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Pharmacology - Block 2 - Part 6

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davidwurbel7's version from 2016-07-05 12:04

Skeletal muscle relaxants

Opioid Analgesics

Question Answer
Natural, synthetic and semisynthetic drugs with morphine- like actionsOpioids
Morphine, Methadone, Meperidine, Fentanyl, Oxymorphone and Hydromorphone are opioids in this classStrong Agonist
Codiene, Hydrocodone and Oxycodone are opioids in this classMild to Moderate Agonist
Buprenorphine, Nalbuphine and Pentazocine are opioids in this classMixed Agonist- Antagonist
Naloxone and Naltrexone are opionids in this classAntagonist
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(Insert 4,5 table)
Question Answer
Inhibition of adenylate cyclase leading to a decrease in cAMP, decreasing kinase activity which inhibit the release of NT ACh, NE, 5-HT, glutamate, and substance P. In addition, decreases neuronal calcium entryOpioid Pre-synaptic Mechanism
Increase K+ currents leading to hyperpolarization and decreasing the firingOpioid Post-synaptic Mechanism
Analgesia- increased pain tolerance, decreased perception and reaction to pain. Euphoria and Sedation. Respiratory depression which increases Pco2 leads to cerebral vasodilation. Suppression of the cough. Miosis. Nausea vomiting. Trunkal rigidityOpioid CNS Effect
Opioids are contraindicated in thisHead Injury
GIT - Constipation due to ↑ muscle tone and ↓ intestinal peristalsis. CVS: most opioids no direct effect on heart except Meperidine- tachycardia because of its antimuscarinic action. Biliary tract: ↑ biliary sphincter tone and pressure (> 10X), which may cause biliary colic (except meperidine)Opioid Peripheral Effects
Tolerance develops to most of opioids effects, with the exception of theseMiosis and Constipation
Adverse effects include Respiratory depression, Nausea, Vomiting, Constipation and MiosisOpioids
Contraindications include use of full and partial agonists which induce withdrawal. Patients with head trauma due to a possible increase in intracranial pressure. Pregnancy - when used in pregnancy withdrawl symptoms in fetus. Patients with impaired pulmonary, renal or hepatic functionOpioids
Opiate overdose is treated with thisNaloxone
In a patient physically dependent on opioids the use of antagonists may precipitate thisWithdrawal
Drug interactions involving opioid analgesics with Ethanol, Sedative-hypnotics, Anesthetics, Antipsychotic drugs, Tricyclic antidepressants, and AntihistaminesAdditive CNS Depression
Concomitant use of certain opioids (e.g., Meperidine) with MAO inhibitors increases the incidence of thisSerotonin Syndrome
Serotonin syndrome occurs because of this property of meperidineWeak SERT Inhibitor
Opioid that has antimuscarinic action on the heart and does not increase biliary tract toneMeperidine
DOC for biliary colicMeperidine
DOC for the relief of pain due to myocardial infarction. High dose iv often the major component of anesthesia for cardiac surgery. Used for treatment of dyspnea due to left ventricular failureMorphine
Antitussive drugs includeCodeine and Dextromethorphan
Selective antidiarrheal opioids includeDiphenoxylate and Loperamide
Management of opioid withdrawal states and in maintenance programs for addictsMethadone and Buprenorphine
What is the reason for using a opioid for opioid addictionLonger Half-Life
The following symptoms of chills, lacrimation, rinorrhea, gooseflesh, mydriasis, hyperventilation, diarrhea, anxiety and hostility are indications of thisOpioid Withdrawl
Synthetic narcotic; actions similar to morphine except pupils may dilate and no anti-tussive effect. Strong k agonist. Toxic metabolite may → CNS excitation, seizures, convulsions and tremors if accumulates. Has Antimuscarinic effect - Used in biliary colic. Can cause tachycardia. Inhibits Serotonin reuptakeMeperidine
Is partial agonist at opioid receptor. It is converted to active form morphine by enzyme CYP2D6. Failure to respond to the drug can be due to genetic variability in CYP2D6Codeine
Codeine is metabolized by this enzymeCYP2D6
Synthetic opioid that is more potent than morphine. Rapid onset and short duration. Used for balanced anesthesia when used with droperidol for neurolept analgesia. Transdermal patch & lollipop that dissolves slowly for transmucosal absorption. Patches are primarily used for chronic malignant pain, with a duration of action of 72 hrsFentanyl
Duration of action for analgesia is longer than morphine (t1/2 15-55 hrs). Used to treat heroin withdrawal and pain of terminal cancer. Causes less sedation, euphoria, and emesis than morphine. Withdrawal is milder, slower in onset, and more prolonged than with heroin or morphineMethadone
Legally banned in U.S. 2-5x as potent as morphine as analgesic. More lipid soluble and crosses BBB faster than morphine. Causes extreme euphoria when administered IVHeroin (Diacetylmorphine)
Antagonist that is used for long term withdrawl treatment. Also approved for alcohol deaddiction (it decreases craving for alcohol)Naltrexone
Antagonist administered PO for maintenanceNaltrexone
Antagonist used for emergency treatment of opioid overdoseNaloxone
Antagonist administered IV for immediate actionNaloxone
Pure opioid receptor antagonistNalmefene
Other name for heroinDiacetylmorphine
1/3 as potent as morphine as analgesic. kappa agonist, mu partial agonist (can precipitate withdrawl). Effective orally; shorter duration and faster onset of action than morphinePentazocine
Strong kappa agonist, mu antagonist (can precipitate withdrawl)Nalbuphine
Potent, long acting. Partial m agonist, weak kappa , delta anatgonist. Use: opioid dependenceBuprenorphine
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Alcohol

