Pain Management in Patients with Hepatorenal Syndrome: A Literature Review

Introduction: Patients with cirrhosis often present with pain as a common complaint. Pharmacological pain management safety depends on the excretion and metabolism of drugs by the kidney and the liver. The analgesic choice in cirrhotic patients can be tremendously challenging, especially in patients with hepatorenal syndrome, a potentially reversible renal impairment associated with an increased drug accumulation and a high risk of potential toxicity. Choice and dose of medications depend on various factors, including the severity of the condition, possible drug interactions, drug dependence, and liver transplant status. Ideally, medications should be titrated from the lowest effective dose to higher strength. This review aims to discuss the pharmacodynamic and pharmacokinetics of analgesics used in cirrhotic patients. The metabolism of each drug, route of administration, pathophysiology, and limitations of their use are discussed to better understand their implementation in patients with cirrhosis and HRS. For this purpose, we performed a systematic literature search in PubMed and Google Scholar. Articles were searched via search terms and keywords. Certain high potency opioids like Sufentanil, Fentanyl, Remifentanil, Oxymorphone, and Butorphanol can be used cautiously. Low potency opioids such as Pentazocine, Tramadol, Nalbuphine, and Tapentadol may also be considered with dose adjustments. Albeit less favorable, some other analgesic options include Gabapentin, Pregabalin, acetaminophen, Duloxetine, Venlafaxine, Fluoxetine, Topical Lidocaine, Capsaicin, and Clonidine. Methodology: A systematic literature search in PubMed and google scholar was conducted between March 5 and August 10, 2021. Articles were searched via search terms and keywords relating to International Classification of Diseases: hepatorenal syndrome, pain, opioids, metabolism, renal clearance. Results: One thousand three hundred eighty-seven articles were identified from database searching. After removal of duplicates, 924 studies were screened for eligibility. After review of titles and abstracts, 665 studies were rejected for relevance reasons. Most of these studies were rejected because they were not relevant, did not meet search criteria, case-control article, case series articles, no English translation, articles did not mention adjustments in patients with liver or kidney disease. One hundred forty-two articles were used for the synthesis.