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Mental Health Pharmacology II. Chelsea Mannebach Pharmacy Resident August 17 th , 2011. Topics. Schizophrenia Bipolar Disorder Anxiety Disorders Eating Disorders. Schizophrenia. Psychiatric disorder characterized by profound disruption in perception, cognition, and emotion
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Mental Health Pharmacology II Chelsea Mannebach Pharmacy Resident August 17th, 2011
Topics • Schizophrenia • Bipolar Disorder • Anxiety Disorders • Eating Disorders
Schizophrenia • Psychiatric disorder characterized by profound disruption in perception, cognition, and emotion • ~1% of the United States population • Types • Paranoid • Disorganized • Catatonic • Undifferentiated • Residual
Diagnosis • DSM-IV Criteria • Two or more of the following in a one month period • Hallucinations • Delusions • Disorganized speech • Grossly disorganized or catatonic behavior • Negative symptoms
Pathophysiology • Dopamine hyperactivity in limbic system • Dopamine hypo-functioning in the prefrontal cortex • Decreased glutamate • NMDA receptor dysfunction
Four Dopamine Pathways • Mesolimbic • Nigrostriatal • Mesocortical • Tuberoinfundibular
Drug Therapy • What are some common drugs used to treat schizophrenia?
Conventional Antipsychotics • Chlorpromazine (Thorazine) • Thioridazine (Mellaril) • Perphenazine (Trilafon) • Fluphenazine (Prolixin) • Haloperidol (Haldol)
Atypical Antipsychotics • Clozapine (Clozaril) • Risperidone (Risperdal) • Olanzapine (Zyprexa) • Quetiapine (Seroquel) • Ziprasidone (Geodon) • Aripiprazole (Abilify) • Paliperidone (Invega)
Mechanism of Action • Conventional • Dopamine-2 Receptor Antagonist • Non-selective • Atypical • Dopamine-2 Receptor and Serotonin Antagonist • Selective mesolimbic D2 blocking • Serotonin blockade causes decreased extrapyramidal side effects and is beneficial with negative symptoms
Side Effects • Sedation • Orthostasis • Weight gain • Anticholinergic effects • Dystonic reactions • Akathisia • Pseudoparkinsonism • Tardive dyskinesia • Neuroleptic malignant syndrome • Dermatologic effects • Hypothalmic effects • Cardiac effects • Opthalmologic effects
Side Effect Management • Dystonic reactions • benztropine (Cogentin) 1-2 mg IM or diphenhydramine (Benadryl) 25-50 mg IM every 30 minutes until reaction resolved • Akathisia • Beta blockers (propranolol), benzodiazepines, clonidine, anticholinergics • Pseudoparkinsonism • Amantadine (Symmetrel) 100 mg BID or anticholinergics • TardiveDyskinesia • No effective treatment
NMS Treatment • Stop offending agent • Administer supportive therapy • Fluid and electrolyte replacement • Temperature reduction • Support of cardiac, respiratory and renal function • Pharmacological therapy • Bromocriptine (Parlodel) • Dantrolene (Dantrium)
Acute Schizophrenia Treamtment • Haloperidol or fluphenazine IR 5-10 mg IM and lorazepam 2 mg IM q4h prn • Olanzapine 10 mg IM may also be used and can be repeated in 2 hrs and again 4 hours later (max 30 mg/d) • Ziprasidone 10 mg IM every 2 hours or 20 mg IM every 4 hours (max 40 mg/d)
Maintenance Therapy • Lifelong therapy usually indicated • Use lowest effective dose to decrease risk of side effects • Monitor • Fasting glucose • Lipids • Blood pressure • Weight • Waist circumference
Expert Consensus Treatment Guidelines • Monotherapy • Switch • Clozapine • Combination
Treatment Pearls • All antipsychotics are equally effective if used properly • Clozapine is the only agent approved for refractory schizophrenia • Use past history to help guide therapy • Administer a trial of at least 4-6 weeks when initiating therapy • Alternative dosage forms and compliance • Haloperidol decanoate, Fluphenazine decanoate, Risperidone injection
Bipolar Disorder • Bipolar I • manic episodes and major depressive episodes • Bipolar II • hypomanic episodes and major depressive episodes • Cyclothymia • numerous episodes of hypomania and depression that cannot be classified as major depressive episodes; at least a 2 year period
Diagnosis • DSM-IV • Mania • Heightened mood, flight of ideas, rapid speech, grandiosity, increased energy, decreased sleep, impulsivity, social or occupational impairment • Hypomania • Less severe form of mania (no social impairment) • Dysphoric (mixed mania) • Manic and depressive features, agitation, suicidal ideation, appetite disturbances • Major depression • Rapid cycling • > 4 mood episodes in a year
Pathophysiology • Neurotransmitter imbalance • Decreased serotonin • Increased norepinephrine • Decreased GABA • Increased glutamate
What pharmacological agents are used to treat bipolar disorder?
