Antipsychotics - Drug Classes Flashcards
What are the first generation antipsychotics?
*Phenothiazines
*Thioxanthenes
*Butyrophenones
*Other drugs
How are phenothiazines distributed throughout the body?
*Usually orally (lungs > liver > adrenals > spleen > brain
*Requires repeated doses to achieve steady state concentrations
*Half-life 24-48hrs, metabolized slowly by liver and slow to leave tissues
What receptors are phenothiazines involved in?
Blockading of D2, AChM1, H1, NE-a1
What sites are phenothiazines involved in?
Medulla, limbic system, frontal lobes, hypothalamus, pituitary, basal ganglia
What are some side effects of phenothiazines?
Extrapyramidal symptoms, tardive dysplasia, associations with involved receptors, pigment alterations, neuroleptic malignant syndrome
Are phenothiazines addictive and/or abusive?
No; doesn’t create dependence or tolerance
How are thioxanthenes different from phenothiazines?
Affects 5-HT and not AChM1 receptors
How are butyrophenones distributed throughout the body?
*Usually orally, may be IM; distributed equally throughout tissues
*Half life 18hrs orally or 3 weeks with decanoate
*Metabolized slowly by liver, slow to leave tissues
What is the binding profile of butyrophenones?
Similar to phenothiazines (block D2, AChM1, H1, NE-a1
What sites are butyrophenones involved in?
Brains stem, basal ganglia, limbic system, frontal lobe, hypothalamus
What is the main side effect of butyrophenones?
High incidence of extrapyramidal symptoms, PD-like symptoms, dystonia, tardive dyskinesia
How are atypical antipsychotics different from its first generation?
*Less motor side effects
*More effective in relieving negative symptoms of schizophrenia
*Also blocks 5-HT in addition to D2
*Common side effects related to metabolism (weight gain, type 2 diabetes, hyperglycemia, cardiac abnormalities [QT prolongation])
