Neuropsychopharm Flashcards

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Q

neuropsych drugs pt 1

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amitriptyline clomipramine fluoxetine sertraline buproprion mirtazapine duloxetine phenelzine chlorpromazine clozapine thioridazine fluphenazine haloperidol olanzapine risperidone quetiapine aripiprazole

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3
Q

Which drugs are used in the treatment of depressive disorders?

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SSRIs, SNRIs, Atypical drugs, Tricyclic antidepressants, MAOIs

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4
Q

5-HT uptake inhibitors

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SSRIs- fluoxetine, sertraline

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5
Q

SSRI side effects

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nausea, insomnia, and sexual dysfunction no food rxns, but dangerous “serotonin reaction” (hyperthermia, muscle rigidity, CV collapse) can occur if given with MAOIs

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6
Q

Do SSRIs have fewer or more adverse effects than TCAs and MAOIs?

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less, so overdose risk is reduced

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7
Q

Symptoms of SSRI withdrawal

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-dizziness, light-headedness, vertigo or feeling faint, shock-like sensation, paresthesia, anxiety, diarrhea, fatigue, gait instability, headache, insomnia, irritability, nausea or vomiting, tremor, visual disturbances -symptoms begin within 1-7 days after stopping an SSRI

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8
Q

SSRI approved uses

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Major Depression OCD Panic disorder Social Anxiety Disorder PTSD Generalized Anxiety disorder PMS (now PDD) Hot flashes associated with menopause

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9
Q

effects on drug metabolism, long half-life active metabolite (7 days or more). now available as a sustained release product. used to treat PMS

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fluoxetine

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10
Q

used to treat OCD, PTSD, Panic attacks; less effects on metabolism than fluoxetine, shorter half life.

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sertraline

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11
Q

block both 5-HT and NE reuptake, side effect profile is more SSRI-like than TCA-like

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SNRI drugs

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12
Q

12-18 hr half-life. also approved for neuropathic pain syndromes, fibromyalgia, back pain, and osteoarthritis pain. What is the drug and which patients to do you have to use caution with?

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duloxetine -use caution in patients with liver disease

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13
Q

neuropsych drugs pt 1

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amitriptyline clompiramine fluoxetine sertraline buproprion mirtazapine duloxetine phenelzine chlorpromazine clozapine thioridazine fluphenazine haloperidol olanzapine risperidone quetiapine aripiprazole

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14
Q

drugs without typical TCA structure of SSRI or SNRI action. May or may not block catecholamine uptake

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Atypical antidepressants

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15
Q

weakly blocks NE and dopamine uptake. No weight gain or sexual dysfunction. what is the drug and what is it also approved for?

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bupropion -also approved for nicotine withdrawal and seasonal affective disorder

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16
Q

blocks presynaptic alpha2 receptors in the brain. increases appetite

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mirtazapine -good for AIDS patients with AIDS wasting syndrome

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17
Q

blocks NE and 5-HT reuptake; first highly effective drugs for the treatment of depression; now used secondarily to SSRIs and other newer compounds

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tricyclic antidepressants

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18
Q

pharmacokinetics of TCAs

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rapidly absorbed after parenteral or oral administration; relatively high concentrations are found in the brain and heart.

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19
Q

demethylated to active metabolites which are used as drugs themselves; long plasma half-life (8-100 hrs)

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amitriptyline

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20
Q

side effects of TCAs

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sedation cardiac abnormalities (due to anticholinergic effects and increased NE concentrations–>palpitations, tachycardia, and arrhythmias) overdoses: acute toxicity (symptoms include hyperpyrexia, hyper- or hypotension, seizures, coma, and cardiac conduction defects)

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21
Q

side effects of TCAs

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sedation cardiac abnormalities (due to anticholinergic effects and increased NE concentrations–>palpitations, tachycardia, and arrhythmias) overdoses: acute toxicity (symptoms include hyperpyrexia, hyper- or hypotension, seizures, coma, and cardiac conduction

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22
Q

contraindications for TCAs?

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recent MIs

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23
Q

TCAs and drug interactions?

