Oral morphine and respiratory function amongst hospice inpatients with advanced cancer.
BACKGROUND
Respiratory depression is the opioid adverse effect feared most by physicians. This may hinder adequate dosing in cancer pain. The study was conducted to examine the respiratory function of patients with advanced cancer receiving significant doses (>100 mg/24 h) of oral morphine.


METHODS
Consecutive pain-free hospice inpatients with advanced cancer receiving high-dose immediate-release oral morphine were evaluated. A single assessment of respiratory rate (RR), arterial blood gas (ABG), and peak flow rate (PFR) was made at assumed morphine steady state. Venous blood was drawn for a trough morphine plasma level.


RESULTS
Of 31 patients who consented to examination, 20 completed the study assessment; 12 had chronic bronchitis. The median morphine dose was 30 mg 4-hourly (range 20 to 90 mg). Only one patient had evidence of ventilatory impairment.


CONCLUSIONS
Morphine does not commonly cause chronic ventilatory impairment when given in this way in this population even in the presence of pre-existing or concurrent respiratory disease. Oral morphine given repeatedly in individualized dosage is a safe and efficacious analgesic in the majority of those with advanced cancer.
The Harry R. Horvitz Center for Palliative Medicine, Cleveland Clinic Taussig Cancer Center, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA. walsht@ccf.org
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Walsh
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Rivera
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Kaiko
D000284:Administration, Oral; D000368:Aged; D000701:Analgesics, Opioid / Q000008:administration & dosage* / Q000009:adverse effects; D016903:Drug Monitoring; D005260:Female; D006302:Health Services Research; D017051:Hospice Care; D006801:Humans; D007297:Inpatients; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage* / Q000009:adverse effects; D009369:Neoplasms / Q000145:classification / Q000150:complications* / Q000503:physiopathology; D010146:Pain / Q000188:drug therapy* / Q000209:etiology; D012129:Respiratory Function Tests; D012131:Respiratory Insufficiency / Q000139:chemically induced / Q000175:diagnosis
D000701:Analgesics, Opioid; D009020:Morphine