6 Antipsychotics and Mood Stabilizers Flashcards

(56 cards)

1
Q

What are some hypotheses for the causes of schizophrenia?

A

Dopamine
• DA receptors may be greater in schizophrenics
• Drugs that increase DA neurotransmission can induce psychosis
• Most antipsychotics block DA receptors

Serotonin (LSD, mescaline)
• 5HT receptors are altered in schizophrenics
• 5HT receptors mediate DA transmission

Glutamate (PCP, ketamine)

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2
Q

What are the “positive” symptoms of schizophrenia?

A

Hallucinations (auditory and visual) and delusions

Catatonic behavior, disorganized speech and thinking

Over-active dopamine pathways in limbic system (mesolimbic)

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3
Q

What are the “negative” symptoms of schizophrenia?

A

Affective behavior, apathetic, withdrawn, anti-social, lack of motivation, depressed

Under-active dopamine pathways in frontal cortex (mesocortical)

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4
Q

What happens to schizophrenics cognitively?

A

Distracted, disorganized thought, memory loss

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5
Q

What are the four dopamine pathways?

A
  1. Mesolimbic - VTA to limbic system (EMOTION)
  2. Mesocortical - VTA to frontal cortex (Cognition, emotion)
  3. Nigrostriatal - SN to striatum (Motor control)
  4. Tuberoinfundibular - Hypothalamus to pituitary (Prolactin)
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6
Q

MOA for “classical” antipsychotics

A

“Neuroleptics”

Block DA D2 receptors

Target the mesolimbic system

Alleviate the POSITIVE symptoms

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7
Q

MOA for “atypical” antipsychotics

A

Block 5HT-2a and DA receptors

Target the mesocortical and mesolimbic system

Alleviate both negative and positive symptoms

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8
Q

_______ receptors predominate in the mesolimbic region

A

DA D2

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9
Q

______ receptors are distributed in the mesocortical region

A

DA D4

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10
Q

DA D2 receptors predominate the ________ region while DA D4 receptors are distributed in the _________ region

A

Mesolimbic

Mesocortical

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11
Q

General effects of antipsychotics

A

Delayed onset - 6 weeks

Decrease aggression, restlessness, anxiety

Psychomotor function is slowed, initiative/motivation decrease

Reduce spontaneous movements

Sedation

Antiemetic (Prochlorperazine)

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12
Q

Most antipsychotics also block _______, _________, and ________ receptors in the brain and periphery

A

Muscarinic

Alpha-adrenergic

Histamine

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13
Q

Why is compliance usually poor with antipsychotics

A

Very common, not very pleasant side effects

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14
Q

Side effects of antipsychotics

A

Decreased seizure threshold

Endocrine - weight gain, increased prolactin secretion

Autonomic - anticholinergic sx, postural hypotension, sedation

Dental - xerostomia and bruxism (grinding teeth)

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15
Q

What are Extrapyramidal Symptoms (EPS)?

A

DA receptor antagonists also block DA receptors in the nigrostriatal pathway —> Parkinson’s like tremor, rigidity, dyskinesias, rocking, pacing, restlessness, anxiety, dystopia

Due to imbalance of striata DA and ACh

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16
Q

How do you treat Extrapyramidal Symptoms?

A

Anticholinergics such as benztropine (Cogentin) to restore ACh/DA balance

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17
Q

Degree of EPS a patient experiences is based on…

A

The anticholinergic activity of the antipsychotic drug (chlorpromazine vs. haloperidol)

Classical antipsychotics tend to cause more EPS than atypicals

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18
Q

Choreiform, uncontrollable, jerky movements of face and limbs, occurring in late disease following long term treatment

A

Tardive dyskinesia (15-25% of patients)

Difficult to treat, often irreversible - d/c drug

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19
Q

Which drugs are most likely to cause tardive dyskinesia?

A

Clozapine and Olanzapine

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20
Q

Life threatening side effect of antipsychotics —> muscle rigidity, hyperpyrexia, changes in BP and HR

A

Neuroleptic Malignant Syndrome

Block of DA D2 receptors in the striatum and hypothalamus

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21
Q

How do you treat Neuroleptic Malignant Syndrome?

A

Dantrolene (Dantrium)

Can also use DA agonists (bromocriptine) to stimulate DA receptors

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22
Q

What happens if you mix antipsychotics with anticholinergics?

A

Just more of the same side effects (dry mouth, urinary retention, constipation etc)

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23
Q

What happens if you mix sedative-hypnotics with antipsychotics?

A

Will increase sedation

24
Q

What happens if you mix TCAs with antipsychotics?

