Narcotic analgesics (tested), Sedatives & hypnotics (not-tested) Flashcards
narcotics not added in yet
(not tested) Physical symptoms of anxiety
(related to adrenergic activation)
Tachycardia
SOB
Nausea
Gastric acid hypersecretion
Trembling
(not tested) Therapeutic rational of anxiety disorders
To correct the over-arousal of CNS
Sedative: Causes sedation, relaxation
Hypnotic (one level stronger than sedative): Induces drowsiness and sleep, may have amnestic effects
Anxiolytic: Reduces anxiety
(not tested) What is the main class of drugs used as therapeutics for anxiety disorders?
Benzodiazepines
Can be used as anxiolytics/sedatives, hypnotics, pre-anesthetics, or for anti-convulsant effects.
(not tested) Examples of benzodiazepines used as anxiolytics/sedatives
Diazepam, lorazepam
(not tested) Examples of benzodiazepines used as hypnotics
Diazepam, triazolam, temazepam
(not tested) Examples of benzodiazepines used as pre-anesthetics
Diazepam, midazolam
(not tested) Examples of benzodiazepines used for anti-convulsant effects
Diazepam
(not tested) Examples of non-benzodiazepines
Barbiturates (e.g. phenobarbital)
Buspirone
Zolpidem
Propanolol
(not tested) What is the GABA and GABA receptor? How does it concern us?
GABA is the brain’s primary inhibitory neurotransmitter. When GABA binds to its receptors, it reduces the likelihood that a neuron will fire an action potential –> This inhibition is essential for maintaining balancing excitatory and inhibitory signals.
GABA A receptor is the primary target for most sedatives and hypnotics:
- Activation allows chloride to flow into the neuron, hyperpolarizing it and making it less likely to fire.
(not tested) MOA of Benzodiazepines
Binds to benzodiazepine site, which in turn potentiates the binding of GABA to the GABA A receptor binding site
Once benzo bound to benzo site, it makes GABA open the chloride channel more easily –> Potentiates influx of chloride ions, leading to hyperpolarization, hence neurons will not be polarised and will not fire –> reduce activation of CNS
Note: Benzodiazepine does not directly bind to GABA binding site!
(not tested) What are some short acting benzodiazepines?
Short acting: Short duration of action
Midazolam: Usually used for anxiety, induction of GA, procedural sedation
Triazolam: Used for insomnia
(not tested) What are some long acting benzodiazepines?
Usually used for more chronic kind of conditions (e.g. alcohol withdrawal syndrome, status epilepticus, refractory seizure)
Chlordiazepoxide
Diazepam (status epilepticus)
(not tested) What are some intermediate acting benzodiazepines?
Usually for anxiety, panic disorders
Lorazepam: Anxiety, insomnia, status epilepticus
Clonazepam: Seizures
(not tested) Which benzodiazepine is used to treat status epilepticus
Long acting benzodiazepine.
Diazepam
(not tested) Adverse effects of benzodiazepines
- Acute toxicity leads to severe respiratory depression
- especially used with alcohol
- treatment is by FLUMAZENIL, a benzodiazepine antagonist - Side effects upon chronic use:
- drowsiness, confusion, amnesia
- impaired muscle co-ordination (impairs manual skills) - Tolerance and dependence
- depends on frequency of use (tolerance develops faster for epilepsy than for use to induce sleep)
- withdrawal effects, important to withdraw gradually
- has abuse potential due to addiction
(not tested) Withdrawal effect of benzodiazepines
- disturbed sleep
- rebound anxiety
- tremor
- convulsions
(not tested) MOA of Zolpidem, a non-benzodiazepine
is a non-benzodiazepine
Also potentiates GABA A mediated Cl- currents at the same site as
benzodiazepines.
– Has good hypnotic effect, primarily used to treat INSOMNIA.
– Not effective as anxiolytics, not useful to treat anxiety disorder
(not tested) MOA of Buspirone, a non-benzodiazepine
is a non-benzodiazepine
- exact MOA is unclear, but involves SEROTONIN AND DOPAMINE receptor system (not just GABA receptor system is involved in anxiety)
- is a serotonin 5-HT1A receptor partial agonist, also binds dopamine receptors
– Indicated for GAD but anxiolytic effects takes 1-2 weeks.
– Lacks anticonvulsant and muscle relaxant properties. (as it does not work on GABA A receptors)
(not tested) MOA of Barbiturates, a IMPORTANT non-benzodiazepine
Also potentiate GABA A mediated Cl- currents, but at a site distinct from benzodiazepines (barbiturate site)
- Not commonly used currently,
due to its tendency to develop tolerance and dependence (even more than benzodiazepines) - HIGH ABUSE POTENTIAL
- Severe withdrawal symptoms
- Flumazenil not effective for treating barbiturate overdose (as barb does not bind to benzodiazepine site)
- At very high does, they can directly open Cl channels as well as block Na+ channels. e.g. phenobarbital
(not tested) What are some long-acting barbiturates?
effect lasts for 1-2 days
usually used as anticonvulsants/antiepileptics
(but NEVER first-line, usually as a last resort)
e.g. phenobarbital
(not tested) What are some short acting barbiturates?
effect lasts for 3-8hrs
usually used as sedative and hypnotics
e.g. pentobarbital and amobarbital