Should risperidone (Risperdal) be discontinued in a patient with possible dementia who experiences increased confusion, thought blocking, and forgetfulness after starting the medication?

Yes, Discontinue Risperidone Immediately

You should stop risperidone immediately in this patient with possible dementia who is experiencing increased confusion, thought blocking, and forgetfulness, as these symptoms represent cognitive worsening that contradicts the primary goal of treatment and may indicate adverse drug effects. 1

Critical Safety Considerations

The FDA explicitly warns that risperidone is not approved for treatment of patients with dementia-related psychosis and carries a boxed warning for increased mortality risk in this population. 1 The cognitive symptoms you describe—increased confusion, thought blocking, and forgetfulness—represent exactly the type of harm that outweighs any potential benefit in dementia patients.

Evidence Against Continuing Risperidone

Harm Demonstrated in High-Quality Studies

• A 2018 randomized controlled trial in palliative care settings found that risperidone was associated with higher delirium symptom severity scores compared to placebo and resulted in poorer overall survival in long-term follow-up. 2

• The ESMO guidelines explicitly state that administration of either haloperidol or risperidone has no demonstrable benefit in symptomatic management of mild-to-moderate delirium and is not recommended in this context. 2

Cognitive Side Effects Are Well-Documented

• The cognitive worsening you're observing (confusion, thought blocking, forgetfulness) aligns with known anticholinergic and sedating effects that can worsen dementia symptoms. 1

• Extrapyramidal symptoms, which can manifest as thought blocking and cognitive slowing, occur in a dose-dependent manner with risperidone, even at low doses in elderly patients. 2, 3

What to Do After Discontinuation

Immediate Actions

• Stop risperidone immediately without tapering if the patient has only been on it for a short period (days to weeks). 1

• Monitor for symptom improvement over 48-72 hours; cognitive symptoms from antipsychotic toxicity often improve within this timeframe. 2

Evaluate Underlying Causes

• Assess for delirium precipitants including infection, metabolic disturbances (hypercalcemia, hypomagnesemia, SIADH), medication effects, or opioid-induced neurotoxicity if applicable. 2

• Review all medications for anticholinergic burden and other cognitive impairing agents that should be deprescribed. 2

Alternative Management Strategies

If behavioral symptoms require treatment after addressing reversible causes:

• Non-pharmacological interventions should be first-line, including environmental modifications, reorientation strategies, and caregiver education. 2

• If pharmacological treatment is absolutely necessary for severe agitation threatening harm, consider:

  • Quetiapine 12.5-25 mg daily (may offer benefit with less cognitive impairment) 2
  • Olanzapine 2.5 mg daily (may offer benefit but monitor metabolic effects) 2
  • These should only be used at the lowest effective dose for the shortest duration possible 2

Common Pitfalls to Avoid

• Do not increase the risperidone dose in response to worsening symptoms, as this will likely worsen cognitive function further. 4

• Do not assume behavioral symptoms require antipsychotics; in dementia patients, these medications often cause more harm than benefit. 2

• Do not restart risperidone even at a lower dose, given the clear temporal relationship between drug initiation and cognitive decline. 1

Documentation and Monitoring

• Document the temporal relationship between risperidone initiation and symptom onset. 1

• Monitor for improvement in confusion, thought processes, and memory over the next 3-7 days after discontinuation. 2

• If symptoms persist after discontinuation, this suggests the underlying dementia or another medical condition rather than drug effect, requiring further evaluation. 2