From the 2019 HVPAA National Conference
Dr. Arjun Gupta (Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins University), Dr. Hui Yang (Texas Tech), Dr. Deepak Agrawal (University of Texas Southwestern), Dr. David Gerber (UTSW), Dr. Carlos Alvarez (Texas Tech)
Background
Opioid-induced constipation (OIC) is the most common side effect in patients prescribed opioids for cancer pain treatment. Oncology and gastrointestinal guidelines recommend routine prescription of a laxative agent for preventing OIC in all patients prescribed an opioid unless a contraindication (such as pre-existing diarrhea) exists. One of the commonly prescribed laxatives is docusate, although studies have demonstrated its inefficacy. We explored patterns of prescription of laxative agents in patients with lung cancer initiating opioids.
Methods
This is a retrospective, observational study evaluating the prescription of laxatives for OIC to adult patients with incident lung cancer (ICD-9 codes 162.0-162.9 and ICD-10 code C34.00-34.90) in the Veteran’s Affairs (VA) Corporate Data Warehouse (CDW), with first opioid prescription between January 1, 2003, and December 31, 2016. The CDW includes inpatient and outpatient diagnosis codes and pharmacy data. Data were analyzed using the VA Informatics and Computing Infrastructure (VINCI). Exposure to laxative agents was categorized as: none provided, docusate alone, docusate + another laxative, and other laxatives only. Prescriptions for laxatives within 1 week of the opioid prescription were considered as prophylaxis.
Results
Overall, 130,990 individuals were included in the analysis – 97.5% men, 73.2% white and14.5% black. Of these, 98,206 (75%) received no prophylaxis, 16,129 (12.3%) received docusate alone, 6,650 (5.1%) received docusate + another laxative, and 9,990 (7.6%) received a laxative(s) other than docusate. In total, 87.3% of patients received inadequate prophylaxis (none or only docusate) and 5.1% received unnecessary addition of docusate to another laxative(s).
Conclusions
In this large retrospective study of veterans with lung cancer, 75% of the patients receiving opioids, contrary to guidelines, were not prescribed any laxatives. Even when laxative prophylaxis was prescribed, it was inappropriate (only docusate, or docusate + another laxative in two-thirds of patients. Further investigation into reasons for inappropriate OIC prophylaxis practice patterns is warranted.
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