4. Neuropharmacology Flashcards
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) Propofol (GABA-A) Baclofen (GABA-B) Valproic acid (high concentration)
Mechanism of flumazenil?
Benzo antagonist (decreases frequency)
What nonbenzo drug binds to benzo receptor?
Zolpidem (sleep)
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
aka Valium
Alprazolam (0.25-0.5 mg TID)
Intermediate/Intermediate (Antidepressant effect)
aka Xanax
Chlordiazepoxide (5-10mg TID)
Intermediate/Long
aka Librium
Lorazepam (1mg TID)
Intermediate/Intermediate (liver ok)
aka Ativan
Temazepam (15-30mg)
Intermediate/intermediate (liver ok)
aka Resteril
What 3 benzos are not metabolized in the liver?
Alprazolam
Temazepam
Oxazepam
What drug increases dopamine function?
Levodopa to dopamine by dopa-decarboxylase
Carbidopa blocks peripheral decarboxylation
Tolcapone and entacapone?
COMT inhibitor
Enhances CNS uptake of L-dopa; reduces on-off effects
Dopamine receptor agonists (2)
Bromocriptine (hallucinations, confusion, psychosis)
Pramipexole/Ropinirole
MAO B inhibitor
Selegiline
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