Flashcards in 4. Neuropharmacology Deck (58)
Most important CNS neurotransmitters?
Glutamic acid, GABA, ACh, DA, NE, 5HT, opioid peptides
Action of glutamic acid?
Direct coupling and G-protein linked on NMDA -> influx of cation -> excitatory
Potential target for ketamine and PCP
Mechanism of ACh?
Excitatory and inhibitory on muscarinic receptors by decreasing/increasing K+ efflux by coupling DAG and cAMP
Mechanism of GABA?
Increase K+ influx by direct coupling -> inhibitory
Potential target for anticonvulsant, sedatives, hypnotics, some muscle relaxants
What drugs act on GABA?
Barbiturates (duration of Cl- ion channel)
Benzos (frequency of Cl- ion channel)
Valproic acid (high concentration)
Mechanism of flumazenil?
Benzo antagonist (decreases frequency)
What nonbenzo drug binds to benzo receptor?
Less tolerance and dependence
Name a nonbenzo anxiolytic
Buspirone (partial 5HT1A receptor)
No dependence or withdrawal
Side effects of benzos
Sedative, amnestic, anxiolytic, antidepressant, muscle relaxant
Not for T1 preg
May result in hypotension/resp depression if with opioids
Benzo withdrawal syndrome
Hypertension, tachycardia, muscle twitching, tremulous, diaphoresis, confusion, dysphoria, seizures
Pharm strategy in Parkinson
Increase DA activity and decrease ACh at muscarinic in striatum
Midazolam (1-2mg IV): onset and duration
Rapid and shortest
Diazepam (2-10mg BID-QID): onset and duration
Rapid and longest
Alprazolam (0.25-0.5 mg TID)
Intermediate/Intermediate (Antidepressant effect)
Chlordiazepoxide (5-10mg TID)
Lorazepam (1mg TID)
Intermediate/Intermediate (liver ok)
Intermediate/intermediate (liver ok)
What 3 benzos are not metabolized in the liver?
What drug increases dopamine function?
Levodopa to dopamine by dopa-decarboxylase
Carbidopa blocks peripheral decarboxylation
Tolcapone and entacapone?
Enhances CNS uptake of L-dopa; reduces on-off effects
Dopamine receptor agonists (2)
Bromocriptine (hallucinations, confusion, psychosis)
MAO B inhibitor
What drugs decrease ACh function?
Benztropine and trihexyphenidyl (M receptor blockers)
Reduce tremor/rigidity, EPS syndrome, but exacerbates tardive dyskinesia and cause atropine-like effects
Why do antipsych drugs cause atropine-like effects, postural hypotension, sexual dysfunction?
Block D2 receptors, muscarinic, alpha receptors
Side effects of DR antagonists?
Akathisia, acute dystonic rxn, extrapyramidal dysfunction, prolactinemia
Chronic dopaminergic receptor bockage?
Akathisia and tardive dyskinesia months later
Neuroleptic malignant syndrome?
Hyperthermia, cardiovascular instability, rigidity, altered MS due to enhanced sensitivity of DR to blocking agents
Tx of NMS?
Bromocriptine and dantrolene
Mechanism of TCA
Block reuptake of NE and 5HT
Also block muscarinic/alpha receptors (sedation, decrease seizure threshold, cardiotoxicity)