(i) An alternate etiology for delirium thought to be more likely than alcohol withdrawal | |
(ii) Age <16 years | |
(iii) Pregnancy (positive assay for ßhCG—a urine assay or blood test will be performed for all women < 55 years) | |
(iv) Current breastfeeding | |
(v) Severe acute hepatitis (AST or ALT >500); liver failure (INR >2 not otherwise explained) | |
(vi) A presenting complaint of neurotrauma, brain mass, or intra-cranial bleed; abnormal cell count or gram stain on lumbar puncture (if performed) | |
(vii) A strong clinical suspicion of recent co-ingestion of depressant drugs (e.g., opioids, toxic alcohols, gamma-hydroxy-butyrate) | |
(viii) Hemodynamic instability (systolic blood pressure [SBP] < 90 mmHg) | |
(ix) History of barbiturate allergy | |
(x) History of porphyria | |
(xi) History of myasthenia gravis | |
(xii) Inability to obtain IV access | |
(xiii) Anticipated transfer to another center | |
(ivx) Stated intent to leave against medical advice | |
(xv) Active outpatient prescription for anti-retroviral therapy for HIV | |
(xvi) Active outpatient prescription for one of the following anti-epileptic drugs: valproic acid, phenytoin, carbamazepine, clobazam, lacosamide, lamotrigine, levetiracetam, topiramate, primidone, or phenobarbital | |
(xvii) Active outpatient prescription for an anticoagulant medication with a significant metabolic interaction with phenobarbital (i.e., warfarin or apixaban) | |
(xviii) Active outpatient prescription for a monoamine oxidase inhibitor (e.g., phenelzine, selegiline, tranylcypromine, isocarboxazid) | |
(ixx) Renal failure, as defined by a creatinine clearance <10 ml/min (as calculated by the Cockcroft-Gault equation) and/or active receipt of renal replacement therapy (dialysis) | |
(xx) Administration of IV or oral phenobarbital during the index admission prior to randomization. |