Neuropsychiatric Drugs

Classification of Neuropsychiatric Medications Based On Their Principle Mechanisms Of Action

Acetylcholine

Cholinesterase Inhibition
donepezil (Aricept) rivastigmine (Exelon)
galantamine (Reminyl)
Muscarinic Acetylcholine Receptor Antagonism
atropine orphenadrine (eg, Norflex)
belladonna oxybutynin (eg, Ditropan)
benztropine (Cogentin) procyclidine (Kemadrin)
biperiden (Akineton) propanthethine (eg, Pro-Banthine)
clidinium (Quarzan) scopolamine (eg, Sopace)
dicyclomine (eg, Bentyl) solifenacin (Vesicare)
glycopyrrolate (eg, Robinul) trospium (Sanctum)
hyoscyamine (eg, Anaspaz) tolterodine (Detrol)
mepenzolate (Cantil) trihexyphenidyl (Artane)
methscopolamine (Pamine)
Also includes: A number of low-potency phenothiazines (See the class below labeled: “5-HT2A, D2 and multiple other receptor antagonism”), a number of tertiary amine TCAs and related antidepressants (See the class below labeled: “Dual norepinephrineand serotonin uptake pump inhibition plus other actions”).
Nicotinic (alpha-4 beta-2 subtype) Receptor Agonism
varenicline (Chantix)

Biogenic Amines (dopamine, norepinephrine, and serotonin)

Catechol-O-Methyltransferase Inhibition
entacapone (Comtan) tolcapone (Tasmar)
Monoamine Oxidase Inhibition
isocarboxazid (Marplan) selegiline (Eldepryl/EMSAM)
phenelzine (Nardil) tranylcypromine (Parnate)
Biogenic Amine Release
Release: Classically NE>DA>SE but rank order of effects on these neurotransmitters may vary amongst the different drugs in this class.
amphetamines (eg, Desoxyn) methamphetamine
benzphetamine (Didrex) methylphenidate (eg, Ritalin)
dextroamphetamine (eg, Dexedrine) phendimetrazine (eg, Prelu-2)
diethylpropion (eg, Tenuate) phentermine (eg, Lonamin)

Dopamine

Dopaminem Agonism (general)
levodopa (dopamine precursor, dopamine agonism [general] component of Sine met).
Dopamine-2 (D2) Agonism
bromocriptine [+partial D1 agonism]: (Parlodel) pramipexole [+ D3 agonism but no D1 activity]: (Mirapex)
pergolide [+D1 agonism]: (Permax) ropinirole [+ D3 agonism but no D1 activity]: (Requip)
Dopamine Uptake Inhibition
amantadine (Symmetrel) cocaine
benzphetamine (Didrex) methamphetamine (eg, Desoxyn)
bupropion (Wellbutrin, Zyban)
Dopa Decarboxylase Inhibitor
carbidopa (Component of Sinemet)
Selective D2 Receptor Antagonism
fluphenazine (eg, Prolixin) piperazine (Entacyl)
haloperidol (eg, Haldol) trifluoperazine (eg, Stelazine)
perphenazine (eg, Trilafon) triflupromazine (eg,Vesprin)
pimozide (Orap)
D2 Receptor Partial Agonism
aripiprazole (Ability)
D2 Receptor Antagonism Plus Multiple Other Effects
See 5-HT2A, D2 and multiple other effects below.

Ethanol

Solubilizes electrically excitable membranes.

GAM

Barbiturates
(enhance the binding of GABA to GABAA receptors and promote rather than displace the binding of benzodiazepines)
amobarbital (Amytal) phenobarbital (eg, Nembutal)
butabital (eg, Butisol) phenobarbital
mephobarbital (Mebaral) primidone (Mysoline)
metharbital secobarbital (Seconal)
Barbiturate-Like Drugs
chloral hydrate (eg, Aquachloral) ethchlorvynol (Placidyl)
Benzodiazepine Binding Site Agonism
alprazolam (eg, Xanax) lorazepam (eg, Ativan)
chlordiazepoxide (eg, Librium) midazolam (eg, Versed)
clonazepam (eg, Klonopin) prazepam (Centrax)
clorazepate (eg, Tranxene) quazepam (Doral)
diazepam (eg, Valium) temazepam (eg, Restoril)
estazolam (eg, ProSom) triazolam (eg, Halcion)
flurazepam (eg, Dalmane) zolpidem (Ambien)
halazepam (Paxipam)
Benzodiazepine-Like Drug
meprobamate (eg, Miltown)
GABA Transaminase Inhibition and Stimulation of Slutaminic Acid Decarboxylase
divalproex sodium (Depakote) valproate sodium (Depacon)
valproic acid (Depakene)
Promotion of Nonvesicular Release of SABA
gabapentin (Neurontin)

Glutamate (N-methyl-D-aspartate receptor)

memantine (Nameda)

Herbals

ginkgo biloba St. John’s Wort
ginseng

Histamine (Centrally Active) (H1) Antagonism

chlorpheniramine diphenhydramine (Benadryl)
cyclobnezaprine (Flexeril) hydroxyzine (Atarax)
Also includes: a number of low potency phenothiazines (See the class below labeled: “5-HT2A, D2 and multiple other receptor antagonism”), a number of tertiary amineTCA and related antidepressants (See the class below labeled: “Dual norepinephrineand serotonin uptake pump inhibition plus other actions”).

