CNS Drugs 1 Flashcards
Intro to drugs of the CNS
What are the 4 binding sites of GABA receptors?
GABA, benzodiazepine, barbiturate, and ethanol binding site
What is the role of the GABA neurotransmitter and receptor?
INHIBIT neurons from firing (Cl- influx causes hyperpolarization, prevents AP)
Name 4 Benzodiazepines
Hint: suffix -am
Diazepam (Valium), alprazolam (Xanax), Lorazepam (Ativan), and clonazepam (Klonopin)
Name the barbiturate used primarily for seizure treatment and its MOA
Phenobarbital, enhances GABA effects to inhibit neurotransmission
What are adverse effects of benzodiazepines?
Fatal with alcohol/opioids, reduced coordination (risk of falls), dependence, addiction and withdrawal, mild anti-cholinergic effects
Adverse effects of barbiturate drugs
Over sedation/fatal OD, respiratory depression, fatal when combined with opioids, alcohol, or benzodiazepines
What order of kinetics do alcochol, barbiturates, and benzodiazepines follow?
ethanol & barbiturates= Zero-order
Benzos=First order
Which CNS drugs are lethal at high doses?
ethanol, barbiturates
What is the MOA of zolpidem (Ambien) & eszopiclone (Lunesta)?
Hint: GABA agonists
Bind to benzodiazepine site on GABA receptor, but have different chemical structure
What do zolpidem & eszopiclone (GABA agonists) treat?
insomnia (short duration of action)
Side effects of non-benzo/barbiturate GABA agonists?
zolpidem & lunesta
sleep disorders (sleepwalking), visual hallucinations, & some anti-cholinergic effects
Which (6) drugs increase serotonin by inhibiting reuptake in neurons? (SSRIs)
citalopram, escitalopram, fluoxetine (Prozac), fluvoxamine, paroxetine, & sertraline
Adverse effects of SSRIs
sexual dysfunction, platelet inhibition (easy bruising/bleeding), serotonin syndrome, & mild anti-cholinergic effects
Name of (2) drugs that increase norepinephrine and serotonin by inhibiting their reuptake (SNRIs)
venlafaxine & duloxetine
Side effects of SNRIs (venlafaxine & duloxetine)
same as SSRIs + raised BP
MOA of TCAs amitriptyline & imipramine
same as SNRIs
Side effects of TCAs amitriptyline & imipramine
Same as SNRIs + sedation and OD fatal (1 pill can kill a toddler), and anticholinergic effects are STRONG
Why is phenelzine (MAOI) rarely used?
food, drink, and drug interactions
What is the MOA of phenelzine? Hint: MAOI
inhibits monoamine oxidase to increase norepinephrine, serotonin, and dopamine
Adverse effects of phenelzine (MAOI)
nystagmus, mild anticholinergic effects, and hypertension that can be lethal with food/drinks that contain tyramine
MOA of the muscle relaxant cyclobenzaprine
somehow increases norepinephrine in the brain causing skeletal muscles to relax, similar chemical structure to TCAs
SIde effects of the muscle relaxant cyclobenzaprine
sedation and STRONG anti-cholinergic effects
Name the (2) serotonin receptor agonists used for migraine
sumatriptan and zolmitriptan
side effects of sumatriptan and zolmitriptan (serotonin receptor agonists used for migraine)
non-arteritic ischemic optic neuropathy (NAION), retinal artery & vein occlusions, heart attack and stroke
MOA of sumatriptan and zolmitriptan (serotonin receptor agonists for migraine)
increases effect of serotonin in CNS blood vessels, causing vasoconstriction and reduced inflammation
MOA of bupropion (Wellbutrin; Zyban)
increases norepinephrine & dopamine levels by inhibiting their reuptake
What else is the antidepressant bupropion used for and what are its side effects?
smoking cessation treatment (Zyban), strong sedation and anticholinergic effects
Side effects of mirtazapine and trazodone.
What are they most used for?
strong sedatives, used more as a sleep air, and anticholinergic effects
Mirtazapine MOA
somehow increases norepinephrine & serotonin release from neurons, blocks histamine binding
Trazodone MOA
blocks serotonin reuptake/binding to 5HT receptors, blocks histamine binding
Adverse effects of lithium
increased IOP and anticholinergic effects
MOA of lithium
reduces norepinephrine and dopamine, narrow therapeutic index
List 4 dopamine pathways in the brain
1.nigrostriatal 2. mesolimbic, and 3. tuberoinfundibular systems 4. chemoreceptor trigger zone in medulla (vomiting center)
Name (3) typical and (1) atypical anti-psychotics and their MOA.
(dopamine receptor antagonists)
(haloperidol, thioridazine, chlorpromazine, aripiprazole) Block dopamine from binding to its receptor, reducing effects of dopamine pathways
Ocular side effects of the phenothiazines thioridazine & chlorpromazine.
(Typical antipsychotics, dopa antagonists)
pigmentation on cornea, anterior stellate cataracts, pigment disruption of RPE, and oculogyric crisis, retinal toxicity
Side effects of ALL Typical antipsychotics (dopa antagonists)
Parkinson’s-like movement disorders & anti-cholinergic effects
Side effects of Atypical antipsychotics
Metabolic disorder (DM, weight gain) & mild movement disorders
Side effects of drugs that increase dopamine
Adrenergic agonist effects and mydriasis (a1 stimulation iris dilator), cardiovascular issues. nausea, vivid dreams, addictive, hallucinogen/psychotic behaviors
MOA and side effects of donepezil (Aricept) used for Alzheimer’s
Hint: acetylcholinesterase inhibitor
(Indirect cholinergic agonist) reversible, inhibits acetylcholinesterase–>increases ACh effects & parasympathetic response (miosis, lower BP, sweating…)
MOA and side effects of the anti-convulsant phenytoin (Dilantin)
blocks Na channels in neurons to decrease firing rate; causes nystagmus, diplopia, EOM palsies, gingival hyperplasia, hirsutism & sedation
MOA and side effects of the anti-convulsant divalproex (Depakote) also used as an anti-mania drug
Inhibits Na channels to reduce firing rate;
causes sedation & low platelets/ increased bleeding
What is the name of the anti-seizure drug that is also used for migraine, weight loss, and more, and what are its 3 MOAs??
topiramate (Topamax) 1. Blocks Na channels 2. increases GABA and 3.blocks glutamate receptors, all to decrease neuron firing rate
Topiramate causes dizziness, sedation, loss of appetite & weight, diplopia, nystagmus, &idiosyncratic drug reaction. Define idiosyncratic drug reaction
A bilateral transient myopic shift that can lead to bilateral angle closure (choroidal swelling pushes everything fwd.
List the uses of gabapentin & pregabalin, their MOA, and side effects.
Nerve pain due to diabetic neuropathy or postherpetic neuralgia (after shingles), anti-convulsant, psychiatric disorders.
Binds to Ca channels to reduce excitatory neurotransmitters like glutamate & norepinephrine; causes sedation & dizziness
