Sue asked
Can you please tell me if Zonisamide and Soduim Valproate are one and the same?
Answer
Zonisamide and sodium valproate are not the same drug, although they are both classified as anticonvulsants.
Zonisamide (brand name Zonegran) is more closely related to two other anticonvulsant drugs, carbamazepine and phenytoin. The exact mechanism of action isn't well known but it is thought that zonisamide works by acting on sodium and calcium channels. The pathophysiology of epilepsy and related seizure disorders is complex but generally speaking, sodium and calcium channels are highly involved in neuronal actions and neuronal dysfunction.
Common side effects with zonisamide include:
- Dizziness
- Ataxia (loss of coordination)
- Sedation
- Nausea
- Headache
- Irritability
- Photosensitivity
- Loss of appetite
- Weight loss
Rare side effects include:
- Skin reactions
- Hyperthermia (due to lack of sweating)
- Kidney stones
Laboratory monitoring of drug levels of zonisamide is generally recommended but not always required.
Sodium valproate, also known as Depakote or valproic acid, is chemically unrelated to other anticonvulsants. Like zonisamide, the exact mechanism of action isn't known but valproate is thought to work by increasing concentrations of gamma-aminobutyric acid (GABA), an inhibitory neurotransmitter, in the brain. It may also affect sodium channels like zonisamide.
Common side effects of vaproate include:
- Nausea
- Hair loss
- Increased appetite
- Weight gain
Rare side effects include:
- Liver toxicity
- Low blood platelets
Different anticonvulsants are approved for different indications and their distinct characteristic needs to be considered when choosing an agent.
