Drugs for CNS Disorders Flashcards
How many different neurotransmitters are in the CNS? How many in the PSNS?
21 in CNS
3 in PSNS
CNS functions of acetylcholine
memory
CNS functions of dopamine
reward circuit
motor control
CNS functions of serotonin
digestion
sleep
anxiety
mood
social behavior
CNS functions of histamine
wakefulness
CNS functions of glutamate
excitation
CNS functions of GABA
inhibition (brain primarily)
CNS functions of glycine
inhibition (spinal cord primarily)
list examples of adaptive changes
cellular atrophy or hypertrophy
metaplasia/dysplasia
alteration in protein synthesis/receptor synthesis
what are adaptive changes
changes that cells undergo to cope w/ new environment
occurs in response to prolonged drug exposure
Which two neurotransmitters (NT) does parkinsons involve? Which is decreased in this disease?
dopamine (decreased)
acetylcholine (allowed to act unopposed)
What are extrapyramidal side effects (EPS)? What type of drugs elicit these effects?
parkinson’s like effects (slowed movement, rigidity, shuffled gait) due to drugs that block dopamine receptors in the CNS
List the drugs that increase dopamine for use in Parkinsons
levodopa
MAO-B
amantadine
What is levodopa
a precursor to dopamine (is converted to dopamine in the CNS and directly activates dopamine receptors)
List two drugs that augment levodopa
decarboxylase inhibitors
COMT inhibitors
How do decarboxylase inhibitors work?
*no therapeutic effects of their own!
inhibit levodopa breakdown in peripheral tissues & intestine
How do COMT inhibitors work?
*no therapeutic effects of their own
inhibit levodopa breakdown in peripheral tissues & intestine
Besides increasing dopamine, how else is Parkinson’s treated?
blocking ACh
restores the ACh/DA balance
Why can we not just give exogenous dopamine?
dopamine can’t cross BBB
dopamine has too short of 1/2 life
List a decarboyxlase inhibitor
carbidopa
List a COMT inhibitor
entacapone
Why should patients on levodopa avoid high protein diets?
amino acids compete for transporters to cross the BBB
(thus less levodopa gets to the CNS)
How long does levodopa work for patients?
approx 5yrs
adverse effects of levodopa
- N/V
- dyskinesias
- postural hypotension
- psychosis (20%)
- anxiety/agitation or cognitive changes
- darkening of sweat/urine
Drug interaction with levodopa
MAOI
(severe HTN risk)
List two types of dopamine agonists
ergot alkaloids (i.e. bromocriptine, cabergoline)
nonergot alkaloids (i.e. pramipexole, ropinirole, etc.)
Adverse effects of the nonergot alkaloids
nausea/vomiting
dizziness
daytime somnolence
constipation
weakness
hallucinations
List three nonergot alkaloid derivatives (dopamine receptor agonists)
pramipexole
ropinirole
rotigotine
When is apomorphine used?
rescue treatment in episodes of hypomobility with advanced Parkinsons