What is the recommended oral dose of haloperidol (antipsychotic medication) for acute agitation in pill form?

Oral Haloperidol Dosing for Acute Agitation

For acute agitation in adults, administer haloperidol 5 mg orally, which can be repeated every 30-60 minutes as needed, with consideration for combining it with lorazepam 2 mg for enhanced efficacy. 1, 2

Standard Oral Dosing Protocol

Adult dosing:

• Initial dose: 5 mg PO 1
• Repeat dosing: Every 30-60 minutes as needed 1
• Maximum daily dose: 40 mg 1
• Time to peak effect: 45-60 minutes, with duration of 6-8 hours 1

Adolescent dosing (13+ years):

• Initial dose: 2-5 mg PO 1
• Repeat: Every 30-45 minutes as needed 1
• Maximum: 30 mg daily 1

Pediatric dosing (6-12 years):

• Initial dose: 0.5-2 mg PO 1
• Alternative weight-based: 0.1 mg/kg PO 1

Combination Therapy Advantage

Haloperidol 5 mg combined with lorazepam 2-4 mg produces significantly superior outcomes compared to monotherapy, including faster sedation (15-30 minutes), fewer repeat doses required, and greater overall agitation reduction. 2 This combination is recommended by the American College of Emergency Physicians as more effective than either agent alone. 2

The oral combination of risperidone 2 mg plus lorazepam 2 mg demonstrated equivalent efficacy to intramuscular haloperidol 5 mg plus lorazepam 2 mg, with similar improvements at 30,60, and 120 minutes. 3

Critical Safety Considerations

QTc prolongation risk: Haloperidol prolongs the QTc interval at steady-state concentrations, though typically not exceeding 500 ms. 1 Avoid use if baseline QTc prolongation exists. 2

Extrapyramidal symptoms (EPS): Have diphenhydramine or benztropine immediately available for acute dystonic reactions, which occur more frequently with haloperidol than atypical antipsychotics. 2 Higher doses and use in young males increase EPS risk. 1

Neuroleptic malignant syndrome: Monitor for hyperpyrexia, rigidity, altered mental status, and autonomic instability. 2

Anticholinergic interactions: Avoid haloperidol in patients with anticholinergic toxicity (hallucinogens, anticholinergic delirium), as it may worsen the condition due to its anticholinergic properties. 1

Age-Specific Dosing Adjustments

Older adults (≥65 years): The recommended starting dose is 0.5-1 mg PO, significantly lower than standard adult dosing. 4, 5 Low-dose haloperidol (≤0.5 mg) demonstrated similar efficacy to higher doses in older hospitalized patients, with no additional benefit from doses >1 mg and significantly greater risk of sedation with higher doses. 4, 5 Higher doses did not decrease duration of agitation or length of hospital stay. 4

Common Pitfalls to Avoid

Do not escalate to large doses during initial treatment, as this results in excessive dosing and side effects without hastening recovery or improving outcomes. 2, 4 In older adults, 37.5% received inappropriately high initial doses (>1 mg), leading to increased sedation without therapeutic benefit. 4

Do not use haloperidol monotherapy when combination with benzodiazepines is available and more effective. 2 The combination requires fewer repeat doses and achieves more rapid control. 2

Recognize that immediate effects are primarily sedation, not true antipsychotic response, which requires 4-6 weeks to properly assess. 2 The onset of oral haloperidol is 20-30 minutes with peak at 45-60 minutes. 1

Monitor for reversible medical causes of agitation before attributing symptoms solely to psychiatric illness, particularly in patients with substance abuse or medical comorbidities. 1