Question Answer
Enzyme that converts alcohol to acetaldehydeAlcohol Dehydrogenase
Enzyme that converts acetaldehydeAldehyde Dehydrogenase
Metabolite that is responsible for antibuse reactionAcetaldehyde
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(Insert 6)
Question Answer
Treatment for this includes Give glucose, Thiamin (100 mg), Prevent seizures, delirium, & arrhythmia and Restore K, Mg, & Phosphate ionsAcute Alcohol Intoxication
Intrauterine growth retardation, Microcephaly, Poor motor coordination, Underdevelopment of midfacial region (appearing as a flattened face) and Minor joint anomaliesFetal Alcohol Syndrome
Clinical features include insomnia, tremor, anxiety, life threatening seizures, visual hallucinations, delirium tremensAlcohol Withdrawn
The first line of drugs for alcohol withdrawal syndromeDiazepam or Chlordiazepoxide
Drug of choice for alcohol withdrawal syndrome in patients with liver diseaseLorazepam or Oxazepam
This drug can be used to reduce the intensity of withdraw symptomsClonidine
Opioid antagonist that can be used for treatment of alcohol dependencyNaltrexone
Aldehyde dehydrogenase inhibitor. If a patient consumes ethanol then acetaldehyde accumulates. This leads to nausea,vomiting, headache, flushing & hypotensionDisulfiram
Drugs with disulfiram like effectsMetronidazole
Intoxication includes visual dysfunction, GI distress, Shortness of breath & loss of consciousness which may cause severe acidosis and retinal damage/blindnessMethanol
Methanol is metabolized to this, which may cause severe acidosis and retinal damage/blindnessFormic Acid
Symptoms include respiratory failure, severe ion gap metabolic acidosis, ocular damageMethanol Poisioning
Treatment for Methanol toxicityIV Ethanol
Drug that inhibits alcohol dehydrogenaseFomepizole
Used to treat severe metabolic acidosisBicarbonate
This precipitates in the urine causing stonesEthylene Glycol
Symptoms of ingestion of this include Excitation followed by central nervous system depression. After a delay of 4–12 hours, severe metabolic acidosis develops from accumulation of acid metabolites and lactate, flank pain and hematouriaEthylene Glycol
Treatment for Ethylene glycol toxicityIV Ethanol
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Anti-Epileptic Drugs

