Pediatrics pharmacology Anticonvulsant Therapy

1. Dr.Azad A Haleem AL.Brefkani
University Of Duhok
College of pharmacy
Pediatrics Department
azad82d@gmail.com
2016

2. Definition
 Seizure (Convulsion): the clinical
manifestation of an abnormal and excessive
excitation of a population of cortical neurons.
 Epilepsy: a disease characterized by
spontaneous, unprovoked recurrent seizures.

3. Basic principles of AED therapy
• Initiation of therapy
• Adding a second drug
• Monotherapy vs. Polytherapy
• Drug-Drug interaction
• Anticonvulsant level monitoring

4. To Treat or Not to
Treat ; that is the
Question ?
• For patients who have had more than 1
unprovoked seizure, treatment with an
anticonvulsant is recommended.

5. • The risk of recurrence in the 2 years after a
first unprovoked seizure is 15-70%.
• Principal factors that increase the risk of
recurrence are an abnormal (MRI) study, an
abnormal electroencephalogram (EEG), and a
partial-onset seizure.

6. Targets for AEDs
• Increase inhibitory neurotransmitter
system—GABA
• Decrease excitatory neurotransmitter
system—glutamate
• Block voltage-gated inward positive
currents—Na+ or Ca++
• Many AEDs —act via multiple mechanisms

7. Action on Ion
Channels
Enhance GABA
Transmission
Inhibit EAA
Transmission
Na+
:
Phenytoin,
Carbamazepine,
Lamotrigine
Topiramate
Valproic acid
Ca++:
Ethosuximide
Valproic acid
Benzodiazepines
(diazepam, clonazepam)
Barbiturates
(phenobarbital)
Valproic acid
Gabapentin
Vigabatrin
Topiramate
Felbamate
Topiramate
Na+:
For general tonic-clonic
and partial seizures
Ca++:
For Absence seizures
Most effective in
myoclonic but also in
tonic-clonic and partial
Clonazepam: for Absence
Classification of Anticonvulsants

8. Carbamazepine
• Indications:
• Used in Generalized tonic-clonic& partial seizures.
• Affective disorders : Bipolar disorder
• Chronic pain syndromes: trigeminal neuralgia.

9. phenytoin
• Used: generalized tonic – clonic , partial
seizures , in status epilepticus.

10. Ethosuximide
• Drugs that Affect Calcium Currents:
• Absence.
• May increase tonic- clonic seizures

11. Phenobarbital
• Uses :
– Generalized tonic – clonic
– Partial seizures
– Neonatal seizures
– Status epilepticus

12. Drugs with multiple mechanisms of
action
• Valproate :
– Mechanism of action:
• Blocks voltage – dependant Na channels.
• Enhances GABA synthesis
• Acts against Ca currents.
• Uses :
– Broad spectrum AED used alone & in combination
for partial seizures & several types of generalized
seizures.

13. Stopping antiepileptic treatment
• After 2 years with no seizers.
• Likelihood of recurrence after 2 years of control 30-
40 %

14. Life long treatment
• Juvenile myoclonic epilepsy
• Progressive myoclonic epilepsy
• Atypical absence seizures
• Lennox-Gastaut

15. Higher rates of recurrence
• Older age at the outset
• Syndromes
• Symptomatic epilepsy
• Poor initial control of seizures
• Change in the type of seizures during
treatment

16. Intractable ??
• Consider the following :
– Wrong diagnosis.
– Inadequate drug level
– Inattention to life style factors ( sleep
deprivation,alcohol,stress)
– Underlying progressive brain disease or metabolic disease.
– Intrinsic intractable syndrome.
– Wrong drug

17. Side effect issues
• Sedation - especially with barbiturates
• Cosmetic - phenytoin
• Weight gain – valproic acid, gabapentin
• Weight loss - topiramate
• Reproductive function – valproic acid
• Cognitive - topiramate
• Behavioral – leviteracetam
• Allergic - many

18. Thanks