Overview of the prevention and management of CINV.

The prevention of chemotherapy-induced nausea and vomiting (CINV) is critically important in reducing morbidity and total healthcare costs in patients receiving emetogenic chemotherapy. The different types of CINV (ie, acute, delayed, anticipatory, breakthrough, and refractory) are controlled through various pathways and neurotransmitters, so the pharmacologic approach to prevention and treatment varies based on the type of CINV. New therapeutic agents and combinations of agents have changed the dynamic of CINV control, and national guidelines have been recently updated based on current evidence. Along with current national guideline recommendations, this educational activity will provide an overview of the pathophysiology of CINV and how the mechanisms of action of various antiemetic agents relate to efficacy and safety in the prevention and treatment of CINV.

Drug-drug interaction profile of components of a fixed combination of netupitant and palonosetron: Review of clinical data.

Neurokinin-1 (NK1) receptor antagonists (RAs) are commonly coadministered with serotonin (5-HT3) RAs (e.g. palonosetron (PALO)) to prevent chemotherapy-induced nausea/vomiting. Netupitant/palonosetron (NEPA), an oral fixed combination of netupitant (NETU)-a new NK1 RA-and PALO, is currently under development. In vitro data suggest that NETU inhibits CYP3A4 and is a substrate for and weak inhibitor of P-glycoprotein (P-gp). This review evaluates potential drug-drug interactions between NETU or NEPA and CYP3A4 substrates/inducers/inhibitors or P-gp substrates in healthy subjects. Pharmacokinetic (PK) parameters were evaluated for each drug when NETU was coadministered with PALO (single doses) and when single doses of NETU or NEPA were coadministered with CYP3A4 substrates (erythromycin (ERY), midazolam (MID), dexamethasone (DEX), or oral contraceptives), inhibitors (ketoconazole (KETO)), or inducers (rifampicin (RIF)), or a P-gp substrate (digoxin (DIG)). Results showed no relevant PK interactions between NETU and PALO. Coadministration of NETU increased MID and ERY exposure and significantly increased DEX exposure in a dose-dependent manner; NETU exposure was unaffected. NEPA coadministration had no clinically significant effect on oral contraception, although levonorgestrel exposure increased. NETU exposure increased after coadministration of NEPA with KETO and decreased after coadministration with RIF; PALO exposure was unaffected. NETU coadministration did not influence DIG exposure. In conclusion, there were no clinically relevant interactions between NETU and PALO, or NEPA and oral contraceptives (based on levonorgestrel and ethinylestradiol exposure). Coadministration of NETU or NEPA with CYP3A4 inducers/inhibitors/substrates should be done with caution. Dose reduction is recommended for DEX. Dose adjustments are not needed for NETU coadministration with P-gp substrates.

Reviewing current and emerging antiemetics for chemotherapy-induced nausea and vomiting prophylaxis.

This review provides background information on chemotherapy-induced nausea and vomiting (CINV) classification and pathophysiology and reviews various antiemetic agents for CINV prophylaxis, including corticosteroids, serotonin receptor antagonists (5-HT3 RAs), tachykinin NK1 receptor antagonists (NK1 RAs), and olanzapine. Other less commonly used agents are briefly discussed. Practical considerations are reviewed as well, including emetogenicity of chemotherapeutic regimens, patient-specific risk factors for CINV, principles of CINV management, health economics outcome research, and quality of life. Available data on the newly FDA-approved antiemetic combination netupitant/palonosetron (NEPA) is also reviewed. Prevention of CINV is an important goal in managing patients with cancer and is especially difficult with respect to nausea and delayed CINV. Corticosteroids are a mainstay of CINV prophylaxis and are usually given in combination with other therapies. The 5-HT3 RA palonosetron has shown increased efficacy over other agents in the same class for prevention of delayed emesis with moderately emetogenic chemotherapy and NK1 RAs improve emesis prevention in combination with 5-HT3 RAs and dexamethasone. Olanzapine has shown efficacy for CINV prophylaxis and the treatment of breakthrough CINV. The new combination therapy, NEPA, has been shown to be efficacious for the prevention of acute, delayed, and overall CINV. Risk factors that have been identified for CINV include gender, age, and alcohol intake. It is important to assess the emetogenicity of chemotherapy regimens as well as the potential impact of patient risk factors in order to provide adequate prophylaxis. Acute and delayed CINV are severe, burdensome side effects of chemotherapy; however, new data on prevention and the discovery of new agents can further improve CINV control.

Darbepoetin alfa: an effective treatment with flexible and simplified dosing for anemia in patients with cancer.

Anemia is common in patients with cancer or myelodysplastic syndrome. Erythropoietic therapy offers an effective way to manage anemia by increasing hemoglobin levels, decreasing transfusion requirements, and alleviating symptoms. We reviewed data showing the feasibility and effectiveness of treatment with the erythropoiesis-stimulating protein darbepoetin alfa at extended dosing intervals to treat anemia in patients with cancer receiving multicycle chemotherapy. We also explored the darbepoetin alfa's potential for treating anemia in patients with myelodysplastic syndrome. Data from clinical studies and drug therapy evaluations confirm that darbepoetin alfa administered weekly, every 2 weeks, and every 3 weeks corrects and maintains hemoglobin levels in patients with chemotherapy-induced anemia. In addition, the data demonstrate that both weight-based and fixed dosing with darbepoetin alfa are effective, and that early intervention to treat anemia has clinical benefits. Darbepoetin alfa also is an effective treatment for anemia in patients with cancer not receiving chemotherapy, at extended dosing intervals of at least 3 weeks. Extended dosing for anemia treatment can provide benefits for patients, caregivers, and clinicians because it reduces the number of clinic visits needed and permits synchronizing anemia treatment with chemotherapy cycles. Data from recent studies suggest that darbepoetin alfa is effective for treating anemia in patients with myelodysplastic syndrome; this potential use is being investigated further in ongoing studies. Thus, darbepoetin alfa is an attractive therapy option for patients with chemotherapy or cancer-induced anemia. It allows increased flexibility and simplified dosing and may offer some benefit in the treatment of anemia in patients with myelodysplastic syndrome.

Disposition of imatinib and its metabolite CGP74588 in a patient with chronic myelogenous leukemia and short-bowel syndrome.

Imatinib mesylate, licensed to treat chronic myelogenous leukemia and gastrointestinal stromal tumors, is metabolized by means of cytochrome P450 3A and excreted primarily in the bile. Although the bioavailability of imatinib mesylate is more than 97%, the exact gastrointestinal site of its absorption is unknown. Liquid chromatography-mass spectrometry was used to quantitate imatinib and its metabolite CGP74588 in the plasma and jejunostomy output of a patient with newly diagnosed chronic myelogenous leukemia. She had previously lost most of her small bowel and all of her colon as a result of mesenteric artery thrombosis and radiation-induced colitis and/or proctitis. Imatinib pharmacokinetics in plasma indicated that approximately 20% of the patient's 400-mg dose was absorbed. The jejunostomy output contained 338 mg of imatinib, which was consistent with 320 mg of a nonabsorbed dose plus approximately 23% of the absorbed dose being excreted unchanged in the bile. These data indicate the importance of considering gastrointestinal anatomic abnormalities or disease states when oral imatinib is dosed.