Chemotherapy side effects, metabolism, etc Flashcards
Which drugs are vesicants?
- Doxorubicin, Dactinomycin
- Vincristine, Vinblastine
- Mechlorethamine
- Dacarbazine (DTIC)
- Rabacfosadine (some people call it an irritant, but Thamm stated in his lecture it should be considered like a vinca alkaloid)
Which drugs cause cardiotoxicity?
Doxorubicin (dogs), HDAC inhibitors, Cyclophosphamide (high dose), 5-FU, cytarabine (high dose)
Which drugs cause pancreatitis?
Elspar, cytarabine
Which drug causes ototoxicity?
Cisplatin
Which drugs cause nail abnormalities?
Hydroxyurea, docetaxel, 5-FU, mitoxantrone, bleomycin
Which drugs cause SIADH?
Cyclophosphamide, vincristine, cisplatin
Which drugs cause dermatologic changes?
Tanovea, Topotecan
Which drugs cause palmar-plantar erythrodysesthesia?
Doxil, 5-FU, capecitabine, sunitinib, sorafenib
Which drugs cause mucosal ulceration?
methotrexate (GI mucositis), 5-FU, bleomycin, cytosar, , topotecan, sunitinib, sorafenib
Which drugs cause hypersensitivity reactions?
Etoposide, Doxorubicin, L-aspar, Paclitaxel, Methotrexate, cytarabine (high dose)
Which drugs cause pulmonary fibrosis?
bleomycin, busulfan, hydroxyurea, Tanovea
Which drugs cause pneumonitis?
Methotrexate, Fludarabine, gemcitabine
Which drugs cause acute emesis?
Cisplatin, Doxorubicin, Dacarbazine
Which drugs cause pulmonary edema?
Cisplatin, ifosfamide (cats), cytarabine (high dose)
Which drugs cause peripheral neuropathy?
Vincristine
Which drugs cause CNS/Neuro toxicity?
5 FU (cats; dogs at high dose), Ifosfamide, Cisplatin, Oxaliplatin, Methotrexate, cyatarbine (high dose)
Which drugs cause sterile hemorrhagic cystitis?
Cyclophosphamide, Ifosfamide
Which drugs cause renal toxicity?
Cisplatin, Carboplatin, Doxorubicin (cats), Streptozotocin, methotrexate (high dose), hydroxyurea, procarbazine, dacarbazine (DTIC)
Which drugs cause hepatotoxicity?
Lomustine (dogs), Methotrexate (fibrosis w/ long term use), topotecan
Which drugs cross the BBB?
- Lomustine, Carmustine
- Cytosine Arabinoside
- Hydroxyurea
- Procarbazine
- Temozolomide
- High dose methotrexate
- 5-FU
- Steroids
- Busulfan?
- Etoposide?
- Topotecan?
Which drugs are excreted unchanged in the urine?
- Carboplatin
- Methotrexate
- Hydroxyurea
Drugs that undergo CYP450 metabolism?
- Chlorambucil
- Cyclophosphamide and ifosfamide
- Procarbazine, DTIC
- Imatinib
- Palitaxel
- Vinca alkaloids
- Valproic acid
Which drugs can be found in urine 7 days after administration?
- CTX: below limit of detection on days 1-3
- VCR: still detected at day 3
- VBL: detected for 7 days after treatment
- Doxo and carbo: detected for up to 21 days after tx
Which drugs are ABCB1 substrates?
Mnemonic: “two vets went to lunch – DVM DVM ATE”
Doxorubicin, VCR, Mito, Daunorubicin, VBL, Mitomycin C, Actinomycin D, Taxanes, Etoposide
Which drugs go through primary hepatobiliary metabolism?
- vinca alkaloids
2. alkylators
Which drugs are radiosensitizers?
Name which ones cause radiation recall.
