EN
SKETCHY PHARMACOLOGY FOR STEP 1 EXAM
QUESTIONS AND ANSWERS
Ethosuximide MoA
ANSWER IS - block T-type Ca2+ channels in thalamic neurons
Methotrexate MoA
ANSWER IS - inhibit DHFR, reducing the amount of DHF reduced to THF, which reduces the amount of
thymine synthesized, which halts cells in S phase of mitosis
Methotrexate AE
ANSWER IS - Folate deficiency (megaloblastic anemia), myelosuppression, pancytopenia
Pulmonary fibrosis (dyspnea, bilateral diffuse opacities, honeycomb bronchioles)
Hepatotoxicity
Alopecia
Stomatitis, soreness of the mouth
5-FU MoA
ANSWER IS - metabolized to active form (F-dUMP), complexes with THF to inhibit thymidylate synthase,
which halts cells in S phase of mitosis
,EN
5-FU AE
ANSWER IS - diarrhea, photosensitivity, hyperpigmentation, myelosuppression (increased infxn risk)
Hydroxyurea MoA
ANSWER IS - blocks ribonucleotide reductase, preventing de novo thymidine synthesis, which halts cells
in S phase of mitosis
Hydroxyurea AE
ANSWER IS - myelosuppression/pancytopenia (increased risk of infxn)
Azathioprine MoA
ANSWER IS - prodrug of 6-mercaptopurine, a cytotoxic purine analog that decreases IMP, decreasing
DNA and RNA synthesis, halting cells in S phase
6-MP MoA
ANSWER IS - activated by HGPRT, active metabolites inhibit IMP synthesis, decreasing DNA and RNA
synthesis, halting cells in S phase
6-MP AE
ANSWER IS - myelosuppression (leukopenia, thrombocytopenia), reactivation of HZV, pancreatitis,
hepatotoxicity (liver enzyme monitoring required)
,EN
Mycophenolate mofetil AE
ANSWER IS - GI upset, myelosuppression, immunodeficiency
Mycophenolate mofetil MoA
ANSWER IS - IMP dehydrogenase inhibitor, decreasing AMP and GMP synthesis, decreased lymphocyte
production
Cladribine MoA
ANSWER IS - purine analog incorporated into DNA and inhibiting DNA Polymerase alpha and beta,
arresting cells in S phase
Cladribine use
ANSWER IS - myelosuppression
Cladribine AE
ANSWER IS - myelosuppression
Cyclophosphamide MoA
ANSWER IS - prodrug metabolized to active form by P450 to a DNA alkylating agent; cell-cycle phase
NON-specific
, EN
Cyclophosphamide AE
ANSWER IS - myelosuppression, hemorrhagic cystitis (dysuria, hematuria), increased risk for bladder
cancer, hyponatremia (SIADH-induction), infertility, premature menopause, irreversible aspermia
Cyclophosphamide rescue drug
ANSWER IS - Mesna
Busulfan MoA
ANSWER IS - alkylating agent that forms DNA intrastrand cross-links, preventing DNA replication and
causing apoptosis; cell phase NON-specific
Busulfan AE
ANSWER IS - lung toxicity (interstitial fibrosis), hyperpigmentation, myelosuppression
Nitrosoureas MoA
ANSWER IS - alkylating agents that require biotransformation in liver, cross BBB, and inhibit DNA
replication; non-cell cycle specific
Nitrosoureas AE
ANSWER IS - neurotoxicity (dizziness, convulsions, ataxia, etc)
SKETCHY PHARMACOLOGY FOR STEP 1 EXAM
QUESTIONS AND ANSWERS
Ethosuximide MoA
ANSWER IS - block T-type Ca2+ channels in thalamic neurons
Methotrexate MoA
ANSWER IS - inhibit DHFR, reducing the amount of DHF reduced to THF, which reduces the amount of
thymine synthesized, which halts cells in S phase of mitosis
Methotrexate AE
ANSWER IS - Folate deficiency (megaloblastic anemia), myelosuppression, pancytopenia
Pulmonary fibrosis (dyspnea, bilateral diffuse opacities, honeycomb bronchioles)
Hepatotoxicity
Alopecia
Stomatitis, soreness of the mouth
5-FU MoA
ANSWER IS - metabolized to active form (F-dUMP), complexes with THF to inhibit thymidylate synthase,
which halts cells in S phase of mitosis
,EN
5-FU AE
ANSWER IS - diarrhea, photosensitivity, hyperpigmentation, myelosuppression (increased infxn risk)
Hydroxyurea MoA
ANSWER IS - blocks ribonucleotide reductase, preventing de novo thymidine synthesis, which halts cells
in S phase of mitosis
Hydroxyurea AE
ANSWER IS - myelosuppression/pancytopenia (increased risk of infxn)
Azathioprine MoA
ANSWER IS - prodrug of 6-mercaptopurine, a cytotoxic purine analog that decreases IMP, decreasing
DNA and RNA synthesis, halting cells in S phase
6-MP MoA
ANSWER IS - activated by HGPRT, active metabolites inhibit IMP synthesis, decreasing DNA and RNA
synthesis, halting cells in S phase
6-MP AE
ANSWER IS - myelosuppression (leukopenia, thrombocytopenia), reactivation of HZV, pancreatitis,
hepatotoxicity (liver enzyme monitoring required)
,EN
Mycophenolate mofetil AE
ANSWER IS - GI upset, myelosuppression, immunodeficiency
Mycophenolate mofetil MoA
ANSWER IS - IMP dehydrogenase inhibitor, decreasing AMP and GMP synthesis, decreased lymphocyte
production
Cladribine MoA
ANSWER IS - purine analog incorporated into DNA and inhibiting DNA Polymerase alpha and beta,
arresting cells in S phase
Cladribine use
ANSWER IS - myelosuppression
Cladribine AE
ANSWER IS - myelosuppression
Cyclophosphamide MoA
ANSWER IS - prodrug metabolized to active form by P450 to a DNA alkylating agent; cell-cycle phase
NON-specific
, EN
Cyclophosphamide AE
ANSWER IS - myelosuppression, hemorrhagic cystitis (dysuria, hematuria), increased risk for bladder
cancer, hyponatremia (SIADH-induction), infertility, premature menopause, irreversible aspermia
Cyclophosphamide rescue drug
ANSWER IS - Mesna
Busulfan MoA
ANSWER IS - alkylating agent that forms DNA intrastrand cross-links, preventing DNA replication and
causing apoptosis; cell phase NON-specific
Busulfan AE
ANSWER IS - lung toxicity (interstitial fibrosis), hyperpigmentation, myelosuppression
Nitrosoureas MoA
ANSWER IS - alkylating agents that require biotransformation in liver, cross BBB, and inhibit DNA
replication; non-cell cycle specific
Nitrosoureas AE
ANSWER IS - neurotoxicity (dizziness, convulsions, ataxia, etc)
