Amitha's Pharm test 3
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- What reaction do beta-lactam agents inhibit? This prevents synthesis of?
- Inhibit the transpeptidation reation or cross-linking that is important for formation of cell walls.
- Which mechanism of resistance to beta-lactam agents is the most problematic clinically?
- Bacterial production of a different penicillin binding protein with less affinity for antimicrobial agents but still effective for its bacterial function
- How are most beta-lactam agents eliminated?
- Most are eliminated renally except for a few penicillins excreted by the liver and biliary system.
- What is the MIC or minimum inhibitory concentration
- MIC is the minimum amount of drug at which the organism stops reproducing.
- What is the most common adverse effect of beta lactam agents?
- Skin rash. Begins on the trunk and can spread if the drug is continued.
- Allergies are mediated by Ig? and drug rashes are mediated by Ig?
-
Allergies- IgE
Drug Rash- IgM - Are allergies dose or duration related adverse effects to drugs?
- No
- How is Penicillin G administered?
- Administered IV as a sodium or potassium salt.
- How is phenoxymethylpenicillin or penicillin V administered?
- Orally
- What microbes are naturaly penicillins (i.e. penicillin G) effective against? (3)
- group A beta-hemolytic stroptococci, meningococci, normal oral flora (both aerobic and anaerobic)
- What types of organsims are extended spectrum penicillins effective against?
- gram negative bacilli
- Two families of drugs in the extended spectrum penicillins are
- Aminopenicillins (i.e. amoxicillin and ampicillin) and ureidopenicillins (i.e. piperacillin)
- Are natural penicillins safe in pregnancy?
- yes
- Cephapirin cefazolin and cephalexin are what generation cephalasporins?
- first
- Earlier generations of cephalosporins are effective against gram __________ bacteria while with each increasing generation there is more coverage of gram ________ bacteria
-
1. positive
2. negative - What is the usual mechanism behind multi drug resistance to chemotherapeutic agents?
- efflux of drugs by membrane pumps
- What are 3 classes of cell specific chemo drugs
- DNA synthesis inhibitors, topoisomerase II inhibitors, mitotic spindle poisons
- And are 3 classes of cell cycle nonspecific inhibitors
- DNA crosslinkers DNA intercalators, and topoisomerase I inhibitors
- What is the main difference between the cell cycle specific inhibitors and cell cycle nonspecific inhibitors
- cell cycle specific inhibitors tend to be used for rapidly proliferating tumors such as leukemia.
- What is the dose limiting toxicity of alkylating agents?
- Bone marrow suppression
- What is the mechansim of action of alkylating agents?
- transfer of alkyl groups to a nucleophile on proteins or DNA hwhich causes a bifunctional crosslink of DNA molecules to prevent separation of the strands and causes cell cycle arrest.
- What are 6 general classes of alkylating agents?
- Nitrogen mustards, nitrosureas, ethylenimines, alkyl sulfonates, traizines, others (including platinums)
- Cisplatin, carboplatin, and oxaliplatin are all in what class of alkylating agents?
- Platinums
- What is the dose limiting toxicity of cisplatin? Which drug has a simlar spectrum of activity without the nephrotoxicity?
- Nephrotoxicity. Carboplatin has a similar spectrum of activity.
- Oxaliplatin is approved as 2nd line treatment for which type of cancer?
- metastatic colon cancer
- Which types of cancer are platinums commonly used for?
- squamous cell carcinomas, esophageal, lung, head, and neck cancers
- What are the mechanisms of resistance to platinums?
- decreased intracellular accumulation, glutathione deactivation, and nucleotide excision repair pathway.
- What are the 3 major groups of antimetabolite chemotherapeutic agents?
- folic acid antagonists, pyrimidine antagonists, purine antagonists
- What are 3 folic acid antagonists?
- methotrexate, ralitrexed, and premetrexed
- What types of cancer is methotrexate useful for?
