MAO-inhibitor

MECH: Irreversable inhibition of MAO-A (oxidizes 5-HT, Tyramine) and MAO-B (oxidizes DA, phenylethylamine).

USE: Depression.

AE: Anticholinergic, orthostatic hypotension, sexual dysfunction, wt. gain, sedation (variable). Life-threatening hypertensive crisis due to inhibition of liver MAO coupled with dietary intake of tyramine (which releases NE from storage vesicles). MAO-inhibitor with SSRI ---> seratonin syndrome (hyperthermia, muscle rigidity, myoclonus, mental status changes and changes in vital signs--can be lethal).

Imipramine

Desipramine (active metabolite)

Tricyclic antidepressant.

MECH: Inhibits both NE and 5-HT reuptake. NE reuptake selective--metabolite even more NE selective.

USE:

AE: Also block muscarinic receptors: blurred vision, constipation, confusion; alpha adrenergic receptor: orthostatic hypotension; histamine receptor: sedation. Also arrythmias (blocks Na channel class Ia antiarrythmic effect), seizures, tremor, insomnia.

Amitriptyline

Nortryptyline (active metabolite)

Tricyclic antidepressant.

MECH: Inhibits both NE and 5-HT reuptake. Amitryptyline blocks both evenly but Nortryptyline is NE selective.

AE: Also block muscarinic receptors: blurred vision, constipation, confusion; alpha adrenergic receptor: orthostatic hypotension; histamine receptor: sedation. Also arrythmias (blocks Na channel class Ia antiarrythmic effect), seizures, tremor, insomnia.

Fluoxetine

Norfluoxetine (active metabolite)

SSRI

MECH: Seratonin reuptake inhibitor.

USE: Longer duration of action over tricyclics. Safer in O.D. than tricyclics--no seizure, no arrythmia. Fewer side effects.

AE: More nausea and sexual dysfunction than tricyclics. Inhibit CYTP450 system--increase concentration of drugs to toxic levels. Do NOT use with MAO-I--seratonin syndrome (hyperthermia, muscle rigidity, myoclonus, mental status and vital sign changes).

SSRI

MECH: Seratonin reuptake inhibitor.

USE: Longer duration of action over tricyclics. Safer in O.D. than tricyclics--no seizure, no arrythmia. Fewer side effects.

AE: More nausea and sexual dysfunction than tricyclics. Inhibit CYTP450 system--increase concentration of drugs to toxic levels. Do NOT use with MAO-I--seratonin syndrome (hyperthermia, muscle rigidity, myoclonus, mental status and vital sign changes).

SNRI

MECH: Seratonin-norepi reuptake inhibitor.

USE: Longer duration of action over tricyclics. Safer in O.D. than tricyclics--no seizure, no arrythmia. Fewer side effects.

AE: More nausea and sexual dysfunction than tricyclics. Inhibit CYTP450 system--increase concentration of drugs to toxic levels. Do NOT use with MAO-I--seratonin syndrome (hyperthermia, muscle rigidity, myoclonus, mental status and vital sign changes).

SNRI

MECH: Seratonin and Norepinephrine reuptake inhibitor.

USE: Longer duration of action over tricyclics. Safer in O.D. than tricyclics--no seizure, no arrythmia. Fewer side effects.

AE: More nausea and sexual dysfunction than tricyclics. Inhibit CYTP450 system--increase concentration of drugs to toxic levels. Do NOT use with MAO-I--seratonin syndrome (hyperthermia, muscle rigidity, myoclonus, mental status and vital sign changes).

Atypical antidepressant.

MECH: 5-HT2A antagonist also inhibits seratonin reuptake.

USE: ONLY agent with selectivity for DA uptake transporter. Used to improve nicotine abstinence.

AE: Lowers seizure threshold.

Atypical antidepressant.

MECH: 5-HT2A antagonist also inhibits seratonin reuptake.

USE: Longer duration of action over tricyclics. Safer in O.D. than tricyclics--no seizure, no arrythmia. Fewer side effects.

AE: More nausea and sexual dysfunction than tricyclics. Inhibit CYTP450 system--increase concentration of drugs to toxic levels. Do NOT use with MAO-I--seratonin syndrome (hyperthermia, muscle rigidity, myoclonus, mental status and vital sign changes).

MECH: May cause selective depression of overactive circuits due to its depletion of IP3 and DAG (second messengers for both alpha adrenergic and muscarinic- cholinergic transmission).

USE: Bipolar Disorder. Mood stabilization with concurrent antidepressant use.

AE: Drowsiness, wt. gain, tremor, polydipsia, polyuria. Also neurotoxicity, cardiac tox., renal dysfunction--look for N+V.

MAO-inhibitor

MECH: Irreversable inhibition of MAO-A (oxidizes 5-HT, Tyramine) and MAO-B (oxidizes DA, phenylethylamine).

USE: Depression.

AE: Anticholinergic, orthostatic hypotension, sexual dysfunction, wt. gain, sedation (variable). Life-threatening hypertensive crisis due to inhibition of liver MAO coupled with dietary intake of tyramine (which releases NE from storage vesicles). MAO-inhibitor with SSRI ---> seratonin syndrome (hyperthermia, muscle rigidity, myoclonus, mental status changes and changes in vital signs--can be lethal).

SSRI

MECH: Seratonin reuptake inhibitor.

USE: Longer duration of action over tricyclics. Safer in O.D. than tricyclics--no seizure, no arrythmia. Fewer side effects.

