Antidepressants Flashcards
Bipolar disorder is characterized by
Mood swings of mania and depression
Bipolar mood swings are…
Not always controlled by the environment
Bipolar mood swings usually occur…
In alternation of mania/depression but both can happen at the same time
What is the monoamine theory of bipolar disorder?
Depression = decreased monoamine transmission
Mania = overactive monoamine transmission
What are monoamines?
(Norepinephrine, serotonin 5-HT, dopamine)
What are single-drug treatments for bipolar disorder?
Mood stabilizers (lithium) and antipsychotics
What are multiple medication treatments for bipolar disorder?
A combination of antidepressants, antipsychotics, and lithium
What does lithium do?
It may increase serotonin and GABA
it may decrease NE, Dopamine and glutamate transmission
What does lithium do to IP3 and DAG?
Lithium decreases production of precursors for IP3 and DAG
What are the 2 treatments for depression?
Therapy and medication
Lithium works better in which phase of bipolar disorder?
It is better at stabilizing the manic phase
What are the different types of antidepressants?
Amine reuptake blockers and Monoamine oxidase inhibitors
What are the 2 categories of amine reuptake-blocking drugs?
Nonselective and selective reuptake inhibitors
What is an example of a nonselective amine reuptake blocker?
Tricyclic Antidepressants
Ex. Impiramine
Prevents reuptake of NE and serotonin
How effective is Imipramine
Imipramine (TCA) is effective in approx 70% of patient
Is imipramine a first-line treatment?
No, the adverse effects and drug-drug effects make it worse than other options for first line
What are the adverse effects of TACs?
Tricyclic antidepressant adverse effects inc.
Block cardiac sodium channels
Antagonize muscarinic receptors (dry mouth, constipation)
Antagonize H1 and Alpha 1 receptors (Sleepiness)
What is an example of a selective serotonin reuptake inhibitor? (SSRI)
Fluoxetine (PROZAC)
What is fluoxetine used for?
Depression, panic disorders, OCD, bulimia
What are the common side effects of SSRIs?
Insomnia and sexual dysfunction
Increased suicide rate
Are SSRIs dangerous?
Not typically unless combined with other antidepressants (inhibits CYP2D6 which metabolizes MAO inhibitors)
Can cause serotonin syndrome?
What is serotonin syndrome?
A condition caused by too much brain serotonin
Symptoms:
Tachycardia, shivering, seizures, diarrhea
How is serotonin syndrome cured?
Benzodiazepines to help with muscle contractions
Cyproheptadine to block serotonin production
What are newer class antidepressants?
Includes drugs like SNRIs and NRIs
What is an example of an atypical antidepressant?
Bupropion
What does bupropion do?
Bupropion inhibits DA and NE reuptake
What is special about bupropion?
It has fewer side effects than TCAs but still inhibits CYP2D6
What are MAO inhibitors?
Monoamine oxidase inhibitors are drugs which inhibit monoamine oxidase, an enzyme that breaks down monoamines.
What is an example of an MAO?
Phenelzine
When are Monoamine oxidase inhibitors prescribed?
When TCAs arent an efficient treatment option
What are the toxicities of MAOs?
Shouldn’t be taken with other antidepressants, can lead to serotonin syndrome
Hypertensive crisis can occur if tyramine-containing foods are ingested.
What monoamine levels do MAOs increase?
inhibiting MAO-A = increased NE, Serotonin, Tyramine
inhibiting MAO-B = increased dopamine
Why are SSRIs usually prescribed first?
They have less side effects and can’t OD on them easily
Antidepressant therapy usually starts with a ___ dose and can take _____ weeks to show effects
Antidepressant therapy usually starts with a low dose and can take 3-8 weeks to show effects
Why do antidepressants take so long to show observable effects?
The adaptive brain changes are likely more important than the immediate chemical changes
Long-term treatment with antidepressants has been reported to…
alter the brains sensitivity levels to various CNS receptors
these changes may “cure the depression”
