Ch29: Antipsychotic & Lithium (Textbook)

Helpfulness: 0
Set Details Share
created 2 years ago by mkeobounna
7 views
Topic 7
updated 2 years ago by mkeobounna
Subjects:
pharmacology
show moreless
Page to share:
Embed this setcancel
COPY
code changes based on your size selection
Size:
X
Show:
1

What is the mechanism of classic antipsychotic drugs?

Block Dopamine Receptor (D2)

2

What is the mechanism of new antipsychotic drugs?

Block Serotonin Receptor (5-HT2)

3

What is an example of a classic Bipolar drug?

Lithium

4

What is an example of a New Bipolar drug?

Carbamazepine

Clonazepam

Olanzapine (also 5-HT2 blocker)

Valproic Acid

5

What is the mechanism of heterocyclic antidepressants?

Inhibit reuptake of NE & (5-HT)

6

Antipsychotic Pharmacokinetics: Half-life?

Metabolism? Solubility?

Half-Life: Long

Lipid soluble: ready to enter CNS

Metabolized by Liver before elimination

7

What prolongs Antipsychotic half-lives?

Inhibition of CYP450 or other liver enzymes

8

Drugs blocking D2 Receptor causes what side effect?

Extrapyramidal Dysfunction: Dyskinesia, Tremor, Rigidity

9

What other receptor has an antipsychotic effect besides dopamine & (5-HT)?

Alpha-Adrenoceptor

10

What are the two hypothesis for cause of Schizophrenia?

  1. Too much Serotonin
  2. Too much Dopamine
11

All Antipsychotic drugs block what receptors?

H1 & alpha1 Receptors

12

What do Atypical drugs do to Extrapyramidal Dysfunction?

Decreases Extrapyramidal Dysfunction

13

What Is Dopamine pathway in the brain affected by Antipsychotic drugs?

Mesocortical-Mesolimbic Pathway

Block this pathway on antipsychotics

14

Receptor blocking drugs have what ADR?

Extrapyramidal Dysfunction

Hyperprolactinemia

15

What are the positive symptoms of Schizophrenia?

  1. Hyperactivity
  2. Hallucinations
  3. Bizarre Ideation
  4. Delusions
16

What type of symptoms do antipsychotics treat in Schizophrenia?

Positive symptoms

17

How long does it generally take for antipsychotics to work?

Weeks

18

Clozapine: old or new drug? What receptor affected?

Effective in what type of pt's?

Lessons symptoms of what disease?

New Drug. (5-HT2) receptor blockade

Effective in antipsychotic resistant pt's.

Lessons Parkinson Symptoms

19

What side effects do Older Antipsychotic Drugs cause? (Think about what older drugs do and whats affected)

Block D2 receptors --> Parkinson's symptoms

Akathisia: Feeling of inner restlessness & inability to stay still

Dystonias: involuntary muscle contraction causing repetitive or twisting motion

20

What other psychiatric neurological Indications are involved with Antipsychotic drugs?

Mania: (new antipsychotic) + (Lithium)

Acute Mania & Bipolar Disorder: Aripiprazole & Olanzapine

Tourette's: Molindone (Antipsychotic)

Alzeihmers & Parkinson's: Atypical Antipsychotics

OD on CNS Stimulants

21

What types of effects do H1 receptor blocking drugs have?

  • Antipruritics (Anti-Itch)
  • Sedative
  • Antiemetic effect
22

What is an example of a reversible and irreversible neurologic Side Effect of antipsychotic drugs?

Reversible: Extrapyramidal Effects (tremor, dyskinesia, rigidity)
Irreversible: Tardive Dyskinesia (Choreanthetoid movements of the muscles of the lips & buccal cavity

23

Tx for Reversible Extrapyramidal Effect?

Tx for Irreversible Tardive dyskinesia?

Tx for Reversible Extrapyramidal Effect: Lower Antipsychotic dose or give Antimuscarinic Drug

Tx for Irreversible Tardive dyskinesia: Increase neuroleptics (Antipsychotics) --> reduce s/s Temporarily

24

What do Antimuscarinic drugs do to both Extrapyramidal effects and Tardive dyskinesia?

Relieves Extrapyramidal effects (lowers Dopamine)

Worsens Tardive dyskinesia

25

In what way do antipsychotics have autonomic effects?

  1. Antimuscarinic receptor drugs (ACh) - Parkinson's
  2. Block alpha-Adrenoceptors (NE)- Antipsychotic
  3. Atropine-Like Effects (dry mouth, constipation, urinary retention, visual problems)
  4. Block muscarinic receptors causing: confusion similar to atropine & tricyclic antidepressants
  5. Postural hypotension: By alpha blockade, common in Older drugs
26

In what way do antipsychotics have Endocrine & Metabolic Effects?

Effects: Hyperprolactinemia, Gynecomastia, Amenorrhea-Galactorrhea Syndrome, Infertility

Cause: D2 receptor blocker in the pituitary & Dopamine inhibits prolactin secretion (By not having dopamine causes lactation)

27

What Endocrine & Metabolic Effects do Clozapine & Olanzapine have?

(Atypical agents)

Hyperglycemia due to diabetogenic action

very problematic in pregnancy

28

Malignant Hyperthermic Syndrome: What is it?

Symptoms? Big issue?

What: Hypermetabolism of skeletal muscle & hyperthermia

Symptoms: Muscle Rigidity, Cant Sweat, Hyperpyrexia(fever), Autonomic instability

Life threatening

29

Malignant Hyperthermic Syndrome Tx?

  1. Dantrolene
  2. Diazepam
  3. Dopamine Agonist
30

What does lithium treat?

Bipolar & Mania

31

Pharmacokinetics of Lithium: What is dependant on its distribution? Metabolised by what organ? Half-life?

Distribution dependent of body water.

Organ: Kidneys

t1/2: 20hrs

32

Things that increase lithium blood toxic levels

  1. Dehydration
  2. Thiazides
  3. Loop Diuretics
  4. NSAIDS
  5. Angiotensin Converting Enzyme Inhibitor (ACEI)
33

Lithium mechanism of action: Not Well Defined

Inhibits many enzymes

Decrease 2nd Messengers:

  1. PIP2
  2. IP3
  3. DAG
34

Why are 2nd messengers important?

Important in Amine (dopamine & Serotonin) Neurotransmission

35

Clinical use of Lithium:

  1. Tx bipolar disorder
  2. lowers mood swings
  3. Monotherapy for mania (Olanzapine & Quetiapine)
36

At the beginning of Lithium treatment, what must you do? Why?

Must combine Lithium w/ an Antipsychotic or Benzodiazepine

Because Lithium has a slow onset of action (Lithium & Valproic)

37

Lithium Protective effects:

  1. Suicidal & self-harm
  2. Antidepressants --> for maintanance
38

Ebstein's Anomaly is a toxic effect of what drug?

Lithium

Pregnancy: congenital cardiac anomaly

39

What is Valproic equivalent to?

Lithium

40

What drugs are used to treat bipolar disorder?

  1. Antipsychotic drugs (Olanzapine & Quetiapine)
  2. Antiseizure Drugs (Carbamazapine & Lamotrigine for acute mania & to prevent depressive phase)
  3. Valproic