Neuro Pt 3 Depression, Schizophrenia, Bipolar Disorder Flashcards
Depression
- Definition:
- Depressed mood most of the time for > __ weeks and/or loss of ____ or _____ in most activities
- DSM V Criteria: __ or more (must include the first 2)
- _____
- _____
- Change in w____ or a____
- I____ or hyper_____
- Psychomotor r_____ or a______
- Loss of e____ or f_____
- ___lessness or g____
- Impaired con_____ or in______
- Thought of d____ or ______ ideation or suicide _____
- Definition
- 2, interest, pleasure
- 5
- Depressed mood
- Loss of interest or pleasure
- weight, appetite
- insomnia, hypersomnia
- retardation, agitation
- energy, fatigue
- worthlessness, guilt
- concentration, indecisiveness
- death, SI, attempt
Pathophysiology of Depression
- Hypotheses
- Neurotrophic - brain derived neurotrophic factor (BDNF) _____
- Neurotransmitters - deficiency of (3)
- Neuroendocrine - hormonal imbalances of (2)
- Genetic factors account for up to 50% of depression
- Treatment
- _____ amount of neurotransmitter available at the synaptic clef (noradrenergic, serotoninergic)
- _____ rate at which neurotransmitter is taken back up into presynaptic neuron
- _______ neurotransmitter’s metabolic degradation
- _____ amount of neurotransmitter available at the synaptic clef (noradrenergic, serotoninergic)
- Hypothesis
- Deficiency
- Serotonin (5HT), Norepinephrine (NE), Dopamine (DA)
- Estrogen, Testosterone
- Tx
- Increase
- Decrease
- Inhibit
- Increase
BDNF is a protein in our brain that helps the growth of neurons
Treatment for Depression
(5)
- Tricyclic Antidepressants (TCAs)
- Monamine oxidase Inhibitors (MAOIs)
- Selective-serotonin reuptake inhibitors (SSRIs)
- Selective-norepinephrine reuptake inhibitors (SNRIs)
- Others (miscellaneous)
- Buproprion (Wellbutrin)
List in order of discovery, worked on AE when making new drugs
Time of Onset
- How long does it take to reach full effect of medication?
- 1-2 wks
- Improved ____
- Reduced _____
- 1-3 wks
- Improved ____, _____
- Increased ____ level, ____ level
- 2-4 wks
- Improved ____
- Reduced ____
- 4-6 weeks (counselling!!)
- 1-2 wks
- sleep
- anxiety
- 1-3 wks
- self-care, concentration
- energy, activity
- 2-4 wks
- mood
- suicidal ideation
Tricyclic Antidepressants (TCA)
Indication
- _____ available (prior to 1980s and discovery of SSRIs)
- Today reserved for _____ disease
- earliest
- refractory
TCA
MOA
- ________ inhibition of ______ and _____ ______ (allows for increased NE to bind to receptors at synaptic cleft)
- Secondary amines more ____ for ___ (potency)
- Other receptor effects:
- a1-adrenergic blockade - (1)
- Histamine 1 receptor (1)
- Anticholinergic (2)
- Sodium and calcium channel blockade (1)
- Non-selective inhibition of norepinephrine (NE) and serotonin (5HT) reuptake
- selective for NE
- orthostatic hypotension
- sedation
- dry mouth, constipation
- cardiotoxicity
TCA
Tertiary Amines (2)
Secondary Amines (1)
Prevalence of use?