- Burkitt's lymphoma, lymphoblastic leukemia, breast cancer, head and nec cancer, ovarian cancer, cervical carcinomas, trophoblastic choreocarcinoma
- Which folic acid antagonist is approved for use against colon cancer?
- ralitrexed
- What is premetrexed approved for use against?
- mesothelioma and lung cancer
- What is the mechanism of action of folic acid antagonists? Which one has an additional mechanism?
- Inhibit folic acid that binds the catalytic domain of DHFR which generages essential cofactors for DNA, RNA, and protein synthesis. Premetrexed also inhibits thymidine synthesis
- What is the major toxicity of folic acid antagonists?
- myelosuppression and oral and GI ulceration
- what are the mechanisms of resistane of folic acid antogonists
- decreased uptake and decreased ability to synthesize polyglutamate (which is needed to keep the druge in the cell), reduced affinity of DHFR within the cell, increased efflux by MRP.
- What type of chemotherapeutic agents are 5-fluorouracil, capecitabine, cytarabine, gemcitabine, and clorfarabine?
- Pyrimidine antogonist.
- Which cancers is 5-fluorouracil effective against?
- colon cancer and other solid cancers
- What is the dose limiting toxicity of pyrimidine antagonists
- myelosuppression and oral and GI toxicity.
- What is the mechanism of inhibition of DNA synthesis of 5-fluorouracil? Where does it cause cell cycle arrest?
- It is a thymidine synthetase inhibitor. Causes arrest in the G1 phase.
- What is the mechanism of resistance of cancers to 5-fluorouracil?
- increased thymidine synthetase.
- What type of chemotherapeutic agents are mercaptopurine, thioguanin, cladribine, and fludarabine?
- purine antagonists
- Which 2 purine antagonists are the major ones used in leukemias ans lymphomas?
- mercaptopurine and thioguanine
- What is the dose limiting toxicity of purine antagonists?
- myelosuppression
- What is the mechanism of resistance to purine antagonists?
- decreased metabolic activation as well as alkaline phosphatase activation
- What type of chemotherapeutic agents are vincristine vinorelbine, and vinblastine?
- vinca alkaloids (a type of plant alkaloid)
- Which vinca alkaloid does not have myelosuppression? What is its dose limiting toxicity?
- vincristine. Neurotoxicity
- What types of cancers are vinca alkaloids used for?
- used for hematological malignancies, solid tumors, and pediatric cancers.
- What is the mechanism of action of vinca alkaloids? Cell cycle arrest occurs in which phase?
- inhibit microtubule polymerization and disrupt the mitotic spindle in rapidly dividing cells thus interfereing with the ability of the chromosomes to separate. M phase cycl arrest
- which type of cancer is irenotecan used for?
- Colorectal cancer
- Which types of cancer is topotecan used for?
- ovarian and small cell lung caner
- What is the dose limiting toxicity with topetecan?
- hemotological toxicity
- What is the dose limiting toxicity with irenotecan?
- diarrhea and myelosuppression
- What are 2 camptothecins?
- irenotecan and topetecan
- What is the mechanism of action of camptothecins? Which phase of the cell cycle is the cell arrested in?
- topoisomerase inhibition and DNA damage by single strand breaks. S phase cell cycle arrest
- What is the mechanism of resistance to camptothecins?
- efflux mechanisms involving the MRP transporter protein
- What are 2 drugs that are epipodophyllotoxins?
- etoposide and teniposide
- Which cancers is etoposide effective against?
- testicular, lung, gastric, and hematological
- Which cancer is teniposide effective against?
- lymphoplastic leukemia in children
- What is the dose limiting toxicity of epipodophyllotoxins?
- nausea, vomiting, myelosuppression, and alopecia
- What is the mechanism of action of epipodophyllotoxins? Cell cycle arrest occurs in which phase
- topoisomerase inhibition, DNA damage by causing single strand breaks. cycle arrest in either S or G2 phase.
- What are 2 drugs that are taxanes
- paclitaxel and docetaxel
- Which types of cancers are taxanes effective against?
