Tx of anxiety Flashcards
Sedative/Anxiolytic vs hypnotic
Calm down, decreases anxiety.
Produces a calming effect with minimum CNS depression.
Sleep. Drowsy. more pronounced cns depression
The only NT only found in the CNS
GABA
All neurons in the CNS contain receptors for GABA
Two types of GABA receptors
GABA A and GABA B
A is more important for therapeutic drug targets
GABA life cycle
Synthesized in the axon terminal.
Glutamine is taken up from extracellular space. Converted to glutamine. Converted to GABA. Then put in storage vesicles.
Removed from gap by transportation back into axon and repackaged into vesicles or into surrounding astrocytes
4 GABA binding sites
GABA, barbiturates, benzos and ethanol.
They all have the same MOA- binding to receptor increases affinity of GABA for it’s receptor.
Binding of GABA causes what?
Membrane pore to open and allow influx of Cl ions. Causes hyper polarization and is inhibitory.
Lack of GABA receptor activation may cause
Overaction of GABA receptor may cause
Lack: Overactivity of neurons.
Overaction: Sedated individual
Sequence of response with increasing binding to GABA receptor
Excitation at first, sedation, sleep, anesthesia, coma, death
Benzo actions
Reduce anxiety Sedative and hypnotic Anterograde amnesia - inability to form new memories after dose. Anit convulsant Muscle relaxant
Benzo admin and pharmokinetics
Oral or IV
Enter brain rapidly and acts quick.
Metabolized in liver and converted to another benzo prior to final metabolism. = long half life.
Benzo functional durations
Short (3-8 hr)
Intermediate (10-12 hr)
Long (1-3 days)
Reverse benzo effects
Flumazenil
Injected IV
Benzo tolerance
Reduced effectiveness with long term use due to reduced sensitivity. not due to more rapid elimination.
Chronic use of alcohol or barbiturates may cause a reduced sensitivity. Ask pt how much alcohol they drink! Cross tolerance.
Benzo dependence and abuse
Taper to prevent signs of withdrawal
Abuse if used along with other drugs. Uncommon alone.
Benzo side effects
Amnesia
Daytime sedation
Disinhibition- $400 at taco bell
Are benzos analgesics?
no, they do not reduce the perception of pain. They are often used as an additive agent in anesthesia/analgesia.
How are barbiturates different from benzos?
STRONG CNS depression. Causes anesthesia, coma, and death at high doses.
can cause respiratory depression and enzyme induction= chronic admin diminishes actions of many drugs including themselves!!
One of few drugs that induces its own liver metabolism
Barbiturates
3 durations of actions of barbiturates
Short 30 mins
Medium 6-8 hours
Long 1-2 days
Can you reverse barbiturates effect by using an antagonist?
No. Competing molecules are not available.
Tolerance of benzos vs barbiturates
Benzos: Reduced sensitivity
Barbs: Reduced sensitivity AND increased metabolism.
barb dependence and abuse
Dependence: Abrupt discontinuation leads to signs of withdrawal.
Abuse: At low doses can cause excitation/arousal. Abuse on the rise.
Barb side effects
Sedation
addiction- highly addictive unlike benzos
Hypotension with IV use
can be lethal in overdose even in the absence of any other drugs. Due to decreased respiratory activity.
Buspirone
What kind of agonist
Used to treat __ and will not induce ___
Serotonin receptor agonist
Used to treat anxiety and will not induce sedation.
Must take chronically. Delayed onset.
2 types of anxiety
Adaptive- normal reaction
Maladaptive- Reaction in a way that disrupts normal activities. Panic disorder, social phobias, PTSD
Why use benzo-like meds to tx insomnia
Short duration of action. Induces sleep within 20-30 mins and lasts only 6-8 hours.
avoids daytime drowsiness.
Why would you use benzos as pre-anesthetic or for outpatient surgery?
Relaxes, induces state of amnesia.
Good for out patient because it can be reversed. Midazolam (Versed)
What meds can be used to tx muscle spasms?
Barbs and benzos.
Effect is within spinal cord, not at skeletal NMJ
Disulfiram MOA
Prolongs hangover. Leaving acetaldehyde in the blood. Flushing Tachy Hyperventilation Nausea, HA
Naltrexone MOA
Long acting opiate antagonist. Used along with counseling to tx alcohol dependence. No adverse effects like with disulfiram.