AE: More nausea and sexual dysfunction than tricyclics. Inhibit CYTP450 system--increase concentration of drugs to toxic levels. Do NOT use with MAO-I--seratonin syndrome (hyperthermia, muscle rigidity, myoclonus, mental status and vital sign changes).

SSRI

MECH: Seratonin reuptake inhibitor.

USE: Longer duration of action over tricyclics. Safer in O.D. than tricyclics--no seizure, no arrythmia. Fewer side effects.

AE: More nausea and sexual dysfunction than tricyclics. Inhibit CYTP450 system--increase concentration of drugs to toxic levels. Do NOT use with MAO-I--seratonin syndrome (hyperthermia, muscle rigidity, myoclonus, mental status and vital sign changes).

SSRI

MECH: Seratonin reuptake inhibitor.

USE: Longer duration of action over tricyclics. Safer in O.D. than tricyclics--no seizure, no arrythmia. Fewer side effects.

AE: More nausea and sexual dysfunction than tricyclics. Inhibit CYTP450 system--increase concentration of drugs to toxic levels. Do NOT use with MAO-I--seratonin syndrome (hyperthermia, muscle rigidity, myoclonus, mental status and vital sign changes).

Anti-convulsant

USE: Also used in Bipolar disorder.

Anti-convulsant

USE: Also used in Bipolar disorder.

Benzodiazepine

MECH: Binds to gamma-2 sub-unit of GABA-A receptor allosterically enhancing GABA binding which opens Cl- channel hyperpolarizing cell and inhibiting action potential.

USE: Sedation, calming, anxiolytic; induce sleep; calming and anterograde amnesia in anesthesia; anticonvulsant; muscle relaxation. Very long half-life with active metabolites lasting even longer.

AE: Drowsiness, synergistic CNS depression with alcohol, anterograde amnesia, dependence.

Benzodiazepine

MECH: Binds to gamma-2 sub-unit of GABA-A receptor allosterically enhancing GABA binding which opens Cl- channel hyperpolarizing cell and inhibiting action potential.

USE: Sedation, calming, anxiolytic; induce sleep; calming and anterograde amnesia in anesthesia; anticonvulsant; muscle relaxation.

AE: Drowsiness, synergistic CNS depression with alcohol, anterograde amnesia, dependence.

Benzodiazepine

MECH: Binds to gamma-2 sub-unit of GABA-A receptor allosterically enhancing GABA binding which opens Cl- channel hyperpolarizing cell and inhibiting action potential.

USE: Sedation, calming, anxiolytic; induce sleep; calming and anterograde amnesia in anesthesia; anticonvulsant; muscle relaxation.

AE: Drowsiness, synergistic CNS depression with alcohol, anterograde amnesia, dependence.

Benzodiazepine

MECH: Binds to gamma-2 sub-unit of GABA-A receptor allosterically enhancing GABA binding which opens Cl- channel hyperpolarizing cell and inhibiting action potential.

USE: Sedation, calming, anxiolytic; induce sleep; calming and anterograde amnesia in anesthesia; anticonvulsant; muscle relaxation. Very long half-life with active metabolites lasting even longer.

AE: Drowsiness, synergistic CNS depression with alcohol, anterograde amnesia, dependence.

Benzodiazepine

MECH: Binds to gamma-2 sub-unit of GABA-A receptor allosterically enhancing GABA binding which opens Cl- channel hyperpolarizing cell and inhibiting action potential.

USE: For short, unpleasant procedures due to short half-life and anterograde amnesia.

AE: Drowsiness, synergistic CNS depression with alcohol, anterograde amnesia, dependence.

Benzodiazepine

MECH: Binds to gamma-2 sub-unit of GABA-A receptor allosterically enhancing GABA binding which opens Cl- channel hyperpolarizing cell and inhibiting action potential.

USE: Sleeping pill due to short half-life so user does not wake up feeling drunk.

AE: Drowsiness, synergistic CNS depression with alcohol, anterograde amnesia, dependence.

Benzodiazepine

MECH: Binds to gamma-2 sub-unit of GABA-A receptor allosterically enhancing GABA binding which opens Cl- channel hyperpolarizing cell and inhibiting action potential.

USE: Sedation, calming, anxiolytic; induce sleep; calming and anterograde amnesia in anesthesia; anticonvulsant; muscle relaxation. First in class--not used as much anymore. Active metabolites have very long half-life.

AE: Drowsiness, synergistic CNS depression with alcohol, anterograde amnesia, dependence.

Omega-1 agonist.

MECH: BDZ-1 selective (specific subtype of GABA-A receptor) allosteric GABA enhancer.

USE: Sleeping pill. Sedation and hypnosis without muscle relaxation or anticonvulsant activity. Short half-life so little hangover. Less habit-forming.

AE: Drowsiness, synergistic CNS depression with alcohol, anterograde amnesia, dependence.

Barbiturate

MECH: Bind to alpha or beta subunit of GABA-A receptor allosterically enhancing GABA effects at low doses.

USE: Fast-on, Fast-off. Used for induction of anesthesia. Fast off is due to lipophilicity--distributes quickly into fat.

AE: Not as safe as benzos due to dose-related CNS depression until coma and death. At high doses barbiturates directly open Cl- channel.

Barbiturate

MECH: Bind to alpha or beta subunit of GABA-A receptor allosterically enhancing GABA effects at low doses.

USE: Some use as anti-epileptic/anti-convulsant in infants.

AE: Not as safe as benzos due to dose-related CNS depression until coma and death. At high doses barbiturates directly open Cl- channel.