Vías alternativas a la vía oral para administración sistémica de opioides en Cuidados Paliativos. Revisión de la literatura

More than 80% of the terminally ill patients have difficulty to swallow oral medications; there is an increasing interest in the development of other routes different than the oral, in order to achieve an adequate symptom control. Using alternatives routes will mainly benefit patients presenting with clinical conditions like: nausea and vomit, dysphagia, bowel obstruction, delirium/sedation, dyspnea and pain; patients that require outpatient or home care. This review of the literature is aimed at describing the indications, the limits and the main aspects of the pharmacokinetics and pharmacodynamics relative to the alternative routes of administration of opioids most commonly used in clinical practice. Subcutaneous, rectal, nebulize, sublingual, transdermal, intranasal and iontophoresis administration routes are examined. The majority of these routes is on experimental phase and hopefully will be of clinical utility in a near future, but currently there is not clear evidence for their use in the clinical practice.