Exam 2 Week 2 Flashcards
(162 cards)
Define
- •Patients exhibit gross disturbances in their comprehension of reality, as evidenced by
- False perceptions (hallucinations) and False beliefs (delusions).
**Explain biological basis
Psychoses
Dopamine hypothesis:
- •Abnormalities in DA neurotransmission in mesolimbic and mesocortical neuronal pathways
Supported by:
- •Drugs which block D2 receptors improve disorder
- •Affinity at D2 receptors correlated with clinical efficacy
- •Drugs which increase DA release (amphetamine) or block reuptake (cocaine) induce psychotic behavior.
Problems with hypothesis:
- •Receptors blocked immediately, psychosis disappears slowly
Explain dopamine tracts and psychoses (5)
Causes of acute psychosis (6)
•Drug abuse and withdrawal
- –Phencyclidine / hallucinogens
- –Amphetamines, cocaine
- –Alcohol withdrawal
- –Sedative-hypnotic withdrawal
•Toxic Agents
- –Heavy metals
- –Digitalis toxicity
- –L-Dopa
•Metabolic Causes
- –Hypoglycemia
- –Acute intermittent porphyria
- –Cushing’s syndrome
- –Hypo/hypercalcemia
- –Hypo/hyperthyroidism
•Nutritional causes
- –Thiamine deficiency
•Niacin deficiency
- –Vitamin B12 deficiency
•Neurological causes
- –Stroke
- –Brain tumor
- –Early Alzheimer’s or Pick’s disease
- –Hypoxic encephalopathy
Schizoprenia
- Positive vs Negative symptoms
Positive symptoms:
- •Probably result from excessive neuronal activity in mesolimbic neuronal pathways; respond well to neuroleptics (antipsychotic drugs)
Negative symptoms:
- •Probably result from insufficient activity in mesocortical neuronal pathways
- •More difficult to treat
- –Often persist after positive symptoms resolve and are associated with a poor prognosis
- –Do not respond as well to neuroleptics; atypical antipsychotics may be more effective
Antipsychotics MoA
- typical vs atypical
- which block serotonin better?
- whcih block dopamine better
- which has more extrepyramidal side effects?
- which treat negative symptoms
- examples of each
•Mechanism of action:
- –Competitive blockade of DA and 5-HT receptors.
- Typical Antipsychotics: Affinity: D2 >5-HT2 receptors:
- Atypical Antipsychotics: Affinity for 5-HT2 > D2 receptors:
- ·Selectivity for mesolimbic over nigro-striatal regions in their effects on the DA system
- ·More likely to be effective in drug-refractory patients
- •Likely to improve positive & negative symptoms
- Less extrapyramidal symptoms with atypicals
Adverse effects of antipsychotics are as a result of? (3)
–Adverse effects are attributed to blockade of the following receptors:
- •a1-adrenergic
- •Histamine H1
- •Muscarinic
pharmacokinetics of antipsychotics
- absorption
- administration
- metabolism
- half life
- excretion
- •Absorbed erratically from GI tract
- •Parenteral administration of some antipsychotics available
- •Metabolized to active/inactive metabolites in liver
- •t1/2 = 20-40 hr
- •Renal excretion of glucuronide conjugates
CNS actions of antipsychotics
- –Positive symptoms subside in 1-3 weeks
- –Spontaneous movement and complex behavior suppressed
- –Less agitation
- –Patient easily aroused, capable of answering direct questions
- –Intact intellectual function
- –Withdrawn patients become more responsive
- –Impulsive behavior decreases
- –Hallucinations, delusions and incoherent thoughts decrease
- Actions of antipsychotics on dopamine receptors
- Dopaminergic neurptransmission
- presynaptic vs postsynaptic effect
Actions at dopamine receptors
- •D2 receptors found pre/postsynaptically
- •D2 receptors coupled to Gi or Go
- •Blockade of D2 receptors results in (acute effects/presynaptic block)
- –DA synthesis and release
- –cAMP
- –¯K+ currents
Dopaminergic Neurotransmission
•Presynaptic Effect
- –Short Term Treatment: Activated neurons
- –Long Term Treatment: Inactivated neurons
•Postsynaptic Effect
- –Short Term Treatment: Receptor Blockade
- –Long Term Treatment: Receptor Supersensitivity
Describe time course of therapy response (antipsychotics)
- 1-3 days
- 1-2 weeks
- 3-6 weeks
Antipsychotics specific drug info/use
- Haloperidol
- use
- Chlorpromazine
- contraindication
- use
- deposit where
- Thioridazine
- deposit where
- what cant be an antiemetic (2)
- prochlorperazine (use)
- scopolamine (use)
•Haloperidol
- –treatment of Gilles de la Tourette’s syndrome/Huntington’s Disease
•Chlorpromazine
- –contraindicated in patients with seizures, lowers threshold
- –used for intractable hiccough, mechanism unknown
- –deposits in the lens and cornea common
•Thioridazine
- –deposits in retina at higher doses
•All except aripiprazole and thioridazine can be used as anti-emetics
- –block D2 receptors in CTZ
•Prochlorperazine
- –useful in treatment of “drug-induced” nausea (chemotherapy)
•Scopolamine
- –drug of choice for motion sickness
Describe
Dopamine; extrapyramidal side effects
Describe adverse effect
Dopamine; tardive dyskinesia
Identify the adverse effect
Dopamine: Neuroleptic Malignant Syndrome
Dopamine; prolactin
adverse effect
Cholinergic (M1):
adrenergic vs histamine adverse effect of antipsychotics
Metabolic side effects of antipsychotics
- **Result in what?