Mood Stabilizers • Lithium (Lithobid) • Divalproex sodium (Depakote) • Carbamezapine (Tegretol) • Lamotrigine (Lamictal)
Lithium (Lithobid) • Indicated for acute treatment and prophylaxis for both manic and depressive episodes • Mechanism of Action • facilitates GABA function, normalizes transmission of norepinephrine, serotonin and dopamine • Contraindications • renal disease, 1st trimester pregnancy, severe CV disease, hx leukemia; caution in patients with thyroid disease, dehydration • Monitoring • TSH, SCr, CBC, electrolytes, ECG, pregnancy status, Lithium level (acute: 0.6-1.2 mEq/L; maintenance: 0.8-1.0 mEq/L)
Lithium cont. • Side Effects • tremor, polydipsia, N/D, weight gain, hypothyroidsim, mental dulling, acne • Toxicity • Mild: Levels 1.5 – 2.0 mEq/L • GI, muscle weakness, fatigue, tremor • Moderate: Levels 2.0-2.5 mEq/L • Ataxia, lethargy, confusion, severe GI upset • Severe: Levels > 3.0 mEq/L • Impaired consciousness, coma, seizures, death
Lithium Toxicity Management • Discontinue lithium • Gastric lavage • Supportive care • Dialysis
Lithium Drug Interactions • Increase Lithium level • NSAIDS • ACE inhibitors • Fluoxetine • Metronidazole • Diuretics • Sodium depletion • Decrease lithium level • Theophylline • Caffeine • Pregnancy • Osmotic diuretics (mannitol and urea)
Divalproex Sodium • First line indication for acute manic episodes; effective in rapid cyclers • Mechanism of Action • thought to increase GABA or mimic its action at the postsynaptic receptor site • Contraindications • hepatic dysfunction*, pregnancy (if risk outweighs benefit supplement with folic acid 4-5 mg/d to decrease risk of neural tube defects) • Monitoring: LFTs, CBC, VPA level ( 50-125 mcg/mL)
Divalproex sodium cont. • Side Effects • GI upset, weight gain, alopecia, increased LFTS, pancreatitis, sedation • Drug Interactions • CYP450 2C19 inhibitor • increased sedation with phenobarbital and benzos • Pearls • take with food • take a multivitamin with selenium and zinc if alopecia occurs
Carbamazepine (Tegretol) • Second line therapy for acute treatment and prophylaxis of bipolar disorder; more effective in rapid cyclers and mixed episodes • Mechanism of Action • Unknown; inhibits transmission at Na channel • Contraindication • previous bone marrow suppression • Monitoring • CBC, electrolytes, LFTs, SCr, levels (optimal 4-12 mcg/mL)
Carbamazepine cont. • Side Effects • dizziness, sedation, slurred speech, aplastic anemia, rash • Drug Interactions • CYP 450 1A2, 2C, and 3A4 inducer • CYP 450 2C8 and 3A4 substrate • Induces metabolism of benzodiazepines, clozapine, corticosteroids, oral contraceptives, VPA, warfarin, phenytoin, TCAs and more! • Is inhibited by cimetidine, clarithromycin, diltiazem, verapamil, propoxyphene, metronidazole, lamotrigine and more!
