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 Benzodiazepine withdrawal

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anesa



Points : 40799
Join date : 2014-02-05

PostSubject: Benzodiazepine withdrawal   Wed Feb 05, 2014 2:42 am

You are the covering night resident when you are called to the orthopaedic ward to assess a 42 year old Mr. John Miller who had been admitted 2 days ago with bilateral, unstable wrist fractures which had been reduced and stabilized with Kirschner wires and immobilized in plaster of Paris under a general anaesthetic. He had recovered well from the operation but earlier today the nurses noticed that Mr. Miller felt increasingly anxious, he was observed to be nauseous, diaphoretic and to have muscle tics. Tonight he suddenly had a witnessed generalised tonic clonic seizure lasting for 30 seconds.
s
Your task is to:
• Assess the patient
• Review the history
• Arrange appropriate investigations
• Discuss the most likely cause of the patient’s seizure and your management with the examine
r.

ROLE PLAYER INSTRUCTIONS:


You have used cocaine, opiates and benzodiazepines (oxazepam / Serepax) on and off for many years (only volunteer this information if asked!).
A couple of days ago you were involved in a drug deal that “went wrong” and you were beaten up by a gang of thugs resulting in bilateral wrist fractures which needed to be operated on. Initially the post operative situation was o.k. because the anaesthetist had prescribed regular morphine for pain control.
Earlier today you started to feel increasingly anxious and nervous, you became quite agitated, you felt nauseated, sweating a lot and developed muscle tics, mainly in your face and twitching of your arm muscles.
You can’t remember what happened tonight.
Now you feel a bit drowsy and tired but not too bad.
When asked about your past history you answer that you have never been sick, never been in hospital, especially no seizures or fits.  



“Can I sue the doctor who started to prescribe benzo’s for me?”


INSTRUCTIONS FOR THE EXAMINER:


This station tests the candidate’s ability to recognize benzodiazepine withdrawal in a patient and to understand the principles of the management for such patients.
Forty eight hours after he was operated on the patient began to show signs and symptoms of benzodiazepine withdrawal, starting with being increasingly anxious and nervous, becoming quite agitated, feeling nauseated, sweating a lot and developing muscle tics, mainly in his face and twitching of his arm muscles. Later nurses observed him to have a generalized, tonic, clonic seizure which lasted for 30 seconds only. He suffered from post-ictal drowsiness for about 5 minutes and the regained full consciousness with retrograde amnesia to the fit.

The candidate is expected to take a thorough history including asking for drug use and to arrange for drug screening (urine toxicology screen is positive for cocaine, opiates and benzodiazepines).
The candidate should recognize benzodiazepine withdrawal in this patient! The main symptoms and signs of benzodiazepines withdrawal are:

Anxiety, tension, agitation, restlessness, sleep disturbance, feelings of unreality or depersonalisation, pain, visual disturbances, depression, paranoid thoughts and feelings of persecution, gastrointestinal symptoms and increased sensitivity to light, noise, taste and smell and eventually seizures. The symptoms are usually more striking in the short acting benzodiazepines. The withdrawal symptoms are basically the opposite of the therapeutic actions (more striking in the short acting benzodiazepines):

• ANXIOLYTIC
• HYPNOTIC
• MYORELAXANT
• ANTICONVULSANT
• AMNESIA

All benzodiazepines act by enhancing the actions of gamma-aminobutyric acid (GABA),  an inhibitory neurotransmitter, slowing the neurons down or stopping them firing, therewith having a general quietening influence on the brain: it is in some ways the body's natural hypnotic and tranquilliser.

This natural action of GABA is augmented by benzodiazepines which thus exert an extra (often excessive) inhibitory influence on neurons. As a consequence of the enhancement of GABA's inhibitory activity caused by benzodiazepines, the brain's output of excitatory neurotransmitters, including norepinephrine (noradrenaline), serotonin, acetyl choline and dopamine, is reduced. Such excitatory neurotransmitters are necessary for normal alertness, memory, muscle tone and co-ordination, emotional responses, endocrine gland secretions, heart rate and blood pressure control and a host of other functions, all of which may be impaired by benzodiazepines. Other benzodiazepine receptors, not linked to GABA, are present in the kidney, colon, blood cells and adrenal cortex and these may also be affected by some benzodiazepines. These direct and indirect actions are responsible for the well-known adverse effects of dosage with benzodiazepines.


It is important to consider the potency and speed of elimination (half-life) of the different benzodiazepines which vary widely:

Benzodiazepine Half-life (hrs) Main function Approximate Equivalent
Alprazolam (Xanax) 6-12 Anxiolytic 0.5 mg
Clobazam (Frisium) 12-60 anxiolytic, antiepileptic 20 mg
Clonazepam (Rivotril) 18-50 Anxiolytic, antiepileptic 0.5 mg
Diazepam (Valium) 36-200 Anxiolytic, muscle relaxant, antiepileptic 10 mg
Flunitrazepam (Rohypnol) 36-200 Hypnotic 1 mg
Oxazepam (Serepax) 4-14 anxiolytic 30 mg
Temazepam (Euhypnos) 8-22 hypnotic 20 mg



Benzodiazepines often lead to tolerance and dependence (physical and psychological).
The candidate should find out that the patient has been taking oxazepam (a short acting benzodiazepine) for many months.

Investigations:

the most relevant investigation here is urine drug screening  

Management:


• Monitoring in HDU or ICU in anticipation of further withdrawal reactions
• Switching patient from short to longer-acting benzodiazepine like flunitrazepam and gradual reductions in dosage to reduce the incidence of withdrawal problems. For patients who have acute withdrawal symptoms diazepam loading (20 mg/h orally) can be used until the symptoms are suppressed. A tapering schedule over 6 to 8 weeks is optimal; however, the dose can be safely decreased by 5% to 10% each day in hospital.
• Training in progressive muscle relaxation, breathing exercises and behavioural goal setting.
• Carbamazepine can be useful in preventing withdrawal seizures




KEY ISSUES:


• Non judgmental approach to patient
• Recognition of benzodiazepine withdrawal
• Outline of appropriate management plan

CRITICAL ERROR: none
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