Metabolic side effects - Weight gain
- •More common with atypical, though can occur with all
- •Substantial, often reversible
- •Sedation, lack of movement
- •Endocrinological changes
•Can result in
- –New Onset or Worsening of Type II Diabetes
- –Hypertension
- –Hyperlipidemia
Other adverse effects of antpsychotics
- WBC values
- what tremor?
- cardiac effects
•Leukopenia, agranulocytosis:
- –Clozapine (1-2% of patients) rare with other antipsychotics
- –Potentially fatal
- –Occurs between 6-18 weeks of treatment
- •Regular monitoring of blood cell counts should be conducted.
•Perioral tremor – “rabbit syndrome”:
- –involuntary, fine, rhythmic motions of the mouth along a vertical plane, without involvement of the tongue.
- –Rare, tends to occur following prolonged antipsychotic use (years)
- –Can treat with anticholinergic antiparkinson drugs
•Cardiac Effects:
-
–Thioridazine leads to minor T wave abnormalities in pharmacological doses
- •Overdose associated with major ventricular arrhythmias
- –Ziprasidone QT prolongation
Contraindication and drug interactions of antipsychosis
Pregnant and nursing mothers
•Drug Interactions
- –Central depressants and opioid analgesics
- –Amphetamines antagonize antipsychotic effects
- –Centrally acting anticholinergics may worsen tardive dyskinesia
- –SSRI’s may worsen extrapyramidal symptoms
- –Most antipsychotic agents can add to hypotensive effect of antihypertensives
List DSM 5 psychtic disorders
DSM-5
- •Brief Psychotic Disorder
- •Schizophreniform Disorder
- •Schizophrenia
- •Schizoaffective Disorder
- •Delusional Disorder
- •*Schizotypal Personality Disorder
- Psychotic Disorder due to a General Medical Condition
- Psychotic Disorder due to a Substance
Schizoprenia
- Important epidemiology fact
Schizophrenia has a lifetime prevalence of 1.1%
Schizophrenia
- Etiology
- Developmental and psychological
-
Genetic
- risk of having it if twin has it
- both parents
- one parent or one siibling
- Etiology
- Multiple causes
- Development and psychological - many therioes
- •Babies born in late winter and early spring have a greater risk
- •True for northern and southern hemispheres
- •Prenatal exposure to a virus suspected
- •Prenatal malnutrition and low birth weight
- •Fetal hypoxia and preeclampsia
- •Theories of the “schizophrenogenic mother” and double-bind communications (no win situations) have been disproven
- •Families with high levels of “expressed emotions” are associated with relapse of symptoms but are not causal for the illness itself.
- •Babies born in late winter and early spring have a greater risk
-
Genetic; familial transmission
- •Risk of disease in 1st degree relative ~10%
- •Identical twins – 40-65% risk
- •Both parents with schizophrenia
- •Risk 40-50%
- •One parent or one sibling
- •Risk 5-20%
Schizoprenia and genetics
- locus and chromosome number
- expression of?
- The most consistent genetic relationship at a population level is associated with the MHC locus on chromosome 6.
- In 2016, researchers at Harvard and Boston Children’s Hospital discovered that
- •Many structurally diverse alleles of complement component 4 (CD4) genes which promote widely varying expression of C4A and C4B
- •Expression of C4A in brain is directly correlated with risk for schizophrenia
- •In the brain, complement receptors are expressed primarily by microglia, the phagocytic immune cells of the central nervous system.
- •Possible that excessive or inappropriate synaptic pruning by microglia during adolescence and early adulthood could explain development of disease in some individuals