study d5

Question 1

sedatives

barbitutes

Answer 1

Barbiturates (phenobarbital)

* more of a powerful sedative than a treatment for anxiety 

* can have a pronounced sedative effect ranging from sedation to anesthesia to death (thiopental was used as an IV anesthetic … but also in the death penalty)
* gradual tolerance to the sedative effect of the drug requires higher and higher doses; at some point, the required dose becomes greater than the lethal dose, resulting in coma and death

Adverse effects:
* lethargy, cardiovascular and respiratory depression
* induction of CYP enzymes
* interaction with alcohol increases the harmful effects

Question 2

antidepressants

1. MAO inhibitors

Answer 2

• phenelzine, pargyline

MAO inhibitors
* MAO inhibitors allow dietary tyramine to displace NA, causing an increased risk of hypertension = excessive stimulation of alpha 1 adrenergic receptors
* the irreversible nature of their antagonism can lead of serious adverse effects

Adverse effects:
* Hypertensive crisis
* inhibited MAO can’t eliminate the excessive levels of NA
* Interactions withany other « NA elevating sympathomimetics drugs are dngetous
* Interaction with meperidine can produce malignant hyperthermia

possible solution:
reversible MAOA inhibitor= moclobemide

MAOB inhibitors (selegiline) aim to increase DA levels and are used to treat parkinso

Question 3

tricyclic antidepressants

Answer 3

Tricyclic Antidepressants
amitriptyline, imipramine

• inhibition of presynaptic reuptake of serotonin, norepinephrine and dopamine
• effective but have several adverse effects
• very lipid soluble –> long half-life as they can be slowly released from body’s adipose tissue
• narrow therapeutic index; must therefore be careful about toxicity especially following overdoses

Adverse effects
* Anti-histaminic
* Anti-muscarinic
* Anti-adrenergic
+ decreased libido

Question 4

SSRIs

Answer 4

Selective Serotonin Reuptake Inhibitors (SSRI)
* increased levels of serotonin in the synapse
* do not have the same adverse effect profile as tricyclic antidepressants

fluoxetine (Prozac) citalopram (Celexa) / escitalopram (Cipralex), paroxetine (Paxil), sertraline (Zoloft)

Adverse effects:
anorexia, insomnia, sexual dysfunction (problems relating to ejaculation or orgasm, decreased sexual drive), anxiety 


Question 5

5HT + NA Reuptake Inhibitors

name the drugs

Answer 5

venlafaxine (Effexor), duloxetine (Cymbalta) desvenlafaxine (Pristiq)

Advantages:
* increased levels of 5-HT and NA
* mechanism of action resembling tricyclic antidepressants

adverse effects similar to SSRIs
nausea, anorexia, agitation, problems with ejaculation, anorgarsmia
possibly, a faster therapeutic effect

Question 6

other treatments of depression

well B and ECT

Answer 6

Buproprion (Wellbutrin, Zyban)
useful to reduce cravings in people trying to quit smoking
also used as an antidepressant

Electroconvulsive therapy (ECT)
only used for cases of severe and refractory depression
adverse effects: confusion, amnesia


Question 7

antipsychotics

mechanism of action

Answer 7

Antipsychotics

Typical and atypical Antipsychotics

Mechanism of action: 

* block dopamine (DA) receptors in the brain

Adverse effects:
* block dopamine (DA) receptors elsewhere in the brain


Question 8

typical antisphycotics –> name them and effects

Answer 8

Typical Antipsychotics
* chlorpromazine, haloperidol
* improve positive symptoms
* do not improve negative symptoms

antimuscarinic effects (anti-M):
* cause sedation, xerostomia, blurred vision (anti-SLUDG)


Antihistaminic effects (anti H1):
* fatigue, weight gain


anti-alpha1-adrenergic effects (anti-α1)
* hypotension, sedation


increased secretion of prolactin
* photosensitivity


Question 9

atypiucal antisphycotics

Answer 9

• clozapine, olanzapine, quetiapine , risperidone
• not only affect dopamine but also serotonin (5-HT) and other neurotransmitters
• improvement of positive symptoms as well as negative symptoms
• fewer extrapyramidal (involuntary muscle spasm) effects

Adverse effects:

* agranulocytosis (clozapine)

* may cause more drowsiness (« pines »)

* increased metabolic risks (clozapine, olanzapine)
* increased appetite, obesity, dyslipidemia (triglycerides), insulin resistance, diabetes, cardiovascular disease

Question 10

aripiprazole

atypical anti

Answer 10

aripiprazole (Abilify)

* partial agonist at dopamine receptors
* fewer adverse effects related to excessive blockade of dopamine receptors (e.g. fewer EPS, less hyperprolactinemia)
* demonstrates less sedative effect, less weight gain and fewer metabolic effects

however, it increases the risk of two types of impulsive behavior:
* pathological (uncontrollable) gambling
* hypersexuality (uncontrollable and/or inappropriate sexual thoughts, urges or behaviours that are so severe or last so long that they cause distress)