Major depressive d/o Flashcards
(35 cards)
What are antidepressants specifically prescribed for?
- Major depressive disorder
- Affective disorders that are characteristized by extreme depression (dysphoria), extreme elation (mania), or both.
- Monopolar depression may affect 15% of all adults during any given year of their lifetime
- Treatment usually takes 2-4 weeks and leads to 85% remission
Affective disorders
- Depression
- Result from a chemical imbalance between 3 NT
- NE, serotonin and perhaps dopamine
- Recent research has suggested that beta-adrenergic receptors may be involved
- Beta blockers often give an antidepressant effect (pts get depressed when they come off of the beta blockers)
As a class of drugs, antidepressants are generally:
- orally administered (IM admin very infrequent and limited to specific drugs)
- very few injectable preparations. Most tx of depression is outpt, so PO is necessary
- 90-95% bound to plasma proteins (DRUG INTERACTIONS. Will have more free drug than should. Only 5-10 percent remain free to produce an effect)
- metabolized by the liver, with metabolites excreatd in urine
- drugs with long “half-lives” (imiparamin-t1/2=24 hours)
- drugs with a relatively small therapeutic index
5 prominent classes of antidepressant drugs:
- Tricyclics
- tertiary amine tricyclics
- secondary amine tricyclics
- Selective Serotonin Reuptake Inhibitors (SSRI)
- Selective Serotonin and Norepinephrine Reuptake Inhibitors (SNRI’s)
- Atypical
- Monomine Oxidase Inhibitors (MAOI’s )
Tricyclics
- attempt to remedy depression by inactivating the “amine” pump on the presynaptic nerve terminal and thus limiting the reuptke of both NE and serotonin.
- Unfortunately, many also have effects at muscarinic receptors, histamine type-1 receptors and alpha-1 receptors
- 2 general types of tricyclics:
- tertiary amine tricyclics
- secondary amine tricyclics
Tertiary amine tricyclics:
bind to the serotonin transporter, which is the predominant binding affinity…
Serontonin is a very complex system, when there is an increase serotonin there is a decrease in appetite….increase in mood..decrease sex libido and function and increase sedation.
-modulatory NT..works with other neurotransmitters, which means that it works with glucomate..NA, etc..no autonomic s/e…
-if the drug interfers with libido or sexual s/e will cause non compliance..you need a good profile on these pt
Secondary Amine Tricyclics:
have affinity for serotonin and an added affinity for NE transporter…increase BP..decrease appetite..increase alertness…anti SLUDE effects
Name 5 tertiary amine tricyclics:
- Amitryptyline (Elavil)
- Clomipramine (Anafranil)
- Doxepin (Sinequan)
- imipramine (Tofranil)
- trimipramine (surmontil)
Amitryptyline (Elavil)
- Tertiary amine tricyclics
- can be given IM
Clomipramine (Anafranil)
- tertiary amine tricyclics
- usually given for obsessive-compulsive d/o (OCD); not very selective, can cause seizures
Doxepin (Sinequan)
- tertiary amine tricyclic
- increased sedation, but absence of cardiovasculare s/e
imipramine (tofranil)
- tertiary amine tricyclic
- can be given IM and a long-acting “pamoate” formulation is available
trimipramine (Surmontil)
- tertiary amine tricyclic
- very sedating and moderately anticholinergic
- opposite SLUDE
Name 5 Secondary Amine Tricyclics
- Amoxapine (Asendin)
- Desipramine (Norpram)
- Maprotiline (Ludiomil)
- Nortryptyline (Pamelor)
- Protryptyline (Vivactil)
Amoxapine (Asendin)
secondary amine tricyclics
a dibenzodiazepine that is a metabolite of the antipsychotic loxapin; therefore, it has a dopaminergic as well as adrenergic mechanism
desipramine (Norpram)
-secondary amine tricyclics
naturally occurring metabolite of imipramine
maprotiline (ludiomil)
secondary amine tricyclics
very new with increased potential for seizures
nortryptyline (pamelor)
secondary amine tricyclics
metabolite of amitryptyline; indicated for elderly patients
protryptyline (Vivactil)
secondary amine tricyclics
lacks sedative properites; often prescribed for “sleepy” depressives
Selective Serotonin Reuptake Inhibitors (SSRI’s)
often first choice for monopolar depression and they appear to be the most effective agents in the treatment of premenstrual dysphoric disorder (PMDD)
- citalopram (Celexa)
- escitalopram (Lexapro)
- fluoxetine (Prozac), t1/2=72 hours
- fluvoxamine (Luvox)
- paroxetine (Paxil)
- sertraline (Zoloft), t1/2=36 hours
escitalopram (Lexapro)
SSRI
also approved for adolescents
Selective Serotonin and Norepinephrine Reuptake Inhibitors (SNRI’s):
these have fewer antimuscarinic and antihistaminic effects than the tricyclics and have more of an adrenergic effect compared to SSRIs
- duloxetine (Cymbalta)
- milnacipran (Ixel)
- venlafaxine (Effexor)
- desvenlafaxine (Pritiq)
paroxetine (Paxil)
SSRI
noted for its anticholinergc s/e; recently approved for social phobia
duloxetine (Cymbalta)
- SNRI has 1:10 affinity for 5-HT and NE transporter, respectively.
- It is also one of two SNRI’s FDS approved for fibromyalgia
- Doctors may prescribe serotonin and norepinephrine reuptake inhibitors (SNRIs) when mood problems are a major symptom of fibromyalgia. SNRIs are also used for people without fibromyalgia who have depression.
- Some people with fibromyalgia who take SNRIs notice an improvement in a number of symptoms, including depression, pain, and fatigue
milnacipran (Ixel)
- SNRI has a 1:1 affinity for 5-HT and NE transporters.
- It is the second SNRI that is FDA-approved for the tx of fibromyalgia
venlafaxine (Effexor)
- a phenethylamine that has been shown to produce withdrawal following chronic tx and rebound effects
- this SNRI has 1:30 affinity for the 5-HT and NE transporters