- solid tumors, particularly breast and ovarian
- What is the mechanism of action of taxanes?
- stabilizes microtubule assembly and inhibits mitosis, blocks cell division in S phase
- What is the mechanism of resistance to taxanes?
- p-glycoprotein mediated efflux and tubulin mutations
- Which drug pump is prevalent in the colon and is responsible for the resistance of colon cancer to taxanes?
- p-glycoproteins
- which anthracyclines are used against acute leukemias?
- daunamycin and idarubicin
- Which anthracyclines are used against solid tumors?
- doxorubicin and epirubicin
- What are the general dose limiting toxicities of anthracyclines?
- meylosuppression and mucositis.
- Which anthracycline has cardiotoxicity
- doxorubicin
- What is the mechanism of action of anthracyclines?
- Very pleotropic- includes topoisomeraes II inhibition, DNA intercalation, alterations in membrane fluiditiy and ion transport, and generation of free radicals.
- What type of cancers is mitoxantrone used against?
- prostate cancer when the cells have become refractory to antiandrogens and require cytotoxic treatments, also non-hodgkin's lymphoma, breast cancer, and myeloid leukemia
- What is the dose limiting toxicity of mitoxantrone?
- myelosuppression
- What is the mechanism of action of mitoxantrone?
- DNA strand breakage and inhibition of DNA and RNA synthesis.
- What type of cancer is dactinomycin used for?
- pediatric solid tumors or choriocarcinoma
- What are the dose limiting toxicities of dactinomycin?
- myelosuppression, anorexia, nausea, and vomiting
- What is the mechanism of action of dactinomycin?
- binds doubl stranded DNA and intercalates between guanine and cytosine to inhibit transcription (blocks RNA polymerase), causes single strand DNA breaks
- What type of cancer can mitomycin be used against?
- hypoxia tumors
- What is the mechanism of action of mitomycin?
- it is a prodrug that undergoes reductive metabolism under hyposic conditions and can target necrotic tumors. It inhibits the DNA by crosslinking.
- What are the dose limiting toxicities of mitomycin
- thrombocytopenia, anemia, and renal failure
- What are the mechanisms of resistance to mitomycin?
- deficient metabolic activation, p-glycoprotein efflux, and intracellular deactivation of the metabolite
- Which type of cancers can bleomycin be used against?
- squamous cell carcinoma of the cervix, lymphoma, and testicular tumors
- What is the mechanism of action of bleomycin?
- DNA copper and iron binding peptide that causes DNA strand breaks
- What is the toxicity of bleomycin?
- pulmonary toxicity
- Which enzyme can be used in combination with vincristine and prednisone against pediatric leukemia?
- aspariginase
- What is the mechanism of action of aspariginase?
- catalysis of deamination of asparagine to form aspartic acid thus depriving neoplastic cells of asparagine
- What is a dose limiting toxicity of asparaginase?
- allergic reaction
- Which types of cancers can interferon alpha be used against?
- leukemia, sarcoma, and squamous cell carcinoma
- What is the mechanism of action of interferon alpha in its use against cancer?
- stimulate tumor cytomacrophages which have direct toxicity to tumor cells.
- Which types of cancers can interleukin-2 be uased against?
- malignant melanomas, squamous cell carcinomas
- What is the mechanism of action of interleukin 2 against cancer cells?
- increase activity of natural killer cells
- What is the mechanism of action of hydroxyureas in the treatment of cancer?
- Inhibit ribonucleotide diphosphate reductase and block DNA synthesis
- What type of cancer is tretinoin used for?
- promyeloid leukemia
- What is the mechanism of action of tretinoin?
- Binds a specific nuclear receptor protein to induce differentiation of tumor cells
- What are the side effects of tretinoin?
- skin dryness and elevation of liver enzymes
- What heavy metal can be used to treat certain types of leukemia?
- Arsenic trioxide
- What type of cancer is thalidomide used against?
- certain types of leukemia
- What type of cancer can estramustine be used for?
