Sedative, Hypnotic, Anxiolytic Use Disorders Workup

Updated: Feb 10, 2017
  • Author: Stephen P Erlach, JD, MD; Chief Editor: Randon S Welton, MD  more...
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Laboratory Studies

Careful review of the patient's history and examination should typically suffice; however, further studies may be performed to rule out an underlying pathology with a similar presentation. This is particularly relevant if the patient presents with severe symptoms or when a reliable history cannot be obtained. Workup depends on presenting symptoms (intoxication/withdrawal), especially if no prior knowledge of ingestion of sedatives is known. [19] If a laboratory workup is necessary, it should include the following:

  • Appropriate laboratory investigations are performed in patients with fever or other signs of infection. CBC, urinalysis, and chest radiography (CXR) should be performed, particularly in elderly patients.

  • Comprehensive metabolic panel to assess for metabolic encephalopathy seen in hepatic and renal failure and other electrolyte derangements that can mimic sedative and anxiolytic intoxication.

  • Fingerstick glucose, to rule out hypoglycemia as the cause of any alteration in mental status

  • Arterial blood gasses to rule out blood gas abnormalities secondary to respiratory depression. Carbon monoxide poisoning should be ruled out, if suspected, by obtaining carboxyhemoglobin level measured by CO-oximetry of a blood gas sample.

  • Urine drug screen including CNS depressants, cannabis, PCP, and stimulants such as amphetamines and cocaine

  • Ethanol and phenobarbital intoxication can be ruled out by obtaining serum concentrations.

  • Serum drug levels if the patient is known to take lithium, carbamazepine, valproic acid, or TCAs, to rule out concomitant psychotropic drug toxicity

  • Acetaminophen and salicylate levels, to rule out these common co-ingestions

  • Thyroid panel, as thyrotoxicosis and hypothyroidism can mimic sedative-hypnotic withdrawal and overdose states, respectively


Imaging Studies

CT/MRI of the head can be performed to rule out mass-occupying lesions and intracranial bleeding if these are suspected.


Other Tests

ECG may be helpful to rule out arrhythmias, which can increase the probability of emboli to the brain and cause altered mental status.

Consider an EEG, as it may show paroxysmal bursts of high-voltage, slow-frequency activities that precede the development of seizures in the setting of sedative-hypnotic withdrawal. In the context of hallucinations, EEG may rule out neurologic conditions such as temporal lobe epilepsy.



Consider a lumbar puncture, if meningitis/encephalitis suspected.