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Source: Doering PL. Substance-Related
Disorders: Overview and Depressants, Stimulants, and Hallucinogens.
In: DiPiro JT, Talbert RL, Yee GC, Matzke GR, Wells BG, Posey LM,
eds. Pharmacotherapy: A Pathophysiologic
Approach. 8th ed. http://accesspharmacy.com/content.aspx?aid=7987346.
Accessed June 9, 2012.
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- Substance-related disorders include disorders of:
- Intoxication
- Dependence
- Withdrawal
- Intoxication is maladaptive behavior during waking state after
recent ingestion and presence in body of substance that causes central
nervous system (CNS) effects.
- Substance dependenceis continued
pattern of substance use in spite of repeated adverse consequences
related to repeated use.
- Physical dependence is state of adaptation manifested by withdrawal
syndrome after:
- Cessation
- Rapid dose reduction
- Decreasing blood levels
- Administration of antagonist
- Withdrawalis development of
substance-specific syndrome after cessation or reduced intake of
substance that had been used regularly.
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- Emergency department (ED) visits involving benzodiazepines
outnumber those of other psychotherapeutic agents.
- In 2006, approximately 195,625 ED visits involved nonmedical
use of benzodiazepines.
- Alprazolam and clonazepam implicated more frequently than
diazepam and lorazepam.
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- Benzodiazepine intoxication
- Manifests
as:
- Slurred speech
- Poor coordination
- Swaying
- Drowsiness
- Hypotension
- Nystagmus
- Confusion
- Does not generally result in life-threatening respiratory
depression.
- Table 1: Characteristics of dependence on benzodiazepines
- Benzodiazepine withdrawal
- Presents similarly
to alcohol withdrawal, with:
- Muscle pain
- Anxiety
- Restlessness
- Confusion
- Irritability
- Hallucinations
- Delirium
- Seizures
- Cardiovascular collapse
- Onset of withdrawal from short-acting benzodiazepines (oxazepam,
lorazepam, alprazolam) within 12–24
hours of last dose.
- Withdrawal from long-acting benzodiazepines (diazepam, chlordiazepoxide, clorazepate) may
be delayed for several days after discontinuation.
- Patients in withdrawal may be in acute distress
and should be treated with benzodiazepine taper to prevent seizures.
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- When toxicology screens necessary, blood or urine should
be collected immediately when patient presents for treatment.
- Qualitative testing useful to confirm presence of benzodiazepines
for diagnostic purposes.
- Quantitative plasma concentrations not usually helpful.
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Differential
Diagnosis
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- Intoxication: Ingestion of other sedative-hypnotics or
alcohol
- Withdrawal:
- Withdrawal from other sedatives
- Cocaine intoxication
- Delirium due to medical illness
- Hypoxia
- Hepatic encephalopathy
- Thiamine deficiency
- Bacteremia
- Anxiety disorder
- Hallucinosis from other causes
- Seizure from other causes
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- Cessation of use of drug
- Termination of drug-seeking behaviors
- Return to normal functioning
- Goals of treatment for withdrawal
- Prevent
progression of withdrawal to life-threatening severity.
- Enable patient participation in treatment program.
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- Likelihood and severity of ...