A

Seizures and cardiac effects

25
What does smoking do if you’re on antipsychotics?
Induces CYP450s - so the antipsychotics don’t work as well
26
MOA for classical antipsychotics
Block DA D2 receptors Requires ~60% receptor occupancy
27
Pharmacokinetics of classical antipsychotics
Readily absorbed from gut following oral administration Most have high first pass metabolism Half lives range from 20 to 35 hours Effects persist for weeks after last administration Metabolized by CYP450s
28
How is Chlorpromazine (Thorazine) used?
Psychosis associated with mania and drugs of abuse Also an antiemetic (prochlorperazine) and a pre-anesthetic May cause TD and neuroleptic malignant syndrome High anticholinergic effects so low incidence of EPS
29
Side effects of Chlorpromazine (Thorazine)
Sedation, postural hypotension, blurred vision, constipation, decreased GI motility, inhibition of ejaculation, jaundice Decreases seizure threshold May cause retinal deposits*** —> “browning” of vision
30
Fluphenazine (Prolixin) is similar to chlorpromazine but...
Selective for DA D2 receptors —> less anticholinergic activity and more EPS
31
Potent blocker of DA D2 receptors that is used frequently in acute situations
Haloperidol (“Vitamin H”) Also has affinity for DA D1, 5HT-2, and H1 receptors
32
Haloperidol has no __________ but does have __________
No anticholinergic activity Extrapyramidal symptoms, esp when used chronically
33
MOA for atypical antipsychotics
Block 5HT-2A receptors but also DA D2 and D4 receptors Alleviate both the negative and positive symptoms
34
Which antipsychotic is the drug of last choice due to agranulocytosis?
Clozapine (Clozaril) Blood must be monitored
35
What is Clozapine (Clozaril)?
Atypical antipsychotic that blocks 5HT-2A and DA D4 EPS and tardive dyskinesia very rare Side effects - hypersalivation, sedation, dizziness, postural hypotension, tachycardia, weight gain Decreased seizure threshold Relapse if d/c abruptly
36
Olanzapine (Zyprexa) is similar to clozapine but...
No agranulocytosis Improves both positive and negative symptoms Some anticholinergic activity EPS symptoms rare
37
Which antipsychotic can cause T2DM?
Olanzapine (Zyprexa) “Zyprexa Diabetes” - hyperglycemia and weight gain are major side effects But it’s also used for bipolar disorder
38
First line drug for psychosis
Risperidone (Risperdal) Blocks 5HT-2A and DA D2 receptors to improve both positive and negative symptoms No significant effect on DA neurotransmission in nigrostriatal pathway so EPS and TD rare
39
What are the side effects of Risperidone (Risperdal)
Hypotension, weight gain, insomnia anxiety Some cardiac effects - Lenghtens QT INTERVAL
40
What drug is used for Tourette’s syndrome and acute mania?
Ziprasidone (Geodon) Blocks DA D2 and 5HT-2A receptors Some antidepressant activity
41
Side effects of Ziprasidone (Geodon)
Prolongs QT interval Causes sedation, impair cognitive and motor skills May cause hyperprolactinemia Used with caution in patients with history of seizure disorders or with drugs that decrease seizure threshold
42
Quetiapine (Seroquel) is similar to clozapine but...
No agranulocytosis and does not elevate prolactin Used to promote sleep onset and maintenance Few EPS but VERY sedating
43
What is Aripiprazole (Abilify)
“Dopamine system stabilizer” • When dopaminergic tone is low - DA receptors activated • When dopaminergic tone is high - DA receptors blocked Low incidence of EPS
44
Major side effect of Aripiprazole (Abilify)
Decreases esophageal motility
45
What is Lurasidone (Latuda)
Blocks D2 and 5HT-2A receptors, and partial agonist at 5HT-1A No antihistamine or antimuscarinc effect Used to treat depression associated with bipolar disorder Some incidence of agranulocytosis and neutropenia, so monitor CBC
46
What is thought to cause bipolar disorder?
A lack of GABAergic activity
47
What are the two main treatments for bipolar disorder?
Lithium (Eskalith) Anticonvulsants Often treated with combos of these drugs and antipsychotics such as olanzapine (Zyprexa)
48
What are the pharmacokinetics of Lithium (Li)
Readily absorbed from the gut Distributed throughout the body (half-life 24 hours) NO METABOLISM - excreted by the kidneys
49
MOA for Lithium
Suppresses 2nd messengers (IP3), which may increase ACh, NE, and DA Effective in about 60% of bipolar patients Calming effect in manic patients Poor compliance - extremely toxic in overdose
50
Where is lithium absorbed?
By the proximal tubule in the kidney Competes with sodium (Na+) for re-absorption • If Na+ decreases —> Li absorption increases —> toxicity*** • If Na+ increases —> Li absorption decreases —> excretion increases • If Li increases —> Na+ absorption decreases —> Hyponatremai***
51
What are the main side effects of lithium
Small therapeutic window (optimal plasma concentration range 0.6-1.2 mEq/L) • >2 mEqL - N/D, weakness, HA, tremor, confusion, etc • >2.5 mEq/L = confusion, sedation, nystagmus, seizures, renal failure, arrhythmias, coma, DEATH Thyroid function reduced Diabetes Insipidus (b/c Li inhibits ADH) - treat with amiloride Not recommended in pregnancy
52
Is it a good idea to mix lithium with antidepressants?
Nope - may increase mania
53
Is it ok to mix benzos or antipsychotics with lithium?
Sure - pretty safe
54
What happens if you take diuretics with your lithium?
Alters sodium excretion —> can also alter Li clearance
55
What happens if you take NSAIDs with your lithium?
Increased Li toxicity - decreased clearance, increased Li uptake
56
What are the alternatives to Lithium for bipolar patients?
Valproic Acid (Depakene) - good for rapid cycling manic/depressive phases but causes surgical bleeding and TERATOGENIC Gabapentin (Neurontin) - also good for rapid cycling Carbamazepine (Tegretol) - good for refractory BD in combo with Li - inc chance of SJS Lamotrigine (Lamictal) - approved for prevention of relapse, depressive state following mania, acute mania