- prostate cancer
- What is a toxicity of thalidomide?
- It is teratogenic
- What is the mechanism of action of thalidomide?
- Inhibits angiogenesis-target is unclear
- What steroid hormone can be used to treat leukemia and lymphoma?
- prednisone
- What are the uses of progestins in anti cancer treatment?
- Endometrial cancer and stimulates appetite in cachectic patients
- What are the indications for use of anti-estrogens?
- estrogen receptor positive breast cancer
- What drug is a selective estrogen receptor modulator?
- Tamoxifem
- What drug is a selective estrogen receptor down regulator?
- Fulvestrant
- What types of drugs are anastrozole and letrozole?
- aromatase inhibitors
- What are the side effects of selective estrogen receptor modulators and estrogen receptor down regulators (SERD)
- cardiovascular toxicity, increased risk of endometrial cancer, nausea and vomiting, hot flashes. SERDs have less toxicity
- What is a side effect of aromatase inhibitors?
- bone loss
- What 2 classes of drugs suppress serum testosterone and can be used in treatment of androgen dependent prostate cancer?
- Androgen receptor antagonists and GnRH agonits
- What are side effects of anti-androgen therapy?
- hot flashes, impotence, and gynecomastia
- What is neoadjuvant therapy with regards to cancer therapy?
- treatment administered prior to primary therapy (i.e. radiation done before surgery)
- What do the terms complete response, partial response, measurable response, stable disease, and progressive disease mean with regards to cancer therapy?
-
CR-elimination of symptoms for one month (does not mean cured!)
PR-greater than 50% reduction
MR- less than 50% reduction
Stable disease-no change
progressive disease-increase in tumor burden - What do the stages mean with regards to cancer diagnosis?
-
Stage I-localized, high probabilty of surgical or radiation cure
II/III-more dangerous local spread, requires the tripod approach of surgical, chemotherapy, and radiation therapy
IV-distant metastases. chemotheraphy must be used - Chemotherapy kills cancer cells following ______ order kinetics
- first
- What is Imatinib (gleevec) used to treat?
- Chronic myelogenous leukemia
- What is the mechanism of action of imatinib (gleevec)?
- Binds to the bcr-abl protein
- How is celecoxib used in cancer therapy?
- Helps induce apoptosis by inhibiting COX 2 which is effective when given with other chemotherapy agents
- Which tissues with high growth fractions are adversely effected with chemotherapeutic agents?
- bone marrow, GI tract mucosal membranes, hair follicles, and skin
- What is the newer oral drug prodrug that is metabolized into active flurouracil?
- Capecitabine
- 5% of people have a deficiency of what enzyme that produces life threatening toxicity to normal doses of 5-Fluorouracil
- Dihydropyrimidine dehydrgenase (DPD).
- High levels of DPD in a tumor means that which chemotherapeutic agent will be less effective?
- 5-fluorouracil
- Echinacea combined with what class of drugs can become toxic?
- Immunosuppressants (corticosteroids)
- What two herbal supplements should a patient taking NSAIDS avoid?
- garlic and ginseng
- St. John's wort should be avoided by a patient taking what class of drug?
- MAO inhibitors
- Evening primrose should be avoided by a patient taking what class of drugs?
- anticonvulsants
- What is St. John's wort used to treat?
- depression
- What 4 botanicals should be avoided?
- Yohibe, comfrey, chaparral, and ephedra
- What substance found in broccoli has been shown to have anti-cancer properties?
- Indole-3-carbinol
- What substance found in garlic has anti-oxidant, anti-inflammatory properties?
- Allicin
- What substance found in St. John's Wort activates a CYP450 enzyme to increase metabolism of cyclosporin and theophylline?
- hypericin
- What are 2 drugs that are polyene antifungals?
- nystatin and amphotericin B
- What is the mechanism of action of Amphotericin B?
- acts against ergosterol to create a pore. The organism is leaky, osmotically fragile, and dies
- Is Amphotericin fungicidal or fungistatic?
