Cost minimization comparison of oral UFT/leucovorin versus 5-fluorouracil/leucovorin as adjuvant therapy for colorectal cancer in Taiwan.

AIM: Oral uracil-tegafur/leucovorin (UFT/LV) and intravenous 5-fluorouracil (FU)/LV are common adjuvant therapies for Stages II and III colorectal cancer. This study aims to determine the most cost-effective treatment alternative between UFT/LV and 5-FU/LV in Stages II and III colorectal cancer from Taiwan's National Health Insurance perspective. PATIENTS & METHODS: The costs were referenced directly from the National Health Insurance reimbursement price. Chemotherapy regimen considered for the cost analysis calculation was adapted from NSABP-C-06 study, and, a time saving calculation was also included. In addition, we compare the treatment outcome. RESULT: A total cost saving of US$3620.80-$3709.16 per patient per treatment was achieved with the UFT/LV treatment. UFT/LV provides the comparable outcome to 5-FU/LV. CONCLUSION: UFT/LV was the more cost-effective treatment as adjuvant chemotherapy.

Comparing the effectiveness of capecitabine versus 5-fluorouracil/leucovorin therapy for elderly Taiwanese stage III colorectal cancer patients based on quality-of-life measures (QLQ-C30 and QLQ-CR38) and a new cost assessment tool.

BACKGROUND: Colorectal cancer (CRC) is a leading cause of cancer-related deaths in developed countries and its incidence increases with age. Intravenous administration of bolus 5-fluorouracil (5-FU) and leucovorin (LV) has been a standard treatment regime for stage III CRC. However, patients generally prefer oral therapy such as Capecitabine. Studies showed that combination of oxaliplatin and capecitabine demonstrated efficacy and safety on par with treatment involving various 5-FU/LV-based regimens in elderly patients as they are in younger ones. However, little is known regarding the cost of adjuvant therapy or the effect of therapy on HRQoL. Thus the aims of this study were to evaluate the influence of different adjuvant care for stage III CRC on the HRQoL of elderly patients and to compare the economic costs associated with capecitabine-based and 5-FU/LV-based adjuvant treatments from a societal perspective in Taiwan. METHODS: A prospective, open-label, observational, multicenter study involving 123 patients aged 70 and over from 11 different centers was conducted between July 2008 and July 2011 in Taiwan. The adjusted monthly costs per patient and HRQoL were evaluated from individual-level data. The HRQoL of patients was assessed before and after adjuvant treatment. Direct and indirect costs of adjuvant treatment were estimated from a number of sources, and QoL scores were compared between groups. RESULTS: After correcting for baseline characteristics of patients, no significant differences were observed in the global HRQoL scores between treatment groups during the study period. According to QLQ-CR38 results, capecitabine-based therapy appeared to alleviate problems related to defecation (4.54 vs. 8.5; P = 0.011); however, micturition problems increased (9.27 vs. 7.51; P = 0.04), compared with 5-FU/LV-based treatment. The adjusted monthly treatment cost per patient was NT$27,300 for capecitabine-based treatment and NT$53,671 for 5-FU/LV-based treatment. The total cost of 5-FU/LV-based treatment was 59 % greater than that of capecitabine-based treatment. CONCLUSIONS: Analyzing from the societal perspective in Taiwan, capecitabine-based therapy incurred lower treatment costs than 5-FU/LV-based therapy and did not jeopardize HRQoL. Therefore, capecitabine, with or without oxaliplatin, could be considered as an alternative treatment option for elderly patients with stage III CRC.

Health-related quality of life and cost comparison of adjuvant capecitabine versus 5-fluorouracil/leucovorin in stage III colorectal cancer patients.

