CNS Depressants and Psychostimulants Flashcards
What is the MOA for benzodiazepines and barbiturates?
- Bind to allosteric site on GABA-A receptors
- Increase affinity of GABA-A receptor for GABA
- Potentiation of GABAergic inhibition of neuronal activity
What are general therapeutic uses for benzodiazepines?
Insomnia, anesthesia, anxiety, seizures, essential tremor, and spasticity
What are general adverse effects of benzodiazepines?
Drowsiness, confusion (esp in older patients), anterograde amnesia, psychomotor impairment, substance use disorder (tolerance and withdrawal)
T/F: Patients that are elderly with liver disease should take lorazepam due to it being safer
True; This is also relevant if they asked about oxazepam or temazepam (also good for cyp inhibitors)
T/F: If BDZ has been used for <3 days taper dose gradually to avoid rebound insomnia or anxiety
False, this is if the BDZ is taken for at least greater than a month
What drug is a benzodiazepine antagonist?
Flumazenil
What is the MOA of flumazenil?
Competitive antagonist at BDZ binding site
What are the clinical uses for flumazenil?
Treats BDZ overdose and used in anesthesiology to reverse effects of BDZs
What are novel BDZ receptor agonists?
Zolpidem, zaleplon, and eszopiclone
What is the MOA of zolpidem, zaleplon, and eszopiclone?
- Bind to allosteric site on GABA-A receptors
- Increase affinity of GABA-A receptor for GABA
- Potentiation of GABAergic inhibition of neuronal activity
What are the clinical uses for novel BDZ receptor agonists (zolpidem, zaleplon, and eszopiclone)?
Sleep onset and sleep maintenance insomnia–> approved for long-term use
T/F: Z-compounds have fewer adverse effects than BDZs
True
What drug is a melatonin receptor agonist?
Ramelteon
What is the MOA of ramelteon?
Agonist at MT1 (regulates sleep) and MT2 (regulates circadian rhythm) melatonin receptors
What are the clinical uses for ramelteon?
Sleep onset insomnia
T/F: Ramelteon is more efficacious than BDZs and Z compounds
False; It is less effective but is the only approved sedative-hypnotic drug that is not controlled
What drug is a orexin receptor antagonist?
Suvorexant
What is the MOA of suvorexant?
Antagonist at OX1 and OX2 orexin receptors
What are the clinical uses for suvorexant?
Sleep-onset and sleep-maintenance insomnia
What are adverse effects of orexin receptor antagonists?
Daytime sedation, impaired driving, substance use disorder
What are the therapeutic uses for the barbiturate pentobarbital?
Insomnia and seizures
What are adverse effects of pentobarbital?
Tolerance, physical dependence, high addition potential, low therapeutic index, induces CYP enzymes, long half life
What is the therapeutic indication and adverse effects seen with H1 antihistamines (diphenhydramine, doxylamine)
- Used for insomnia
- Adverse effects: significant daytime sedation (has a long half life) and anticholinergic effects (off target effects)
What are clinical uses of psychostimulants?
- Treatment of excessive sleepiness and fatigue (narcolepsy)
- Improvement of attention (ADHD)
What is the MOA of indirect acting sympathomimetic drugs?
Increase synaptic concentration of endogenous catecholamines–> increased NE, DA, and 5-ht
What drug is part of the “releasing agents” class?
Amphetamine
What drugs are part of the “reuptake inhibitors” class?
Cocaine, methylphenidate, and modafinil/armodafinil
What are predictable effects of psychostimulants?
NE: Increased arousal and less need for sleep
DA: euphoria, reward, potential for abuse, abnormal movements, psychosis
5-HT: hallucinations and decreased appetite
What is the MOA of amphetamine?
Displaces stored catecholamines: uptake via NET and VMAT-2 and replaces DA in vesicles which leads to DA release via DA
What are the clinical uses for amphetamine?
ADHD and narcolepsy
What adverse effects are seen with amphetamine?
From increased NE: higher bp, cardiac arrhythmias, insomnia
From increased DA: growth inhibition
From increased 5-HT: anorexia
What adverse effects are seen with amphetamine?
From increased NE: higher bp, cardiac arrhythmias, insomnia
From increased DA: growth inhibition
From increased 5-HT: anorexia
What is the MOA for methylphenidate?
Blocks NET and DAT which leads to higher levels of dopamine and norepinephrine
What are the clinical uses for methylphenidate?
ADHD and narcolepsy
T/F: Adverse effects of methylphenidate are similar to amphetamine
True
What is the MOA of modafinil?
May block NET and DAT which leads to higher levels of dopamine and norepinephrine
What are the clinical uses for modafinil?
Narcolepsy or other disorders that cause excessive sleepiness
What are the adverse effects of modafinil?
Less adverse effects than amphetamine or methylphenidate (d/t less sympathomimetic effects)
T/F: Bupropion and atomoxetine can be used to treat ADHD and is first line
False; Bupropion and atomoxetine are indeed used to treat ADHD but are not first line
T/F: All reuptake inhibitors are stimulants
False; TCAs, SSRIs, and SNRIs have different indications like depression and are not used for ADHD
