Treatment of Psychosis Flashcards
Psychoses
patient with gross disturbances in comprehension of reality as evidenced by hallucinations and delusions
Resulting from abnormalities in DA neurotransmission in mesolimbic and mesocortical neuronal pathways
Schizophrenia
Positive Symptoms: excessive mesolimbic (agitation, delusions, disorganized speech, disorganized thinking, hallucinations, insomnia) respond well to neuroleptics
Negative Symptoms: insufficient mesocortical (apathy, affective flattening, lack of motivation, lack of pleasure, poverty of speech, social isolation) do not respond well to neuroleptics, use atypicals
Typical Antipsychotics
Phenothiazines: chlorpromazine, fluphenazine, thioridazine, trifluoperazine, mesoridazine, perphenazine
Thioxanthenes: thiothixene, chlorprothixene
Butyrophenones: Haloperidol, Spiperone
Azepines: loxapine
Dihydroindolone: Molindone
Atypical Antipsychotics
Azepines: Clozapine, Olanzapine, Quetiapine
Benzisoxazole: Risperidone, Aripiprazole
Benzisothiazolypiperzine: Ziprasidone
Antipsychotics
Mechanism: Competitive blockade of DA and 5-HT receptors
Typical: DA > 5HT
Atypical: 5HT> DA; works on positive and negative symptoms
Adverse effects happen from blockade of alpha1 adrenergic, Histamine (H1) and Muscarinic
Absorbed from GI, Metabolized in liver, half life= 20-40 hours, Renal excretion of glucuronide conjugates
Dopamine Receptors
D2 receptors found pre/postsynaptically, coupled to Gi or Go
Blockade of D2 results in increased DA synthesis and release, increased cAMP, and decreased K+ currents
Time Course of Antipsychotic Therapy
1-3 Days: decreased agitation, aggression, anxiety, and normalization of eat/sleep
1-2 weeks: increased socialization, self care, and mood
3-6 weeks: increased thought disorder, decreased delusions/hallucinations, appropriate conversations
Haloperidol
Tx of Gilles de la Tourette’s and Huntington’s
Chlorpromazine
Tx of intractable hiccups
deposits in lens and cornea
contraindicated in patients with seizures, lowers the threshold
Thioridazine
deposits in retina, cannot be used as an antiemetic (neither can aripirprazole)
Prochlorperazine
Tx of drug-induced nausea (chemo)
Scopolamine
Tx of motion sickness
Droperidol
component of neuroleptanesthia
Negative Side Effects at Dopamine Receptors - Extrapyramidal
Akathisia, Pseudoparkinsonism, Dystonias
From all the drugs, more common in D2 specifics (haloperidol, fluphenazine, thiothixene)
Atypicals have lower incidence
Tx: Trihexyphenidyl, Benztropine mesylate, Procyclidine HCL, Biperidin
Negative Side Effects at Dopamine Receptors - Tardive Dyskinesia
More common in typicals, incidence low with Clozapine, results from “supersensitivity” from long term blockade
No Tx