Summary of Epileptic Drugs
- Clinical Manifestations
These result in impairment of consciousness from the outset. There are various types:
- Tonic Clonic Seizures
These are often called ''Grand Mal'' attacks. Without warning, the patient suddenly goes stiff, falls to the ground and convulses with laboured breathing, diaphoresis and excessive salivation. Cyanosis, incontinence and tongue biting may occur. The convulsions ceases after a few minutes leaving the patient drowsy and confused.
- Absence Attacks
These are often termed ''Petit Mal'', however, these are a much rarer form of generalized seizure. They happen most exclusively with younger individuals and adolescents. The child goes blank and stares; fluttering of the eyelids and flopping the head may occur. The attacks last only a few seconds and often go unrecognized by the child experiencing them.
- Myoclonic Seizures
These are abrupt, very brief involuntary shock-like jerks, which may involve the whole body or just part of it and usually occur shortly after wakening. The patient may fall to the ground but recovery is immediate.
- Atonic Seizures
These comprise a sudden loss of muscle tone causing the person to collapse to the ground. Recovery is quick. These are rare, accounting for 1% of seizures. They usually last less than 15 seconds and the typical gyration involves loss of muscle tone around the neck ''dropping head''.
Partial or Focal Seizures
- Simple Partial Seizures
In these seizures, the discharge remains localized and consciousness remains fully preserved. What actually happens during a partial seizure is wholly dependent on the location of the excessive synaptic discharges. If this type of seizure is accompanies by loss of consciousness, then its termed a complex partial seizure.
- Complex Partial Seizures
The person may present with ''automatic'' behavior; plucking his or her clothes, lip smacking or chewing movements, grimacing, performing aimless activities. Most of these seizures originate in the frontal or temporal lobes of the brain and can sometimes progress to secondary generalized seizures.
- Secondary Generalized Seizures
These are partial seizures, either simple or complex, in which the discharge spread to the entire brain.
- Status Epilepticus
If a seizure persists for more than 10mins, then intravenous or rectal administration of 10-20mg diazepam, with lower doses being used in children, is advisable. Initial management of status epilepticus is supportive and may include:
- Positioning the person to avoid injury
- Supporting respiration
- Maintaining blood pressure
- Correcting hypoglycaemia
Drugs used include intravenous lorazepam or diazepam. Alternative medicines include midazolam in cases where the person has not responded to first line agents. Alternatively, buccal midazolam has been advocated and is increasingly being used.
In severe cases, phenytoin, phenobarbital sodium or clonazepam may be required.
- Febrile Convulsions
Convulsions associated with fever are termed febrile convulsions and may occur in the young. Brief febrile convulsions are managed conservatively with the primary aim of reducing the temperature of the child. Tepid sponging and use of paracetamol is recommended. Prolonged febrile convulsions lasting 10-15minutes or longer in a child with risk factors for brain damage may require hospitalization.
The drug of choice is diazepam by intravenous or rectal administration .
- Withdrawal of these Agents
AED''s should not be withdrawm abruptly. Withdrawing from carbamazepine has the following withdrawal algorithm:
- 100-200mg every 2 weeks (as part of a drug change)
- 100-200mg every 4 weeks (total withdrawal)
|Seizure Type||First-Line Treatment||Second Line Treatment|
|* Partial Seizures||Carbamazepine |
|* Generalized Seizures|
|1. Tonic Clonic||Sodium Valproate||Lamotrigine|
|5. Atypical Absences||Sodium Valproate|
|7. Myoclonic||Sodium Valproate||Levetiracetam|
The newer AED''s (such as Lamotrigine, Vigabatrin, Gabapentin, Tiagibine, Topiramate, Zonisamide, and Lacosamide) have established themselves as 2nd line agents. However, lamotrigine is considered the first line agent in women of child bearing potential who have idiopathic generalized epilepsy because of the teratogenic profile of sodium valproate.
- Vigabatrin is suitable for first-line treatment of young children with a rare type of infantile spasm called West''s Syndrome.
- Lamotrigine, Oxcarbazine, or topiramate can be given to children as sole treatment for epilepsy.
- Children should be treated with one AED where possible.
- Gabapentin, tiagabine, and vigabatrin are generally used as combination therapy with another drug.
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