PSYCHIATRIC PHARMACOLOGY

Receptor typeEffects of psychiatric drugsReceptor type

Dopamine (D2)Antagonists antipsychotic effect, relief of + symptoms of schizophrenia, extrapyramidal symptoms, increased prolactin levelsSerotonin 3 (5-HT3)

Serotonin 1A (5-HT1A)Agonists antidepressant & anxiolytic effectsAlpha-1 adrenergic (-1)

Serotonin 2A (5-HT2A)Antagonists improvement in neg symptoms of schizophrenia and improved cognitionHistamine (H1)

Serotonin 2C (5-HT2C)Antagonists weight gain and associated risksMuscarinic (m1)

Class & MOAGeneric AgentBrandInfo

SSRIs: inhibit reuptake of serotonin as well as slight effects on histamine-R, 1-R, and muscarinic-RFluoxetineProzac

-Longest half-life = highest risk for serotonin syndrome-Many drug interactions-Most stimulating SSRI-Lowest weight gain = good for eating disorders

-AEs: GI, CNS, sexual, sedation, fatigue, dry mouth, hypotension, withdrawal if d/c abruptly, prolonged QT, rash, insomnia, asthenia, seizure, tremor, somnolence, mania, suicidal ideation, worsened depression-Risk of serotonin syndrome: shivering, hyperreflexia, myoclonus, ataxia, n/v/d

CitalopramCelexa-Low risk of sexual AEs

EscitalopramLexapro

FluvoxamineLuvox

SertralineZoloft-Few drug interactions-Highest risk of GI problems

ParoxetinePaxil-Shortest half-life = highest risk of d/c symptoms-Most sedating SSRI and greatest weight gain and greatest sexual AEs-Greatest anticholinergic activity

SNRIs: inhibits reuptake of both serotonin and norepinephrineVenlafaxine (ER avail)Effexor-HTN-Sedating-Equally effective as SSRIs for treating major depression-May be more effective in the setting of diabetic neuropathy, fibromyalgia, msk pain, stress incontinence, sedation, fatigue, and patients with comorbid anxiety-AEs: GI, HTN, CNS, permanent sexual?, diaphoresis, dizziness, fatigue, insomnia, blurred vision, suicidal ideation, dysuria, worsened depression-Fewer drug interactions

DuloxetineCymbalta-Less AEs than venlafaxine-Works well for fibromyalgia-Good for sleep and pain

DesvenlafaxinePristiq

Atypical AntidepressantsBupropionWellbutrin

-May increase sexual function-Has stimulant effects = good for comorbid ADHD or for helping quit smoking but dont use if comorbid anxiety or eating disorder-AEs: lower seizure threshold, insomnia, nervousness, agitation, anxiety, tremor, arrhythmias, HTN, tachycardia, S-J, weight loss, GI, arthralgia or myalgia, confusion, dizziness, HA, psychosis, suicidal ideation

Mirtazapine

Remeron-Less nausea and sexual AEs-Overdose is generally safe-AEs: the most sedating antidepressant (= good for insomnia!), weight gain, orthostatic hypotension, dizziness, dry mouth

NefazodoneSerzone

Trazodone

Oleptro-AEs: arrhythmia, hyper or hypotension, diaphoresis, GI, hemolytic anemia, leukocytosis, dizziness, HA, insomnia, lethargy, memory impairment, seizure, somnolence, priapism, weight gain

Class & MOAGeneric AgentBrandInfoClass & MOA

Tricyclic Antidepressants: inhibits reuptake of both serotonin and norepinephrineAmitriptylineElavil

-Good for sleep, pain, and depression

-AEs: anticholinergic, CV, CNS, weight gain, sexual dysfunction, decreased seizure threshold-CV effects: orthostatic hypotension, conduction disturbance, cardiotoxicity consider EKG prior to initiation-Overdose can be lethal

ClomipramineAnafranil

DesipramineNorpramin-Least sedating

DoxepinSilenor

ImipramineTofranil

NortriptylinePamelor

MAOIs: block destruction of monoamines centrally and peripherallyPhenelzineNardil-Irreversible-MAO-A acts on norepinephrine and serotonin-MAO-B acts on phenylethylamine and DA-AEs: anticholinergic, lower seizure threshold, weight gain, rash, orthostasis, sexual dysfunction, insomnia or somnolence, HA, HTN crisis in presence of monoamines-Must be on tyramine-free diet = no wine, beer, cheese, aged food, or smoked meats-Overdose is lethal-2 week washout period of other antidepressants needed before starting in order to prevent serotonin syndrome

