Organic brain syndromes and opioid administration for cancer pain

Abstract

To clarify the range of potential etiologies that may contribute to organic brain syndrome in patients receiving systemic opioids for cancer pain, we describe 15 patients who presented this complication. In 11 cases, concomitant conditions were found that could contribute to the onset of organic brain syndrome. These data illustrate that multiple causes often play a role in the development of mental status changes in advanced cancer. Opioids are seldom the only causal factor implicated.

Delirium, Confusion, and Agitation at the End of Life

“…7 ' 8 ' 22 -23 ' 29 " 31 In cases of delirium apparently produced by opiates, other potentially causative factors are almost always present. 29 In fact, for all instances of delirium, particularly delirium at the end of life, multifactorial cause is the rule and not the exception. 2^1 ' 10 -13 -16…”

The panorama of opioid‐related cognitive dysfunction in patients with cancer

“…• Educate family regarding nature of opioid-related cognitive dysfunction and delirium: psychomotor agitation, perceptual disturbance, delusions, and communication difficulties [107][108][109][110] • Establish goals of care, evaluate pros and cons of intervention in the context of the patient's clinical situation, previously expressed wishes, and family wishes 128 • Monitor delirium severity with an instrument that is either partly 118,119 or wholly observational 42,122,123 • Consider either opioid dose reduction or opioid switch [129][130][131][132][133] • Discontinue or minimize use of all unnecessary medications, especially other psychotropics 4 • Consider all other contributory causes, especially concurrent reversible causes 4 • Assess renal function and adjust dose of opioid or other drugs accordingly [92][93][94][95][96][97] • Assess hydration and supplement with parenteral fluids if necessary 4 • Commence symptomatic treatment of delirium with neuroleptic such as haloperidol 8,150,151 • Environmental manipulation: minimal noise, reorientation, encourage presence of family member 116 • Prevent recurrence: if delirium is reversed, address risk factors for recurrence in future (see Table 6) and emotional lability to be misinterpreted as poor pain control. 108,109 The use of psychostimulants has been advocated in the treatment of opioid-induced sedation, [157][158][159] and cognitive benefit has been demonstrated with neuropsychologic testing in a randomized, doubleblind, placebo-controlled, crossover trial of methylphenidate in patients receiving a continuous infusion of opi...…”

“…2,17,130 It is speculated that in the context of opioid-induced delirium, switching to a different opioid allows achievement of analgesia on the newly substituted opioid, whereas the potentially toxic metabolites of the prior opioid are eliminated. 17,130 Although one might intuitively anticipate some amelioration of opioid-induced cognitive dysfunction when the opioid dose is reduced, and brief survey reports suggest so, 131 this has not been specifically evaluated in the context of a well-designed prospective study, particularly in relation to maintenance of analgesia. Meanwhile, opioid rotation has been studied, albeit retrospectively, and an associated improvement in the "leading symptom' (mostly neurotoxic symptoms: cognitive impairment, myoclonus, and perceptual disturbance) and pain intensity was demonstrated in approximately 70% of patients.…”

Opioid use in cancer pain. Is a more liberal approach enhancing toxicity?

“…Hallucinations have been previously described in patients requiring opioid analgesia (53)(54)(55)(56)(57)(58)(59)(60). Most of the reports have described visual hallucinations.…”