The use of antihistamine and antihistamine-like drugs for cancer-related pain: a narrative review

Purpose: Antihistamines, commonly used for their anti-inflammatory properties, also possess analgesic effects, although their use in pain management, particularly cancer-related pain, is not widely recognized. This narrative review aimed to evaluate the efficacy of antihistamines and antihistamine-like drugs in reducing cancer-related pain intensity. Secondary objectives included assessing the impact on analgesic consumption, quality of life, and adverse event profiles among cancer patients. Methods: PubMed and Embase were searched through August 2025 to identify clinical studies on antihistamines for cancer-related pain. Search terms included “antihistamine,” “cancer pain,” “histamine antagonist,” “H1 antagonist,” “H1 blocker,” and “pain.” After deduplication, 310 articles were screened, 46 were assessed for eligibility, and 11 studies were included. These studies were evaluated based on effect sizes and the degree of pain relief provided by antihistamines or antihistamine-like drugs, using various pain measurement methods. Results: The most commonly studied conditions were oral mucositis and chemotherapy-related peripheral neuropathy, with doxepin, loratadine, and mirtazapine being the most frequently studied drugs. The 11 studies found that antihistamines helped reduce symptoms to some extent. Conclusion: Analysis of these studies demonstrated meaningful evidence that antihistamine and antihistamine–like drugs may offer some benefit for treating cancer-related pain.