- Fungicidal
- How is amphotericin administered?
- IV
- What toxicity limits the use of Amphotericin?
- Nephrotixicity
- What is amphotericin used to treat?
- common agents such as candida, aspergillus, coccidiodides, histoplasma, blastomyces, cryptococcus, and zygomycetes
- What are risk factors for nephrotoxicity with aphotericin use? How would one prevent this?
- use of other nephrotoxins, agents that make pt. volume depleted underlying renal disease. Prevent and manage nephrotoxicity by giving volume expanding drugs and avoiding diuretics.
- What toxicities are related to Amphotericin infusion?
-
Most common- fever
Rare-myalgias, bronchospasms, anaphylaxis - What are the advantages of lipid formulations of amphotericin B?
- Less nephrotoxicity- L-AmB has only 15% of the nephrotoxicity but maintains infusion toxicity
- Which lipid formulations of AmB can target the prain and can thus be used for cryptococcal meningitis?
- AmB-D and L-AmB
- How is ketoconazole administered/
- topically or orally
- What is the mechanism of action of azoles?
- Inhibits synthesis of ergosterols from lanosterol by inhibiting 14-alpha demethylase
- Are azoles fungistatic or fungicidal
- fungistatic
- What is the most important treatment for systemic and mucosal candida infections and cryptococcal meningitis worldwide?
- Fluconazole
- Which is the only azole available for once daily dosing?
- Fluconazole
- What is the first line therapy for aspergillosis?
- Voriconazole
- Which is the broadest spectrum oral antifungal agent?
- Posaconazole
- What is the treatment for zygomycosis?
- An induction dose of AmB to get the infection under control and then switch poconazole
- Which 2 azoles have CNS availability
- voriconazole and fluconazole
- Which azole must be taken with a high fat meal?
- posaconazole
- What toxicities are common to all azoles?
- hepatic toxicity rash, and vomiting
- Which azole has unique visual abnormalities such as photopsia an dhallucinations?
- voriconazole
- Which is the only azole that is renally excreted?
- fluconazole
- What class of drugs are anidulafungin caspofungin, an dmicafungin?
- echinocandin antifungals
- what is the mechanism of action of echinocandins?
- inhibit 1,3 beta-D glucan synthesis. Without a cell wall a fungi becomes osmotically fragile and dies
- Which organisms are echinocandins active against?
- Aspergillus and candida
- Are echinocandins orally available?
- No
- How are echinocandins metabolized?
- hepatically metabolized
- What is the mechanism of action of flucytosine
- Goes through the cell wall and is metabolized into 5-FU and inhibits DNA synthesis
- Why is flucytosine not used very often as monotherapy (except for UTIs)
- Induced resistance rapidly.
- What is the spectrum of activity of flucytosine?
- cryptococcus and candida
- What are the toxicities of flucytosine?
- bone marrow suppression, anemia, GI ulcers
- What is the dosing of echinocandins?
- once a day or once every other day
- What is the dosing of flucytosine
- 4 times a day-short half life
- How is flucytosine metabolized?
- renally excreted
- Which antifungal drugs exhibit time dependent killing?
- flucytosine and triazoles
- Which antifungals exhibit concentration dependent killing?
- AmB and Echinocandins
- What is the traditional gold standard anti-fungal therapy
- AmB
- What species are not susceptible to AmB?
- Aspergillus terreums, Fusarium, candida glabrata
- What is the first line treatment for blastomycosis?
- Itraconazole
- What is the first line treatment for pulmonary infection with Histoplasmosis?
- Itraconazole
- What drugs can be used to treat lyphocutaneous sporotrichosis
- supersaturated potassium iodide, itraconazole, fuconazole/terbinfine
- What is the mechanism of action of sulfonamides?
- Competitive inhibitor of para-aminobenzoic acid which prevents PABA from being incorporated into folic acid-safe for humans because we unlike bacteria can use preformed folate
- What do sulfonamides still have good activity against?
