Capecitabine

Bone marrow suppression may occur, hematologic toxicity is more common when used in combination therapy; use with caution; dosage adjustments may be required. The product labeling recommends that patients with baseline platelets 3 and/or neutrophils 3 not receive capecitabine therapy and also to withhold therapy for grade 3 or 4 hematologic toxicity during treatment.

Cardiotoxicity has been observed with capecitabine, including myocardial infarction, ischemia, angina, dysrhythmias, cardiac arrest, cardiac failure, sudden death, ECG changes, and cardiomyopathy. These adverse events may be more common in patients with a history of coronary artery disease. In a scientific statement from the American Heart Association, capecitabine has been determined to be an agent that may either cause reversible direct myocardial toxicity or exacerbate underlying myocardial dysfunction (magnitude: moderate/major) (AHA [Page 2016]).

Stevens-Johnson syndrome and toxic epidermal necrolysis (TEN) have been reported (some fatal); permanently discontinue capecitabine if a severe dermatologic or mucocutaneous reaction occurs.

May cause diarrhea (may be severe); median time to first occurrence of grade 2 to 4 diarrhea was 34 days and median duration of grades 3 or 4 diarrhea was 5 days. Withhold treatment for grades 2 to 4 diarrhea; subsequent doses should be reduced after grade 3 or 4 diarrhea or recurrence of grade 2 diarrhea. Antidiarrheal therapy (eg, loperamide) is recommended. Dehydration may occur rapidly in patients with diarrhea, nausea, vomiting, anorexia, and/or weakness; adequately hydrate prior to treatment initiation. Elderly patients may be at higher risk for dehydration. Interrupt treatment for grade 2 or higher dehydration; correct precipitating factors and ensure rehydration prior to resuming therapy; may require dose modification (based on precipitating factor). Necrotizing enterocolitis (typhlitis) has been reported.

May cause hand-and-foot syndrome (palmar-plantar erythrodysesthesia or chemotherapy-induced acral erythema); characterized by numbness, dysesthesia/paresthesia, tingling, painless or painful swelling, erythema, desquamation, blistering, and severe pain. The median onset is 79 days (range: 11 to 360 days). Persistent hand-and-foot syndrome (grade 2 and higher) could eventually lead to fingerprint loss. If grade 2 or 3 hand-and-foot syndrome occurs, interrupt administration of capecitabine until the event resolves or decreases in intensity to grade 1. Following grade 3 hand-and-foot syndrome, decrease subsequent doses of therapy.

Grade 3 and 4 hyperbilirubinemia have been observed in patients with and without hepatic metastases at baseline (median onset: 64 days). Transaminase and alkaline phosphatase elevations have also been reported. If capecitabine-related grade 3 or 4 hyperbilirubinemia occurs, interrupt treatment until bilirubin ≤3 times ULN. Bilirubin elevations may also require dose reductions. Disease-related concerns:

Patients with certain homozygous or heterozygous mutations of the dihydropyrimidine dehydrogenase (DPD) enzyme are at increased risk for acute early-onset (potentially severe, life-threatening, or fatal) toxicity due to total or near total absence of DPD activity. Toxicity may include mucositis/stomatitis, diarrhea, neutropenia, and neurotoxicity. Patients with partial DPD activity are also at risk for severe, life-threatening, or fatal toxicity. May require therapy interruption or permanent discontinuation, depending on the onset, duration, and severity of toxicity observed. No capecitabine dose has been shown to be safe in patients with complete DPD deficiency; data is insufficient to recommend a dose in patients with partial DPD activity.

Use with caution in patients with mild to moderate hepatic impairment due to liver metastases. The effect of severe hepatic impairment has not been studied.

Dehydration may occur, resulting in acute renal failure (may be fatal); concomitant use with nephrotoxic agents and baseline renal dysfunction may increase the risk. Use with caution in patients with mild to moderate renal impairment; reduce dose with moderate impairment (exposure to capecitabine and metabolites is increased) and carefully monitor and reduce subsequent dose (with any grade 2 or higher adverse effect) with mild to moderate impairment. Use is contraindicated in severe impairment. Concurrent drug therapy issues:

Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.

In patients with colorectal cancer, treatment with capecitabine immediately following 6 weeks of FU/LV therapy has been associated with an increased incidence of grade ≥3 toxicity, when compared to patients receiving the reverse sequence, capecitabine (two 3-week courses) followed by FU/LV (Hennig 2008).

Concomitant use of proton pump inhibitors and capecitabine may alter capecitabine dissolution and absorption due to higher gastric pH levels. Secondary analysis of a large phase III study comparing capecitabine and oxaliplatin with or without lapatinib for the treatment of gastroesophageal cancer showed decreased overall survival in patients who received concurrent proton pump inhibitors (Chu 2017). Consider avoiding proton pump inhibitors (if possible) in patients receiving capecitabine.

Capecitabine may increase the anticoagulant effects of warfarin; bleeding events, including death, have occurred with concomitant use. Clinically significant increases in prothrombin time (PT) and INR have occurred within several days to months after capecitabine initiation (in patients previously stabilized on anticoagulants), and may continue up to 1 month after capecitabine discontinuation. May occur in patients with or without liver metastases. Monitor PT and INR frequently and adjust anticoagulation dosing accordingly. An increased risk of coagulopathy is correlated with a cancer diagnosis and age >60 years. Special populations:

Use with caution in patients ≥60 years of age; the incidence of treatment-related adverse events may be higher. Other warnings/precautions:

Uridine triacetate (formerly called vistonuridine), has been studied in cases of fluoropyrimidine overdose. In a clinical study of 98 patients who received uridine triacetate for fluorouracil toxicity (due to overdose, accidental capecitabine ingestion, or possible DPD deficiency), 96 patients recovered fully (Bamat 2013). Of 17 patients receiving uridine triacetate beginning within 8 to 96 hours after fluorouracil overdose, all patients fully recovered (von Borstel 2009). An additional case report describes accidental capecitabine ingestion by a 22-month-old child; uridine triacetate was initiated approximately 7 hours after exposure. The patient received uridine triacetate every 6 hours for a total of 20 doses through nasogastric tube administration; he was asymptomatic throughout his course and was discharged with normal laboratory values (Kanie 2011). Refer to Uridine Triacetate monograph.