Benzodiazepines_Flashcards
What neurotransmitter’s effect is enhanced by benzodiazepines?
Benzodiazepines enhance the effect of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA).
How do benzodiazepines enhance the effect of GABA?
Benzodiazepines enhance the effect of GABA by increasing the frequency of chloride channels.
What are some uses of benzodiazepines?
Benzodiazepines are used for sedation, as hypnotics, anxiolytics, anticonvulsants, and muscle relaxants.
What are some risks associated with benzodiazepine use?
Patients commonly develop a tolerance and dependence to benzodiazepines, and care should be exercised when prescribing these drugs.
What is the recommended duration for prescribing benzodiazepines according to the Committee on Safety of Medicines?
The Committee on Safety of Medicines advises that benzodiazepines are only prescribed for a short period of time (2-4 weeks).
What advice does the BNF give on withdrawing benzodiazepines?
The BNF advises that the dose of benzodiazepines should be withdrawn in steps of about 1/8 (range 1/10 to 1/4) of the daily dose every fortnight.
What is a suggested protocol for patients experiencing difficulty withdrawing from benzodiazepines?
A suggested protocol for patients experiencing difficulty withdrawing from benzodiazepines is to switch patients to the equivalent dose of diazepam and reduce the dose of diazepam every 2-3 weeks in steps of 2 or 2.5 mg. The time needed for withdrawal can vary from 4 weeks to a year or more.
What condition may occur if patients withdraw too quickly from benzodiazepines?
If patients withdraw too quickly from benzodiazepines, they may experience benzodiazepine withdrawal syndrome, a condition very similar to alcohol withdrawal syndrome.
What are some features of benzodiazepine withdrawal syndrome?
Features of benzodiazepine withdrawal syndrome include insomnia, irritability, anxiety, tremor, loss of appetite, tinnitus, perspiration, perceptual disturbances, and seizures.
How do benzodiazepines affect chloride channels?
Benzodiazepines increase the frequency of chloride channels.
How do barbiturates affect chloride channels?
Barbiturates increase the duration of chloride channel opening.
SUMMARISE BENZODIAZEPINES
Benzodiazepines
Benzodiazepines enhance the effect of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) by increasing the frequency of chloride channels. They therefore are used for a variety of purposes:
sedation
hypnotic
anxiolytic
anticonvulsant
muscle relaxant
Patients commonly develop a tolerance and dependence to benzodiazepines and care should therefore be exercised on prescribing these drugs. The Committee on Safety of Medicines advises that benzodiazepines are only prescribed for a short period of time (2-4 weeks).
The BNF gives advice on how to withdraw a benzodiazepine. The dose should be withdrawn in steps of about 1/8 (range 1/10 to 1/4) of the daily dose every fortnight. A suggested protocol for patients experiencing difficulty is given:
switch patients to the equivalent dose of diazepam
reduce dose of diazepam every 2-3 weeks in steps of 2 or 2.5 mg
time needed for withdrawal can vary from 4 weeks to a year or more
If patients withdraw too quickly from benzodiazepines they may experience benzodiazepine withdrawal syndrome, a condition very similar to alcohol withdrawal syndrome. This may occur up to 3 weeks after stopping a long-acting drug. Features include:
insomnia
irritability
anxiety
tremor
loss of appetite
tinnitus
perspiration
perceptual disturbances
seizures
GABAA drugs
benzodiazipines increase the frequency of chloride channels
barbiturates increase the duration of chloride channel opening
Frequently Bend - During Barbeque
…or…
Barbidurates increase duration & Frendodiazepines increase frequency
A 72-year-old man who is having trouble sleeping is prescribed temazepam. What is the mechanism of action of temazepam?
Inhibits the effect of acetylcholine
Enhances the effect of gamma-aminobutyric acid
Inhibits the effect gamma-aminobutyric acid
Inhibits the effect of glutamate
Inhibits the effect of noradrenaline
Enhances the effect of gamma-aminobutyric acid
Benzodiazepines enhance the effect of GABA, the main inhibitory neurotransmitter
The correct answer is Enhances the effect of gamma-aminobutyric acid. Temazepam belongs to a class of drugs known as benzodiazepines. Its mechanism of action involves enhancing the effect of gamma-aminobutyric acid (GABA), an inhibitory neurotransmitter in the brain. This enhancement is achieved by increasing the frequency of chloride channel opening within the GABA-A receptor complex, leading to hyperpolarisation of neurons and ultimately decreased neuronal excitability.
Discussing the incorrect options:
Inhibits the effect of acetylcholine is not correct. Anticholinergic drugs inhibit the effects of acetylcholine, a neurotransmitter involved in many functions including muscle movement, heart rate regulation, learning and memory. Examples include atropine and scopolamine. Temazepam does not have this mechanism.
Inhibits the effect gamma-aminobutyric acid is also incorrect. Drugs that inhibit GABA usually increase neuronal activity rather than decrease it, which can lead to seizures or anxiety rather than sedation. An example would be flumazenil, a GABA antagonist used as an antidote for benzodiazepine overdose.
Inhibits the effect of glutamate is not correct either. Glutamate is an excitatory neurotransmitter in CNS and its inhibition would indeed result in reduced neuronal activity similar to enhancing GABA’s effects. However, temazepam doesn’t work by inhibiting glutamate; drugs that do this are typically NMDA receptor antagonists like memantine used in Alzheimer’s disease treatment.
Finally, Inhibits the effect of noradrenaline is also incorrect. Noradrenaline (norepinephrine) inhibitors are typically used as antihypertensives or antidepressants such as beta-blockers or selective noradrenaline reuptake inhibitors (NARIs). They do not primarily induce sleep or reduce anxiety which are key therapeutic effects of temazepam.