- Doxorubicin (can cause radiation recall)
- Gemcitabine
- Hydroxyurea (can cause radiation recall)
- 5-FU
- Mitomycin-C
- Fludarabine
- Taxanes
- Carboplatin/Cisplatin
- Vinca alkaloids (block cell cycle in G2/M)
- Mitoxatrone
Which drugs require dose modification for hepatic dysfunction?
doxo, taxanes, vinca alkaloids, mitoxantrone, etoposide, irinotecan, procarbazine, DTIC
Which drugs require dose modification for renal insufficiency?
Methotrexate, Cisplatin, Carboplatin, Streptozotocin, Hydroxyurea, Cytoxan, ifosfamide, procarbazine, dacarbazine, fludarabine, topotecan
What are the general mechanisms associated with resistance (Dr. Childress review)
Give the drugs with each:
1. Decreased uptake?
2. Increased Efflux?
3. Decreased Rx Activation/Increased RX Metabolism?
4. Increased/Decreased levels of target enzyme?
5. Alterations in Target Enzyme?
6. Inactivation by binding to sulfhydryls, increased DNA repair, decreased apoptosis?
- Decreased uptake: Methotrexate, Cisplatin, nitrogen mustards
- Increased Efflux: Anthracyclines
- Decreased Rx Activation/Increased RX Metabolism: Antimetabolites
- Increased/Decreased levels of target enzyme: Methotrexate
- Alterations in Target Enzyme: Methotrexate
- Inactivation by binding to sulfhydryls, increased DNA repair, decreased apoptosis: Cisplatin, Alkylators (in the form of glutathione), Anthracyclines
In case you want to challenge yourself, Chabner’s list is much more exhaustive :)
Give the drugs with each:
1. Decreased uptake?
2. Increased efflux?
3. Decrease in drug activation?
4. Increase in drug catabolism?
5. Increase or decrease in target enzyme levels?
6. Alterations in target protein?
7. Inactivation by binding to sulfhydryls?
8. Increased DNA repair?
9. Decreased ability to undergo apoptosis?
- Decreased uptake: methotrexate, other antimetabolites, cisplatin, nitrogen mustard
- Increased efflux: anthracyclines, vinca alkaloids, etoposide, taxanes, methotrexate, 5-FU, TKIs
- Decrease in drug activation: many antimetabolites (5-FU, ara-C)
- Increase in drug catabolism: many antimetabolites (5-FU, ara-C)
- Increase or decrease in target enzyme levels: methotrexate, topoisomerase inhibitors, 5-FU, TKIs
- Alterations in target protein: methotrexate, other antimetabolites, topoisomerase inhibitors, TKIs
- Inactivation by binding to sulfhydryls: alkylating agents, cisplatin
- Increased DNA repair: alkylating agents, cisplatin, anthracyclines
- Decreased ability to undergo apoptosis: alkylating agents, cisplatin, anthracyclines, etoposide
What are the cell cycle specific drugs and where do they best have effect?
- Antimetabolites: S phase specific
- Antimicrotubule Agents: m phase specific
- Topoisomerase I: Camptothecins, Topotecan, Irinotecan- S phase specific
- L-Asparaginase: maximal effect in G1
Drugs that have require metabolic activation or are considered prodrugs?
- cyclophosphamide, ifosfamide
- procarbazine, dacarbazine
- Fluorinated pyrimidines: 5-Fluorouracil
- Cytosine arabinoside (gemcitabine)
- irinotecan
Cyclophosphamide –> phosphoramide mustard
Procarbazine –> azoprocarbazine –> benzylazoxyprocarbazine, methylazoxyprocarbazine
5-FU –> FdUMP (thymidine synthase), FdUTP (DNA), and FUTP (RNA)
Cytosar –> ara-CTP
Irinotecan🡪 active metabolite SN-38
Which drug can cause thrombotic microangiopathy leading to hemolytic uremic syndrome?
gemcitabine
Which drugs go through extensive hepatic/billiary excretion?
vincas taxanes cyclophosphamide irinotecan anthracyclines mitoxantrone 5-FU cytosar gemcitabine 6-MP and azathioprine, 6-TG hydroxyurea (maybe, unknown)
- Just memorize what is renal elimination and then you will know the rest are liver
Which drugs are inactivated in the blood stream by conjugation to sulfhydryl groups and are 90% eliminated in the urine?