PURPOSE: The purpose of this study was to compare health-related quality of life (HRQoL) and costs associated with 2 adjuvant chemotherapy regimens [capecitabine-based therapy versus 5-fluorouracil/leucovorin (5-FU/LV)-based therapy] in stage III colorectal cancer patients. METHODS: We conducted a prospective, open-label, observational, multicenter study from July 2008 to July 2011. The European Organization for Research and Treatment of Cancer QLQ-C30 and QLQ-CR38 questionnaires was used to assess HRQoL before, during, and after treatment. The direct and indirect costs of adjuvant treatment were estimated from a specially prepared questionnaire, the National Health Insurance Research Database, and other published sources. We used propensity scoring to match samples between groups and performed multivariate analyses to adjust for differences in patient demographics and clinical characteristics. RESULTS: A total of 497 patients were enrolled, and 356 completed the surveys. Following propensity score matching, 239 patients were included in the analysis (122 in the capecitabine-based group, 117 in the 5-FU/LV-based group). Global HRQoL scores did not differ significantly between the two groups. However, compared to patients in the 5-FU/LV-based group, patients in the capecitabine-based group had less nausea and vomiting (mid-term, P = 0.024; final, P = 0.013), appetite loss (mid-term, P < 0.0001; final, P = 0.001), and fewer side effects from chemotherapy (mid-term, P = 0.017). In addition, the monthly cost of capecitabine-based therapy was lower than those of 5-FU/LV-based therapy [NT$31,895.46 (US$1063.18) vs. NT$79,159.24 (US$2638.64) per patient]. CONCLUSIONS: Capecitabine is a reasonable alternative and cost-effective treatment option under current conditions for patients with stage III colorectal cancer.

Cost-effectiveness of aspirin adjuvant therapy in early stage colorectal cancer in older patients.

BACKGROUND & AIMS: Recent observational studies showed that post-operative aspirin use reduces cancer relapse and death in the earliest stages of colorectal cancer. We sought to evaluate the cost-effectiveness of aspirin as an adjuvant therapy in Stage I and II colorectal cancer patients aged 65 years and older. METHODS: Two five-state Markov models were constructed separately for Stage I and II colorectal cancer using TreeAge Pro 2014. Two hypothetical cohorts of 10,000 individuals at a starting age of 65 years and with colorectal cancer in remission were put through the models separately. Cost-effectiveness of aspirin was evaluated against no treatment (Stage I and II) and capecitabine (Stage II) over a 20-year period from the United States societal perspective. Extensive one-way sensitivity analyses and multivariable Probabilistic Sensitivity Analyses (PSA) were performed. RESULTS: In the base case analyses, aspirin was cheaper and more effective compared to other comparators in both stages. Sensitivity analyses showed that no treatment and capecitabine (Stage II only) can be cost-effective alternatives if the utility of taking aspirin is below 0.909, aspirin's annual fatal adverse event probability exceeds 0.57%, aspirin's relative risk of disease progression is 0.997 or more, or when capecitabine's relative risk of disease progression is less than 0.228. Probabilistic Sensitivity Analyses (PSA) further showed that aspirin could be cost-effective 50% to 80% of the time when the willingness-to-pay threshold was varied from USD 20,000 to USD 100,000. CONCLUSION: Even with a modest treatment benefit, aspirin is likely to be cost-effective in Stage I and II colorectal cancer, thus suggesting a potential unique role in secondary prevention in this group of patients.

Cost-Effectiveness Analysis of Adjuvant Stage III Colon Cancer Treatment at Veterans Affairs Medical Centers.

The objective of this study was to evaluate the real-world cost effectiveness of adjuvant stage III colon cancer chemotherapy regimens, given that previous analyses have been based on data from clinical trials. The study was designed using integrated decision tree and Markov model, which was developed to evaluate the cost effectiveness of 5-fluorouracil/leucovorin (5-FU/LV), capecitabine, and the combination of each with oxaliplatin. The analysis was performed from a US Veterans Affairs perspective via retrospectively collected data, over a 5-year model time horizon. Outcome and cost data were used to calculate cost per quality adjusted life year (QALY), and one-way and probabilistic sensitivity analyses were performed. In the base case analysis, capecitabine and capecitabine plus oxaliplatin both cost more and were less effective than other regimens, and 5-FU/LV plus oxaliplatin, compared to 5-FU/LV alone, resulted in a cost of $25,997 per QALY gained. Model results were generally robust to parameter variation. Capecitabine plus oxaliplatin could be economically reasonable if full dosing occurred ≥76% of the time (base case 42%). In a real-world setting, the addition of oxaliplatin to 5-FU/LV is more effective but also more costly than 5-FU/LV alone. If full dosing of capecitabine-containing regimens can be assured, they may also be cost-effective strategies.

Pharmacoeconomic analysis of capecitabine versus 5-fluorouracil/leucovorin as adjuvant therapy for stage III colon cancer in Taiwan.