- Toxoplasmosis, Nocardia asteroides, topical use for conjunctivitis w/ Chlamydia trachomatis, topical use for burn wounds
- How are sulfa drugs administered?
- topically, orally, IV
- Which one of the following drugs can penetrate the CNS; sulfonamides, tetracyclines, macrolides, and clindamycin?
- sulfonamides
- What combination fo drugs can treat plasmodium falciparum?
- sulfadoxine with pyrimethamine
- What are common toxicities of sulfonamides?
- Gi distress, hypersensitivity, Stevens Johnson syndrom, vasculitis, crystal induced nephropathy, hemolytic syndromes, bone marrow suppression
- Should sulfa drugs be used in pregnancy?
- No
- Trimethoprine is commonly used in combination with which drugs
- Sulfonamides
- How are sulfonamides metabolized?
- excreted renally
- Which enteric pathogens is the combination of Trimethoprin/sulfamethoxalone used for?
- shigellosis, salmonella, and enteropathogenic E. Coli
- What is the drug of choice to treat CA-MRSA
- Trimethoprin/sulfamethoxalone (bactrim)
- What drug is used both in prophylaxis and treatment for pneumocyctis carnii pneumonia
- Trimethoprin/sulfamethoxalone
- What is the mechanism of action of tetracyclines?
- bind to the 30s ribosome inhibiting access of tRNA to mRNA and inhibiting bacterial protein synthesis-bacteriostatic
- What drug is used to treat tick borne pathogens?
- doxycycline
- What is the drug of choice for chlamydia infections?
- doxycycline
- Can tetracyclines be used in pregnancy?
- No
- What is the druge of choice for brucellosis and tularemia?
- doxycycline
- What fetal defects can tetracyclines cause?
- defect in permanent teeth (turns them a greyish color) and possibly fetal bones
- What toxicities can be caused by tetracyclines in general?
- GI distress, locally corrosive, photosensitive skin reactions, acute fatty liver of pregnancy, candida superinfections, pseudomotor cerebrii
- What is the only organism that is usually resistant to tigecycline?
- Psudomonas aeruginosa
- How is tigecycline administered?
- IV
- What are 3 macrolides?
- erythromycin, clarithromycin, and azithromycin
- What is the mechanism of action of macrolides?
- bind to 50s ribosome and block the transpeptidation reaction. bacteriostatic
- What is erythromycin active against?
- gram positive cocci
- Is dose adjustment necessary in renal failure for macrolides?
- No
- What drug is useful for treatment of diarrhea or enteritis caused by campylobacter jejuni?
- erythromycin
- What drug is used to eliminate the carrier state of corynebacerium diphtheriae?
- erythromycin
- Erythromycin causes activation of the receptors for which hormone? What systemic effect does this have?
- motilin, hormone responsible for inducing peristalsis and thus causes nausea.
- What is a specific side affect caused by demeclocycline that allows it to be used to treat SIADH?
- nephrogenic diabetes insipidus
- vertigo, ataxia, and vestibular dysfunction occur with which tetracycline?
- minocycline
- Absorption of erythromycin and azithromycin is increased or decreased with food?
- decreased
- absorption of clarithromycin is increased or decreased with food?
- increased
- What adverse affect caused by erythromycin can cause ventricular arrhythmias?
- prolonged QT intervals
- What adverse effect can occur when erythromycin is used in neonates?
- syndrome of hypertrophic pyloric stenosis
- Clarithromycin and azithromycin are effective against which 2 important respiratory tract pathogens?
- H. influenzae and moraxella catarrhalis
- What is the mechanism of action of clindamycin?
- blocks the 50s ribosome blocking transpeptidation reaction blocking protein synthesis. bacteriostatic
- What is clindamycin used primarily to treat?
- anaerobic infections
- what antibiotic causes antibiotic associated colitis caused by C. difficile?
- clindamycin
- What 2 drugs can be used to treat C. difficile coliis?
- metronidazole or vancomycin