Antiepileptics Flashcards
(31 cards)
Anti-epileptics/ anticonvulsants and drug class.
Hydantoin: Phenytoin Iminostilbenes: Carbamazepine Dialkylacetate: Valproic acid Suxinamides: Ethosuximide GABA analogs: Gabapentin, pregaba, vigabatrin and baclofen Phenyltriazine: Lamotrigine
Phosphate ester of phenytoin, rapidly hydrolyzed to pheny in vivo. Neutral pH 7 so less irritating
Fosphenytoin
Why Phenytoin Na when injected is irritating?
must be buffered to an alkaline pH to maintain solubility thus very irritating when injected.
Phenytoin and Carbamazepine MOA via Na.
P: decreases Na content of nerve in brain, dec. excitability of cells for seizures
C: blocks Na channels, reducing abnormal impulses in brain
Phenytoin SEs.
Explain Hydantoin syndrome.
Gingival hyperplasia (needs mouth hygiene) tx= Chlorhexidine 0.15%, encephalopathy blood dyscrasias, nystagmus hirsutism, SJS Hy Syndrome: congenital defect: cleft palate
Phenytoin metabolism. Similar to what drug?
Metabolized by p-hydroxylation followed by conjugation similar to Phenobarbital.
Carbamazepine SEs.
Rash, inc. liver enzymes, neutropenia
Chronic: drowsiness vertigo SJS aplastic anemia coma hyper irritability convulsions resp depression
Topiramate SEs.
cognitive dysfunction headache, KIDNEY STONES and WEIGHT LOSS
Clobazam SEs.
Tolerance, insomia depression dizziness drowsiness light headedness ataxia
True absence seizures
petit mal- 10-30 secs causes alteration of consciousness, starts w occasional blinking (Nystagmus)
Sudden brief involuntary jerking of facial lim and trunk muscles or all body.
Myoclonic seizures
DOC for petit mal.
What drugs not to be used?
Ethosuximide
-Avoid Pheny and Carb
Tonic-clonic seizure is also called? And separately signs or symptoms.
Grand mal. Tonic- gen. in children, muscle stiffening (tone)
Clonic- musc contraction w relaxation, sudden loss of consciousness, become rigid, falls to ground, lasts 1 min.
DOC for partial, tonic clonic sz and trigeminal neuralgia.
DOC for partial and generalized seizures.
Carbamazepine
Lamotrigine
Phenytoin dosage forms and percentages.
100% -susp and chewable,
Pheny 90% Na 10% -caps and IV
BZPs:
DOC for status epilepticus.
Highest tolerance.
- Diazepam
- Clobazam
DOC for trigeminal neuralgia. Avoid with what because it decreases its bioavailability?
Gabapentin. Avoid w antacids
Antiepileptics that decreases efficacy of OCPs.
Carbamazepine, Phenytoin, Clonazepam
DI: Lorazepam (highest)
Antiepileptics that do not decrease efficacy of OCPs.
Gabapentin (least), Valproic acid, Lamotrigine
Antiepileptics that cause SJS SE.
Carbamazepine, Valproic acid, Divalproex
Phenobarbital and Phenytoin stimulates this type of organ enzyme.
Hepatic microsomal enzymes.
Antiepileptics indicated for diabetic neuropathy and post hepatic neuralgia.
DOC for trigeminal neuralgia.
Pregabalin and Gabapentin (DOC)
Alternate antiepileptic DOC in pregnancy, why?
Lamotrigine, low teratogenicity
Monitoring parameters for Phenytoin.
Plasma pheny levels, liver function test, CBC, BP, vital signs (with IV use)
