CNS Drugs: Unique Features Flashcards
inhibits aldehyde dehydrogenase…
disulfiram
inhibits alcohol dehydrogenase…
fomepizole
Which has a ceiling effect? BZs or Barbs?
BZs
Describe the dose response curve of barbiturates and what this means…
steep, low margin of safety
Duration of action?
Diazepam
flurazepam
temazepam
chlordiazepoxide
Long acting
Duration of action?
alprazolam
lorazepam
oxazepam
Intermediate acting
Duration of Action?
midazolam
triazolam
very short acting
do BZs depend on GABA binding the receptor?
yes
Flumazenil has what C/I?
hx of seizure
Describe the margin of safety for Z drugs…
high margin of safety
Which Z drug is unique in that it has a long half-life and is used in long-term treatment?
eszopiclone
What type of psychotic sxs?
hallucination, delusion
catatonic behavior
disorganized speech/thoughts
positive sxs
overactive limbic system DA pathways describes…
positive mesolimbic symptoms
underactive DA pathway in PFC describes
Negative mesocortical sxs
What type of psychotic sxs?
Affective behavior Apathy Withdrawal Anti-social Lack of motivation depression
negative sxs
How long for antipsychotic onset?
6 weeks
The below mechanism describes what type of psychotic sxs?
DA receptor blockade in nigrostriatal pathway
Imbalance of striatal DA and ACh → Parkinson’s like sxs
extrapyramidal sxs
Choreic, uncontrolled jerky movements of face and limbs
S/E of long-term tx, often irreversible
tardive dyskinesia
which two antipsychotics are least likely to cause tardive dyskinesia
clozapine
olanzapine
what is the tx for EPS?
benztropine (anticholinergic)
which antipsychotic class is more likely to cause EPS?
classic antipsychotics
** LIFE THREATENING **
Block of Striatal and Hypothalamic DA D2 receptors → Muscle Rigidity, Hyperpyrexia
neuroleptic malignant syndrome
neuroleptic malignant syndrome can be treated with what two drugs?
1st line: dantrolene (muscle relaxant for hyperthermia, rigidity)
2nd line: bromocriptine (DA agonist)
The below antipsychotics have increased risk of…
Lurasidone
clozapine
agranulocytosis
describe the metabolism of lithium
no metabolism
The below have what major S/E?
Carbamazepine phenytoin phenobarbital lamotrigine valproate
SJS
What type of seizure?
Begin in focused cortical area, then may spread
partial
What type of seizure?
No LOC, 20-90s
Grimacing
Focal clonic jerking of extremity
simple partial
what type of seizure?
AMS or LOC, Hallucination, < 120s
Temporal lobe
Automatic movements
Simple complex
What type of seizure?
LOC
Muscle contractions alternating w. relaxation
Partial w. Secondary Generalized Tonic-Clonic
What type of seizure?
15-30s tonic rigidity → tremor → clonic jerking
LOC, AMS (stupor, confusion)
Arise from reciprocal firing of thalamus and cortex
Generalized tonic-clonic
What type of seizure?
sudden onset, 15-30s, no LOC
Loss of Awareness
Generalized absence
What type of seizure
brief spasm/rigidity, seconds long
secondary to other seizure d/o
Generalized myoclonic
What type of seizure?
sudden loss of postural tone
patient falls down
Generalized atonic
The below drugs have what benefit?
ethosuximide vigabatrin levetiracetam topiramate TCAs
safe in pregnancy/non-teratogenic
Describe the kinetics of phenytoin at therapeutic doses?
zero order
topiramate can increase the metabolism of what other meds?
OCPs
what prolongs the absorption of valproate?
food
seizures and sedation are more common in what class of TCAs?
Tertiary Amines (amitriptyline, imipramine)
What increases the metabolism of…
OCPs
digoxin
protease inhibitor
warfarin
st. john’s wort
schizophrenia occurs with progressive loss of…
grey matter
sxs of parkinson’s occur due to…
loss of DA in substantia nigra
This is an aggregation of alpha-synuclein/proteins in the nigrostriatal system
lewy body
sxs of parkinson’s appear when there is ___% of DA neurons
70-80%
The decreased DA production from substantia nigra in parkinson’s leads to a change in the ratio of…
DA:ACh
Alzheimer’s is a function of accumulating…
beta amyloid plaques
tau protein tangles
What causes the decreased memory/cognition in alzheimers?
degeneratio of cholinergic neurons in the nucleus of meynert
Alcohol is metabolized by and induces CYP ____
CYP2E1
The primary pathway for alcohol metabolism is thru…
EtOH to acetaldehyde via ADH
and acetaldehyde to acetate via ALDH
the ADH pathway of alcohol metabolism via oxidation requires which cofactor, which can be diminished in chronic users?
NAD+
The minor metabolic pathway of alcohol is _____
Microsomal-ethanol oxidizing system via CYP2E1
CYP2E1 increases toxicity of…
acetaminophen
these BZs are useful for the person who has trouble staying asleep
flurazepam, temazepam