TranylcypromineParnate-Irreversible

SelegilineEmsam (transdermal)-Reversible

Mood StabilizersCarbamazepineTegretol-MOA: antiepileptic; inhibits voltage-gated Na channels-AEs: diplopia, dizziness, drowsiness, nausea, Stevens-Johnson (dont use in Asians), hypoCa, hypoNa, SIADH, hematologic, hepatitis monitor CBC, LFTs, mental status, bone density, levels-Contraindicated with bone marrow depression-Decreases effectiveness of OCPs and warfarin-Pregnancy D

ValproateDepakeneDepakote-MOA: antiepileptic; increases GABA-AEs: GI upset, sedation, unsteadiness, tremor, thrombocytopenia, palpitations, immune hypersensitivity, ototoxicity monitor CBC and LFTs and levels-Contraindicated with liver disease-Many drug interactions-Pregnancy D

LamotrigineLamictal-MOA: blocks voltage-gated Na channels and inhibits glutamate release-AEs: nausea, diplopia, dizziness, unsteadiness, HA, rash, Stevens-Johnson, hematologic, liver failure-Overdose can be fatal-Interaction with valproate-Pregnancy C

LithiumEskalithLithobid-Inhibits adenylate cyclase-AEs: diabetes insipidus, cognitive complaints, tremor, weight gain, sedation, diarrhea, nausea, hypothyroidism-Many drug interactions-Requires baseline BMP, TSH, EKG, Ca as well as monitoring of BMP and TSH q 6-12 mo-Monitoring for signs of toxicity: nausea, tremor, polyuria, thirst, weight gain, diarrhea, cognitive impairment-Need to monitor levels -Pregnancy D for neural tube defects

GabapentinNeurontin-AEs: somnolence, dizziness, ataxia, fatigue, leukopenia, weight gain, Stevens-Johnson

Class & MOAGeneric AgentBrandInfo

Benzodiazepines: GABA-R agonists CNS inhibitionChlordiazepoxideLibrium-Long-acting-Used often during EtOH withdrawal

ClorazepateTranxene-Long-acting

DiazepamValium-Long-acting

FlurazepamDalmane-Long-acting

AlprazolamXanax-Intermediate acting-Approved for panic disorder

ClonazepamKlonopin-Intermediate acting-Approved for panic disorder

LorazepamAtivan-Intermediate acting

TemazepamRestoril-Intermediate acting

OxazepamSerax-Short acting

TriazolamHalcion-Short acting

Other AnxiolyticsBuspironeBuSpar-5-HT partial agonist-Gradual onset in 2 weeks-Does not potentiate effects of alcohol = useful in alcohols-Low addiction potential = good for pts who were addicted to benzos or other drugs-AEs: sexual, dizziness, nausea, HA-Drug interactions

Typical Antipsychotics: nonselective DA-R antagonistsHaloperidol (inj avail)Haldol-Good for acute agitation as onset is 30 min

FluphenazineProlixin

PerphenazineTrilafon

ThioridazineMellaril-AE: retinitis pigmentosa-Less risk of EPSEs

ChlorpromazineThorazine-Less risk of EPSEs

Atypical Antipsychotics: block postsynaptic DA-R, block serotonin-R, variable effect on histaminic and cholinergic-R

AripiprazoleAbilify

Asenapine (SL tablet avail)Saphris-Costs $$$

Olanzapine (inj avail)ZyprexaZyprexa Relprevv (inj)-High risk of weight gain and metabolic syndrome-Injectable can cause post-injection delirium must give at healthcare facility and monitor for 3 hours

QuetiapineSeroquel-Need q 6 month eye exams due to risk of cataracts

RisperidoneRisperdalConsta (inj)-Least amount of AEs-Highest risk of hyperprolactinemia

ZiprasidoneGeodon-AE: dose-related QT prolongation-Less wt gain

Clozapine

Clozaril-The only atypical antipsychotic proven effective in treatment of schizophrenia-Use limited by AEs: high risk of weight gain and metabolic syndrome, seizures, agranulocytosis, myocarditis, lens opacities need to monitor WBC and ANC frequently

IloperidoneFanapt-Costs $$$-Not proven better than other atypical antipsychotics

LurasidoneLatuda-Best choice for reversing metabolic effects

Paliperidone (inj avail)InvegaInvega Sustenna (inj)

Management of Psychiatric Drug Adverse Effects

Dystonias-Benztropine-Biperiden-Diphenhydramine-Trihexyphenidyl

Akathisias = restlessness-Propranolol-BenzosParkinsonianism-Amantadine-Levodopa

Extrapyramidal Symptoms-Parkinsonian syndrome, acute dystonias, akathisia-Benztropine-Benadryl