antidepressants Flashcards
Imipramine (Tofranil, Janimine)
TCA, prototype
blocks reuptake of NE and 5-HT
treatment of enuresis and urinary incontinence, neuropathic pain
TCAs cheaper than newer drugs
Amitriptyline (Elavil)
TCA
more sedation and anticholinergic activity than imipramine
Fluoxetine (Prozac)
SSRI, prototype
OCD, GAD, PMDD, bulimia, anorexia nervosa
-less sedation antiACh and CV effects than TCAs
SEs: ha, anxiety, tremor, agitation, nausea, and sexual dysfunction in males. (suicide?)
-liver metab., req. 4-5 wks of tx to reach steady state/be cleared
Fluvoxamine (Luvox)
SSRI
Selective inhibitor of 5‐HT reuptake that is similar to fluoxetine
-used for OCD in US
Sertraline (Zoloft)
SSRI
selective inhibitor of 5‐HT reuptake, effects/SEs like fluoxetine, less drug interactions
-relatively slow elimination (T1⁄2 = ~24 hours)
Paroxetine (Paxil)
SSRI
selective inhibitor of 5‐HT reuptake, effects/SEs like fluoxetine, can have drug interations
-more rapidly metabolized (T1⁄2 = ~10 hours) and it does not form active metabolites.
more weight gain than other SSRIs
Citalopram (Celexa)
SSRI, newer
-similar to other SSRIs (esp. sertraline) -fewer drug interactions than fluoxetine.
Escitalopram (Lexapro)
SSRI, newer
-similar to other SSRIs (esp. sertraline) -fewer drug interactions than fluoxetine.
Venlafaxine (Effexor) and desvenlafaxine (Pristiq)
SNRI
Serotonin‐Norepinephrine Reuptake Inhibitors (and dopamine!)
-depression, GAD, social anxiety disorder, panic disorder, PTSD, OCD
-more rapid onset (1-2 wks?)
-less CV SEs than TCAs
-may have stimulant activity (used for ADHD in kids)
-may work when don’t respond to SSRIs
SEs: nausea, nervousness, anxiety, sweating, HTN, tachycardia, palpitations, sexual dysfunction.
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Duloxetine (Cymbalta)
SNRI, newer
neuropathic pain
other SNRIs: desvenlafaxine, levomilnacipran, milnacipran.
Trazodone (Desyrel)
Second generation antidepressant
FA:
Primarily blocks 5-HT2, α1-adrenergic, and H1 receptors; also weakly inhibits 5-HT reuptake.
use: mostly insomnia, as high doses are needed for antidepressant effects
-lower incidence antiACh and CV SEs than TCAs
SEs: priapism, sexual dysfunction in males, sedation (used at night)
Nefazodone (Serzone)
Second generation antidepressant
inhibit the reuptake of 5‐HT but also block 5‐HT‐2 receptors. (similar to trazadone)
Bupropion (Wellbutrin)
Second generation antidepressant
selectively inhibits DA reuptake (FA: inhibits dopamine»NE uptake via unknown mechanism)
-has mild stimulant activity; “psychic energizer”
-more likely than other antidepressants to produce seizures
-tx of nicotine, cocaine and amphetamine dependence
Mirtazepine (Remeron)
Second generation antidepressant, chemically different from TCAs and SSRIs
-α2-antagonist (^release of NE and 5-HT), potent 5-HT2 and 5-HT3 receptor antagonist and H1 antagonist
SEs: like TCAs (mild ACh, hypotension, tachy)
FA: Sedation, ^serum cholesterol, ^appetite
-both antidepressant and anxiolytic activity
Atomoxetine (Strattera)
Selective Norepinephrine Reuptake Inhibitor
-ADHD, different than stimulants
SEs: suppression of appetite, decreased weight gain, increased blood pressure, tachycardia, sexual dysfunction in adult males
Phenelzine (Nardil)
MAO Inhibitors (both A and B) contains a hydriazide group that can form covalent bonds with MAO-->can irreversibly inactivate MAO
Tranylcypromine (Parnate)
MAO Inhibitors (both A and B)- binds tightly
Selegiline (Emsam)
MAO Inhibitors
selective inhibitor of MAO‐B
-available as a patch preparations (EMSAM) for treatment of depression
-Parkinson’s disease
-does NOT undergo the classic interactions with tyramine and other sympathomimetics
Lithium carbonate (Eskalith and others)
mood stabilizer
- most effective drug for manic-depressive disorder (bipolar)
- ionic theory ‐ may alter the neuronal distribution or effect of Na+, K+ or Ca2+ in the CNS.