Ion Channel Inhibition

carbamazepine (eg, Tegretol) slows the recovery of voltage-activated Na+ channels.
dantrolene (Dantrium) interferes with the release of Ca++ from sacroplasmic reticulum.
felbamate (Felbatol) inhibits NMDA-evoked responses and potentiates GABA-evoked responses.
lithium (eg, Eskalith) substitutes for multiple ions.
lamotrigine (Lamictal) [has the effects of carbamazapine] plus inhibition of glutamate release.
mephenytoin (Mesantonin) slows recovery of voltage-activated Na+ channels.
phentyoin (eg, Dilantin) slows recovery of voltage-activated Na+ channels.
topiramate (Topamax) reduces voltage-gated Na+ currents, enhances postsynap-tic GABAA receptor currents, and limits activation of AMPA-kainate subtypes of the gluta mate receptor.
Other CNS drugs with potentially clinically relevant effects on ion channels at usual concentrations include: a number of low potency phenothiazines (See the class below labeled: “5-HT2A, D2 and multiple other receptor antagonism”), a number of tertiary amine TCAs and related antidepressants (See the class below labeled: “Dual norepinephrine and serotonin uptake pump inhibition plus other actions”). Thioridazine has a black box warning because of such effects.

Norepinephrine

alpha-1 Antagonism
This mechanism is not known to mediate any desired CNS effect, thus no neuro-psychiatric medications were developed to have only this specific mechanism of action. Nevertheless, several neuropsychiatric medications do achieve concentrations under clinically relevant dosing conditions, which block this receptor. These medications include: amitriptyline, chlorpromazine, clozapine, quetiapine, nefazodone, risperidone, thioridazine, and trazodone. See Tables 2, 8, and 9 for relative binding affinities to this receptor by these drugs.
alpha-2 Agonism
clonidine (eg, Catapres)
Norepinephrine Uptake Pump Inhibition
atomoxetine (Strattera) nortriptyline (eg, Pamelor)
cocaine phentermine (eg, lonamine)
desipramine (eg, Norpramin) protriptyline (eg, Vivactil)
maprotiline (eg, Ludiomil) reboxetine (Vespar)
Dual Norepinephrine and Serotonin (NE>SE) Uptake Pump Inhibition Plus Other Actions
amitriptyline (eg, Elavil) doxepin (eg, Sinequan)
amoxapine (eg, Ascendin) imipramine (eg, Tofranil)
clomipramine (eg, Anafril) trimipramine (eg, Surmontil)

Opiate Receptors

alfentanil (Alfental) nalbuphine (eg, Nubain)
buprenorphine (Buprenex) opium (eg, Paregoric)
codeine oxycodone (Roxicodone)
fentanyl (eg, Sublimaze) pentazocine (eg, Talwin)
hydrocodone (eg, Vicodin) prophyphene (eg, Darvon)
hydromorphine (eg, Dilaudid) sufenatil (eg, Sufenta)
meperidine (eg, Demerol) tramadol (Ultram)
methadone (eg, Dolophine)

Serotonin

5-HT1A Partial Agonism
buspirone (eg, Buspar)
5-HT1B/D Agonism
ergotamine (eg, Ergomar) dihyrdoergotamine (D.H. E. 45)
naratriptan (Amerge) sumitriptan (Imitrex)
rizatriptan (Maxalt) zolmitriptan (Zomig)
5-HT2 Receptor Antagonism
cyproheptadine (Periactin) nefazodone (Serzone)*
methysergide (Sansert) trazodone (eg, Desyrel)*
mirtazapine (Remeron)*
* See Table 8 for relative effects on neuroreceptors.
5-HT2A, D2 and Multiple Other Receptor Antagonism – Newer Antipsychotics**
asenapine (Saphris) quetiapine (Seroquel)
iloperidone (Fanapt) risperidone (Risperdal)
olanzapine (Zyprexa) ziprasidone (Geodon)
paliperidone (Invega)
** See Table 9 for relative effects on neuroreceptors for all of these drugs.
5-HT2A, D2 and Multiple Other Receptor Antagonism – Older Antipsychotics
chlorpromazine (eg, Thorazine)*** prochlorperazine (eg, Compazine)
clozapine (eg, Clozaril)*** promethazine (eg, Phenergan)
loxapine (eg, Loxitane)*** promazine (eg, Sparine)
mesoridazine (eg, Serentil) thiethylperazine (Torecan)
propiomazine (Largon) thioridazine (eg, Mellaril)***
*** See Tables 2 and 9 for relative effects on neuroreceptors.
Serotonin Uptake Inhibition
dexfenfluramine (Redux) Fenfluramine (Pondimin)
Selective Serotonin Uptake Inhibition
citalopram (Celexa) fluvoxamine (eg, Luvox)
escitalopram (Lexapro) paroxetine (Paxil)
fluoxetine (eg, Prozac) sertraline (Zoloft)
Dual Serotonin and Norepinephrine (5-HT≥NE) Uptake Pump Inhibition
desvenlafaxine (Pristiq) sibutramine (Meridia)
duloxetine (Cymbalta) venlafaxine (Effexor)
milnacipran (Savella)

5-HT = serotonin; D2 = dopamine-2; TCAs = tricyclic antidepressants; NE = norepinephrine; DA = dopamine; SE = serotonin; GABA = Ύ-aminobutyric acid; NMDA = N-methyl-D-aspartate AMPA = α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid; CNS = central nervous system.

Psychotherapeutic Drugs:
* Antidepressants
* Antipsychotics/Antimanics
* Antianxiety Drugs
* Stimulants and Non-stimulants for ADHD
* Smoking Cessation Drugs, Drug Addiction Treatments and Other Psychotherapeutics

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