Influence of muscle mass on the estimation of glomerular filtration rate in Japanese terminal cancer patients.

BACKGROUND: Estimated glomerular filtration rate (eGFR) based on serum cystatin C (Scys) is useful for patients with decreased muscle mass, but has been also reported to be affected by cancer. The usefulness of Scys in eGFR in terminal cancer patients with decreased muscle mass is unknown. Therefore, we analyzed appropriate eGFR formulae for terminal cancer patients. METHODS: Study design was a retrospective observational study. Based on creatinine height index (CHI), 184 terminal cancer patients were stratified into CHI ≥ 90% (normal muscle mass, 59 patients); CHI 60-89% (mildly to moderately decreased muscle mass, 64 patients); and CHI < 60% (severely decreased muscle mass, 61 patients) groups. Twenty-four-hour creatinine clearance was measured and converted to the glomerular filtration rate (GFR) as a renal function measure. To estimate GFR, various eGFR formulae for Japanese were used: eGFRScys, eGFRScr5 and eGFRScr3, eGFRaverage and eGFRScys-Scr, and eGFRCG, based on Scys, serum creatinine (Scr), Scys and Scr combined, and Cockcroft-Gault formula (CG), respectively. Errors between measured and estimated values of renal function were verified using mean prediction errors (ME). When a 95% confidence interval (CI) of ME included 0, the accuracy of the eGFR formula was graded as good. RESULTS: eGFRScys ME was 0.2 (95% CI lower limit - 3.7, upper limit 4.0) mL/min/1.73 m2 in CHI 60-89% group and 9.2 (6.1, 12.9) mL/min/1.73 m2 in CHI < 60% group. eGFRScys was most accurate among the eGFR formulae. CONCLUSIONS: eGFR based on Scys was demonstrated as useful in terminal cancer patients with decreased muscle mass.

A Clinical Study on Administration of Opioid Antagonists in Terminal Cancer Patients: 7 Patients Receiving Opioid Antagonists Following Opioids among 2443 Terminal Cancer Patients Receiving Opioids.

There have been few detailed reports on respiratory depression due to overdoses of opioids in terminal cancer patients. We investigated the situation of treatment with opioid antagonists for respiratory depression that occurred after administration of opioid at optimal doses in terminal cancer patients, to clarify pathological changes as well as causative factors. In 2443 terminal cancer patients receiving opioids, 7 patients (0.3%) received opioid antagonists: 6, morphine (hydrochloride, 5; sulfate, 1); 1, oxycodone. The median dosage of opioids was 13.3 mg/d, as converted to morphine injection. Respiratory depression occurred on this daily dose in 4 patients and after changed dose and route in 3 patients. Opioids were given through the vein in 6 patients and by the enteral route in 1 patient. Concomitant drugs included nonsteroidal anti-inflammatory drugs in 3 patients and zoledronic acid in 2 patients. In morphine-receiving patients, renal functions were significantly worsened at the time of administration of an opioid antagonist than the day before the start of opioid administration. These findings indicate that the proper use of opioids was safe and acceptable in almost all terminal cancer patients. In rare cases, however, a risk toward respiratory depression onset is indicated because morphine and morphine-6-glucuronide become relatively excessive owing to systemic debility due to disease progression, especially respiratory and renal dysfunctions. At the onset of respiratory depression, appropriate administration of an opioid antagonist mitigated the symptoms. Thereafter, opioid switching or continuous administration at reduced dosages of the same opioids prevented the occurrence of serious adverse events.