Pharmacologic Properties of Anticonvulsants
- 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.
- Phenytoin (dilantin-brand)
- Primidone (metabolite phenobarb)
- 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.
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
- 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
- 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?