OBJECTIVES: To assess the cost-effectiveness of oral capecitabine compared with intravenous bolus 5-fluorouracil/leucovorin (5-FU/LV) in the adjuvant treatment of stage III colon cancer in Taiwan from payer (Bureau of National Health Insurance [BNHI]) perspectives. METHODS: A health state-transition model was developed to estimate the incremental costs and effectiveness of capecitabine versus 5-FU/LV. The time horizons studied were: treatment duration (24 weeks) plus 36 months, 48 months, 60 months, 120 months, and lifetime. Costs were expressed in Taiwanese new dollars (NT$). Clinical outcomes, medical resource use, and utilities were extracted from published sources. Unit costs were estimated from BNHI fee schedules, published sources, and local expert opinion. Outcomes and future costs were discounted at 3%. Cost-effectiveness was expressed as cost per quality-adjusted life-month (QALM). The effects of uncertainty were explored through a one-way sensitivity analysis. RESULTS: For the 24-week time period, drug acquisition costs were higher for capecitabine than 5-FU/LV (NT$114,405 vs. NT$4,904 per patient); however, these were offset by the higher administration costs of 5-FU/LV (NT$2,573 vs. NT$204,201 per patient). Overall direct costs for the 24-week treatment period were less with capecitabine than 5-FU/LV (NT$129,327 vs. NT$233,873 per patient). Cost savings with capecitabine were also evident when longer time horizons were considered. Over a lifetime, the projected survival benefit for capecitabine was 7 QALMs. CONCLUSIONS: From the perspectives of the BNHI and society in Taiwan, capecitabine not only saves costs but also improves health outcomes compared with 5-FU/LV in the adjuvant treatment of stage III colon cancer.

Budget impact of erlotinib for maintenance therapy in advanced non-small cell lung cancer.

OBJECTIVE: Assess the budgetary impact of adding erlotinib for maintenance therapy (MTx) in advanced non-small cell lung cancer (NSCLC) from a US health plan perspective. METHODS: A budget impact model was developed to analyze the costs (drug, administration, adverse events) associated with adding erlotinib MTx to a hypothetical 500,000 member US health plan. Treatment durations and dosing were derived from randomized controlled trials, FDA labeling, and National Comprehensive Cancer Network guidelines. Treatment patterns and assumptions were based on market research data, the SEER registry, and published literature. Cost data were obtained from Centers for Medicare and Medicaid Services payment rates and a drug pricing database. Sensitivity analyses were conducted to assess uncertainty. RESULTS: Overall health plan expenditures increased by $0.010 per member per month (PMPM). The main driver of additional cost was the erlotinib drug cost (∼$66,000) with the administration ($464) and side-effect ($47) costs being relatively modest. One-way sensitivity analyses showed that the results were most sensitive to the proportion of members receiving MTx; however, the PMPM did not exceed $0.013. CONCLUSIONS: The overall budget impact to a health plan of expanding the use of erlotinib from the 2nd/3rd-line advanced NSCLC setting to include the maintenance setting was relatively small. This was primarily due to the proportion of patients who would receive erlotinib MTx, the low cost of side-effects and minimal cost of drug administration. Additional research may be warranted to estimate the relative clinical and economic impacts of erlotinib MTx versus alternative MTx treatments.

Ambulatory high-dose methotrexate administration among pediatric osteosarcoma patients in an urban, underserved setting is feasible, safe, and cost-effective.

BACKGROUND: We describe the safety, feasibility, and provide a cost-estimate of outpatient high-dose methotrexate administration (HDMTX) among an urban, underserved population. PROCEDURE: A retrospective analysis of ambulatory HDMTX administration among osteosarcoma patients, at Montefiore Medical Center's Children's Hospital (Bronx, NY) was performed. HDMTX (12 g/m(2)) was given intravenously (IV) over 4 hr after urine alkalinization. Patients were discharged home to continue IV hydration and alkalinization delivered via a home infusion pump. Families were instructed to monitor urine pH overnight and management was adjusted according to our institution's treatment algorithm until MTX level ≤ 0.1 µmol/L. A cost estimate was performed to assess the difference in costs for outpatient versus hypothetical inpatient administrations. RESULTS: Of the 97 ambulatory HDMTX administrations, 99% were successfully completed. One patient failed outpatient administration secondary to home infusion pump malfunction. This patient successfully completed subsequent courses as an outpatient. Most patients (72%) had a MTX level of < 10 µmol/L at 24 hr post-HDMTX. No patients were found to have a MTX level of > 50 µmol/L at 24 hr. About 26% of courses were associated with grade III or IV neutropenia, 4% were associated with grade III or IV thrombocytopenia and 1% were associated with grade III/IV leukopenia. Compared to a hypothetical hospital inpatient stay, the hospital costs for ambulatory HDMTX were an average of $1400 less per cycle. CONCLUSION: Ambulatory HDMTX administration among an underserved, urban population is safe, feasible, and cost-effective.

