Medicine or drugs used in convulsion

1. Anti convulsant drugs

2. Epilepsy: Epilepsy is a chronic disorder of brain
function characterized by the recurrent and
unpredictable occurrence of seizures.
Seizure: A seizure can be defined as the occurrence
of signs and/or symptoms due to abnormal,
excessive or synchronous neuronal activity in the
brain.

3. Pathophysiology:
To function normally, the brain must maintain a
continual balance between excitation and inhibition.
The inhibitory transmitter gamma-aminobutyric acid
(GABA) is particularly important, acting on ion
channels to enhance chloride inflow and reducing
the chances of action potential formation. Excitatory
amino acids (glutamate and aspartate) allow influx
of sodium and calcium, producing the opposite
effect. It is likely that many seizures result from an
imbalance between this excitation and inhibition.

4. Classification of Seizure :
1. Focal onset (formerly partial onset) seizures:
>Focal aware seizure (formerly simple partial seizure)
>Focal impaired awareness seizure (formerly complex partial seizure)
>Focal-to-bilateral tonic-clonic seizure (formerly partial seizure
secondarily generalized or grand mal seizure)
2. Generalized onset seizures:
>Generalized tonic-clonic seizure(GTCS) (formerly primary generalized
tonic-clonic seizure or grand mal seizure)
>Generalized absence seizure (formerly petit mal seizure; occurs, for
example, in absence epilepsy).
>Myoclonic seizure
>Atonic seizure

6. Classification of Anticonvulsants:
According to clinical use:
>Focal onset and/or secondary GTCS: Lamotrigine, Carbamazepine,
Levetiracetam , Sodium valproate, Topiramate, Clobazam,
Gabapentin, Phenobarbital, Phenytoin, Pregabalin
>Generalized tonic- clonic seizure (GTCS): Sodium valproate,
Levetiracetam, Lamotrigine, Topiramate, Carbamazepine,
Phenytoin, Phenobarbital, Acetazolamide
>Absence seizure: Ethosuximide, Sodium valproate, Lamotrigine,
Clonazepam
>Myoclonic seizure: Sodium valproate, Levetiracetam, Clonazepam,
Lamotrigine, Phenobarbital

7. According to mood of action:
1. Sodium channel blockers: Carbamazepine,
Oxcarbazepine, Phenytoin, Lamotrigine, Lacosamide
2. GABA potentiators : Sodium valproate,
Barbiturates(phenobarbital), Benzodiazepines
(Lorazepam ,Diazepam ,Clonazepam),
Vigabatrin(irreversibly inhibiting GABA-transaminase)
3. Calcium channel blockers: Gabapentin, Pregabalin,
Ethosuximide
4. Carbonic anhydrase inhibitors: Topiramate,
Zonisamide, Levetiracetam

8. Guidelines for antiepileptic drug therapy:
1. Start with one first-line drug
2. Start at a low dose; gradually increase dose until effective control of seizures is
achieved or side-effects develop
3. Optimise adherence (use minimum number of doses per day)
4. If first drug fails (seizures continue or side-effects develop), start second first-line
drug, followed if possible by gradual withdrawal of first
5. If second drug fails (seizures continue or side-effects develop), start second-line
drug in combination with the preferred baseline drug at maximum tolerated dose
(beware interactions)
6. If this combination fails (seizures continue or side-effects develop), replace
second-line drug with alternative second-line drug
7. If this combination fails, check adherence and reconsider diagnosis (Are events
seizures? Occult lesion? Treatment adherence/alcohol/drugs confounding
response?)

9. CARBAMAZEPINE:
Carbamazepine is one of the most widely used antiseizure drugs.
M/A: Carbamazepine acts predominantly as a voltage-dependent sodium channel
blocker, thereby reducing membrane excitability.
Uses : Partial seizures with or without secondary generalisation, Drug of first
choice for Trigeminal neuralgia, Bipolar disorder
Side effects : Dizziness, diplopia, ataxia, nausea and reversible blurring of vision,
drowsiness (depresses electrical excitability in the CNS, this results in cerebellar
and brainstem dysfunction), depression of cardiac atrioventricular (AV) conduction,
Rashes including serious reactions such as Stevens–Johnson syndrome,
osteomalacia and folic acid deficiency may occur due to enhanced metabolism of
vitamin D and folic acid due to hepatic induction property (Elderly patients
receiving any enzyme-inducing drug should be screened for osteoporosis with
bone-density scanning, and treated with bisphosphonates if necessary), headache,
blood disorders, e.g. leucopenia, syndrome of inappropriate antidiuretic hormone
(causing hyponatraemia).

10. Phenytoin:
M/A: Phenytoin acts principally by blocking neuronal voltage-dependent Na ion
channels; this action is described as membrane stabilising, and discourages the
spread of seizure discharges.
Phenytoin is a potent inducer of hepatic enzymes that metabolise other drugs
(carbamazepine, warfarin), dietary and endogenous sub-stances (including vitamin
D and folate), and phenytoin itself.
Uses: Status epilepticus, partial seizures with or without secondary generalisation,
membrane-stabilising effect of phenytoin finds use in cardiac arrhythmias,
trigeminal neuralgia and myotonic dystrophy (an inherited disorder in which
skeletal muscle becomes over-excitable)
Adverse effects: CNS side effects include cognitive impairment, cerebellar ataxia,
dyskinesias, tremor and peripheral neuropathy, Cutaneous reactions include rashes
(dose related), coarsening of facial features, hirsutism, lupus-like syndrome, gum
hyperplasia (due to inhibition of collagen catabolism), and Dupuytren’s contracture
(caused by free-radical formation), Haematological effects include: macrocytic

11. Sodium valproate:
 M/A: Sodium valproate acts on Na and Ca channels, as well as GABA receptors,
the latter action by virtue of inhibiting GABA transaminase (thereby increasing
GABA levels, and hence neuronal inhibition).
 Uses: generalised and partial epilepsies, as well as for migraine prevention and
mania (for which it acts as a mood stabiliser)
Adverse effects: Weight gain, Impaired glucose tolerance, Teratogenicity,
Polycystic ovary syndrome and Loss of hair, Nausea and dyspepsia (ameliorated by
using an enteric-coated formulation),