Anti-Depressants, Mood Stabilizers & Anxiolytics Flashcards
Depression definition
Biogenic amine hypothesis –> depression is caused by a deficiency of monoamines, particularly NE & 5HT
Receptor sensitivity hypothesis –> post-synaptic neuron tries to compensate for a lack of stimulation & deficiency of NE & 5HT & takes up all the NTs leading none for other neurons
Depression Treatment Focus
- Block action of MAO
- Block re-uptake of monoamines so they’re more readily available for other neurons & down regulation of the
- Desensitization of super-sensitized/upregulated neurons
Lag period
Time between starting the medication & obtaining full symptom relief; believed to occur as a result of down regulation
Down regulation
Reducing stimulation at the post-receptor (post-synaptic) site; cell is less sensitive to the neurotransmitter
Guidelines for Antidepressant use
- start low & go slow –> too fast & they’re more likely to have adverse effects
- Many have “lag period”
- Most SE’s occur in 1-2 weeks or upon dose changes
- Suicide risk increases with energy level –> black box warning; it takes a while to increase up to the desired baseline so during the process they are still in a depressed state with potential suicidal thoughts while the meds give them increased energy which could increase the likelihood to act on those thoughts
Antidepressant medication selection
- target symptoms
- side effect profile (ie. giving a med with lethargy side effects to someone who has sleeping problems may be beneficial)
- Medical illness/other medications
- Relative’s response/genetics (ie. if patient’s mom did well on med, patient might too)
- Suicide risk (ie. how fatal the med is if overdose occurs)
Tricyclics Antidepressants (TCAs)
MOA –> inhibits reuptake of NE & 5HT, and intermediary neurochemical events and/or changes occur over time
-have varying affinity for cholinergic, adrenergic, histamine & DA receptors
Monitoring –> need to titrate/taper down the medication when stopping the med, need a baseline ECG & follow-ups, draw plasma levels
TCAs Adverse Effects
- Hypotension
- Anticholinergic effects
- Sedation (possibly a good thing if patient needs help sleeping)
- Diaphoresis
- Cardiotoxicity –> arrhythmias
- Seizures –> med decreases seizure threshold
- Hypomania –> less severe form of mania (affects patients with bipolar)
- Yawngasm
TCAs Interactions & Toxicity
Interactions: CNS depressants, anticholinergics, sympathomimetics, MAOIs
Toxicity: cadiotoxic (direct & indirect effects), anticholinergic symptoms (agitation, confusion, seizures, coma)
TCAs Patient Education
Measures to minimize adverse effects of orthostatic hypotension (stand up slowly), anticholinergic effects (drink water), hazards of sedation & other (report suicidality & chest pain)
Measures to minimize adverse interactions: avoid anticholinergic drugs, CNS depressants
Monoamine Oxidase
Enzyme present in monoamine-containing neurons that converts monoamine transmitters into active products (ie. MAO-A & MAO-B) which work to breakdown NTs; inactivates NE & 5HT after reuptake
Monoamine Oxidase Inhibitors (MAOI)
MOA –> prevent the inactivation of NE & 5HT, allowing for increased amounts of transmitters to be released
-result in irreversible inhibition (10-14 days) meaning recovery requires new synthesis of the enzyme
MAOI Drug Interactions
Decreasing MAO in the liver results in a decrease in metabolism of other drugs (can lead to toxic levels of other meds)
- Anesthetics
- Narcotics
- Antidepressants
- Sympathomimetics
- Cocaine
- Anti-hypertensives
MAOI Food Interactions
Interacts with TYRAMINE (occurs naturally in food & is degraded by MAO) and causes a Hypertensive Crisis
- foods that have aged & have to be ripened before being eaten
- Examples: avocado, bananas, liver, caffeine, cheese, papaya, pickled herring, raisins, soy sauce, sour cream, yogurt
Hypertensive Crisis
Sudden severe increase in BP
- puts patient at risk for intracranial hemorrhage
- Warning signs: throbbing occipital headache, rtetroorbital pain, stiff neck, apprehension, nausea, chils/fever, pallor, sweating, flushing of skin, palpitations, chest pain
MAOI Patient Education
Measures to minimize adverse effects: HTN crisis, orthostatic hypotension, food education
Measures to minimize adverse interactions: MANY drug-drug interactions; use only one pharmacy to ensure no interactions occur
SSRI Pharmacokinetics
- highly bound to plasma proteins
- extensive hepatic metabolism with resulting active metabolites
- prolonged half-life –> steady state plasma levels in about 4 weeks