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TCAs effect absorption and metabolism of other drugs TCAs block guanethidine uptake sympathomimetic drugs; particularly indirect acting agents

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24
Q

therapeutic uses of TCAs

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major depressive disorder (3rd choice) enuresis in childhood- imipramine chronic pain (neuropathic pain that opiates do not handle as well)- amitriptyline OCD- clomipramine and SSRIs

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non-selective MAOI
phenelzine
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produces mood elevation in depressed patients; may progress to hypomania particularly in bipolar disease; corrects sleep disorders in depressed patients; may produce stimulation in normals; antidepressant action takes about 2 weeks
MAOIs
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symptoms of actue toxicity of MAOIs
agitation, hallucinations, hyperpyrexia, convulsions, and changes in bp
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what do you have to restrict in patients on MAOIs?
dietary intake of tyramine
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therapeutic uses of MAOIs
major depression (not first drug of choice, however) narcolepsy
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other treatments for depression
electroconvulsive shock therapy (ECT) transcranial magnetic stimulation (TMS) cortical and subcortical electrical stimulation (still experimental)
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nonspecific blockers of NE and 5-HT reuptake
amitriptyline
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selective serotonin reuptake inhibitors (SSRIs)
fluoxetine, sertraline
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serotonin-norepinephrine reuptake inhibitors (SNRIs)
duloxetine
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monamine oxidase inhibitors (MAOI)
phenelzine
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drugs with other monamine mechanisms
bupropion, mirtazapine
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SSRI-like; used to treat OCD
clomipramine
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actions of antipsychotic drugs
(treatments are not curative) decrease in psychotic behavior (negative symptoms of schizophrenia are not well treated by older typical agents) sedation
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actions of antipsychotic drugs
decrease in psychotic behavior (negative symptoms of schizophrenia are not well treated by older typical agents) sedation extrapyramidal effects (biggest concern; dystonias, parkinsonism, akathisia, tar dive dyskinesia)
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side effects of antipsychotic drugs. How can the long-term side effects be prevented?
extrapyramidal effects (biggest concern; dystonias, parkinsonism, akathisia, tardive dyskinesia); tardive dyskinesia can be prevented by "drug holidays" anticholinergic (dry mouth, blurred vision, urinary retention) orthostatic hypotension neuroendocrine effects (result of dopamine receptor blockade; prolactin effects and gynocomastia) allergic and idiosyncratic effects (liver, blood, and cutaneous) cardiac effects (thioridazine) decreased seizure threshold (particularly phenothiazines) weight gain (diabetes related events are more common with atypicals, particularly olanzapine, risperidone, clozapine, and quetiapine)
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what is the potentially lethal side effect of antipsychotic drugs and what does it involve? How do you treat this?
neuroleptic malignant syndrome; potentially lethal hypodopaminergic side effect) hyperthermia, parkinson-like symptoms (muscular rigidity and tremor), mutism, and possible death treatment: cooling and hydration, bromocriptine and dantrolene (muscle relaxants, most common when used with SSRIs or SRNIs
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original antipsychotics, currently less commonly used
phenohiazines
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phenothiazine; aliphatic side chain; low to medium potency, sedative, pronounced anticholinergic actions
chlorpromazine
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phenothiazine; piperidine side chain; low potency, sedative, less exrapyramidal actions, anticholinergic
thioridazine
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phenothiazine; piperazine side chain; high potency, less sedative, more exrapyramidal reactions, less cholinergic
fluphenazine
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why are atypical antipsychotics used over older typical antipsychotics?
need for better antipsychotic drugs, more acceptable side-effect profile, more efficacious in treating negative symptoms of schizophrenia in general, atypical antipsychotics have lower incidence of extrapyramidal symptoms (better compliance), possible lower incidence of tardive dyskinesia, improve negative symptoms, improve positive symptoms in many antipsychotic-resistant or refractory patients, less impact on cognitive functioning (??), more cost effective (???)
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why are atypical antipsychotics used over older typical antipsychotics?
