Utilization of gabapentin for cough in cancer: A case series.

Abstract

241 Background: Refractory cough is a significant problem for cancer patients. Therapeutic options are suboptimal and based on low quality of evidence. Gabapentin is a gamma aminobutyric acid analog that may regulate neurotransmitter release via activity at the alpha-2-delta subunit of voltage dependent calcium channels. It is hypothesized to ameliorate cough through a central mechanism and is effective in relieving chronic refractory idiopathic cough. However, gabapentin has not been studied in cancer patients with cough. We report the use of gabapentin for chronic, refractory cough in adult cancer patients. Methods: We identified 3 male patients with metastatic cancer evaluated by palliative care for refractory cough. Data regarding diagnosis previous treatments for cough, dosage of gabapentin, and symptomatic outcomes are reported. Results: Case 1 is a 68 y.o. male with NSCLC and malignant pleural effusion had chronic cough despite thoracentesis that was associated with fatigue, sleep disturbance, and worsened with movement, pain, and sitting upright. Previous treatment for cough included benzonatate, codeine, dextromethorphan, albuterol inhaler, and ranitidine, without relief. He received gabapentin 300 mg three times a day. Case 2 was a 68 y.o. with NSCLC and a left mainstem bronchus obstructive mass not amenable to stent. Cough was associated with eating and sleep disturbance, and he could not lie flat for radiation planning. He received gabapentin 300 mg at night. Case 3 was a 48 y.o. with salivary duct carcinoma and a cavitary S. Pyogenes pneumonia treated with antibiotics and chest tube drainage and had persistent cough. He received gabapentin 300 at night. All patients had cough relief within 24 hours and were controlled until death. Conclusions: Gabapentin at doses up to 1800 mg per day has been studied in refractory chronic idiopathic cough and found effective relative to placebo with significantly more improvement in cough frequency, severity, and quality of life. Chronic cough in cancer patients can be a debilitating symptom and interventions are inadequately effective, with little quality evidence to support their use. Our case series suggests that further studies of gabapentin in cancer-related chronic cough are warranted.