antidepressant meds Flashcards
1
Q
First line tx of depression?
A
- SSRIs
- no real diff in efficacy
2
Q
List of SSRIs?
A
- prozac
- zoloft
- paxil
- celexa
- luvox
- lexapro
3
Q
SSRIs are used to tx what conditions?
A
- depression
- panic disorder
- OCD
- generalized anxiety disorder
- social anxiety disorder
- PTSD
- body dysmorphic disorder
- bulimia nervosa
- binge eating disorder
- premenstrual dysphoric disorder
- somatoform disorders
4
Q
Citalopram and escitalorpam similarities?
A
- isomers of eachother, same side effect profile
- less drug interactions b/c they inhibit less liver enzymes than other SSRIs
- good for pts who are already on mult. meds
5
Q
MOA of SSRIs?
A
- block presynaptic serotonin reuptake pump
- increases the time that serotonin is available in synapse
- increases postsynaptic occupancy - downregulate receptor sites
6
Q
SSRIs pharmacokinetics?
A
- well absorbed in GI tract
- reach peak plasma levels in 1-8 hrs
- bind to proteins that are then distributed throughout the body
- metabolism and elimination occur in the liver
- metabolites are inactive except for fluoxetine has an active metabolite
7
Q
What are the downstream effects of SSRIs?
A
- increased production of neuroprotective proteins such as brain-derived neurotrophic factor
- down-regulation of 5HT1A receptors ( when bound with serotonin inhibits neuron from releasing serotonin) so less inhibition = more firing and increased release of serotonin in presynaptic neuron
8
Q
Half lives of SSRIs?
A
- in general half life range: 20-30 hrs
- except fluoxetine (prozac) half life is up to 3 days and it’s active metabolite can last 4-16 days
- fluvoxamine’s (luvox) half life is about 15 hrs
9
Q
SSRIs inhibit what P450 enzymes? What happens when another drug is intro that also works at these enzyme sites?
A
- 2D6, 2C9, 2C19, 2B6, 3A4, 1A2
- diff ones in each SSRI
- citalopram and escitalopram don’t seem to be affected by these
- can have build up of other drugs and decreased metabolism or build up of SSRI - depends on which drug is the stronger inhibitor
10
Q
SSRI drug interactions - to use with caution?
A
- azole antifungals
- macrolide abx
- omeprazole
- hepatic impairment
- CI if taking MAOis w/in 2 weeks due to risk of serotonin sydrome
- paroxetine and fluoxetine are CI with tamoxifen - used to tx breast cancer
11
Q
SSRI side effects?
A
- sexual dysfxn (17%)
- drowsiness (17%)
- wt gain (12%)
- dizziness (11%)
- insomnia (11%)
- anxiety (11%)
- diaphoresis
- diarrhea
- hyperprolactinemia
- HA
- dry mouth
- blurred vision
- nausea
- rash or pruritus
- tremor
constipation - diarrhea
- SIADH
- hyponatremia
12
Q
Withdrawal syndrome if abrupt d/c of SSRIs?
A
- dyphoria
- dizziness
- GI distress
- fatigue
- chills
- myalgias
- more common with fluvoxamine and paroxetine (shorter half lives)
13
Q
Response time of SSRIs?
A
- some will feel better in a few weeks
- others 4-6 wks
14
Q
Admin. of SSRIs?
A
- usually once a day
- if it makes them sleepy - take at night
- if it causes insomnia - take in am
- warn of common SEs: HA, dizziness, nausea, diarrhea when first starting so they know that these are expected
15
Q
Duration of SSRI therapy?
A
- for many it is lifelong
- don’t stop it for 1 yr after resolution of sxs
- stopping med too early may cause recurrence of severe depressive episode
16
Q
When is citalopram (celexa) indicated? risks?
A
- 20-40 mg
- good to use when concerned about drug interactions (doesn’t hav P450 enzyme inhibition as strong as other SSRIs)
- risk of QT prolongation at doses over 40 mg, or in those on 20 mg and high risk for arrhythmia:
- hepatic impairment
- older than 60
on other Cyp219 inhibitors (cimetidine)
17
Q
Use of escitalopram (lexapro)?
A
- 10-20 mg
- isomer of citalopram
- similar to citalopram as has fewer drug interactions than others in the class
18
Q
Dosing, CI, pros of fluoxetine (prozac)?
A
- 90 mg delayed release capsule for weekly dosing - 20-40 mg daily
- CI with tamoxifen
- used to tx premenstrual dysphoric disorder
- more likely to cause activation than others - helps pts with low energy and motivation
- least problems with wt gain
19
Q
Dosing of fluvoxamine (luvox), SEs?
A
- 50-200 mg daily, 2x daily dosing if at 200 mg daily
- wt gain up to 2.6% of body wt
- **more likely to have nausea and sedation compared to most other SSRIs
20
Q
SEs and CI, dosing of paroxetine (paxil)?
A
- 20-40 mg daily
- Nausea and sedation more likely to occur than most others
- sig withdrawal sxs
- ***causes most wt gain among SSRIs (upt to 3.6% of baseline)
- CI in use with tamoxifen
21
Q
Sertraline (zoloft) dosing and most notorious SE?
A
- 50-200 mg daily
- Diarrhea
22
Q
Other more serious side effects of SSRIs?
A
- may increase risk of suicide as pt recovers (risk greatest in ages 18-24)
- may increase risk of abnorm bleeding - inhibit platelt fxn
- possible increase in bone fractures
- may affect male fertility: abnormal levels of DNA fragmentation in sperm were noted compared to baseline 50% vs 10%