need for better antipsychotic drugs, more acceptable side-effect profile, more efficacious in treating negative symptoms of schizophrenia
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atypical antipsychotic agents (5)
clozapine, olanzapine, risperidone, quetiapine, aripiprazone
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blocks D4 and 5-HT2 receptors, little effect of D2, muscarinic antagonist, improves positive symptoms even in patients not helped by other drugs, improves negative symptoms
clozapine
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side effects of clozapine
lowers seizure thresholds more than other antipsychotics (5-10% incidence) can cause fatal agranulocytosis, which requires monitoring!!
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potent 5-HT2 antagonist, D1 and D2 antagonist, some D4, few extrapyramidal symptoms (5-HT\>D)
olanzapine
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side effects of olanzapine
weight gain and diabetes related adverse events reports of olanzapine abuse no agranulocytosis less seizure incidence than clozapine
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combined D2 and 5-HT2 antagonist, greater reduction in negative symptoms and less extrapyramidal symptoms than traditional antipsychotics; paliperidone is the active metabolite, both are available as intramuscular depot preparations
risperidone
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side effects of risperidone worse or better than clozapine?
less seizure activity and less antimuscarinic than clozapine
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structurally related to clozapine, similar to risperidone and olanzapine in effects on schizophrenia symptoms and side effects; shorter half-life; approved for augmentation in depression. any abuse?
quetiapine; some reports of abuse
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partial D2 agonist and 5-HT2 antagonist; also approved as an adjunct in depression (augmentation)
aripiprazole
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uses of antipsychotic drugs
acute psychotic episodes (no matter what the cause) chronic schizophrenia manic episodes, bipolar disorder (aripiprazole, olanzapine, quetiapine, risperidone) schizoaffective disorder (paliperidone) augmentation in depression (aripiprazole, olanzapine, quetiapine) Tourette's syndrome (haloperidol, pimpozide) antiemesis (not thioridazine)
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monovalent cation, blocks manic behavior, no behavioral effects in "normals" inhibits phosphatase that converts IP2 to IP1 unbound to plasma proteins, 95% of dose eliminated in urine narrow therapeutic window
lithium levels raised by diuretics, ACE inhibitors, Ang II receptor blockers
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lithium side effects
fatigue, tremor, GI symptoms, ataxia higher levels cause hyperactive deep reflexes, rigidity, coma
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CI of lithium
pregnancy
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clinical uses of lithium
mania, prevent recurrences of bipolar disease, cluster headaches
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alternatives to lithium
carbamazepine, valproic acid for initial control of manic symptoms: haloperidol
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blocks sodium channels, no interaction with GABA unpredictable absorption, hepatic enzyme induction used for partial seizures
carbamazepine
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blocks repetitive neuronal firing, can reduce some Ca currents, increases GABA concentrations bound to plasma protein, in extracellular fluid used as first line drug in bipolar disease, sedating
valproic acid inhibits metabolism of drugs including carbamazepine
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treatment of depressive episodes associated with bipolar disease (drug combination)
olanzapine and fluoxetine
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carbamazepine side effects
CNS side effects such as sedation, confusion and ataxia, diplopia
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valproic acid side effects
GI upset, weight gain, hair loss not dose related: hepatotoxicity and teratogenic (spinal bifida)
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somatic correlates of anxiety
ANS arousal, voluntary muscle activation (jitteriness, tremor) complications: substance abuse
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treatment of anxiety and insomnia
benzodiazepines, SSRIs, buspirone, classical antihistamines, EtOH, cannabis, opiates, barbiturates
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benzodiazepine receptor agonists
diazepam, zolpidem
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benzodiazepine receptor antagonists
flumazenil
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partial agonist for 5-HT 1A, also binds to dopamine receptors delayed onset, little sedation, no dependence or cross-tolerance used for GAS
buspirone
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benzodiazepines used to treat anxiety
diazepam, alprazolam, lorazepam
