Psychopharmacology: Treatment of Affective Disorders Flashcards
What are the barbiturates we need to know?
Phenobarbital
What are the benzodiazapenes we need to know?
- diazepam
- triazolam
- alprazolam
- clonazepam
- midazolam
What are the benzodiazipine Receptor Agonists that We Need to Know?
- zolpidem
- eszopiclone
What benzodiazipine receptor antagonist do we need to know?
flumazenil
What is a melatonin congener?
ramelton
What is a 5-HT1a (minor) receptor agonist?
Non-sedative anxiolytic - buspirone
What drug classes act at the GABA receptor?
Barbituates
Benzodiazepenes
Benzodiazipine receptor agonists
Benzodiazipine receptor antagonist
Define sedative
drug causing a calming effect; tranquilizer
(Ideally, minimal effect on motor fxn or mental status)
Define hypnotic
sleep-inducing or promoting drug
What are the anxiolytics?
For reduction of anxiety
Note: not all are sedatives
What does the dose-responsive curve for older sedatives (e.g., barbiturates) look like?
Linear - anxiolytic and sedative at low doses, at high doses coma and death
What does the dose-response curve for benzodiazepines look like?
Linear, but levels off at high doses
anti-anxiety and sedation at low doses
at high doses, harder to cause coma and death (SAFER than older sedatives)
What is the drug of choice for panic disorders?
1st line - antidepressants (SSRIs)
2nd line - alprazolam (benzo)
What are the side effects of alprazolam in treatment of anxiety?
rebound anxiety when discontinued
risk of dependence
What are the SSRIs?
fluoxetine
escitalopram
sertraline
What is an SNRI?
duloxetine
What are two TCAs?
amitriptyline
desipramine
What is an MAOI anti-depressant?
tranylcypromine
What are two “other” antidepressants?
bupropion
mirtazapine
What is true about the onset of therapeutic effects for all antidepressants?
therapeutic effects are delayed onset - about 2-6 weeks
Serotonin is converted from what and to what?
from L-tryptophan
to melatonin (in the pineal gland)
serotonin interferes with the signaling of what other biomolecules?
platelets
fluoxetine
SSRI
sertraline
SSRI
escitalopram
SSRI
What is the mechism of action of SSRIs?
selectively block the serotonin uptake transporter (SERT), inhibiting the reuptake of 5-HT
what drugs are generally first line for treatment of depression?
SSRIs - better tolerated than older drugs
What drug-drug interactions do SSRI’s mainly have?
CYP-2D6
(big ones -warfarin, tamoxifen is metabolite of CYP)
what are the t1/2 of most SSRIs?
long - about 24 hours
What are the common side effects of SSRIs?
- CNS stimulation (insomnia, agitation)
- GI problems (nausea, bleeding, diarrhea)
- sexual dysfunction
Why should you never combine SSRIs with MAO inhibitors?
serotonin syndrome
escitalopram has what important side effect?
may prolong the QT interval
Other than depression, what are other common indications for SSRIs?
- anxiety disorders
- eating disorders
- Premenstrual dysphoric disorder (PMDD)
- ADD/ADHD
Duloxetine
SNRI
What is the key difference in mechanism of action for SNRI’s vs. SSRIs?
at medium to high doses, they block the reuptake of norepinepherine
*important - 5-HT and alpha-2 receptors are on BOTH noradrenergic and serotonergic neurons
duloxetine has a __________ t/12
short. shortest of the antidepressants
how are SSRIs and SNRIs excreted?
hepatic and renal
what is a unique adverse effect of SNRIs?
increase BP at high doses
duloxetine has two unique indications - what are they?
fibromyalgia
diabetic neuropathy
No one knows the mechanism here
What other drugs have high MAOI inhibitor activity and therefore should not be taken with SSRIs or SNRIs?
St. John’s wort
linezolid
What is serotonin syndrome?
if you OD on SSRIs/SSNRIs, you will get this (can get it other ways):
hyperthermia
muscle rigidity
myoclonus
fluctuating vital signs & mental status
hyperreflexia
Why would you give an SNRI vs. an SSRI?
Individualized - some patients respond better to one class as opposed to the other
amitryptyline
TCA (tertiary amine)
desipramine
TCA (secondary amine)
Why are TCA’s not the first line for treament of depression?
They have a low TI - dangerous in overdose and they have more drug-drug interactions than SSRI/SNRIs
What is the mechanism of action for TCAs?
They block the neuronal reuptake pumps for both 5-HT and NE
Secondary preferentially block NET
teritary preferentially block SERT
BUT, tertiary are metabolized to secondary, so they really do BOTH
What is it about TCA’s that caues so many side effects?
They block the receptors for many NT
muscarinic
alpha-1 adrenergic
histamine
What is the t1/2 of most TCAs?
Long, as are the metabolites
What are the adverse effects of TCAs?
