What antipsychotic and anti-delirium medications are contraindicated for concurrent use?

From the Guidelines

The concurrent use of olanzapine and benzodiazepines, such as lorazepam, should be avoided in elderly patients due to the increased risk of excessive sedation and respiratory depression, as noted in the study by 1. When considering the management of delirium, it is essential to carefully evaluate the potential interactions between antipsychotic and anti-delirium medications. The study by 1 provides guidance on the pharmacological interventions for delirium symptoms in adult patients, highlighting the importance of cautious medication management. Some key points to consider when selecting antipsychotic and anti-delirium medications include:

• The potential for extrapyramidal side effects (EPSEs) with certain medications, such as haloperidol and risperidone, as noted in the study by 1
• The risk of QT prolongation with medications like haloperidol and chlorpromazine, as mentioned in the study by 1
• The potential for sedation and respiratory depression with combinations of medications, such as olanzapine and benzodiazepines, as highlighted in the study by 1
• The importance of careful dose titration and monitoring, particularly in vulnerable populations like the elderly or those with multiple medical conditions, as emphasized in the study by 1 In terms of specific medication combinations to avoid, the following are notable:
• Olanzapine and benzodiazepines, such as lorazepam, in elderly patients, due to the increased risk of excessive sedation and respiratory depression, as noted in the study by 1
• Haloperidol and droperidol, due to the increased risk of QT prolongation, as mentioned in the study by 1
• Quetiapine and metoclopramide, due to the increased risk of EPSEs, as noted in the study by 1
• Risperidone and promethazine, due to the increased risk of sedation and neuroleptic malignant syndrome, as mentioned in the study by 1 Ultimately, the selection of antipsychotic and anti-delirium medications should be guided by a careful consideration of the potential benefits and risks, as well as the individual patient's medical history and current condition, as emphasized in the study by 1.

From the FDA Drug Label

5.16 Use in Combination with Fluoxetine, Lithium, or Valproate 7 DRUG INTERACTIONS 7.1 Potential for Other Drugs to Affect Olanzapine 7.2 Potential for Olanzapine to Affect Other Drugs

The FDA drug label does not answer the question.

From the Research

Antipsychotic and Anti-Delirium Medications

The following medications have been studied for the treatment of delirium:

• Haloperidol: a typical antipsychotic that may cause adverse extrapyramidal symptoms among patients 2
• Risperidone: an atypical antipsychotic that is as effective as haloperidol in controlling delirium, but has a lower incidence of extrapyramidal adverse effects 2
• Olanzapine: an atypical antipsychotic that is as effective as haloperidol in controlling delirium, but has a lower incidence of extrapyramidal adverse effects 2
• Quetiapine: an atypical antipsychotic that has been used to treat delirium, but there is limited evidence to support its use 2, 3

Contraindications for Concurrent Use

There is no direct evidence to suggest that any of these medications are contraindicated for concurrent use. However, it is recommended to use antipsychotics with caution and to monitor patients closely for adverse effects, especially when using high doses of haloperidol 2, 4. Additionally, benzodiazepines and neuroleptics should be used with caution in palliative care patients, as they can aggravate or precipitate delirium, and result in adverse events with substantial distress or unfavorable survival outcomes 5.

Safety and Efficacy

The safety and efficacy of antipsychotics in treating delirium have been evaluated in several studies:

• A systematic review and meta-analysis found that antipsychotics were superior to placebo in terms of response rate, delirium severity scales scores, and Clinical Global Impression-Severity Scale scores 6
• A study found that low-dose haloperidol was effective in decreasing the severity and duration of delirium in post-operative patients, but high-dose haloperidol was associated with a greater incidence of side effects, mainly parkinsonism 2
• A review of randomized controlled trials found that risperidone and haloperidol were not superior to placebo in treating delirium in palliative care patients, and were associated with higher mortality and morbidity 5