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2. Benzodiazepines = Useful. Medical disordersMuscular spasmConvulsive disordersPsychiatric disordersAnxiety disordersSituational stressorsJet lagWork shift change. BUT. . .. 3. Key Points. Daily use of benzodiazepines (BZDs) is riskyCertain situations increase riskPrescribing practices Patient characteristicsTaper BZDs slowly if daily use ~2 weeks.
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1. 1 Benzodiazepines and Similar Drugs:Misuse, Abuse, and Dependence Randy Brown, MD
University of Wisconsin, Madison
Alcohol Medical Scholars Program
2. 2 Benzodiazepines = Useful
Medical disorders
Muscular spasm
Convulsive disorders
Psychiatric disorders
Anxiety disorders
Situational stressors
Jet lag
Work shift change
3. 3 Key Points Daily use of benzodiazepines (BZDs) is risky
Certain situations increase risk
Prescribing practices
Patient characteristics
Taper BZDs slowly if daily use ~2+ weeks
4. 4 Overview Pharmacology
Adverse effects
Situations of ? risk
Misuse, abuse, dependence
Tapering BZDs
5. 5 Benzodiazepines (BZDs) Sedative-hypnotic
Flurazepam (Dalmane)
Temazepam (Restoril)
Triazolam (Halcion)
Anxiolytic
Alprazolam (Xanax)
Chlordiazepoxide (Librium)
Clonazepam (Klonopin)
Diazepam (Valium)
6. 6 Non-BZD BZD Receptor Agonists (BZRAs)
Used as sedative-hypnotic
Zaleplon (Sonata)
Zolpidem (Ambien)
Zopiclone (Imovane)
7. 7 Pharmacodynamics:What The Drug Does To The Body
Nerve impulse ? GABA released
GABA binding ? chloride (Cl) influx into post-synaptic neuron
Post-synaptic neuron inhibited
8. 8 BZRAs Pharmacodynamics
Similar to BZDs
Selective for GABA receptor subtype 1
May ? adverse effects
Less anxiolytic effects
9. 9 Pharmacokinetics:What The Body Does To The Drug
10. 10 Lipid Solubility ? lipid solubility ? more rapid effects
Low: clonazepam
Intermediate: lorazepam
High: clorazepate, diazepam
11. 11 BZD Half-Lives Anxiolytics
Oxazepam 8 hrs (6-20 hrs)
Alprazolam 11 hrs (6-20 hrs)
Diazepam 24 hrs (20-100 hrs)
Sedative-hypnotics
Triazolam < 6 hrs
Temazepam 10 hrs (6-20 hrs)
12. 12 Half-Lives
BZRAs
Zolpidem 2 hrs
Zopiclone 4 hrs
13. 13 Adverse Effects: Motor Impairment
Slowed response time
Increased risk
Age > 65
Alcohol or >1 BZD use
14. 14 Adverse Effects: Cognitive Impairment
Anterograde amnesia = impaired recall of new information
Sedation/drowsiness
15. 15 Adverse Effects: Cognitive Impairment Increased risk
Patient
Age > 65
Alcohol use
Medication
High lipid solubility
16. 16 Misuse Long-term use (2+ weeks) = risky
? Side effects, tolerance
Non-medical use (to get high)
~5% ever, 0.3% in last year
? among age 25-44 & alcoholics
17. 17 Abuse 1+ in 12 months of:
Failure to fulfill major obligations
Recurrent hazardous use
Recurrent legal consequences
Ongoing use despite interpersonal problems
Lifetime prevalence ~ 0.4%
Risk factors similar to those for dependence
18. 18 Dependence 3+ in 12 months of:
Tolerance
Withdrawal
Larger amts/longer periods than intended
Persistent desire/failed attempts to quit/control use
Much time obtaining/using/recovering
Important activities sacrificed
Continued use despite adverse effects
19. 19 Physical Dependence:Only Part Of Substance Dependence Physiologic adaptation to substance ? tolerance & withdrawal
Withdrawal relieved by substance
? Dont stop abruptly if taken 2+ weeks
20. 20 Patient Risk Factors:Misuse, Abuse, & Dependence Substance dependence history
BZDs, alcohol +
Psychiatric history
Anxiety, depression +
Social & demographic factors
Unemployment, poor social support +
21. 21 Medication Factors:Misuse, Abuse, & Dependence Dose/duration
High dose (outside usual range)
> 2 weeks daily use
Short half-life
Highly lipid soluble BZD
22. 22 BZRAs:Misuse, Abuse, & Dependence
Risk < BZDs
Dependence develops with long-term use
Risk factors similar to BZDs
23. 23 Risky Patients Age > 65
Substance dependence history
Psychiatric history
Life stresses
24. 24 Risky Practice BZD characteristics ? risk:
high lipid solubility/rapid onset
short half-life
Prescribing practices ? risk:
Long-term daily use (2+ weeks)
High dose (outside usual range)
25. 25 Detecting Misuse, Abuse, Dependence Did patient:
? dose on own?
take meds for additional reason (euphoria)?
have risk factors for abuse/dependence?
give a believable story?
Consider speaking with close family
26. 26 Detecting Misuse, Abuse, Dependence Behavior:
Early refills, Rx loss/theft
Functional decline
Overly focused on med
Fails non-med appointments
Adverse effects with use
27. 27 BZD Withdrawal Chronic use (2+ weeks) ?
? GABAergic inhibitory function
? glutamate/NMDA function
Abrupt discontinuation ? unopposed excitatory CNS activity
Less severe: anxiety, diaphoresis, ?BP/HR
More severe: hallucinosis, seizures
28. 28 Tapering BZDs:Usual Taper 1) Divide daily dose 2-4 x daily
2) Taper by 25% every 3 days
3) Slow rate during last half of taper
Provide support
behavioral therapy
engage close family
29. 29 Tapering BZDs:Difficult Taper Unsuccessful taper
? dose/duration or ? t1/2 ? ? difficulty tapering
? Consider longer-acting agente.g.:
10 mg alprazolam = 100 mg diazepam
Divide 2-4x daily
Taper 25% each week
Slow during last 1/2
30. 30 Case Vignette 32 yo ?
6 mo h/o ?ing daily bzd use: 2 mg alprazolam QID
Dx: panic disorder
Substance use: EtOH 6 drinks on 4-6 nights/mo
DWI (BZD + EtOH) x 3 over last 12 mo
31. 31 Case: Treatment Issues Dx: BZD dependence, EtOH abuse. . .
Tx: BZD taper
Same agent
Alprazolam 2 mg QID x 3 days ? 2 mg TID etc.
Long-acting
Diazepam 20 mg QID x 3 days ? 20 mg TID etc.
Adjuntive Tx (behavioral, social, frequent f/u)
32. 32 Summary Long-term use (> 2 weeks) ? risk for:
Side effects
Misuse, abuse, & dependence
Physical dependence & withdrawal
Prescribing practices & patient characteristics ? risk
If taken for > 2 weeks, taper slowly