Abstract

Background:
Patients beginning cancer treatment consistently list chemotherapy- induced nausea and vomiting as one of their greatest fears. Inadequately controlled emesis impairs functional activity and quality of life for patients, increases the use of health care resources and may occasionally compromises adherence to treatment.
The goal of this study was to evaluate the effectiveness of gabapentin, in prevention of delayed chemotherapy induced nausea, vomiting and neuropathic pain in cancer patients receiving highly and moderatly emetogenic chemotherapy.

Patients and methods:
125 chemotherapy-naive cancer patients, who were scheduled to receive moderately and highly emetogenic chemotherapy were enrolled in the study. Patients were stratified according to gender, age and they were allocated to one of three groups:
Group І: received 20mg oral dexamethasone with 5HT3 receptor antagonist ondansetron (Zofran) 24 mg on day1 and oral gabapentin300mg once daily on day2 through 6 of chemotherapy.
Group п: received 20mg oral dexamethasone with 5HT3 receptor antagonist ondansetron (Zofran) 24mg on day1, and oral prochlorperazine (Emedrotec) 3mg twice daily on day 2 through 6 of chemotherapy.
Group ш: received 20 mg oral dexamethasone with 5HT3 receptor antagonist ondansetron (Zofran) 24mg on day1 and oral ondansetron (Zofran) 8mg daily on day2 through 6. The average severity of nausea and vomiting during days 2 to 6 after chemotherapy was assessed for every patient, using National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE) and this assessment was repeated for every chemotherapy cycle for 6 cycles.

Results:
The reported average severity of nausea during cycle 1, 2, 3, 6 was lower in patients receiving ondansetron and gabapentin compared to emedrotec (p<0.05).
As regard average severity of vomiting scores there was significant decrease in vomiting scores in patients received either gabapentin or ondansetrone in cycles 2,3,4,5,6 compared to patients received emedrotec (p<0.05). A percentage of patients required rescue medication to alleviate CINV during the study period, 8(19.5%) patients taking ondansetrone compared with 10 (24.3%) patients in the gabapentin group and 17(39.5%) patients in the Emedrotec group. Rescue medication used was ondansetron (zofran) 24 mg IV. Inter groups comparison for the DN4 during the 6 cycles showed significant reduction in the gabapentin group compared to both emedrotec and ondansetrone groups (p<0.05). The incidence of neuropathic pain (DN4 ≥ 4) was significantly reduced in gabapantin group in the 3rd cycle compared to emedrotec and ondansetrone groups (p =0.048).

Conclusion: Gabapentin is a useful drug for the management of delayed chemotherapy- induced nausea and vomiting and it also reduced incidence of chemotherapy-induced neuropathic pain.