Rotación de opioides: Cuándo y cómo

In recent years, there has been a significant increase in the dose and duration of treatment with opioids for cancer pain in most countries. The changing pattern in opioid use has resulted in more comfort and better management of the pain a variety of newer adverse effects, including opioid induced neurotoxicity (OIN). The phenomenon of tolerance may result in a greater risk of side effects due to an increase in opioid toxic metabolites. High opioid doses and prolonged opioids exposure, quick dose escalation in difficult pain syndrome, dehydration and renal failure has been described as risk factors for OIN. Several studies have shown opioid rotation as a safe and reliable method to de-crease neurotoxicity maintaining analgesia. The major indication for switching opioids is represented by poor controlled pain with unacceptable adverse effects due to opioid toxicity. The equianalgesic dose table provides evidence-based values for the relative potencies among different opioid drugs and their values were derived from well-controlled single-dose assays conducted in cancer populations with limited opioid exposure. The individualization of the opioid dose through a process of gradual dose titration is very important. The results of clinical experiences and the previous studies suggest the much higher potency of methadone compared to other opioid agonists, and confirm the correlation between methadone and the previous dose of opioids. The goal is to personalize therapy re-assessing the patient continuously and titrating dose carefully based on pain control and adverse effects.