Folic Acid Analogues: MTX and Pemetrexed

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What is the main mechanism of action of purine analogs like 6-Mercaptopurine and 6-Thioguanine?

They inhibit the activity of topoisomerase enzymes, leading to DNA damage.

They intercalate into DNA, preventing transcription and replication.

They inhibit the synthesis of DNA by interfering with the biosynthesis of purine bases. (correct)

They alkylate and crosslink DNA strands, leading to cell death.

Which of the following is a common adverse effect of purine analog drugs like 6-Mercaptopurine and 6-Thioguanine?

Bone marrow suppression (correct)

Neurotoxicity

Cardiotoxicity

Hepatorenal toxicity

Why is allopurinol often given to patients receiving cancer chemotherapy with drugs like 6-Mercaptopurine?

Allopurinol inhibits xanthine oxidase, which metabolizes 6-Mercaptopurine, leading to higher plasma levels.

Allopurinol enhances the antitumor activity of 6-Mercaptopurine by inhibiting purine synthesis.

Allopurinol protects against the cardiotoxic effects of 6-Mercaptopurine.

Allopurinol prevents the formation of uric acid, which can lead to gout and kidney stones during chemotherapy. (correct)

Which of the following is a potential drug interaction with methotrexate that can lead to toxicity?

Concomitant use of NSAIDs like aspirin Signup and view all the answers

How can toxicity from methotrexate be managed?

All of the above Signup and view all the answers

Which of the following leukemias is 6-Thioguanine commonly used to treat?

Acute myeloid leukemia Signup and view all the answers

Which enzyme does methotrexate inhibit in mammalian cells?

Dihydrofolate reductase Signup and view all the answers

What is the primary dose-limiting toxicity of methotrexate and pemetrexed?

Myelosuppression Signup and view all the answers

Which drug is indicated for the treatment of non–small cell lung cancer and mesothelioma, in combination with cisplatin?

Pemetrexed Signup and view all the answers

What is the management strategy known as leucovorin rescue used for?

Reducing methotrexate toxicity to normal cells Signup and view all the answers

What adverse effect can long-term use of methotrexate cause?

Hepatotoxicity Signup and view all the answers

How can alkalinization of urine help in reducing methotrexate toxicity?

Reduce renal toxicity Signup and view all the answers

What is the mechanism of action of nitrogen mustard prodrugs like cyclophosphamide and ifosfamide?

Require activation by hepatic cytochrome P450 enzymes Signup and view all the answers

Which type of cancer is non-Hodgkin lymphoma commonly treated with?

Breast cancer Signup and view all the answers

What adverse effect is commonly associated with nitrogen mustard agents like cyclophosphamide and ifosfamide?

Hemorrhagic cystitis Signup and view all the answers

Which sulfhydryl compound is often coadministered to prevent hemorrhagic cystitis caused by nitrogen mustard agents?

2-mercaptoethanesulfonate (Mesna) Signup and view all the answers

Which platinum analog is used to treat colorectal cancer?

Oxaliplatin Signup and view all the answers

What is the main adverse effect associated with cisplatin among the platinum analogs?

Nephrotoxicity Signup and view all the answers