Antiepileptics Flashcards
what are the two types of seizures
Focal
Generalized
What are the two criteria which determine Status Epilepticus?
If seizure lasts longer than 5 minutes or
2 or more seizures between which pt does not regain full consciousness
Anti-epileptic drugs (AEDs); class and names of drugs (5)
Class = Benzodiazepines Lorazepam Diazepam Clonazepam Chlorazepate Clobazam
What is the preferred benzodiazepine of choice for status epilepticus? and why
Lorazepam
due to long duration of action in CNS and better protection
Mode of action of Carbamazepine
Sodium channel blocker
What is a possible complication of Carbamazepine?
Rash;
can get as severe as Stevens-Johnson syndrome
What is the allele tested for before use of Carbamazepine? and what/which ethnicities are most likely to be effected?
HLA-B 1502 allele
(10 fold elevated risk of Stevens Johnson syndrome)
Asians and Indians
ADRs of Carbamazepine
Leukopenia, aplastic anemia
Stimulates release of ADH (SIADH, hyponatremia (Na))
decreased levels of Vit D (decreases Ca absorption, increases gradual bone loss)
MOA of Phenobarbital
binds to GABA receptor and opens Cl channels
ADRs of Phenobarbital
Cognitive impairment Drowsiness Physiological dependence CNS depression -- Don't discontinue abruptly; Sz and withdrawal can occur Vit D and Ca deficiency
MOA of Phenytoin
Sodium channel blocker
Phenytoin; if given via IV, what is max rate and complication if given too fast?
max rate: 50 mg/min, diluted in normal saline
Hypotension if too fast
Drug which has 90% albumin binding?
Phenytoin
ADRs of Phenytoin (Dose related)
(Dose related) Ataxia (dysfunctional muscle movements) Dizziness Nystagmus (involuntary eye movement) Slurred speech Diplopia (double vision) Lethargy Cognitive impairment
ADRs of Phenytoin (non-dose related)
(non-dose related) Gingival hyperplasia Skin thickening Hirsutism (excessive body hair) Coarsening facial features Ca and Vit D deficiency with bone loss Folate deficiency
MOA of Fosphenytoin
Sodium channel blocker
pro-drug of phenytoin
MOA of Valproic Acid
Ca and Na channel blocker
Enhance GABA release and activity
ADRs of Valproate (Valproic acid)
Hepatotoxicity Thrombocytopenia Interference with platelet aggregation Alopecia Weight gain Menstrual irregulations
Major class and drugs that have drug interactions with Valproate, causing significant reduction in valproate serum concentrations and increase risk of seizures
Class: "carbapenems" Meropenem Imipenem Ertapenem Doripenem
MOA of Lamotrigine
Decreases glutamate and aspartate release
blocks Na channels
ADRs (and considerations) of Lamotrigine
Estrogen containing Oral Contraceptives may increase lamotrigine clearance
Rash
Dose titration needed
Concomitant Valproate use increases lamotrigine levels and higher risk of ADRs including rash
MOA of Levetiracetam
Ca channel blocker
Facilitate GABA inhibitory effects
(No significant drug interactions)
MOA of Oxcarbazepine
Na channel blocker
ADRs of Oxcarbazepine
Serious skin reactions (25-30% cross-reactivity if rash with carbamazepine)
Vit D and Ca deficiency, bone loss
(more hyponatremia than with carbamazepine; SIADH)
(Lower risk for leukopenia than with carba…)
