Epilepsy Parkinsons ADHD Flashcards
Type of sz
Partial sz:
- simple partial ( no loc, 20-60 sec)
- complex partial ( impaired con, 45-90 sec)
- secondarily generalized ( 1-3 min)
Generalized seizure
- tonic - clonic ( grand mal)
- absence ( petit mal)
- atonic ( loss of muscle tone)
- myoclonic ( sudden muscle contraction )
- Statis epilepticus ( 15-30)
- febrile
Seizure disorder
Excessive neuronal discharge occurs throughout all or part of the brain. The threshold is low
Goals of treatment
- reduce seizure to a level that allows the patient to live as normal a life as possible
- balance the desire for complete seizure control with acceptable side effects
MOA of anti-epileptic drugs
- Modulation of voltage gated ion channels - surpresa CA + and NA + influx
- Inhibition of sympathetic excitement ( antagonism of glutamate )
- Enhancement of sympathetic excitement (potentiation of GABA)
Drug evaluation
Antiepiléptic drug trial period
Doseage adjustment
Sz frequency chart
Monitor plasma drug levels
Promote patient adherence
Withdrawing ( wean and taper)
Suicide risk
High risk drugs: topiramate, lamotrigine
Lower risk : valproic acid, carbamazepine
Traditional AED
- Phenytoin ( Dilantin )
- Carbamazepine ( tegretol )
- Valproic Acid / sodium ( depakene, depakote)
- Phenobarbital (luminal)
- Ethosuximide (Zarontin)
Newer AED
Topamax
Nuerontin
Lamictal
Keppra
Phenytoin ( Dilantin )
Use: partial and tonic-clonic sz, Epilepsy
MOA: inhibitor of sodium channels
Long half life
Therapeutic levels : 10-20 mcg/ml
Lots of Side effects and drug interactions
Pt education:
- give with food, individualized
- urine may turn pink, red, brown
- avoid abrupt withdrawal
Generalized adverse effects of antielpileptic drugs
Nystagmus, sedation, ataxia, diplopia, cognitive impairment , hepatotoxicity, pancreatitis, teratogenic effects
Gingival hyperplasia
Valproic Acid ( depakene, depakote, depacon)
MAO: supresses high freq neuronal firing through blockade of sodium channel , suppresses calcium , may augment the inhibitory influence of GABA
Uses: sz, bipolar, mirgraine
Black box warning :Hepatotoxicity, pancreatitis, teratogenesis (use oral contraception)
Tegretol ( carbamazepine)
Uses: epilepsy, bipolar, trigeminal neuralgias
MOA: supresses high freq neuronal discharge in and around sz foci ( making it local not all the brain)
Adverse: luekopenia, anemia, thrombocytopenia
Monitoring: Drug levels at 3,6,9 Goal is 4-12 mcg/ml Once in goal check ever 2 month Check CBC 3-4 months
Check the HLA-B1502 and if absent may indicate increase in risk for Steven Johnson syndrome ( rash)
Watch for interaction with grapefruit juice
Drug interactions generalized
Warfarin, oral contraceptives, grapefruit juice , isoniazid
Phenobarbital
MOA: potentiates the effects of GABA, reduces sz without causing sedation, anticonvulsant
Uses: epilepsy, sedation, induction of sleep
Adverse: dependency
Zarontin ( ethosuximide)
MOA: delaying calcium influx
Uses: to of absence sz
Monitoring: check levels 1-3 weeks after initiation
Range: 40-100mcg/ml
ADR’s: granulocytopenia
Lamotrigine ( Lamictal )
Uses: adjunctive treatment of primary generalized tonic-clonic sz and partial sz in adults , bipolar,
In combo with : valproic acid and phenytoin
Adverse: black box ( Steven Johnson)
Pt edu: avoid alcohol, aviod OTC
Gabapentin ( nuerontin)
MOA: binds to CA+ channel to reduce nuerotransmitter release
Uses: add on therapy for refractory partial sz, nueropathic onion
No routine monitoring
Serious adverse: leukopenia and thrombocytopenia
Keppra
MOA: unknown
Uses: adjunctive to of partial onset sz and myoclinic, generalized tonic -clonic sz
Children 4 older - adjunct partial sz
Children 6 older - primary generalized tonic clonic
Does not use P450
Sz free from the first day of keppra
Topamax ( topiramate)
Uses: general and partial sz, mirgraines, off label uses
MOA: suppresses focal sz and spread by blocking sodium and calcium channels
PK: rapid absorption, peaks 2 hours
Well tolerated
Management of status epilepticus
Continuous series of tonic -clonic sz
Medical emergency
Maintain ventilation, correct hypoglycemia, terminate sz,
- IV benzos
- once stopped initiate phenytoin and cerebyx
AED’s and pregnancy ( agents)
Choose agent based on likelihood to become pregnant
Agents okay:
- lacmictal
- keppra
- tegretol
- tomapamax
Avoid:
Valproic Acid
Phenytoin
Phenobarbital
