E5 Flashcards
What is the drug of choice for bipolar disorder?
Lithium
How long does it take to see improvement with lithium?
Several weeks
What is the spectrum of lithium? (Narrow/wide)
narrow
What are the pharmacological effects of lithium? (4)
Prevents release of NT.
Increases uptake of serotonin precursor tryptophan.
Decreases rate of serotonin synthesis.
Inhibits serotonergic and andronergic receptor mediated acting of cAMP and second messenger cascades.
What are the side effects of lithium?
CV; CNS: blackouts, coma, seizures, sedation, slurred speech, vertigo, fatigue; hypothyroidism; diabetes insipidus; GI: nausea, vomiting, diarrhea; Neuromuscular: tics, hand tremors, muscular weakness, restlessness; Vision problems; Polyuria - renal damage; Thinning of hair, sking rash, acne; Sexual dysfunction
What are the important drug interactions in dentistry with lithium?
Diuretics; NSAIDS; Anticonvulsants, Antihypertensives
Why are NSAIDS contraindicated with lithium?
Inhibit renal excretion of lithium (use acetaminophen instead)
What are the three (3) distinct effects produced by benzodiazepines?
Effects on behavior.
Anticonvulsant effects.
Muscle relaxation.
What are the behavior effects of benzodiazepines (BDZ)?
Reduces aggression and hostility.
Anxiety reduction at low doses.
Drowsiness/depression at high doses.
Anterograde amnesia - forgetful after surgery
Which drug causes anterograde amnesia and is known as a rape drug?
BDZ
What are the anticonvulsant effects of BDZ?
Prevent/arrest generalized seizure activity produced by electric shock or analeptic agents.
Diazepam (valium) and midazolam (Versed) prevents and arrests local anesthetic-induced seizures in dentistry
Where are the receptor sites of BDZ?
CNS
What is the effect of BDZ on GABA (nt)?
Enhances the inhibitory effect of GABA on neuronal excitability –> hyperpolarization and neuronal stabilization.
Acts on GABA in spinal cord and other brain regions at low doses.
What can the GABA receptor embedded in neuronal plasma membranes bind?
Both GABA and BDZs
What are the uses of benzos in medicine?
Antianxiety. Skeletal muscle relaxation. Hypnotic to treat insomnia –> promotes sleep. Treat w/drawal symptoms of alcoholism. Pre-op medication to reduce apprehension (Valium)
What is the effect of apprehension on anesthesia?
May reduce anesthesia effects, so benzos such as Valium are given to get properly anesthesized
What are the uses of benzos in dentistry?
Reduce pre-op anxiety. IV sedation and amnesiac. Emergency intervention for seizures.
Why is lorazepam (Ativan), a benzo, a good choice for denstistry?
Rapidly metabolized to inactive compounds - no significant accumulation
What is the effect of benzos on the CNS?
CNS depression: fatigue, drowsiness, muscle weakness, ataxia
What are the effects of parenteral administration of benzos?
Acute hypotension, muscle weakness, apnea and cardiac arrest
Which pts are more likely to have acute effects to parenteral administration of benzos?
Pts receiving opiates, sedatives (barbiturates), and/or alcohol
T/F Benzos can cause xerostomia with long term use
T
T/F Benzos can have an additive effect with other CNS depressants
T. Reduce opiates by 1/3 of normal dose if benzo is added to counteract CNS effect
Why should pts taking benzos avoid alcohol?
Can result in respiratory depression
What are the popular benzos?
diazepam, chlordiazepoxide, lorazepam, alprazolam, oxazepam, triazolam, midazolam. DCLAOTM
Is buspirone (BuSpar) a benzo?
No, but it is used to treat anxiety. Binds serotonin receptors w/out affecting GABA receptors
What is the mechanism of action of major tranquilizers?
Reduce dopaminergic activity by blocking D2 receptors
What are the major side effects of tranquilizers?
Movement disorders/resting tremors
Tranquilizers are antagonistic to what receptors?
Dopaminergic, alpha 1 & 2 adrenergic, serotonergic, muscarinic, H1 histamine, sigma opioid
Where is the primary site of dopaminergic neurons where tranquilizers work?
Striatum, limbic system, and prefrontal cortex
What is the therapeutic index of all tranquilizers (high/low?
high TI
Which tranquilizer is the exception in its potency (low, while most higher potency)?
clozapine (Clozaril) is a low D2 antagonis
Effective doses (potency) are directly proportional to what?
Their D2 antagonism (w/ the exception of clozapine)
T/F tranquilizers are great for chemo pts with severe nausea and vomiting
T
Where do tranquilizers exert their receptor blockade?
Prefrontal cortex and limbic areas. Extrapyramidal side effects (movement disorders); Blockade basal ganglia.
T/F Tranquilizers are antiemetic
T. They they block the chemoreceptor trigger zone of medulla
What is the dopaminergic hypothesis of Schizophrenia?
Overactivity of dopaminergic system: antipsychotics reduce dopaminergic activity by blocking D2 receptors
What are the limitations of the dopaminergic hypothesis of Schizophrenia?
Receptors are blocked within 2-4 hours but therapeutic effects don’t materialize for several weeks of tx.
What is the therapeutic effect related to in the dopaminergic hypothesis of Schizophrenia?
Slow developing depolarization block of dopaminergic neurons
With the dopaminergic hypothesis of Schizophrenia, drugs help to recover normal cell morphology. What happens when drug is discontinued?
Morphological abnormalities come back and symptoms of disease return
What are the major side effects of antipsychotics (tranquilizers)?
Extrapyramidal (movement). Sedation and autonomic effects. Hematologic disturbances (WBC count). Altered QT interval.
Antipsychotics potentiate CNS effects of what three classes of drugs?
Sedatives, analgesics, antihistamines
What is the interaction effect of opioids with antiphychs?
Respiratory depression
What is the interaction effect of antacids with antiphychs?
decrease absorption of antipsychs
What is the interaction effect of anticonvulsants with antiphychs?
decrease plasma levels of antipsychs
What is the interaction effect of antihypertensives (lisinopril) with antiphychs?
Alters efficacy (lowers?)
What are the typical major antipsychs?
chlorpromazine (Thorazine). haloperidol (Haldol). prochlorperazine (Compro, Compazine). fluphenazine (Prolixin). pimozide (Orap). promethazine (Phenadoz, Phenergan, Promethegan) (used for nausea and vomiting in chemo). thiothixene (Navane).
What are the ATYPICAL major antipsychs?
aripiprazole (Abilify) - used as cross over for bipolar disorder. clozapine (Clozaril). risperdone (Risperdal) - used in older people. olanzapine (Zyprexa). olanzapine and fluoxetine (Symbyax). paliperidone (Invega). quetiapine (Seroquel). ziprasidone (Geodon).
What are the indications for use of tranquilizers (antipsychs)?
Psychotic disorders: schizophrenia, paranoia.
Acute delirium and dementia.
Manic episodes during induction of lithium.
Movement disorders: Huntington’s, Tourette’s, ballismus.
Intractable hiccups.
Severe nausea and vomiting.