- tachycardia, palpitations
- conduction block, arrhythmias
- orthostatic hypotension
- dry mouth, constipation, urinary retention
- sedation, confusion, memory impairment
- increased appetite, weight gain
- sexual
What are other indications for TCAs?
enuresis
anxiety disorders
pain (neuropathic and migraine)
What are some major concerns with TCAs and overdose?
cardiac arrhythmias
low TI, used for suicide
Tranylcypromine
Monoamine Oxidase Inhibtor (MAOIs)
What is the mechanism of action of MAOIs?
they irreversibly inhibit monoamine oxidase, an enzyme involved in the break down of 5-HT and NE [and dopamine, but that’s from another lecture]
*two types MAO-A and MAO-B - found in brain and at periphery
most inhibit both types
MAOIs have a high incidence of ___________?
side effects
What is the difficulty of changing drugs with MAOIs?
must allow a long time before changing to or from them, or you risk serotonin syndrome
MAOIs have what unusual side effect?
postural hypotension
What foods can you not eat with MAOIs?
foods containing tyramine
cheese, wine
*acts as an indirect sympathomimetic
What are MAOIs best for treating?
atypical depression
SSRIs might work, but NOT TCAs
What do atypically depressed people crave?
carbohydrates
Bupropion
dopamine reputake inhibitor
Mirtazapine
autoreceptor antagonist
Buproprion is used for what besides depression?
smoking cessation
What is unique about mirtazapine?
It has strong sedative properties and it is also an appetite stimulant
Buproprion’s mechanism of action?
block both dopamine norepinephrine reuptake
Also: potent antagonist at nicotinic receptor
how is buproprion metabolized
hepatic
What are the notable possible AE of buproprion?
anxiety (weird)
seizures (esp. in eating disorders)
but, less sexual side effects
How does mirtazapine work?
potent alpha 2 antagonist
*also at 5-HT2A/C receptors
how is mirtazapine excreted?
hepatic CYP metabolism
what are the advantages and disadvantages of mirtazapine?
advantage: fewer sexual side effcts, sedative effects can be useful, good in resistant patients
disadvantages: increast appetite, weight gain, drug-drug interaction
What should you do with a depressed patient who is pregnant?
best to give SSRI - fluoxetine or sertraline
lowest risks for these - others have bigger risks to fetus
What is the only anti-depressant drug labeled for use in children?
fluoxetine
escitalopram
What are the 5 Ds of antidepressant therapy for poor responders?
- dose?
- duration? 1-6 weeks
- diagnosis?
- drugs? (additional to increase response)
- Different treatment?
what are the drugs used to treat bioplar disorder?
lithium
olanzapine
valproate
lamotrigine
What would you use olazopine to treat in bipolar disorder?
acute manic episode - sedation
this is an atypical antipsychotic
What can you use to treat an acute manic episode in bipolar disorder?
atypical antipsychotics
benzodiazepines
valproate - anticonvulsants
What is the leading mood stabilizer used in the treatment of bipolar disorder?
lithium
What can we use to treat bipolar disorders at both poles?
- lithium
- anticonvulsants - valproate, lamotrigene
- atypical antipsychotics - olanzapine
What is the mechanism for action for Lithium?
unknown, dampens IP3 messenger system
What else is lithium indicated for?
depression as an adjunct
schizoaffective disorder (along with antipsychotics)
How is lithium excreted?
urine
narrow TI - need blood monitoring
Don’t use lithium with which drugs?
loop diuretics
NSAIDS
ACE inhibitors
When is it useful to treat with valproic acid in bipolar disorder?
useful for rapid cycling, mixed states
what is unique about lamotrogine in the treatment of bipolar disorder?
has significant anti-depressant activity (this is not proven for other anticonvulsants)
What is a serious side but rare side effect of lamatrogine?
Stevens-Johnson’s syndrome
What are the side effects of olanzapine?
weight gain
hyperlipidemia
hyperglycemia
(basically antipsychotic effects)
What is the drug of choice to treat social phobia?
clonazepam
what is the first line treatment for agoraphobia
alprazolam
what drugs are used as sedatives?
antipsychotics
antidepressants - TCA, mirtazapine
barbiturates
benzodiazepines
what is the major inhibitory neurotransmitte in the brain?
GABA
phenobarbital is what kind of drug?
a barbituate
what is the mechanism of action for barbituates?
binds to site on GABAa - increase Cl- flux
supress glutamate transmission via AMPA
what is the t1/2 life of phenobarbital
long - over 60 h
how is phenobarbital eliminated?
hepatic metabolism/renal elimination
what are the dangers with barbituates?
relatively low TI
additive with EtOH
dependence and addiction
phenobarbital is used for what today?
seizure disorders
What is the mechanism of action for benzodiazepines?
Binds to GABAa and facilitates Cl- influx
Needs GABA to act (cannot open channel alone)