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rapid onset of action, long duration used as hypnotic
flurazepam
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fast onset of action, high lipid solubility, rapid redistribution muscle relaxant due to actions in spinal cord
diazepam
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less lipophilic, slower absorption and onset of action, longer duration of action after single dose used as hypnotic
lorazepam
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CNS effects of benzodiazepines
decreased anxiety, sedation, hypnosis, muscle relaxation, anterograde amnesia, anticonvulsant action, minimal CV/resp actions alone
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benzodiazepine drug interactions
produce additive CNS depression with other depressants, can affect hepatic metabolism of drugs like cimetidine
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clinical uses of benzodiazepines
anxiety states, sleep disorders, seizure treatment, IV sedation and anesthesia some used for alcohol withdrawal, acute manic episodes
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benzo used for alcohol withdrawl
chlordiazepoxide
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benzo used for acute manic episodes
clonazepam
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symptoms of benzo withdrawal
anxiety, insomnia, irritability, headache, hyperacusis, hallucinations, seizures
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other treatments for anxiety
SSRIs & SNRIs, beta-blockers, other sedatives (rarely)
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hypnotic that binds to BDZ receptor on GABA complex weak anxiolytic, muscle relaxant and anticonvulsant preserves stage 3 and 4 sleep, duration 5-6hr
zolpidem
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adverse effects of hypnotic effects
daytime sedation, ataxia, rebound insomnia, tolerance and dependence, occasional idiosyncratic excitement and stimulation
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act at GABA A, rapidly absorbed and distributed, highly lipid soluble, renal excretion, additive with other CNS depressants used as anticonvulsant
barbiturate
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barbiturate side effects
general CNS depression, anticonvulsant, respiratory depression tolerance (not uniform) physical dependence with withdrawal symptoms (seizures)
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skeletal muscle relaxants
used to reduce muscle tone associated with spasticity related to MS injuries/other musculoskeletal disorders
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GABA-mimetic agent working at GABA B receptors, interferes with release of NT used to reduce spasticity less sedation
baclofen
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alpha2 adrenergic agonist, relieves muscle spasm side effects include drowsiness, hypotension, dry mouth interacts with CYP1A2 inhibitors
tizanidine
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other agents used as muscle relaxants
botulinum toxin, dantrolene
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what is the single "dose" size for alcohol. What is the dosing for beer, wine, and 80 proff liquor?
about 14 grams this is the amount in: 12 ounces of beer 5 ounces of wine 1.5 ounces of 80 proof liquor
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when a 70 kg person consumes 14 g of alcohol what does their blood alcohol become?
30 mg/dl 30mg% 0.03% w/v This is equal to 7mM concentration
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pharmacokinetics of alcohol
primary route of administration is oral rapid absorption primarily from the sall intestine, but can be absorbed through the GI tract
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what factors effect the absorption of alcohol?
increased by gastric emptying enhanced by carbonated beverages decreased by the presence of food
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what is effects the rate of absorption of alcohol
ethanol concentration rate of ethanol consumption
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distribution of ethanol? does it cross membranes? distribution to organs?
total body water thus, Vd is equal to the volume of body water; essentially equal to the body weight crosses membranes freely (including INTO the alveolae from the lung capillaries=basis for the brethalizer test of expired air) distribution to individual organs depends on the degree of tissue vascularization and the amount of blood flow
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what is ethanol metabolized to?
90-98% of ethanol that is ingested is metabolized to **acetaldehyde** by two enzymatic routes (the remainder is eliminated unchanged in the breath, sweat, and saliva)
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does ethanol undergo a first pass effect?
Yes, ethanol has a significant first pass effect by both gastric and liver alcohol dehydrogenases
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what is the primary, rate-limiting pathway of alcohol metabolism? what type of kinetics does this enzyme undergo?
