Abstract
Background: Adverse drug reactions are a major contributor to morbidity and hospitalization in patients and have been held responsible for as much as 5% of hospital admissions. This is especially relevant in cancer patients undergoing palliative care because they often suffer from advanced/terminal cancer and the adverse drug reactions from the palliative care drugs can affect their remaining quality of life.

Aim and Objectives: The aim of this study was to study the adverse drug reaction profile of palliative drugs used in cancer patients undergoing palliative care at the Pain and Palliative Care OPD and their association with gender, age, dose, and duration of opioid intake.

Materials and Methods: After receiving permission from the Institutional Ethics Committee, TDMC Alappuzha, 138 eligible cancer patients receiving palliative care from the pain and palliative care OPD were included in the study. The necessary data were obtained through interviews with the patients, who had given their consent to the study and the information was used to fill a questionnaire.

Results: Out of the 138 study participants, 96 were male and 42 were female. The age composition ranged from 35 years to 88 years of age. There were 30 diabetic patients, 28 hypertensive patients, and 13 patients with CAD. The most frequent adverse effects, seen within 2 weeks of a 5 mg dose oral morphine regimen, were nausea (58.26%), constipation (51.18%), vomiting (43.30%), insomnia (33.07%), sedation (31.49%), dry mouth (25.19%), abdominal discomfort (24.04%), edema (20.47%) and tremors (19.68%). Using the modified Naranjo algorithm, 12% of ADRs were doubtful, 40% of ADRs were possible, 32% of ADRs were probable, and 16% of ADRs were definite. Among male patients taking 5 mg oral morphine, the most frequent ADRs were nausea (56.25%), constipation (45.31%), vomiting (40.62%), insomnia (34.37%), sedation (26.56%), dry mouth (21.87%), abdominal discomfort (18.75%), and edema (17.18%). Among female patients, the most frequent ADRs were vomiting (58.62%), nausea (55.17%), constipation (55.17%), abdominal discomfort (34.48%), dry mouth (31.03%), insomnia (31.03%), tremors (31.03%), sedation (24.13%), edema (20.68%), and pruritus (20.68%). Almost no significant associations were seen w.r.t to age, dose, and duration of opioid intake.

Conclusion: The study identified the adverse effects associated with palliative care and their relative incidence. It also attempted to derive a correlation between the incidence of adverse effects and the age and gender of patient, the dose, and duration of opioid use.

Key words: Palliative Care; Adverse Drug Reaction; Opioid Use; Comorbidities; Morphine