Keys to AED and pregnancy
Risk to fetus from uncontrolled sz > than risk from AED’s
Use lowest effect drug, one drug
Reduce neural tube defects by providing folic acid before conception and preg
Increased risk for bleeding ( give vit K during last week of preg and at birth
Key points for AED
May take several drugs
Pt can not drive on drug trial period
Drug should be not considered ineffective until sufficiently high dosage and for a reasonable amount of time
Plasma drug levels
Provide info to permit dosage adjustment
Monitoring drug adherence
Determine cause of loss of sz control
Identify cause of toxicity ( when taking more than one drug)
Key points ( withdrawing and suicide, generic)
Withdraw drugs slowly over 6 weeks
If pt is taking 2 drugs they should be withdrawn sequentiality
Suicide risk 1-24 week after starting meds
CNS depression worsen by alcohol
Fetal risk minimized by one drug for at the lowest effective dosage
Generic drugs are not equivalent to trade drugs and switching is not recommended
Parkinson’s goals
Ideal treatment that reverses neuronal degeneration or prevents further degeneration - currently doesnt exist
The goal is to improve the patients ability to carry out ADL’s
Initial treat - Drug selection
Mild symptoms - MAO-B - Selegiline
More severe symptoms: levodopa ( combined with carbidopa) or dopamine agonist
Management of motor fluctuations
- “ off times” - domaine agonists, COMT, MÃO-B
Levodopa
Only given in combo with carbidopa
Cornerstone of PD, is more effective than dopamine agonists but long term use = disabling dyskinesias
Rapidly absorbed from small intestine
- food delays absorption, high protein food reduce therapeutic effects
Well controlled for 2 yes and returns to pretreatment state at end of 5 yrs
No direct effects of its own, is converted to dopamine its achieve form , it helps properly balanced between dopamine and Ach
Check vitamin b6
Levodopa - weaning off
Three ways to minimize
- shortening the dosing interval
- giving a drug that prolongs levodopa plasma half life
- giving a direct-acting dopamine agonist
Levodopa - adverse effects
N/v - give additional carbidopa
Cardio, postural hypotension, increase intake of salt and water, psychosis, behavioral changes
Can reduce levodopa but it will reduce beneficial effects
Levodopa - Dyskinesias
The med is given to alleviate movement disorder, but it also causes some movement disorders
Dyskinesias can be managed in three ways
- reduce dosage of levodopa
- amantadine
- surgery and ECT
Darken swear and urine - watch skin assessment
Carbidopa
Purpose: blacks peripheral dopa, increases amount of levodopa entering the brain
Effects: decreases peripheral adverse affect such as N/V, cardiac irritability and orthostatsis
Levodopa - drug interactions / food interactions
- antipsychotics, MAO-I, anticholinergic
- meals with high protein content can reduce therapuetic responses
- spread protein evenly throughout the day
Levodopa / Carbidopa ( sinemet ) advantages
Most effect therapy in PD
Levodopa - goes across blood brain barrier
Carbidopa - does not
Carbidopa - enhances levodopa
- the combination allows for decreased levodopa dosage which reduces cardio s/e and n/v
Levodopa / Carbidopa - disadvantage
Carbidopa - no adverse effects on its own
Abnormal movements and psychiatric disturbances can occur soon and more intense than with levodopa alone
COMT inhibitors
Tamar and Comtan
- must be given with levodopa
Effects: increases levodopa half-life and AUC
Dopamine Agonist
Mirapex, parlodel, dostinex
MOA: directly stimulates dopamine receptors, monotherapy or adjunct therapy with levodopa
Ad: no metabolic conversion, longer half life
Adverse:: possibility of patient falling asleep - mirapex
Monoamine Oxidase - B inhibitors
Selegiline, Rasagiline
MAO: black metabolism of dopamine, extends duration of action of levodopa
Centrally acting anticholinergic drugs: cogentin, artane
Reduces tremor and possible rigidity
Most appropriate for younger patients with mild symptoms
Used as second line therapy for tremor
Avoided in the elderly who are intolerant of CNS side effects ( hallucinations)
Amantadine ( symmetrel )
Dopaminergic agent
Responses diminish in 3-6 months
Not first line
Pramipexole ( mirapex)
DA receptor agonist
Used as monotherapy in early stage PD
Can improve motor performance
Also used for restless leg syndrome
