under what 3 clinical circumstances is it best to administer prophylactic antibiotics?
Definition
Surgery
Bacterial Endocarditis
Neutropenia
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