alcohol dehydrogenase primarily in liver and GI tract zero order kinetics (ex. 10g/hr in 70kg person-since one drink is 14g, takes about 1.5 hours to metabolize one drink)
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what pathway does alcohol get shunted to once the alcohol dehydrogenase pathway becomes overwhelmed?
mixed function oxidase system (MFOS) through CYP2E1
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pharmacokinetics for CYP2E1 pathway of ethanol metabolism?
high Km for ethanol (low affinity) induced in chronic alcoholics results in important drug interactions
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what enzyme converts acetaldehyde to acetic acid during ethanol metabolilsm?
aldehyde dehyrdogenase
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what are some properties of aldehyde dehydrogenase?
mitochondrial enzyme inhibited by disulfiram genetic polymorphisms in the gene that are very prevalent in Asian cultures
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what are two consequences of alcohol metabolism? and what do these two things cause/lead to?
increased NADH (causes inhibition of the TCA cycle; reduced gluconeogenesis; reduced fatty acid oxidation) increased acetaldehyde (protein adduct formation; results in inflammation; inhibition of microtubules which can interfere with cellular and liver function; depletion of glutathione)
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metabolic changes from alcohol metabolism can cause what side effects?
fatty liver hepatic inflammation induction of CYP2E1 (metabolism of xenobiotics to carcinogenic agents) --\>Bad news for the liver!!
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what can heavy ethanol loads produce?
heavy alcohol load produces transient hypogylcemia (due to insulin secretion) alcohol-induced ketoacidosis (increased serum ketones along with a mild increase in glucose; when our bodies start to use fat as fuel we get acid-base and metabolic dysfunction)
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what are the CNS effects of ethanol?
several ion channels are sensitive to the presence of ethanol most important is the GABAreceptor-ligand gated chloride channel (causes a hyperpolarization) disturbs the balance between excitatory and inhibitory neurotransmission in the brain; promotes inhibition
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acute effects of ethanol?
dose-dependent; CNS depressant effects from alcohol: sedation, "euphoria", increased reaction time, poor motor function, ataxia, emesis, stupor, coma, and death
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chronic ethanol effects? | (Liver and GI specific effects)
Liver and GI effects: steatosis (fatty liver) Hepatitis C (often a co-morbid disease) cirrhosis (due to liver necrosis and chronic inflammation) gastritis, pancreatitis, malabsorption of vitamins chronic diarrhea cancers, including esophageal, liver, and bladder
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chronic ethanol effects on the CNS?
tolerance occuring due to: adaptive neuronal changes (chronic ethanol--\>CNS depression--\>up-regulation of excitatory transmission to compensate) and metabolic tolerance (due to up-regulation of CYP2E1) both psychological (craving) and physical dependence (withdrawal can be dangerous, especially because of seizures if metabolic imbalance occurs) alcohol addiction
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how prevalent is alcoholism?
alcohol addicition occurs in 5-10% of men and 3-5% of women
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what are the effects of neurotoxicity of alcoholism?
neuralgias and peripheral nerve injury memory impairment; blackouts thiamine deficiency associated with chronic use can produce: cerebral/cerebellar atrophy, Wericke's encephalopathy, Korsakoff's psychosis
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what are the teratogenic effects of alcohol?
associated with chronic maternal alcohol abuse traid of symptoms in new born: retarted body growth facial abnormalities CNS dysfunction Ethanol and/or acetaldehyde affect embryonic cell proliferation dose-dependent, but minimum dose is not known
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do alcohol/ drug interactions occur?
Yes CNS depressants are additive (barbituates; benzodiazepines; opiates; neuroleptics) interactions with drug metabolism (acute, high doses can inhibit CYP-mediated metabolism; chronic ethanol induces CYP2E1, therefore accelerates metabolism of some drugs) acetaminophen toxicity (is worse in alcoholics of when intoxicated because glutathione is depleted)
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clinical pharmacology of ethanol-actue toxicity? how can you treat acute alcohol toxicity?
acute intoxication: generally 400mg/dl is lethal (12 drinks) support respiration and prevent aspiration of vomit correct any metabolic problems (ex. dehydration, hypoglycemia, ketosis, electrolyte imbalance)
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what are the signs of alcohol withdrawal and how do you treat alcohol withdrawal?
signs: alcohol craving, agitation, anxiety, insomnia, seizures, mood swings, sweating, tachycardia goal: prevent seizures, delirium, arrythmias therapy: short acting benzodiazepines: diazepam and chlordiazepoxide (subtutes for alcohol, then can taper off gradually; remember that the brain has increased excitatory transmission in response to chronic alcohol; atenolol is used to prevent cardiac arrythmias)
