Anticonvulsants & Antidepessants

ANTICONVULSANTS

Pharmacologic Properties of Anticonvulsants

General Properties

• Anticonvulants are a diverse group of pharmaceuticals used in the treatment of epileptic seizures. Thus, they are also referred to as Antiepileptics.
• They primarily alter the transmission of nerve impulses to prevent epileptic seizures.

epileptic seizure

Generic Names

1. Carbamazepine
2. Ethosuximide
3. Phenobarbital
4. Phenytoin (dilantin-brand)
5. Primidone (metabolite phenobarb)
6. Valproic Acid

Analysis of Anticonvulsants

• Immunoassay technique- It is the method of choice.
• it only takes a few minutes
• the test is fairly simple
• centrifugal analyzers allows batch processing of large numbers of samples
• Gas Chromatography or HPLC
• requests for multiple drug assays
• study of drug metabolites might be of value

This video shows us how Phenytoin (anticonvulsant) works. 

ANTIDEPRESSANTS

Antidepressants

General Properties

     2 Major classes

• Tricyclic antidepressants
• act by blocking the uptake of norepinephrine and serotonin by the presynaptic nerve endings. This blockage prolongs the time of transmission of the nerve impulse.
• They are used slowly and cautiously
• Frequently ineffective in the relief of depression
• Administered orally

• Monoamine oxidase inhibitors (MAOIs)
• Effective in treating atypical depression
• They are not widely used because of their effect on blood pressure

Assay Techniques 

• Gas Chromatography
• most effective means of therapeutic drug monitoring for Tricyclics
• It is preferred because multiple drugs may be given and active metabolites are often present
• The specific compounds can be separated and quantitated, and the total amount of active drugs can be reported.
• It also permits identification of specific antidepressants.

Side Effects and Toxic Signs

Overdosage

• Overdose of Tricyclics
• ingestion of more than the therapeutic dose 
• Attempted suicide with tricyclics

• Effects of overdosage on the cardiovascular system
• Impairment of cardiac function

• Elevated amount produces respiratory depression and seizures.

Video: How do antidepressants work?