How to manage hypotension in patients taking antipsychotics?

Managing Hypotension in Patients Taking Antipsychotics

For patients experiencing hypotension while taking antipsychotics, implement non-pharmacological strategies first, followed by medication adjustments and, if necessary, specific pharmacological interventions such as fludrocortisone for persistent symptomatic orthostatic hypotension. 1

Understanding the Problem

Orthostatic hypotension is a common adverse effect of antipsychotics that can:

• Delay or prevent titration to effective antipsychotic doses
• Lead to serious complications including syncope, transient ischemic attack, stroke, myocardial infarction, and death 1
• Increase fall risk, particularly in older adults 2

Different antipsychotics have varying effects on blood pressure:

• Clozapine significantly reduces systolic BP and is associated with hypotension 3
• Olanzapine and risperidone can paradoxically raise systolic BP initially 3
• Levomepromazine (methotrimeprazine), chlorpromazine, olanzapine, quetiapine, and risperidone are specifically noted to cause orthostatic hypotension 4

Assessment and Monitoring

1. Proactive monitoring is essential as patients with psychotic disorders often don't report orthostatic symptoms 1

   • Measure BP in both supine and standing positions
   • Monitor at baseline and regularly during treatment

2. Risk factors to identify:

   • Disorders of the autonomic nervous system
   • Fluid imbalance
   • Concomitant medications affecting hemodynamic tone 1
   • Older age, especially with dementia 2
   • Polypharmacy with other hypotension-inducing medications

Management Algorithm

Step 1: Non-pharmacological Interventions (First-line)

• Patient education on slowly rising from supine position 1
• Adequate hydration
• Compression stockings
• Elevating the head of the bed at night
• Avoiding alcohol and hot environments

Step 2: Antipsychotic Medication Adjustments

• Consider dose reduction if clinically appropriate
• Switch to an antipsychotic with lower risk of orthostatic hypotension:
  • Consider aripiprazole, which has less likelihood of causing orthostatic effects 4
  • Avoid clozapine if hypotension is severe 3
  • Use caution with chlorpromazine, levomepromazine, olanzapine, quetiapine, and risperidone 4

Step 3: Pharmacological Management (for persistent symptomatic orthostatic hypotension)

• First choice: Fludrocortisone 1

  • Mineralocorticoid that increases sodium retention and plasma volume
  • Start with low dose and titrate based on response

• Alternative options (if fludrocortisone is ineffective):

  • Midodrine (alpha-1 agonist)
  • Desmopressin
  • Note: These have limited evidence and potential safety concerns 1

Step 4: Specific Considerations for Psychiatric Patients

• For patients with psychiatric disorders and hypotension:
  • RAS-inhibitors and diuretics are preferred antihypertensives if the patient has hypertension requiring treatment 4
  • Use CCBs and alpha-1 blockers with caution in patients with orthostatic hypotension 4
  • Consider beta-blockers (except metoprolol) for drug-induced tachycardia 4

Important Cautions

1. Avoid adrenaline (epinephrine) infusions in patients with quetiapine overdose, as this can paradoxically worsen hypotension. Norepinephrine is preferred in these cases 5

2. Monitor closely in:

   • Elderly patients, who have higher risk of orthostatic hypotension and falls 2
   • Patients with Alzheimer's disease, where long-term antipsychotic use is associated with orthostatic hypotension and increased fall risk 2

3. Be aware that orthostatic hypotension can persist even in chronically medicated patients (77% prevalence at 1 minute after standing in one study) 6

4. Consider drug interactions that may worsen hypotension:

   • Diazepam and alcohol can potentiate the orthostatic effect of olanzapine 7
   • Antidepressants, particularly those with anticholinergic properties

By following this structured approach, clinicians can effectively manage hypotension in patients taking antipsychotics while maintaining therapeutic efficacy of the psychiatric treatment.