ANTIDEPRESSANTS & ANTIDEPRESSANTS & Mood StabilizersMood Stabilizers
Antidepressants
Actions:
Block the reuptake of serotonin and norepinephrine (neurotransmitters) so that more are available in the brain to transmit messages.
Antidepressants
Indications: Recurrent depressive disorders Psychomotor retardation Depression with no clear precipitating event Family history of depression Chronic pain Eneuresis
Antidepressants
Have a long half life and can often be given once a day.
Therapeutic effects of some may not be seen until 3-4 weeks.
Three classifications
SSRIs/ SNRIsTricylcics
Mono-amine Oxidase Inhibitors
A. Selective Serotonin reuptake Inhibitors (SSRIs)
Fluoxetine HCL (Prozac)
Non-tricyclic, less sedation, fewer side effects
Sertraline HCI (Zoloft)
Lower risk of toxicity in overdose, fewer side effects, shorter half-life than prozac
SSRI Antidepressants (cont’d.)
Paroxetine HCI (Paxil):
Effectiveness comparable to Imipramine (Tofranil), shortest half-life, safer for
elderly.
Fluvoxamine (Luvox)
Citalopram (Celexa)
Escitalopram oxalate (Lexapro)
SSRIs Block transport mechanism that
returns unbound serotonin left in synaptic cleft into the presynaptic neuron
Terminates transmission of the message carried by that receptor
When blocked, more serotonin is available to the postsynaptic receptor
A. Serotonin & norepinephrine reuptake inhibitor SNRIs Effexor (Venlafaxine)
Inhibits serotonin & norepinephrine re-uptake
Side effects include: dizziness, migraine, weight gain
Pristiq (Desvenlafaxine) Serzone (Nefazadone) Trazodone HCL (Desyrel)
Norepinephrine-Dopamine Antagonist
Bupropion Hycrochloride (Wellbutrin) Increases norepinephrine and dopamine Provides mild dopamine reuptake Blocks reuptake of norepinephrine Does not affect serotonin reuptake Does not inhibit monoamine oxidase
Side Effects SSRIs and SNRIs Weight gain Impotence and ejaculatory
problems Arousal problems
B. Trycyclic Antidepressants TCAs
Imipramine…….Tofranil
Desipramine……Norpramine, Pertofrane
Amitriptyline……Elavil, Endep
Nortriptyline……Pamelor, Aventyl
Protriptyline……Vivactil
Doxepin…………Sinequan
Trycyclic Antidepressants
Affect norepinephrine, serotonin acetylcholine and histamine receptors
Increase availability of norepinephrine, serotonin
Inhibit transport back into the presynaptic neuron
Side Effects: TCAs
Anticholinergic effects: Common and troublesome in tricyclics: interfere with patient compliance.
dry mouth constipation urinary hesitancy/retention
sweating drowsiness blurred vision
Cardiovascular: Postural hypotension, tachycardia, heart conduction defects.
– TCAs Side Effects
Anticholinergic effects: Closed angle glaucoma worsened Toxic: confusion, psychosis
Other:Weight gain, lowered seizure threshold, EPS
Overdose: 1000 – 4000 mg is fatal
TCAs Side effects
Managing Side Effects of Tricyclic Antidepressants (Cont’d.)If these dangerous side effects occur, advise the patient either to call provider stop the medication, or reduce the dosage.
Orthostatic hypotension Marked, persistent sedation Atropine-like psychosis Cardiovascular conduction defect Seizures Severe anticholinergic effect: urinary retention, etc.
C. Mono-amine Oxidase Inhibitors MAOIs
phenelzine….…………Nardil
isocarboxazide ……….Marplan
tranylcypromine………Parnate
MAO Inhibitors
Actions: Monamine oxidase is an enzyme responsible for destroying epinephrine, norepinephrine and serotonin. MAO inhibitors block this enzyme. The effect is CNS stimulation and increased psychomotor activity.
symptoms relieved in 2-4 weeks
Potential hypertensive crisis it certain foods or medicines ingested
MAOIs
Dietary restrictions necessary: foods high in
tyramine must be avoided: aged cheese, chicken
liver, beer, Chianti wine, cold or sinus medicines,
diet pills, blood pressure regulating meds. Severe
atypical headache is usually the first sign
Side effects: autonomic: orthostatic hypotention,
dizziness, increased appetite anticholinergic effects are
rare.
