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33 Cards in this Set
- Front
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504-2: ANTICONVULSANT and ANTI-PARKINSONIAN DRUGS
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504-2: ANTICONVULSANT and ANTI-PARKINSONIAN DRUGS
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Name 4 prototype drugs for epilepsy.
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1. tegratol
2. zarontin 3. depakene 4. ativan |
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Name 4 prototype drugs for Parkinsonism.
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1. L-Dopa
2. sinemet 3. parlodel 4. eldepryl |
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Epilepsy
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1. neurologic disorder
2. unpredictable seizures |
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Anticonsulvants for epilepsies
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1. low therapeutic index
2. toxicity is not uncommon 3. hepatic metabolism |
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Mechanisms of anticonvulsant action
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Act by reducing excessive cortical excitability.
NOTE: these drugs only treat the symptoms. |
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What means do anticonvulsant use to reduce cortical excitability?
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1. block Na channels to prevent repetitive firing.
2. block Ca channels 3. potentiate synaptic inhibition mediated by GABA. |
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What drug helps to prevent repetitive firing by blocking Na channels?
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Tegratol
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Pharmacokinetics of tegratol?
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1. induces liver microsomal P450 system which reduces the half life.
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Symptoms of tegratol?
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1. diplopia (double vision)
2. ataxia (loss of muscle coordination) 3. GI upset 4. leukopenia |
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What drug helps to block calcium channels?
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Zarontin: the drug of first choice for generalized absence seizure.
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Mechanism of Zarontin?
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Blocks T-type calcium channels in thalamic and cortical neurons.
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What are the toxicities of zarontin?
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1. gastric pain
2. nausea when initial dose is too high. |
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What drugs help to potentiate inhibition mediated by GABA?
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1. valproic acid
2. benzo |
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Valproic acid pharmacokinetics
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Efficacious against absence seizures.
Preferred over ethosuximide Rapidly absorbed 90% bound to plasma proteins. |
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Toxicity of valproic acid?
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1. gastric pain
2. nausea 3. hepatotoxicity in infants |
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What is status epilepticus?
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Continual seizures lasting at least 20 mins.
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What is the most common precipitating factor?
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Noncompliance
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Status epilepticus lasting more than 30-45 mins will result in?
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Cerebral injury
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What is the management of status epilepticus?
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1. assess airway
2. monitor vital signs 3. perform rapid glucose assay 4. start IV infusion in this order: lorazepam, fosphenytoin, phenobarbital, midazolam or propofol to induce anesthesa. |
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What should pregnant epileptic women take daily?
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1 mg folic acid per day
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Parkinson's disease
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Associated with degeneration of dopaminergic neurons in substantia nigra pars compacta.
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L-Dopa
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Helps to replace the lost dopamine.
1. crosses blood brain barrier and is converted to dopamine. |
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What is carbidopa?
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Allows more L-Dopa to reach the brain.
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What is sinemet?
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The combination of carbidopa with L-Dopa.
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What are the 3 strategies of treating Parkinsons?
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1. replace the lost dopamine
2. directly activate dopamine receptors in striatum. 3. neuroprotection with free radical scavenger, and block dopamine metabolism. |
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What drug is used to directly activate dopamine receptors?
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Bromocryptine
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Side effects of using bromocryptine?
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CNS side effects since all D2 dopamine receptors are activated.
NOTE: bromocryptine may also be a D1 antagonist. |
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What is eldepryl?
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A monoamine oxidase B blocker.
Action: 1. improve motor function 2. delay the development of symptoms requiring L-Dopa. |
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What is Huntington's Disease (Chorea)?
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1. neurodegenerative disorder
2. leads to cognitive decline and dementia (loss of cognitive ability). 3. affects muscle coordination |
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HD's symptoms?
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1. absentmindedness
2. uncontrolled movements of extremeties (chorea) 3. slurred then incomprehensible speech 4. no cognitive functions 5. motor deficits 6. death |
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What type of genetic inheritance is HD?
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Autosomal dominant
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What is the proximal cause of HD?
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Degeneration of GABAergic and cholinergic neurons
NOTE: no medications are available that can slow the progress of the disease. |
