-
What are the 4 prototype drugs for tx of EPILEPSY?
- carbamazepine
- ethosuximide
- valproic acid
- lorazepam
-
What are the 4 prototype drugs for tx of PARKINSONISM?
- L-DOPA
- Sinemet and Sinement-CR
- bromocryptine
- selegiline
-
Sinemet is for tx of ________ and is combo of the drugs _________ and _________
- Parkinsons
- L-DOPA and carbidopa
-
Epilepsy is a CHRONIC Neuro disorder, characterized by periodic, unpredictable _____________
seizures
-
Seizures are cause by:
disordered firing of lrg # of CNS neurons
-
Pharm Tx of Epilepsy is:
symptomatic
-
Is toxicity common in anticonvulsants?
YES
-
anticonvulsants have ______ TI.
LOW
-
anticonvulsants are cleared mainly by
hepatic metabolism
-
The main type of hepatic metabolism of anticonvulsants is by _______________
glucuronidation
-
The main actions of anticonvulsants is to reduce what?
excessive cortical excitability
-
The 3 mechanisms of actions of anticonvulsants include:
- 1) Blocking Na channels, enhancing spike inactivity
- 2) Block Ca channels
- 3) potentiate GABA
-
Carbamazepine pharmacokinetics:
- slow absorption and slow clearance.
- induces liver P450, and during chronic use can reduce half life to 8-12 hrs.
-
What drug is used as first line tx of partial complex seizures?
Carbamazepine
-
Toxic sx of Carbamazepine:
Diplopia and ataxia, GI upset, bleeding disorders
-
What 2 drugs are in the anticonvulsants class that blocks Na channels?
-
What anticolvulsant drug is in the that blocks Ca channels?
Ethosuximide
-
What drug is the first choice for generalized absent seizures?
Ethosuximide
-
Ethosuximide mechanism
blocks t-type Ca channels in thalmic and cortical neurons
-
Ethosuximide pharmacokinetics:
NO plasma protein binding, so CSF and blood levels equal. Long half life (40). linear relation btw dose and plasma levels.
-
Ethosuximide toxicity
Gastic pain and nausea can occur. Avoided by: start level low and raise slowly
-
What drugs are included in the GABA potentiation group of anticonvulsants?
-
What drug works well for absence seizures?
Valproic Acid
-
Why would Valproic Acid be preferred over ethosuximide?
If absence seizures include generalized clonic-tonic seizures.
-
Pharmacodynamics of Valproic Acid:
90% bound to plasma protein. rapid absorption, half life 9-8.
-
Valproic Acid Toxicity:
- gastric pain and nausea. avoided by starting with low levels.
- Hepatoxic in infants
-
Benzodiazepines are absorbed _______ and have a _____ T1/2.
rapidly, LONG
-
can tolerance develop with benzos?
YES
-
Tx of status epilepticus
- 1- asses airway, vitals, blood glucose assay
- 2- lorazepam 0.1mg/kg (10-15min)
- THEN IF IT DOESN"T STOP
- 3- fosphenytoin
- 4- phenobarbitol
- 5- midaz or propofol to induce gen anesthesia
-
Topiramate is a recently introduced anticonvulsant acting with which 2 mechanisms?
- Na channel blocker
- GABA potentiating
-
In what ways can anticonvulsants be teratogenic?
- reduce folic acid
- form active metabolites
-
What causes Parkinsons disease?
degeneration of dopaminergic neurons in the substantia negra
-
What are the 3 strategies to tx of parkinsons?
- 1- replace lost dopamine
- 2- activate dopamine receptors in striatum
- 3- neuroprotect w/ free radical scavenger, block dopamine metabolism
-
L-dopa used in which strategy?
1
-
does L-dopa cross the blood-brain barrier?
YES
-
in the brain, L-dopa in converted to ___________
dopamine
-
What does carbidopa do?
allows more L-dopa to reach the brain
-
bromocryptine is used for which parkinsons strategy?
2
-
bromocryptine causes _____ dyskinesias than L-dopa
fewer
-
bromocryptine has high CNS side-effects because...
all D2 dopamine recpetors are activated
-
What drug is used in parkinsons strategy 3?
Selegiline
-
Selegiline is a _____ __________ ___ blocker
monoamine oxidase B
-
Selegiline improves motor function when used, but....
worsens motor function when discontinued
-
Selegiline somtimes used to delay motor complications of what drug?
L-dopa
-
Huntington's is a autosomal ______ dz.
DOMINANT
-
What genetic defect is caused by Huntington's?
expansion of a CAG repeat, encoding a polyglutamine stretch in the target protein.
-
What is the frequency of Huntington's?
5 on 100,000
-
Huntington's causes what to occur in the body?
Degeneration of GABAergic and colinergic neurons of striatum.
-
Huntington's Tx?
None proven. Only tx of depression, anxiety and psychosis that are often seen in these pt's.
|
|