Other Antidepressant Medications
Psychostimulants
Methylphenidate Hydrochloride (Ritalin)
Dextroamphetamine Sulfate (Dexedrine)
Pemoline (Cylert)
Source: Gomez (1993)
Serotonin Syndrome Occurs when serotonin excitement
occurs A second antidepressant is given
before the first has cleared-need 3 weeks
Overdose of any classification
Serotonin syndrome Altered mental state Fever Tachycardia Tremors High or low blood pressure Clonus
Mood Stablilizers Lithium Antic-convulsants
Lithium Effective in manic excitement and preventative for
manic and depressive recurrences in bipolar 1 patients. Also used in other psychiatric disorders that do not
respond to other drug therapies. Can lead to toxic reactions which may be fatal.
Blood level monitoring is necessary to maintain intherapeutic range.
Therapeutic levels range from .7 to 1.5. Higher levels are used to treat manic or psychotic excitement.
Lithium
Common Indications:Acute ManiaBipolar Prophylaxis
Possibly Effective:BulimiaAlcohol AbuseAggressive BehaviorSchizoaffective disorder
Lithium
Mechanism of ActionUnclear
DosingNarrow therapeutic
indexMonitor blood levels q 2-3 days initially then q 1-3 months levels must be
below 1.5mEq/L
Adverse Effects
Excessive drug
levels
Therapeutic drug
levels
Drug Interactions
Diuretics
Anticholinergic
drugs
LithiumSide effects:Neuromuscular and CNS: tremor (fingers) cog wheeling and mild parkinsonism possible. sluggishness and forgetfulness treated by decreased dose. GI: Chronic nausea, diarrhea, take with food.Weight gain and endocrine effects: Increased appetite and
excessive thirst may cause weight gain - transitory Decreased thyroid levels: Thyroid medication may be necessary.
Renal: polyuria and polydypsia may occur. Dose of drug should be lowered.
LithiumAllergic rashes – may be due to some ingredient in the
capsule. Drug form can be changed to liquid citrate. Cause birth defects
Lithium
Common Causes for Increased Lithium Level:Decreased sodium intakeDiuretic therapyDecreased renal functioningFluid-electrolyte loss (sweating, diarrhea,
dehydration)Medical illnessOverdose
Anti-convulsants– used to promote mood stabilization
Carbamazepine (Tegratol): Used in patients who do not respond to lithium. More effective for rapid-cycling bipolar patients (4 or more affective episodes per year).Blood levels should be monitored weekly for the first eight weeks. Dose should be adjusted to maintain a serum levels of 6-8 mg/L.
Anti convulsants
Side effects: sedation, mal coordination (common) agranulocytosis, aplastic anemia (rare) regular blood counts unnecessary . Watch for fever and sore throat.
Can cause increased liver enzymes but serious hepatic problems rare.
Associated with birth defects.
Anti convulsants
Valproate (Valproic acid) – Depakene, Depakote used in manic and schizoaffective patients (treatment resistant) Improvement occurs in 1-2 weeks. Blood levels should be obtained every few days until 50 mg/l is reached.
Side effects – Major concern – severe hepatotoxicity (may be fatal). Liver function tests should be done every month. Decreased platelet levels can occur.Associated with neural tube birth defects. Very toxic when taken in suicide attempt.
Anti-convulsants Lamitrogine- Lamictal
Anit-convulsant used for type 2 BPD
Side effect- rash, nausea, vomitting and diarrhea.
Other Mood Stabilizers(cont’d.)
Clonazepam (Klonopin) – Benzodiazepine which is useful in treating acute mania
Side effects: sedation, atoxia, disinhibition effect.