Antidepressant Agents Flashcards
What are the signs and symptoms of depression?
- Low energy
- Sleep disturbances
- Altered appetite
- Altered libido
- Inability to perform activites of daily living
- Overwhelming feelings of sadness, despair, hopelessness, and disorganization
- Altered affect
What is the
Biogenic Theory of Depression?
- Depression results from a deficiency of norepinephrine (NE), dopamine, and serotonin (5HT)
- Monamine oxidase may break them down to be recycled or restored in the neuron
- Rapid fire of neurons may lead to their depletion
- The # or sensitivity of receptors may increase, depleting neurotransmitter levels.
Antidepressant Therapy
Mechanisms of Action
- Inhibit the effects of MAO => increased NE or 5HT in the synaptic cleft
- BLOCK reuptake by the releasing nerve => increased neurotransmitters in the synaptic cleft
- Regulate receptor sites and breakdown of neurotransmitters, leading to an accumulation of neurotransmitters in the synaptic cleft
Types of Antidepressants
- Triclycic antidepressants (TCAs)
- MAO inhibitors (MAOIs)
- Selective serotonin reuptake inhibitors (SSRIs)
- Serotonin neorepinephrine inhibitors (SNRIs)
- Others
Considerations for use of antidepressants
in Children
- Rule out medical reasons first
- First choice: SSRIs and SNRIs
- Response is unpredictable
- Possible long term effects
- Studies have not proven efficacy
- Many black box warnings r/t increased sucidal ideation/behavior
- Avoid MAOIs d/t drug-food interactions
Considerations for use of antidepressants
in Adults
- Rule out medical reasons first
- Effects may not be seen for 4 weeks or more
- Caution during pregnancy/lactation
Considerations for use of antidepressants
in Older Adults
- Rule out medical reasons first
- More susceptible to adv. effects (especially CNS effects)
- Renal and hepatic impairment: Start LOW and Go SLOW
- TCAs can worsen Benign Prostatic Hyperplasia (BPH) because they decrease bladder contractions
TCAs
Mechanism of Action
Reduces the reuptake of 5HT AND NE into the nerves => increase in the synaptic cleft
TCAs
Indications
- Depression
- Sleep disorders
- Enuresis (nightime bedwetting)
- Anxiety
- Chronic Pain
TCAs
Drug Names
“-triptyline”
* Amitriptyline
* Nortriptyline
“-pramine”
* Clomipramine
* Despramine
* Imipramine
* Trimipramine
Doxepin
TCAs
Contraindications
Absolute:
* Allergy
Relative:
* Recent MI (can cause it to worsen or reoccur)
Cautions:
* CV disease
* Anticholinergic conditions (BPH, glaucoma, urinary retention)
* Manic-depression/ bipolar (can shift into manic phase)
* Seizure disorders (can lower the threshold for seizures)
TCAs
Adverse Effects
- CNS: sedation, sleep disturbances, fatigue, hallucinations, ataxia (lack of voluntary muscle control)
- GI: Dry mouth, constipation, n&v, anorexia, decreased salivation
- CV: tachycardia, hypertension, arrhythmias
TCAs
Drug Interactions
- MAOIs
- Cimetidine (Histamine-2 antagonist)
- Fluoxetine (SSRI)
Risk of death
TCAs
Assessment
History:
* Cardiac dysfunction/disease
Labs:
* ECG
TCAs
Implementation/Patient Teaching
- Limit drug access if pt is suicidal (dec. risk of overdose)
- Parenteral form only if Oral is not feasible
- Reduce dose if minor adv. effects occur
- Discontinue slowly if major adv. effects occur
- Take at bedtime if drowsiness occurs
- Void before meds if urinary retention occurs
- sugarless lozenges for dry mouth
- small meals/take with meal for GI upset
- Takes 4 weeks to take effect
MAOIs
Mechanism of Action
Irreversibly inhibits monoamine oxidase
Allows NE, 5HT, and dopamine to accumulate in the synaptic cleft
NOT 1st line/1st choice
MAOIs
Indications
Depression