Oral Chemotherapeutic Agents

Abstract

Oral chemotherapeutic agents have been available for decades, and there has been an accelerated expansion in their development during the recent decade. Oral chemotherapeutic agents offer obvious advantages in terms of convenient and noninvasive administration, flexibility and adaptability of dosing, as well as financial and staff time savings. Compared to intravenous agents, oral chemotherapeutic agents generally exhibit substantial interindividual pharmacokinetic variability. Many factors contribute to this variability, including physiological, pathological, environmental, and genetic factors. Unique to oral agents, poor and variable bioavailability is one important source of the interindividual pharmacokinetic variability. This chapter discusses the factors influencing bioavailability of oral chemotherapeutic agents, with focus on the first‐pass metabolism by cytochrome P450 3A4 (CYP3A4), intestinal efflux by ABCB1 transporter, and other factors such as concomitant administration of antiacid medications, food effect, and surgery. Oral chemotherapeutic agents can be classified as traditional cytotoxic agents and novel molecularly targeted agents, hormonal agents, and immune‐modulating agents. Each class of agents is unique with regard to its mechanisms of action, pharmacokinetics, mechanisms of drug resistance, and clinical use. This chapter provides an overview of the major classes of oral chemotherapeutic agents, particularly highlighting examples whereby genetic variations in the genes involved in the drug disposition or drug–target interaction influence the pharmacokinetics and/or response.

The Effect of Telephone-Based Follow-Up on Adherence, Efficacy, and Toxicity of Oral Capecitabine-Based Chemotherapy

“…7,8 There was a recent shift in the oncology workflow to patients' homes by the entrance of oral chemotherapeutic agents such as capecitabine. 9,10 These agents offer many advantages as their administration does not need an invasive access, [11][12][13] they decrease hospitalization frequency, 14 the need for caregiving staff, 15 and are associated with lower administration costs. 12,13 In addition to these advantages, they also allow dose adaptation according to tolerability 12 and provide patients with more time at home, 13 thereby providing better quality of life for patients.…”

“…9,10 These agents offer many advantages as their administration does not need an invasive access, [11][12][13] they decrease hospitalization frequency, 14 the need for caregiving staff, 15 and are associated with lower administration costs. 12,13 In addition to these advantages, they also allow dose adaptation according to tolerability 12 and provide patients with more time at home, 13 thereby providing better quality of life for patients. 16 However, these advantages can be of less value because of patients' adherence 16,17 and safety 13 challenges.…”