What is the initial approach to managing substance-induced psychosis during a physical examination?

Physical Examination of Substance-Induced Psychosis

The initial physical examination approach for substance-induced psychosis must prioritize ruling out life-threatening medical emergencies and identifying reversible causes, followed by targeted assessment for intoxication/withdrawal states and neurological complications, while maintaining patient and staff safety. 1, 2

Immediate Safety and Stabilization Assessment

• Assess vital signs immediately to detect autonomic instability from intoxication or withdrawal (tachycardia, hypertension, hyperthermia, or hypothermia) 3
• Evaluate level of consciousness and orientation - consciousness should be intact in pure psychosis, whereas altered consciousness suggests delirium or medical emergency requiring different management 1
• Screen for acute medical emergencies including signs of CNS infection (fever, meningismus), traumatic brain injury (focal deficits, signs of trauma), or metabolic derangement 2
• Assess immediate risk for self-harm or aggression to determine if physical restraints or emergency medication are needed 4

Targeted Substance-Related Physical Findings

• Examine pupils for size and reactivity: mydriasis suggests stimulant intoxication (amphetamines, cocaine), miosis suggests opioid co-ingestion, nystagmus suggests phencyclidine or ketamine 5
• Inspect nasal mucosa and septum for evidence of intranasal drug use (perforation, inflammation, bleeding) 5
• Check skin for injection track marks, abscesses, or signs of poor self-care 5
• Assess for signs of chronic substance use: dental decay (methamphetamine), jaundice (alcohol), tremor (alcohol withdrawal) 3, 5

Neurological Examination Priorities

• Perform focused neurological exam looking for focal deficits that would suggest structural brain lesion requiring urgent imaging 1, 2
• Evaluate for extrapyramidal signs if patient has received antipsychotics, as these side effects reduce future medication adherence 4
• Assess motor behavior for catatonia, agitation, or abnormal movements that characterize psychotic presentations 1
• Test for asterixis and myoclonus which suggest metabolic encephalopathy rather than pure substance-induced psychosis 1

Distinguishing Features from Primary Psychosis

• Document temporal relationship between substance use and symptom onset - substance-induced psychosis should resolve within 30 days of sobriety 3
• Note that patients with substance-induced psychosis typically demonstrate: better insight, fewer negative symptoms, more depressive and anxiety symptoms compared to primary psychotic disorders 3
• Recognize that one in four patients initially diagnosed with substance-induced psychosis will later be diagnosed with schizophrenia spectrum disorder, making thorough documentation critical 6

Critical Medical Workup During Physical Exam

• Obtain urine drug screen to confirm suspected substances and identify polysubstance use 3, 5
• Check core temperature as hyperthermia from stimulants or serotonin syndrome requires immediate intervention 5
• Assess hydration status through mucous membranes, skin turgor, and orthostatic vital signs 5
• Examine cardiovascular system for tachycardia, arrhythmias, or signs of endocarditis in injection drug users 5

Common Pitfalls to Avoid

• Don't assume all psychosis in substance users is substance-induced - approximately 25% will have or develop a primary psychotic disorder requiring different long-term management 6
• Don't miss delirium - fluctuating consciousness, disorientation, and inattention distinguish delirium from psychosis and require different urgent evaluation 1
• Don't overlook withdrawal states - alcohol or benzodiazepine withdrawal can cause both psychosis and life-threatening seizures requiring immediate benzodiazepine treatment 1
• Don't delay neuroimaging in new-onset psychosis when focal neurological signs, head trauma history, or atypical features are present 1, 2

Initial Management Considerations During Examination

• Consider short-term benzodiazepines as adjuncts for acute agitation during the examination, which aids both safety and diagnostic assessment 4
• Avoid large initial antipsychotic doses if medication is needed during examination, as they increase side effects without hastening recovery 4, 2
• Coordinate with family members during assessment to obtain collateral history about baseline functioning, substance use patterns, and psychiatric history 4, 2