Hello friends in this video we will talk about the classification of the anti-electric drugs and the uh phenytoin drug so let’s begin the first drug is the index which includes the phenytoin and phosphine then we have the barbie tube which includes phenobarbital and we have immunostims which include carbamazepine and oxcar basically one of the most commonly used
Ntf it has a selective anti-electric effect and does not produce significant drowsiness and produce significant drought what is the mechanism of action of the phenytoin it’s stabilizing neuronal membrane and prevents spread of seizure discharges basically the sodium channels exist in three forms resting activated and the inactivity state what does the phenytoin
Do phenytoin delays recovery of sodium channels from inactivated state so basically the sodium cannot depolarize the membrane because it it is not going into the activated state because here the phenytoin delays the recovery of sodium channels from the inactivated state so the sodium can’t get into the activated state and depolarize the membrane and hence it
Reduces the neuronal excitator and inhibits high frequency firing frequency is also reduced at higher constant concentration phenomena inhibits calcium influx into neurons so the depolarization become less and the excitability will be reduced reduced glutamate levels and increases responses to gaba by reducing the glutamate level it also reduces excitability
And gaba is the inhibitory neurotransmitter so also reduces the excitability glutamate is the excitatory neurotransmitter then we will move up into the pharmacokinetics phenytoin is absorbed naturally the gi tract widely distributed and highly bound to plasma proteins completely metabolized by is the point completely metabolized by your hydroxylation and
Glucoronite conjugation uh a repeated uh administration of anything causes enzyme induction and increases the rate of metabolism of co-administration drugs so what happens when you are dependent on repeatedly it will cause the enzyme induction and metabolize the other drugs which you will be taking so it’s efficacy efficacy will be reduced now phenylalanine
Also exhibits those dependent illumination at low concentration elimination occurs by first order nearly about 10 to 24 hours as the rate of administration increases the metabolizing enzymes get saturated kind of exchange to zero order plasma increases and the toxicity occurs so what uh utar is saying that when you increases the concentration the metabolic
Enzymes are getting it saturated so as we all know that low concentration of first order kinetics will happen in at higher concentration when the enzymes get situated zero order kinetics will be taken so what happens that now the enzyme will not metabolize the phenytoin uh more so the phenytoin toxicity will occur so the therapeutic monitoring of training
Is essential for adjustment of procedures now we will move on to the uses the uses of the phenytoin first is the uh it will used in general as tony clonic is a grand male epilepsy then parcels is trigeminal and other neuralgia and the status epileptic it will it will administer intervenously normal saline it precipitates in glucose solution now the uh phenyls
Does depend on toxicity as we will discuss about so what is the edwards effect hypertrophy and hyperplasia bombs due to defect in collagen metabolism chronic therapy and minimized by proper oral hygiene then hypersensitivity reactions then it’s suitable due to increased dendrogen secretion then hyperglycemia due to decreased insulin resistance then near the
Mechanoblastic anemia to follow deficiency so there is a deficiency of calcium so hypocalcemias also contribute to decrease absorption of calcium from the cut then we have fetal indian joint syndrome left left left collar there will be the deficiency of vitamin d so the bone can not uh mature properly so it will result in osteomalacia as well and the due to
Hypocalcemia also the bone can not is it controls the movements motor movements so there will be improvement in the water movements in the center cardiovascular system there will be hypotension and cardiac arrhythmias in this gi in the git adverse effects will be nuclear movement in this lecture and it will be minimized by giving phenytoin after food so
This is all about the paint and drug in the next video we will talk about some other drugs of the epilepsy to treat epilepsy thank you for watching
Transcribed from video
MASTER THE PHARMACOLOGY:ANTIEPILEPTICS: PHENYTOIN By INTEGRATED MEDICINE