Economic evaluation of capecitabine as adjuvant or metastatic therapy in colorectal cancer.

Capecitabine, an oral prodrug of 5-fluorouracil, is indicated for adjuvant treatment in patients with Dukes' C colon cancer and for subsequent lines in metastatic colorectal cancer. The aim of this article is to review the literature on the economics of capecitabine for the treatment of colon cancer. A systematic review was conducted to search for articles published from January 2003 to December 2009 that met the inclusion criteria. For abstracts that were considered acceptable, full-text articles were then reviewed. Of the 42 potential studies that were identified, 13 original studies (16 publications) met the inclusion criteria. To date, the economic evaluation literature has consistently projected or found that capecitabine is not only a cost-effective treatment for adjuvant or for metastatic colorectal cancer (i.e., providing good value for money) but, furthermore, would actually be cost saving in the majority of country settings.

Cost-effectiveness analysis of capecitabine compared with bolus 5-fluorouracil/l-leucovorin for the adjuvant treatment of colon cancer in Japan.

OBJECTIVE: A cost-effectiveness analysis of oral capecitabine versus intravenous bolus 5-fluorouracil/l-leucovorin (FU/LV) as adjuvant therapy in patients with stage 3 colon cancer was performed from a Japanese healthcare payer perspective. METHODS: Adjuvant therapy comprised 24 weeks of treatment with either oral capecitabine 1250 mg/m(2) twice daily on days 1-14 of a 21-day cycle or intravenous bolus FU 500 mg/m(2) and LV 250 mg/m(2) weekly for 6 weeks of an 8-week cycle (Roswell Park regimen). The analysis comprised short-term (1 year after initiation of adjuvant therapy) and long-term (up to 15 years) components. The long-term analysis involved a three-state (disease-free, recurrence and death) Markov model. Estimates for transition probabilities, costs and utilities were derived from the X-ACT trial, a Japanese phase II trial, and other published sources. Cost estimates were considered from the perspective of a healthcare payer. Costs were expressed in Japanese Yen (yen), year 2007 values. A discount rate of 3% was applied to costs and outcomes. Cost effectiveness was expressed as a cost per QALY. The effects of uncertainty were explored through one-way and probabilistic sensitivity analyses. RESULTS: In the 1-year analysis, direct costs were yen440,000 ($US4000) less per patient with capecitabine than with FU/LV. In the long-term analysis, differences between treatments in direct medical costs ranged from yen470,000 ($US4300) to yen580,000 ($US5300) depending on the time horizon used. Capecitabine was also projected to increase the number of QALYs compared with FU/LV. The sensitivity analysis suggested that the model outcome was robust. The probabilistic sensitivity analysis estimate of capecitabine being the dominant regimen was 96.6% at a zero willingness to pay. Direct costs remained lower with capecitabine if the price of generic LV was >OR=50% of the branded product. CONCLUSION: This analysis suggests that capecitabine improves health outcomes and lowers direct costs compared with bolus FU/LV (i.e. dominant treatment strategy) when used as adjuvant therapy in patients with stage 3 colon cancer in Japan.

Capecitabine, alone and in combination, in the management of patients with colorectal cancer: a review of the evidence.

Capecitabine, an oral prodrug of fluorouracil (5FU), has shown efficacy in terms of progression-free and overall survival at least equivalent to standard folinic acid (leucovorin)-modulated intravenous 5FU bolus regimens in patients with metastatic colorectal cancer. Moreover, capecitabine has demonstrated a better tolerability profile, producing a significantly lower occurrence of severe stomatitis than 5FU plus folinic acid regimens, making this drug particularly attractive for treating elderly patients. In addition, capecitabine can be combined with other active drugs such as irinotecan or oxaliplatin. Indeed, the combination of capecitabine plus oxaliplatin (XELOX regimen) now represents a new standard of care for the metastatic disease and is also under evaluation in the adjuvant setting. The combination of new biological drugs, such as bevacizumab, with the XELOX regimen was shown to further prolong the time to progression of metastatic disease, and might reduce the risk of recurrence for those with resected colon cancer with poor risk factors. Cost-effectiveness analyses have demonstrated that, despite higher acquisition costs, capecitabine appears to be more cost effective than standard treatments for the management of colorectal cancer patients.

Using economic analysis to evaluate the potential of multimodality therapy for elderly patients with locally advanced pancreatic cancer.