- biogenic amine theory may later the release, reuptake, or metabolism of NT amine.
- phospholipid theory ‐ may alter the metabolism of phospholipids that are involved in the phosphoinositide signaling pathway
Valproic Acid Analogs (Depakene/Depakote)
mood stabilizer
manic-depressive disorders/bipolar
Carbamazepine (Tegretol)
mood stabilizer
manic-depressive disorders/bipolar
Clonazepam (Klonopin)
mood stabilizer
manic-depressive disorders/bipolar
drugs that can induce depression
reserpine, B-blockers
pharm manangement for depression
(effective in 70-80% of pts)
1st line: SSRIs and 2nd gen
2nd/3rd: TCAs and MAO’s (potential toxicity)
-benzos (alprazolam (Xanax)) for anxiolytic effects
-antipsychotics (2nd gen) for schizo symptoms
Manic-depressive disorder pharm management
(effective in 80%)
Lithium: reduce the fluctuation in mood swings.
Antipsychotics are used in severe phases of mania.
Antidepressants can help in some severely depressed patients, but may also trigger a switch to the manic phase
FA TCAs
Amitriptyline, nortriptyline, imipramine, desipramine, clomipramine, doxepin, amoxapine.
FA TCA mechanism and use
Block reuptake of norepinephrine and less so 5-HT. (3o amines have a greater effect on 5‐HT than the 2o)
Major depression, OCD (clomipramine), peripheral neuropathy, chronic pain, migraine prophylaxis.
FA TCA SEs
Sedation, α1-blocking effects including postural hypotension, and atropine-like (anticholinergic) side effects (tachycardia, urinary retention, dry mouth). 3° TCAs (amitriptyline) have more anticholinergic effects than 2° TCAs (nortriptyline). Can prolong QT interval.
Tri-C’s: Convulsions, Coma, Cardiotoxicity (arrhythmia due to Na+ channel inhibition); also respiratory depression, hyperpyrexia. Confusion and hallucinations in elderly due to anticholinergic side effects (use nortriptyline).
Tx: NaHCO3 to prevent arrhythmia.

FA SSRIs
Fluoxetine, paroxetine, sertraline, citalopram.
“Flashbacks paralyze senior citizens.”
FA SSRI Mechanism and SEs
5-HT–specific reuptake inhibitors.
Fewer than TCAs. GI distress, SIADH, sexual dysfunction
FA SSRI uses
Depression, generalized anxiety disorder, panic disorder, OCD, bulimia, social anxiety disorder, PTSD, premature ejaculation, premenstrual dysphoric disorder.
CNS effects of TCAs/2nd gens
- sedation (tolerance develops: tricyclic tertiary amines > tricyclic secondary amines > second generation drugs)
- effect takes time (2-4 wks)
- may also tx OCD, panic attacks, GAD, social phobias
- CNS stim: 10%, may induce manic phase in bipolar pts
- decreased seizure threshold
Acute effect of TCAs/2nd gens
inhibition of the synaptic reuptake of NT amines (NE, 5‐HT, and DA)
Bupropion (Wellbutrin) SEs
stimulant effects (tachycardia, insomnia), headache, seizures in anorexic/bulimic patients. No sexual side effects.
Trazodone (Desyrel) SEs
sedation, nausea, priapism, postural hypotension. Called traZZZobone due to sedative and male-specific side effects.
Chronic effect of TCAs/2nd gens
alterations in the density and sensitivity of
receptors for NT amines
TCAs/2nd gens may directly interact with ??
certain NT receptors
-agonists or antagonists at muscarinic, serotonin, alpha adrenergic or dopaminergic receptors
may also INdirectly influence receptors
TCA/2nd gen Anticholinergic side effects
dry mouth, constipation, urine retention, loss of visual accommodation, etc
-Usually more severe than those of antipsychotic drugs.