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pharmacologic treatment of alcholism?
naltrexone, acamprosate, disulfiram (antabuse)
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mu opiate receptor antagonist, can reduce craving, increase self-control in alcoholics, best when used in combo with psychosocial therapy
naltrexone
119
GABAA agonist, decreased drinking frequency and relapse, thought to normalize dysregulated neurotransmission (remove ethanol, left with unopposed increase in excitation)
acamprosate
120
SE of acamprosate?
diarrhea
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inhibitor of alcohol dehydrogenase, results in the accumulation of acetaldehyde (very uncomfortable for the patient) used as aversion therapy in alcoholics
disulfiram (antabuse) (not very effective, requires considerable will-power to conform)
122
what is the role of CNS stimulants on CNS neurons? what is a SE of all CNS stimulants at sufficient doses?
increase activity of CNS neurons (can be produced either through enhancement of excitation or suppression of inhibition) in sufficient doses all CNS stimulants can produce convulsions
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what is the clinical usefulness of CNS stimulants?
attention-deficity, hyperactive disorder narcolepsy
124
a methylxanthine, similar structure to purines, competitive antagonist of adenosine receptors. where is this compound found?
caffeine found in coffee beans, cocoa beans and kola nuts, is also added to OTC stimulants and analgesics (ex. Excedrin)
125
compounds with similar structure to caffeine found in tea
theophylline and theobromine
126
mechanism of action of caffeine?
primary effect at normal caffeine doses: competitive antagonist of adenosine receptors (postsynaptic adenosine receptors produce IPSPs--\>hyperpolarize the membrane; presynaptic adenosine receptors inhibit glutamate release) =\>caffeine **inhibits** these inhibitory effects (**dis-inhibition**) resulting in CNS stimulation and excitation
127
what effects does caffeine have at higher doses?
at higher doses, caffeine inhibits cAMP phosphodiesterase (results in increased cAMP; responsible for its beneficial effects in the treatment of asthma-not as efficacious as other methylxanthines, however) at higher doses, it also induces the release of calcuim from intracellular (ER) stores
128
pharmacological actions of caffeine when delivered in caffeine-containing drinks?
CNS stimulant increased alertness, increased attention during sustained tasks decreased fatigue and drowsiness can cause nervousness, restlessness, tremors high doses stimulate medullary respiratory and CV centers; can get tachycardia
129
peripheral effects of caffeine?
positive ionotropic and chronotropic effects (direct effects on the myocardium) dilates coronary and systemic blood vessels; constricts cerebral blood vessels (this may underlie the beneficial effects of caffeine in headache) produces diuresis increases gastric secretions modest bronchodilation
130
therapeutic usefulness of caffeine?
primarily used as an aid to stay awake in various OTC preparations added to some aspirin preparations to treat headache (Excedrin)
131
toxicity and consequences of chronic use of caffeine?
"overdose" results in excessive CNS stimulation (nervousness, insomnia, excitement) consequences of chronic use: - tolerance develops to the stimulant effects of caffeine - physical dependence develops to caffeine at the dose of two cups of coffee per day - withdrawal symptoms include feelings of fatigue and sedation; headaches and nausea; vomiting (rare)
132
what are the three sympathomimetic stimulants that act through enhancement of catecholaminergic neurotransmission?
cocaine, amphetamines, methylphenidate
133
extracted from the coca plant, major use is illicit, weak base (unionized in the unprotonated form [B] which predominates at alkaline pH)
cocaine
134
two major forms of cocaine
hydrochloride salt and free base forms
135
how is free base cocaine formed? what is the benefit of having a free base form of cocaine for users?
free base cocaine (crack cocaine that can be smoked) is made by extracting the hydrochloride salt from an alkaline solution into ether or another organic solvent free base is absorbed more quickly across membranes; but more importantly it is **volatile** and can be smoked
136
pharmacokinetics of cocaine?
well absorbed through any mucous membrane time to peak effect and duration of action are dependent upon the route of administration (shortest are i.v. and smoked) metabolized in plasma and liver short plasma half-life (50 min); CNS half-life is even shorter (10-30 min) urine screens detect metabolites
137
mechanism of action of cocaine?
potent inhibitor of the reuptake of norepinephrine, dopamine, and serotonin cocaine binds to the transporter itself and inhibits the bindng of the neurotransmitter (reinforcing effects are due to increased dopamine in the synapse) increases the activity of tyrosine and tryptophan hydroxylases (due to loss of end-product-monamine- inhibition) is a loca anesthetic and vasoconstrictor