PURPOSE: Development of new and expensive drugs with activity against pancreatic cancer has made economic considerations more relevant to treatment decision-making for advanced disease. Economic modeling can be used to explore the potential of such novel therapies and to inform clinical trial design. METHODS AND MATERIALS: We developed a Markov model to evaluate the cost-effectiveness of radiation plus fluorouracil (RT-FU) relative to no treatment in elderly patients with locally advanced pancreatic cancer (LAPC) and to determine the economic potential of radiation plus gemcitabine (RT-GEM), a novel regimen for this disease. We used the SEER-Medicare database to estimate effectiveness and costs supplemented by data from the literature where necessary. RESULTS: Relative to no treatment, RT-FU was associated with a cost-effectiveness ratio (ICER) of $68,724/QALY in the base case analysis. Compared with RT-FU, the ICER for RT-GEM was below $100,000/QALY when the risk of dying with the new regimen was <85% than with the standard regimen. However, >1,000 subjects would be necessary to demonstrate this level of efficacy in a randomized trial. The ICER of RT-GEM was most sensitive to utility values, and, at lower efficacy levels, to costs of gemcitabine and treatment-related toxicity. CONCLUSIONS: In elderly patients with LAPC, RT-FU is a cost-effective alternative to no treatment. The novel regimen of RT-GEM is likely to be cost-effective at any clinically meaningful benefit, but quality-of-life issues, drug acquisition, and toxicity-related costs may be relevant, especially at lower efficacy levels.

The clinical and cost-effectiveness of oxaliplatin and capecitabine for the adjuvant treatment of colon cancer: systematic review and economic evaluation.

OBJECTIVES: To assess the clinical and cost-effectiveness of oxaliplatin in combination with 5-fluorouracil/leucovorin (5-FU/LV), and capecitabine monotherapy (within their licensed indications), as adjuvant therapies in the treatment of patients with Stage III (Dukes' C) colon cancer after complete surgical resection of the primary tumour, as compared with adjuvant chemotherapy with an established fluorouracil-containing regimen. DATA SOURCES: Ten electronic bibliographic databases were searched from inception to January 2005. Searches were supplemented by hand searching relevant articles, sponsor and other submissions of evidence to the National Institute of Health and Clinical Excellence and conference proceedings. REVIEW METHODS: A systematic review and meta-analysis (where appropriate) of clinical efficacy evidence and a cost-effectiveness review and economic modelling were carried out. Marginal costs, life years gained and cost-effectiveness acceptability curves were estimated. Probabilistic sensitivity analysis was used to generate information on the likelihood that each of the interventions was optimal. RESULTS: Three randomised active-controlled trials, of varying methodological quality, were included in the review. The MOSAIC trial and NSABP C-07 study considered the addition of oxaliplatin to adjuvant treatment (albeit administered in different 5-FU/LV regimens) and the X-ACT study compared oral capecitabine with bolus 5-FU/LV alone. A review of the available evidence indicated that in patients with Stage III colon cancer, oxaliplatin in combination with an infusional de Gramont schedule of 5-FU/LV (FOLFOX4) was more effective in preventing and delaying disease recurrence than infusional 5-FU/LV alone (de Gramont regimen). Serious adverse events and treatment discontinuations due to toxicity were more evident with oxaliplatin-based regimens (FOLFOX4 and FLOX regimen) than infusional or bolus 5-FU/LV alone (de Gramont and Roswell Park regimen). Oral capecitabine was at least equivalent in disease-free survival to the bolus Mayo Clinic 5-FU/LV regimen for patients with resected Stage III colon cancer. Although, the safety and tolerability profile of capecitabine was superior to that of the Mayo Clinic 5-FU/LV regimen, it has not been evaluated in comparison with other less toxic 5-FU/LV regimens currently in common use in the UK. Based on the assumptions and survival analysis methods used, the cost-effectiveness analysis using economic modelling estimated that capecitabine was a dominating strategy and resulted in a cost-saving of approximately pound 3320 per patient in comparison with the Mayo Clinic 5-FU/LV regimen, while also providing an additional 0.98 quality-adjusted life-years (QALYs) over a 50-year model time horizon. Oxaliplatin in combination with 5-FU/LV (FOLFOX4 regimen) is estimated to cost an additional pound 2970 per QALY gained when compared with the de Gramont 5-FU/LV regimen and demonstrated superior survival outcomes with marginal costs. The uncertainty analysis suggests that both interventions have a high probability of being cost-effective at a threshold of both pound 20,000 and pound 30,000. An indirect comparison of the FOLFOX4 and Mayo Clinic 5-FU/LV regimens suggests that the use of FOLFOX4 in place of the Mayo Clinic 5-FU/LV regimen would cost an additional pound 5777 per QALY gained. An incremental cost-effectiveness ratio (ICER) is estimated to be approximately pound 13,000 per QALY gained from treatment with FOLFOX4 compared with capecitabine. However, if the Mayo Clinic and the de Gramont 5-FU/LV regimens are assumed to be equivalent in terms of effectiveness, the ICER of FOLFOX4 in comparison with capecitabine may be greater than pound 30,000 per QALY. CONCLUSIONS: The evidence suggests that both capecitabine and FOLFOX4 are clinically effective and cost-effective in comparison with 5-FU/LV regimens (Mayo Clinic and de Gramont schedules). Further research is suggested into the effectiveness, tolerability, patient acceptability and costs of different oxaliplatin/fluoropyrimidine schedules in the adjuvant setting; the effects of treatment duration on efficacy; adverse events; resource data collection strategies and reporting of summary statistics; subgroups benefiting most from adjuvant chemotherapy; and methods for estimating mean survival.