-amitriptyline is the worst,
SSRI’s the least
TCA/2nd gen CV SEs
- postural hypotension ‐ due to alpha blockade and interference with hemostatic reflexes in the CNS
- tachycardia ‐ due to potentiation of the effects of NE and an anticholinergic effect in the heart.
- flattening or inversion of the T‐wave
- arrhythmias
- BBW: may increase suicidal ideation in children
TCA/2nd gen metabolism
-demethylation and aromatic hydroxylation in liver ‐ caution in
patients with liver disease and large potential for drug interactions
-conversion of some agents to active metabolites
-relatively narrow therapeutic windows (in general)
TCA/2nd gen Toxic Reactions and Side Effects
anticholinergic
CNS: tremor, agitation, manic phase, parkinsonism (rare), inc. seizure risk in epileptic pts
CV: hypotension, tachy, arrhythmias
-weight gain w. TCAs
-impotence due to alpha blockade; may have retrograde ejaculation
-possible teratogenic effects
-blood dyscrasias (rare but may be fatal)
TCA/2nd gen (atypicals) acute poisoning
fairly common ‐ serious toxicity at doses 5‐10 times normal therapeutic doses, life‐threatening emergency!
-CNS agitation–>grand mal seizures–>coma
-extreme hypotension, tachycardia, and arrhythmias progressing
to total CV collapse.
-classic “anticholinergic” symptoms
tx: supportive, NaHCO3 reduces cardiotoxic effects of TCAs (or antiarrhythmics, B-blockers, CCBs)
TCA/atypical drug interactions
anticholinergics
sedatives, alcohol
biogenic amines and adrenergic drugs ‐ potentiation
guanethidine ‐ antidepressants decrease its effect by blocking its uptake by nerve ending
drugs metabolized by microsomal system, many complex interactions
MAO inhibitors: “serotonin syndrome”
anticoagulants – complex effects through hepatic metabolism and through clotting mechanism (serotonin is involved in platelet aggregation and blood clotting)
serotonin syndrome
tremors, hypertension, hyperpyrexia and seizures
-At least 2‐4 weeks should elapse before switching from a tricyclic or second generation antidepressant to an MAO inhibitor and vice‐versa.
other antidepressant uses
- enuresis and urinary incontinence (imipramine)
- pain from neuropathies (tricyclics, duloxetine and others)
- adjuncts in the management of chronic pain
- cocaine and amphetamine dependence
- GAD and panic/phobia disorders
- OCD
MAO-inhibitors: acute and chronic effects
acute effect ‐ increased synaptic levels of NE, 5‐HT and DA
chronic effect ‐ decreased number and sensitivity of adrenergic and serotonergic
receptors
FA: MAO-inhibitors
Tranylcypromine, Phenelzine, Isocarboxazid, Selegiline (selective MAO-B inhibitor). (MAO Takes Pride In Shanghai).
FA: MAO-i mechanism and use
Nonselective MAO inhibitionlevels of amine NTs (NE, 5-HT, DA).
Atypical depression, anxiety, (bulimia, OCD, PTSD, narcolepsy)
FA: MAO-i SEs
HTN crisis (most notably with ingestion of *tyramine*, which is found in many foods such as aged cheese and wine), can be lethal, seen w. non-selectives-->HTN, fever, convulsions CNS stimulation. Contraindicated with SSRIs, TCAs, St. John’s wort, meperidine, dextromethorphan (to prevent serotonin syndrome).
MAO-inhibitor CNS effects
little effect initially
antidepressant action usually takes several weeks to develop
normalization of sleep patterns
CNS stimulation in some patients (tremors, insomnia, hallucinations);
switch to manic phase in patients with bipolar phase.
