Ch 12 - Antipsychotics - DONE Flashcards
What are antipsychotic drugs?
Antipsychotics are drugs used primarily to treat psychotic states
Antipsychotics =
neuroleptics
Give examples of psychotic states:
- Schizophrenia
- Delusional disorders
- Other hallucinatory states
What is the mechanism of action of antipsychotic drugs?
- Antipsychotics blocks various receptors including cholinergic, adrenergic, seretonergic, muscarinic, and histamine receptors.
- However, their antipsychotic actions are primarily thought to be due to blocking of dopamine receptors in the CNS, particularly the D2 receptors in the mesocortical and the mesolimbal system of the brain
Do antipsychotic agents differ in potency?
Yes- a drug´s potency parallells its affinity for the D2 receptors.
Give examples of high-potency antipsychotic drugs:
Haloperidol and Thiothixene are high-potency drugs because they have high affinity for the D2 receptors
Give examples of low-potency antipsychotic drugs:
Chlorpromazine and Thioridazine are low-potency drugs because they have low affinity for the D2 receptors.
Do antipsychotic differ in efficacy?
No. The traditional antipsychotics are all considered to be equivalent in efficacy
How are the antipsychotic usually administered?
- orally (most cases)
- IM (if the patient is noncompliant)
Describe the absorption and metabolism of the traditional antipsychotics:
They are variably absorbed orally but they pass into the brain easily and have a large volume of distribution. Metabolism occurs by the cytochrome P-450 system in the liver
What is the onset of action of antipsychotics?
- Antipsychotics may not become effective for several weeks to months.
- However sedation and other side effects can occur rapidly
Can the antipsychotic drugs cure illnesses such as schizophrenia?
No! Antipsychotics only reduce the symptoms of the illness; they cannot cure the illness.
How are the antipsychotics classified?
- Classification is base on the structural differences.
The major classes of antipsychotics include:
- Phenothiazines
- Butyrophenones
- Dibenzoxazepines
- Thioxanthine
- Benzioxazole
Give examples of phenothiazines:
- Chlorpromazine
- Fluphenazine
- Trifluoperazine
- Perphenazine
What distinctive side effects does thioridazine cause?
- pigmentary retinopathy
- may cause cardiac arrhythmias and conduction block
Name two Butyrophenones:
- haloperidol
- droperidol
Other than psychotic states, for what can haloperidol be used for?
- Tourette´s syndrome
- Huntington´s disease
- Phencyclidine overdose-DOC
What type of side effects is especially pronounced with haloperidol?
Extrapyramidal side effects
Name a dibenzoxazepine:
loxapine
Name a thioxanthenes:
thiothixene
What are the clinical application of traditional antipsychotic agents?
- treatment of any agitated or psychotic state
- antiemetic therapy
- treatment of Tourette´s syndrome
- treatment of intractable hiccups
- antipruritic therapy