Capecitabine monotherapy: safe and effective treatment for metastatic breast cancer.

Optimal management for metastatic breast cancer frequently involves cytotoxic chemotherapy. Over the years, several complex multidrug regimens have been developed that were based upon a rationale of synergistic antitumor activity and nonoverlapping toxicities. However, recently the clinical value of these complex regimens has been called into question as several drugs used alone (monotherapy) or in sequence (serial single agent) have been shown to be both efficacious and better tolerated. Capecitabine (an orally administered fluoropyrimidine carbamate) is one such agent that has been proven to be effective when used alone for metastatic breast cancer, metastatic colorectal cancer, and adjuvant colon cancer. In this review, published (or reported in abstract form) data examining various aspects of clinical response and tolerability with single-agent capecitabine for (primarily) first- and second-line metastatic breast cancer are examined. For the most part, response rates are comparable with those of the more complex regimens. Dose reductions from the labeled dose of 1,250 mg/m(2) twice daily are relatively common. Toxicities (following dose reductions if needed) are generally manageable, even by more frail patients. Elderly patients are more likely to have impaired renal function or be receiving warfarin treatment, and special attention to these factors is warranted. Nonetheless, the drug administered alone is a reasonable choice when single-agent chemotherapy is entertained as a treatment option for metastatic breast cancer, including in the first-line setting.

What's happening in PHARMAC--where do all the submissions go? On the trail of gemcitabine.

The process and progress of submissions to PHARMAC for funding of new treatments is unclear. There appears to be a lack of communication or transparency regarding funding applications, decisions, or expected timelines to reach an endpoint. It is difficult to have confidence in a process that lacks such definition. A recent clinician submission for funding of an oncology treatment (gemcitabine) for bladder cancer highlights these issues.

High-dose methotrexate-doxycycline interaction.

OBJECTIVE: To report a case in which an interaction occurred between doxycycline and high-dose methotrexate (HD-MTX) and discuss its clinical, quality of life, and economic repercussions. CASE SUMMARY: A 17-year-old girl diagnosed with high-degree osteosarcoma in her left femur was admitted to our hospital to receive her eleventh postoperative cycle of HD-MTX, according to the clinical protocol approved at our hospital. Simultaneously, due to a palpebral abscess in her left eye, the patient received systemic treatment with doxycycline 100 mg every 12 hours. As in previous cycles, pharmacokinetic monitoring of methotrexate (MTX) plasma concentrations was performed to improve leucovorin calcium rescue. The biological half-life 12 and 24 hours after infusion showed that the patient was at high risk of intoxication. She then developed hematologic as well as gastrointestinal toxicity and remained hospitalized for 11 days. The patient was readmitted 48 hours after hospital discharge because of a febrile episode that required an additional hospital stay of 12 days, and the twelfth cycle of HD-MTX had to be postponed 18 days because of the results of the previous cycle. DISCUSSION: Significant differences (p < 0.05) were observed in the eleventh HD-MTX cycle for plasma concentrations and pharmacokinetic parameters compared with the previous 10 cycles. The interaction resulted in clinical, quality of life, and economic repercussions. CONCLUSIONS: The potential interaction between MTX and doxycycline may cause pharmacokinetic changes, and its clinical repercussions on the quality of life of the patient and associated costs should be considered.