- Tertiary Amines
- Amitriptyline (Elavil)
- Doxepin (Sinequan)
- Secondary Amines -> Lack active metabolites and have linear kinetics (wide therapeutic window)
- Nortriptyline (Pamelor)
- First class of antidepressant medications available, however, side effects have limited their use
Secondary amines are the newer group
TCA
AE (5)
- Antihistamine (sedation, weakness, fatigue)
- Anticholinergic (dry mouth, blurred vision, constipation, urinary retention)
- a1-receptor blockade (hypotension)
- Sodium channel blockade (arrhythmias, QTc prolongation)
- Other (sexual dysfunction, seizure potential, weight gain, photosensitivity, hepatotoxicity, withdrawal if stopped abruptly (titrate slowly))
- BC its SO NONSELECTIVE - it causes all these AE*
TCA
Drug Interactions (3)
-
MAOI
- MAOIs inhibit the breakdown of neurotransmitters (dopamine, serotonin, norepinephrine)
- HTN, tachycardia, confusion, seizures
- Serotonin syndrome
- MAOIs inhibit the breakdown of neurotransmitters (dopamine, serotonin, norepinephrine)
- SSRIs - may lead to Serotonin Syndrome
-
Alcohol and other CNS depressants
- Additive effects (drowsiness, diziness)
- Worsen depression
Almost never given with any other antidepressant - don’t really see combinations
Monamine Oxidase Inhibitors (MAOIs)
Indication
Due to potential serious adverse effects from drug and food interactions, NOT used as first line therapy (more for refractory)
MAOI
MOA
Irreversible inhibition of monamine oxidase (1-2 wks to restore)
Responsible for metabolism of NE, 5HT, Dopamine within the neuronal synapse
MAO-A - nonselective (NE, 5HT)
MAO-B - selective for dopamine
In depression, we do the opposite of PD where we use lower doses - we want higher doses to target the NE and 5HT
MAOI
Agents
Selegiline (Emsam)
(non-selective inhibits both MAO-A and B)
MAOI
Significant AE
- Postural Hypotension
- Hypertensive Crisis (food interaction)
- Sleep disturbances
- Weight gain
MAOI
Significant Drug Interactions
Drug-Food Interactions
- TCAs
- SSRIs
- Sympathomimetic agents (cocaine)
- Linezolid (abx) - also has MAOI properties so you can see additive effects of blocking those
- MAO inhibition may persist up to 10-14 days following discontinuation (remember irreversibly binds)
- Tyramine content (aged cheeses, meats, yeast extract, red wine) Bananas, dried fruits
Selective Serotonin Reuptake Inhibitors (SSRIs)
Indication
Targeted the results of TCAs without the histamine/cholinergic/adrenoceptor properties
GOLD STANDARD DRUG OF CHOICE*
SSRI
MOA
Blocks serotonin transporter (SERT)
- Blocking reuptake of 5HT into presynaptic neuron = increased circulating 5HT for post synaptic uptake
SSRI
Agents
Late 1980s
Fluoxetine (Prozac, Prozac weekly)
Paroxetine (Paxil, Paxil CR)
Sertraline (Zoloft)
Fluvoxamine (Luvox)
Citalopram (Celexa)
Escitalopram (Lexapro)
SSRI
Fluoxetine
Half life?
Active Metabolites?
- ~5 days (requires 5 week washout)
- YES
Remember, takes about 5 half lives for drug to be eliminated
SSRI
AE
- CNS
- CV
- Hematologic
- GI
- Sexual Dysfunction
- Weight gain
- Withdrawal syndrome (4)
- Incidence of orthosatic hypotension, sedation, anitcholinergic SE, and CV effects are significantly less than ____
- Fluoxetine - activating (insomnia) take in the morning, Paroxetine - sedating take at night so not tired all the time
- QT prolongation with citalopram and escitalopram
- Increased risk for bleeding (esp w ASA, NSAIDs, anticoag)
- N/V, diarrhea (GI effects more early on esp if started with high dose thats why we start slow and titrate up)
- SSRIs have highest incidence
- Paroxetine > all others
- GI complaints, flu-like symptoms, anxiety, insomnia (if abruptly dc’d)
- TCAs
SSRI
Drug Interactions (3)
- Timing if converting between SSRIs and MAOIs
- *fewest drug interactions with (3)
MAOIs, TCAs, Linezolid (has MAO inhibition)
- Wait up to 5 weeks after stopping (Fluoxetine) SSRI before starting MAO
- Wait 2 weeks after stopping MAOI before starting SSRI
- citalopram, escitalopram, sertraline
- ex) if pt on SSRI and admitted for infection and given linezolid = given together can cause hypertensive crisis/serotonin syndrome*
- UP to 5 weeks since other ones take shorter to clear*
AB is a 33 yo F started on fluoxetine (Prozac) for depression. Fluoxetine has a half life of ________, should be taken in the ______, and is known to cause _____ side effects when compared to amitriptyline
- 24 hrs, morning, less
- 24 hrs, evening, less
- 5 days, morning, less
- 5 days, evening, less
- 5 days, morning, more
5 days, morning, less
Serotonin Syndrome
Life threatening central excitatory syndrome rd INCREASE serotonin
- Hyperthermia, confusion, agitation, autonomic hyperactivity, myoclonus, hyperreflexia, diaphoresis, tremor, diarrhea, neuromuscular abnormalities, ocular clonus
- Tx: stop + supportive care
- Non antidepressant meds associated (anti-emetics, dextromethorphan, fentanyl, linezolid, meperidine, serotonin agonists sumatriptan, tramadol, valproic acid)
Buproprion (Wellbutrin)
Indications
MOA
Route
Pharmacokinetics
Significant AE (3)
- Adjunctive tx for depression
- Blocks reuptake of dopamine and norepinephrine
- PO only
- Hepatically metabolized through CYP2D6
- Lowers seizure threshold (high doses/abrupt withdrawal), Activating (tremor, insomnia), No sexual dysf/weight gain
- The newer the drugs the MOA gets shmancy*
- Doesn’t touch serotonin - also used off label for smoking cessation so if pt has both can help both*
- However if pt suffers from epilepsy don’t want to use bc lowers seizure threshold*
- Just know its a SUBSTRATE of CYP - so if given with inducer may lower serum levels*