(Insert 1-29)
Question Answer
Electrical abnormality throughout cerebral cortexGeneralized Seizures
Electrical abnormality limited to one part of cerebral cortexLocal Seizure
Phenytoin, Carbamazepine, valproic acid and Phenobarbitone(at high doses) are examples of drugs that block these channelsVoltage-Dependent Sodium Channels
Benzodiazepines- Diazepam, Clonazepam, Lorazepam, Nitrazepam; Barbiturates - Phenobarbitol; GABA transaminase inhibitors - Valproate (valproic acid) and Vigabatrin are examples of drugs that open these channelsChloride Channels
Prolong duration of GABA-mediated chloride channel openingsBarbiturates
Increase frequency of GABA-mediated chloride channel openingsBenzodiazepines
Open Cl- channel (by Enhancing GABA transmission). Blocks voltage-dependent sodium channels. Blocks T-type calcium currentsValproate
Ethosuximide and Valproate are examples of drugs that block these channelsCalcium Channels
Ethosuximide and Valproate can be used to treat thisAbsent Seizures
Preferred drug of choice for absent seizures in child due to reduced hepatic toxicityEthosuximide
The mechanism of action of these drugs bind to presynaptic voltage gated N type of Ca2+channel - synaptic release of glutamateGabapentin, Pregbalin
The mechanism of action of this drugs irrevrisibly inhibits GABA transaminase (GTA)Vigabatrin
The mechanism of action of this drugs prolongs inactivation of Na channels, presynaptic voltage gated N type of Ca2+channel - synaptic release of glutamateLamotrigine
The mechanism of action of this drugs block GABA reuptake by blockade of GAT (GABA transporter)Tiagabine
The mechanism of action of this drugs bind to synaptic vesicular protein (SV2A) – synaptic release of glutamateLevetiracetam
The mechanism of action of this drugs block NMDA (glutamate) receptorsFelbamate
The mechanism of action of this drugs block high frequency firing via action on Na channelsZonisamide
High Protein binding. Metabolism - enzymes responsible for degradation get saturated at therapeutic concentration. High doses -zero order kinetics of elimination. Plasma concentration is not linearly related to the dose. Therapeutic drug monitoring is requiredPhenytoin
Carbamazepine, phenobarbitone, phenytoin do this to CYP enzymeCYP Enzymes Inducer
Valproic acid does this to CYP enzymeCYP Enzymes Inhibitor
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(Insert 22)
Question Answer
The adverse effects of this drug include diploplia, ataxia, hyponatremia(Drug Induced SIADH) , teratogenic (cleft lip and palate)Carbamazepine
The adverse effects of this drug include sedation, drowsiness, mood changesPhenobarbitone
The adverse effects of this drug include nausea, vomiting, weight gain, Hepatotoxicity (children), Spina bifidaValproic Acid
The adverse effects of this drug include fatigue, headache, nauseaEthosuximide
The adverse effects of this drug include Nystagmus, Ataxia, vertigo, Gingival Hyperplasia, Hirsutism, Megaloblastic anaemia (effects folic acid metabolism), Osteomalacia (effects Vitamin D metabolism), Teratogenic and DrowsinessPhenytoin
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Question Answer
Seizure in which the person suddenly falls rigid and unconscious. May begin to shake, or to convulse with vigorous and regular muscle contractionsGeneralized Tonic Clonic (GTC) Seizure
Seizure in which consciousness is preserved. Convulsions confined to group of muscles or localised sensory disturbanceSimple Partial Seizure
Seizure which is seen in children ,Generally noticed by mother or teachers in nursery school. Star gazing, Looking at space constantly, or Dropping pencil. Brief loss of consciousnessAbsence seizures
Seizure in which confused, repetitive and inappropriate behavior. The person is usually unaware of his surroundings or of what he is doing involuntary activities such as smacking the lips, chewingComplex Partial Seizures
Seizure which is characterised by repeated attacks of GTC seizures in quick succession in a brief period. Mostly by not regaining the consciousness in between the attacks Status Epileptics
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Treatment
Question Answer
Phenytoin, Carbamazepine, Valproate, phenobarbital and newer drugs can be used to treatGeneralized Tonic Clonic, Simple Partial Seizures
Phenytoin, Carbamazepine Valproate can be used to treatComplex Partial Seizures
Valproate and Ethosuximide can be used to treatAbsence Seizures
Febrile convulsionsDiazepam
Myoclonic seizuresValproic acid, Zonisamide,
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Status epilepticus: Diazepam, Lorazepam,
Question Answer
Status epilepticus maintenancePhenytoin or Phenobarbital
Trigeminal neuralgiaCarbamazepine
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