Platinums
Which drugs go through extensive renal excretion?
platiunums
topotecan
epipodophyllotoxins (etoposide, tenoposide)
methotrexate
Which drug is a level X teratogen?
Methotrexate
Which breeds are at highest risk for MDR mutation?
Collie > Long-haired whippet > Aussie > Sheltie
Which breed has the highest % mut/mut PGP?
a. Border collie
b. Aussie
c. Sheltie
d. OES
e. GSD
Aussie
Which drugs have glutathione mechanism of resistanc?
Alkylators, Anthracyclines (doxo), platiunums
What is the difference in MOA of leucovorin with MTX and 5-FU?
leucovorin is given with MTX to decrease toxicity; in contrast, it increases 5-FU toxicity
Which chemotherapeutics have a drug interaction with heparin?
doxorubicin and mitoxantrone
Which cancer has shown a decreased response to epirubicin?
T cell lymphoma
• Included in multi-drug protocol as doxorubicin substitute for LSA (n=97) (Elliott et al, VCO, 2013)
o Only 16% were neutropenic; overall hospitalization for entire protocol was only 9% (comparable to CHOP)
o 100% ORR (96% CR)
o Median TTR 216 days, MST 342 days – compares favorably to CHOP
o Negative prognostic indicators on univariate analysis: T-cell immunophenotype, hypercalcemia, substage b
A large Vd (a value larger than the total volume of the body water is possible) represents what type of drug binding?
extensive binding of drug in tissue (eg, vincas)
T/F: Drugs with extensive high protein-tissue binding or with high lipid solubility exhibit prolonged elimination phases because the release of bound drug from tissues is slow?
True
Fill in the blank with increases or decreases:
High plasma protein binding ___a___ Vd?
High tissue binding ___b___ Vd?
a. decreases
b. increases
In regards to 1st order kinetics what happens to the AUC if the drug clearance is constant?
If clearance remains constant, AUC will increase in proportion to drug dose
Answer the following questions about Phase I drug metabolizing enzymes:
- Modifies the target via which process?
2 Reactions via which superfamily?
- T/F: Leads to inactivation, activation, or no change in toxicity?
- Produces what type of metabolites (active or inactive)?
- oxidation, reduction, hydrolysis
- superfamily of cytochrome P450
o Also includes NADPH, quinone oxidoreductase, aldo-keto reductase, peroxidases - True
- produces metabolites that retain therapeutic activity or convert an inactive prodrug to an active moiety
Answer the following questions about Phase II drug metabolizing enzymes:
- Metabolites are conjugated with?
- Produces what type of metabolites (active or inactive)?
- Eliminated by the body how?
- a charged species such as glutathione, sulfate, glycine, or glucuronic acid
- generally, produce inactive metabolites
- eliminated from the body by biliary or renal excretion
UDP-glucuronosyltransferase, sulfotransferase, arylamine N-acetyltransferase, glutathione S-transferases
Fill in the blank for the Goldie-Coldman hypothesis:
The probability of at least one drug resistant cell in a tumor population is dependent on size. The likelihood of acquiring such a mutation increases with cell # and these events are likely to begin at sizes between _______ and _______?
10^3 and 10^6 cells (clinical detection = 10^9)
What is the MOR of docetaxel?
- Upregulation of Pgp (ABCB1) or MRP1 (ABCC1)
- Alterations in tubulin binding sites or microtubule dynamics
- Decreased apoptosis due to altered cell signaling
The AUC is most important for which drugs?
cisplatin, carboplatin, doxorubicin, alkalaytors
Which are the most common drugs to cause sepsis?
Dogs: doxo (OR 12.5) followed by VCR (9.0); Sorenmo et al, JAVMA, 2010
Cats: CCNU followed by vinca alkaloids; Pierro et al, VCO, 2017
- Which drugs block serotonin receptors (5-HT3 receptor antagonists)?
- Where do these drugs act?