MAO-i SEs (proz)
orthostatic hypotension ‐ normal effect at therapeutic doses
HTN ‐ in overdose or in interaction with sympathomimetic
GI effects (nausea, constipation)
headache, dizziness, vertigo
CNS stimulation
liver damage
allergic reactions, skin rashes, etc…
other MAO-i potentiations (like tyramine effect)
pheochromocytoma
amphets, cocaine, DA
TCAs and other antideps (wait 3-4 wks)
-may slow metab of other drugs
lithium metabolism
excreted by kidneys
-caution in patients with impaired renal function
-enhanced reabsorption in sodium depleted patients
-any drugs (i.e. NSAIDs, diuretics, etc..) that after renal function can
influence the renal excretion of lithium
-low therapeutic index (2-3): therapeutic range 0.8‐1.4 mEq/l; severe toxicity above 2.0 mEq/l
symptoms of acute lithium intoxication
GI: N/V/D
NM: fatigue, weakness, fine tremor, ataxia, hyperirritability
neurosens: blurred vision, tinnitus
CNS: slurred speech, dizziness, confusion,
restlessness, grand mal seizures, stupor, coma
CV: arrhythmias, hypotension, circulatory collapse
may appear drunk
tx of lithium intoxication
remove drug, symptomatic support: maintain fluids and electrolytes, administer
anticonvulsants, antiarrhythmics, and CV drugs as needed.
induce diuresis
hemodialysis
other lithium toxic effects
a. EKG changes; arrhythmias
b. hypothyroidism*
c. polydipsia, polyuria
d. kidney damage* ‐ nephrogenic diabetes insipidus
e. weight gain
f. dermatological problems
g. teratogenic effects*
*avoid in these pts
lithium has been tried for these conditions
cluster headache, premenstrual syndrome, tardive dyskinesia, hyperthyroidism and post partum affective psychosis.
lithium drug reactions
- ^^ levels by NSAIDs and diuretics (interfere with renal excretion of lithium)
- Carbamazepine, antidepressants, antipsychotics, and methyldopa can enhance the neurotoxic effects of lithium.
- Lithium can enhance the effects of antidepressants and other CNS drugs.
FA: lithium SEs
tremor, hypothyroidism, polyuria (causes nephrogenic diabetes insipidus), teratogenesis. Causes Ebstein anomaly in newborn if taken by pregnant mother. Narrow therapeutic window requires close monitoring of serum levels. Almost exclusively excreted by kidneys; most is reabsorbed at PCT with Na+. Thiazide use is implicated in lithium toxicity in bipolar patients.
LMNOP—Lithium side effects:
Movement (tremor)
Nephrogenic diabetes insipidus
HypOthyroidism
Pregnancy problems
moderate‐severe endogenous depression
SSRI’s: first choice
TCAs and other second generation antideps may be preferred in some pts
MAO inhibitors are alternative drugs ‐ remember to clear TCAs before starting
mild acute depression with anxiety
antianxiety drugs, especially alprazolam (Xanax)
bipolar
manic‐depressive disorders
lithium
antipsychotic drugs (for severe acute manic phase)
antidepressants (for severe depressed phase)
valproic acid analogs (Depakene/Depakote) is also gaining in use
carbamazepine (Tegretol) – is becoming more widely used
A withdrawal syndrome that includes ?? can occur when antidepressant drugs are abruptly discontinued after long term usage. Accordingly, the dose of the drug should be gradually tapered off over a period of ??Discontinuation problems are more severe with shorter acting drugs like ? and less severe with longer acting drugs like ?.
lethargy, chills, neurologic disturbances and muscle aches
2‐4 weeks.
paroxetine
fluoxetine
only FA: buspirone
Stimulates 5-HT1A receptors.
GAD. Does not cause sedation, addiction, or tolerance. Takes 1–2 weeks to take effect. Does not interact with alcohol (vs barbiturates, benzodiazepines).
“I’m always anxious if the bus will be on time, so I take buspirone”
FA: serotonin syndrome
3 A’s: neuromuscular Activity (clonus, hyperreflexia, hypertonia, tremor, seizure), Autonomic stimulation (hyperthermia, diaphoresis, diarrhea), and Agitation. Treatment: cyproheptadine (5-HT2 receptor antagonist).
only FA: varenicline
Nicotinic ACh receptor partial agonist. Used for smoking cessation. Toxicity: sleep disturbance.

