ANTICONVULSANT 2 Flashcards
Benzodiazepines are usually used as
sedative hypnotics
Give examples of benzodiazepines
Lorazepam
Clonazepam
Diazepam
Clorazapate dipotassium
Clobazam
Nitrazepam
Modazolam
Give the metabolism of benzodiazepines
Metabolised by CYP3A4 to active metabolites
Give an important PK of the benzodiazepines
Half life of 40hrs
Cross the placental barrier and may depress foetal vital functions
Give the MOA od benzodiazepines
potentiating the effect of GABA
1) Diazepam is give through which ROA
What is the main clinucal use of diazepam
IV or IM , not usually for long term oral due to tolerance
GTC status epilepticus
Continuous seizure activity is termed as
status epilepticus
Lorazepam is more effective than diazepam in stafus epilepticus , true or false
True
Clonazepam is termed as what acting and is used in
Clonazepam causes
long acting
Myoclonic , Absence and Infantile spasms
marked sedation
Clorazepate dipotassium is used as
an adjunct in complex partial seizures in adults
The active metabolite of Clobazam is
Norclobazam
Tolerance develops for clobazam
true
Give general clinical applications of BDzs
Anxiolytic
Anticonvulsant
Muscle relaxant
Sleep aid
Pre-ooetative anaesthesia
Give two main limitations of BDzs
Marked sedation
Tolerance
Give the toxivity of BDZs
1)Sedation , impaired judgement
2) Teratogenic
3) Hypersensivity - rash
Give the DDI of BDZs
Additice effects woith other CNS depressants such as alcohol , opoids , TCAs , phenothiazines
Give the structure of Gabapentin
GABA molecule covalently bonded to a cyclohexane ring
Gabapentin is able to pass through the BBBdue to
its high lipid solubility
Give the structure of Pregabalin
GABA molecule covalently bounded to isobutane
Pregabalin and gabapentin moa
Bind to a2delta subunits of voltage gated calcium channels thus inhibit calcium entry and inhibits presynaptic release of glutamate
Gabapentin PK
Not bound to plasma proteins and not metabolised in humans
Give the clinucal use of
1) Gabapentin
2Pregabalin
Gabapentin - adjunct in partial and GTCS , Bipolar disorder , Migraine , Chronic pain
Pregabalin - partial seizures , painful diabetic peripheral neurppathy , Fibromyalgia , Postherpetic neuralgia , Genaralized anxiety disorder
Give the MOA of Vigabatrin
A structural analog of GABA that inhibits GABA transaminase used in GABA degradation
Vigabatrin is usually reserved for patients with failed alternative therapues due to
Progressive and permanent bilateral vision loss
Guve the structure lf Tiagabine
Its is a derivative of nipecotic acid
Give the MOA of Tiagabin
Inhibits the GABA transporter GAT-1 prolonging its effects at inhibitory synapses
Give the effects of phenytoin carbamezapine and phenobarbital to the haalf life of tiagabine
Usually 8hrs but reduced to 2-3 hrs when codaministered with the above drugs
Give the effects of Tiagabin and food
taken with food to minimoze A/E
Tiagabin is mainly excreted via
feces
Give the moa of Retigabine
Opens voltage gated potassium channels thus inhibiting release of glutamate
Give the structure of Levetiracetam
pyrrolidine
Give the MOA of Levetiracetam
Binds selectively to SVA2 decreasing release of glutamate
Levetiracetam is metabolised in the
blood
Give the MOA of Perampanel
Ingibits AMPA receptors , a type of glutamate receptors
Give the Metabolism and DDI of perampanel
Extensive hepatic metabolism by CYP3A4
Inducees of CYP3A4 such as Carbamezapine and phenytoin increase clearance
Guve the clinical ise of Felbamate
Refractory focal seizures
Atonic seizures
Lennox-Gastaut syndrome
Felbamate works via
Blockade of NMDA receptors
Potentioation of GABA
Give the MOA of acetazolamide as an anticonvulsant
Its is a carbonic anhydrase inhibitor thus reduces bicarbonate ions which are important in depolarization
Give a limitation of acetazolamide
Tolerance
Give two drugs with the lpwest risk of congenital abnormalities in pregnancy
Lamotrigine
Levetiracetam