- Which drug blocks NK1 receptors (substance P antagonists)?
- Where does this drug act?
- Which drug blocks dopamine receptors (D2 antagonist)?
- Where does this drug act?
- Which drug blocks H1 receptors?
- Where does this drug act?
- ondansetron, dolasetron
- Vomiting center, CRTZ, GI tract
- Cerenia
- Vomiting center, CRTZ, GI tract
- Metoclopramide
- CRTZ +/- GI tract
- Benadryl
- Vomiting center, Vestibular nuclei
MTD of vinorelbine in cats?
11.5mg/m2 IV once weekly
Sodium Thiosulfate for which drug extravasation
mechlorethamine
Which drug would actively compete with melphalan for active transport and can block its uptake?
leucine
Do cats experience clinically significant hepatotoxicity from CCNU?
Clinically significant hepatotoxicity appears rare in cats (Musser et al, JFMS, 2012)
6.8% (n=2) developed elevated ALT after 4 weeks, 1 of which had assoc. clinical signs
What occurs to liver enzymes in dogs when CCNU administered with Denamarin?
Increased LE occurs in 84% of dogs with CCNU and 68% receiving concurrent Denamarin
Which cancer has the highest response rate to CCNU?
Epitheliotropic LSA: 78-83%
Discuss % of CCNU canine fatal hepatotoxicity?
Most articles report 1-2% fatal hepatotoxicity; a single article (Hosoya JAAHA 2009) reports up to 16.6%
Clinically significant hepatotoxicity reported in 3-6%.
Mechanism of nephrotoxicity of ifosfamide?
• In the liver, ifosfamide undergoes N-chloroethylation (catalyzed by P450) to form chloroacetaldehyde this metabolite is neurotoxic
o Renal tubules also possess CYP450 form chloroacetaldehyde nephrotoxicity
• Damages proximal tubule, resulting in Fanconi-like syndrome (loss of glucose, Phos, bicarb, AA and protein into the urine)
Fatal toxicity of ifosfamide in cats?
fatal nephrotoxicity and 1 developed fatal pulmonary edema
Carboplatin nadir for neutropenia and thrombocytopenia?
Double nadir – neutrophil and platelet nadirs common at day 14 and 21
What is the DLT or unique AE that occurs with Doxil?
cutaneous toxicity resembling palmar-plantar erythrodysesthesia (PPES)
What is the efficacy of cisplatin and piroxicam when given together for TCC?
One study (dogs with TCC) had to reduce cisplatin to 40mg/m2 to give along with piroxicam; little anti-tumor activity and a high frequency of nephrotoxicity (86%) and GI toxicity were noted. Another study found MTD of cisplatin was 50mg/m2 when given with piroxicam, and the addition of an NSAID did not affect drug clearance.
A histone deacetylase inhibitor or DNA demethylator could impact impact p53 expression in an experiment on cell culture in what way?
P53 is a tumor suppressor gene. So treatment with an HDAC inhibitor would cause re-expression of p53 and inhibit cell growth
What is the difference in side effects between Palladia dosing of 2.5 vs 3.25 mg/kg?
Biologic activity is similar to 3.25mg/kg dose, but there were NO grade 3 or 4 GI toxicities in 2.5mg/kg group
What is the MTD of vinblastine when administered with Palladia for the tx of TCC?
MTD of VBL = 1.6mg/m2 q 14 days when given with Palladia; no increased response seen with TCC
Most common AE of Palladia in cats (different than dogs?)
Merrick et al, VCO, 2017
• GI upset (21.8%), thrombocytopenia (16%), neutropenia (9%), azotemia (14.5%), elevated ALT (7.2%)
o GI toxicity is improved compared to dogs (40-59%)
o Hematologic toxicity was mild and thrombocytopenia was more common than neutropenia; this is also different than dogs (neutropenia more common)
Dogs: one study reported 45% neutropenia, 28% thrombocytopenia, though another said 11% neutropenia and no episodes of thrombocytopenia
o Cats with lower body weights were less likely to develop CBC changes