Lamotrigine (Lamictal) • Maintenance treatment of bipolar I disorder • Requires dose titration to avoid rash • Side effects • dizziness, headache, nausea, rash, sedation, anxiety • Caution • Black box warning for severe rash (Stevens-Johnson syndrome) • Drug Interactions • Carbamazepine, phenytoin, oral contraceptives, rifampin, and phenobarbital decrease Lamictal concentrations • VPA increases Lamictal concentrations
Other Potential Therapies • Atypical antipsychotics • All have proven efficacy • Need to dose on higher end • Gabapentin (Neurontin) • Adjunctive therapy • Oxcarbazepine (Trileptal) • Topiramate (Topamax) • Calcium Channel Blockers (last line) • Verapamil for mania
Treatment Guidelines • Acute • Lithium, divalproex sodium, carbamezapine, or antipsychotic • Short term use of a benzo • Maintenance • Monotherapy if possible • Lithium, divalproex sodium, lamotrigine • Depressed phase • Use antidepressants with caution
Anxiety Disorders • Generalized Anxiety Disorder • Panic Disorder • Obsessive-Compulsive Disorder • Social Anxiety Disorder • Simple Phobias • Post-Traumatic Stress Disorder • Substance-Induced Anxiety Disorder
Benzodiazepines • Alprazolam (Xanax) • Chlordiazepoxide (Librium) • Clonazepam (Klonopin) • Clorazepate (Tranxene) • Diazepam (Valium) • Estazolam (ProSom) • Flurazepam (Dalmane) • Halazepam (Paxipam) • Lorazepam (Ativan) • Oxazepam (Serax) • Prazepam (Centrax) • Quazepam (Doral) • Temezapam (Restoril) • Triazolam (Halcion)
Mechanism of Action • Potentiate the inhibitory actions of GABA • Reduce neuronal firing and therefore symptoms of anxiety • Onset • More lipophilic = faster onset of action • Alprazolam • Diazepam • Clorazepate • Flurazepam
Side Effects • Sedation • Dizziness • Confusion • Blurred vision • Psychomotor and cognitive disturbances
Metabolism and Drug Interactions • Patients with hepatic dysfunction or elderly • Use lorazepam, oxazepam, temazepam (LOT) • Metabolized by CYP 3A4 • Alprazolam, diazepam, triazolam • Watch if taken with 3A4 inhibitors (ketoconazole, erythromycin, nefazodone)
Clinical Pearls • Paradoxical reactions in children and cognitively impaired elderly patients • Never abruptly discontinue benzodiazepines, can cause status epilepticus; taper gradually • Use “LOT” in elderly patients to avoid against falls • Avoid use in pregnancy (cleft palate risk) • Abuse potential high • Tolerance is common
Buspirone (Buspar) • Mechanism of Action • Non-benzodiazepine anxiolytic • 5HT-1A partial agonist • No action on GABA • Antianxiolytic effect takes longer to achieve • 2-3 weeks • Side Effects • GI upset, headache, nervousness • Less sedating than benzos, no psychomotor or cognitive impairment, no withdrawal symptoms, little abuse potential
Other therapies • Antidepressants • SSRIs and SNRIs are first line for many patients with comorbid depression and substance abuse problems • Titrate doses slowly • Higher doses are needed to treat anxiety than depression • TCAs and MAOIs are third line • Poor side effect profile • Beta blockers (propranolol, atenolol) • Hydroxyzine
Treatment Guidelines • Start in combination with a serotonergic drug • Taper benzodiazepine after 4-12 weeks • once benefit from SSRI or SNRI has been achieved • Taper slowly over 4-10 weeks • Risk of withdrawal • Often used on PRN basis
Eating Disorders • Anorexia nervosa • Bulimia nervosa • Binge eating disorder
Drug Therapy • SSRIs • Help patients maintain weight after it has been gained • May be more effective in patients with bulima • Fluoxetine (Prozac): higher doses up to 60 mg/day • Topiramate (Topamax) and Zonisamide (Zonegran) • Beneficial in binge-eating disorder and bulima nervosa