Pharmacology of Epilepsy Flashcards
What are the first three steps for pharmacology?
Identify the patient’s problem
Specify the therapeutic objective
Select a drug
What are the patient’s symptoms?
Collapse with jerking Loss consciousness and then came around a min later Disorientated Confusion Stressed Not much sleep Convulsing Quick jerk of her arms Similar episode 18 moths
What is the patient’s problem?
Epilepsy
Tonic clonic seizures
Myoclonic seizures
What are the types of seizures?
Absence Focal Generalised tonic-clonic Myoclonic Tonic or atonic
What are the stages of tonic-clonic seizures?
Tonic stage: lose of consciousness, stiffening of the body
Clonic stage: Jerk
What did the EEG show?
Interictal epileptiform discharge - risk of seizure recurrence
What is the therapeutic objective for the patient?
Reduce severity of seizures
Reduce frequency of seizures
Prevent long term effects
Identify triggers (stress, lack of sleep etc.)
Educate patient
Friends and family should be educated on management of seizures
What are the main goals of anti-epileptic drug treatment?
Eliminate seizures or reduce frequency
Evade the adverse effects associated with long term treatment
Aid patients in maintaining or restoring their usual psychical and vocational activities and in maintaining a normal lifestyle
What drugs could be give to treat tonic-clonic seizures in women of child bearing age?
Lamotrigine or Carbemazepine
What is the mechanism of action of Lamotrigine?
Blocks voltage gated Na+ channels preventing Na+ influx. Prevents depolarisation of glutamatergic neurones and reduces glutamate excitotoxicity
Why is sodium valproate not given to women of child bearing age?
Can cross placental barrier and cause physical birth defects or developmental uses
e.g. Neural tube defects
Decreased IQ
Why might the COP affect Lamotrigine concentration?
COP may impact lamotrigine absorption so less gets into the blooding the first place
COP may enhance metabolism so more is cleared from the blood
COP may enhance excretion of Lamotrigine
She begins taking the OCP, why might she be feeling more drowsy during the fourth week of her cycle?
During the fourth week of contraceptive cycle you stop taking the OCP. Therefore the concentration of the anti-epileptic while be twice as high in the fourth week as there is nothing reducing its concentration.
Increasing the side effects of Lamotrigine one of which is drowsiness
What are the side effects of Lamotrigine?
Dizziness Diarrhoea Loss of balance Abnormal eye movements Trouble speaking Drowsiness
What is the mechanism of action levetiracetam?
Inhibition of the synaptic vesicle protein SV2A. It inhibits this protein and prevents vesicle exocytosis. A reduction in glutamate secretion is reduces glutamate excitotoxicity
