Medical Pharmacology Practice Questions: Chapter 33-34 Protein Tyrosine Kinase Inhibitors of EGFR: Medical Pharmacology Practice Questions: Chapter 33-34 Protein Tyrosine Kinase Inhibitors of EGFR: Medical Pharmacology Practice Questions: Chapter 33-34 Protein Tyrosine Kinase Inhibitors of EGFR: Gefitinib (Iressa)

Medical Pharmacology Practice Questions: Protein Tyrosine Kinase Inhibitors of EGFR: Gefitinib (Iressa)

Gefitinib (Iressa):
1. Is classified as a tyrosine kinase inhibitor.
2. Irreversibly inhibits kinase activity.
3. Both
4. Neither
Gefitinib administration prevents tyrosine residue of autophosphorylation of the EGFR receptor.
1. True
2. False
Gefitinib is more likely to bind (exhibits a higher affinity) to wild-type (naturally occurring) EGFR compared to certain EGFR mutational forms (e.g. EGFR (Mutations: exon 19 deletion; exon 21 substitution).
1. True
2. False
Gefitinib pharmacokinetics/pharmacodynamics:
1. Oral bioavailability: about 60%
2. Absorption increased by drugs that increase gastric pH and by food.
3. Both
4. Neither
Gefitinib pharmacokinetic/pharmacodynamics:
1. Gefitinib metabolism: mainly by the cytochrome P450 drug metabolizing system utilizing principally CYP3A4 enzyme isoform.
2. Agents that increase CYP3A4 activity tend to increase gefitinib plasma levels and efficacy.
3. Both
4. Neither
Gefitinib (Iressa) in cancer treatment:
1. Gefitinib is appropriately used and approved for some patients with metastatic non-small cell lung cancer (NSCLC).
2. Gefitinib efficacy and safety has not been established in patients with metastatic NSCLC associated with EGFR mutations other than exon 19 or exon 21
3. Both
4. Neither
With respect to adverse effects: following gefitinib administration, skin reactions and diarrhea may be noted in >20% of patients.
1. True
2. False
Concerning gefitinib adverse effects:
1. Most adverse effects appear late in treatment (greater than six months after treatment initiation)
2. Most adverse effects associated with gefitinib administration are amenable to resolution with medications.
3. Both
4. Neither
Patients using warfarin may exhibit reduced extrinsic blood coagulation during concurrent gefitinib therapy.
1. True
2. False
Because gefitinib may cause damage to the fetus when administered to a pregnant female, females with reproductive potential should practice contraception during and for at least two weeks after gefitinib administration.
1. True
2. False