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28 Cards in this Set
- Front
- Back
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OP01 [Mar96] With regards to pethidine’s physical properties:
A. It has an octanol coefficient of 10 B. It has a pKa of 8.4 C. It has a volume of distrubution similar to Alfentanil D. Metabolised in the liver by N-demethylation to methyl-pethidine E. Is not available as an oral formulation |
ANSWER B
A. FALSE: Octanol coeff 40 B. TRUE: approx 8.5 C. FALSE: Pethidine Vd approx 4L/kg, Alfent Vd= 0.5L/kg D. FALSE: metabolised in the liver by N-demethylation to norpethidine E. FALSE: Is available in 50mg tablets Pethidine is phenylpiperidine |
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OP02 [Mar96] Which factor does NOT predispose to bradycardia with fentanyl in doses of 50 mcg/kg?
A. Calcium channel antagonist B. Beta-blocker C. Benzodiazepines D. Laryngoscopy E. Slow injection of drug |
ANSWER E
Factors predisposing to bradycardia/asystole during opioid induction * presence of beta and/or calcium channel blockade * premedication or concomitant use of benzodiazepines * rapid administration * muscle relaxants with little or no vagolytic properties * vagotonic muscle relaxants (e.g. suxamethonium) * added vagal stimuli (e.g. laryngoscopy) |
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OP03 [Mar96] [Mar99] [Jul99] [Feb00] [Apr01] Naloxone:
A. Is not an antagonist of agonist-antagonist drugs B. Is not an antagonist at ?mu & sigma receptors C. Causes pulmonary oedema D. Can cause hypotension in experimental shock animal models E. May cause an abrupt increase in sympathetic tone |
ANSWER E
A - ? incorrect; naloxone as a competitive antagonist should antagonise partial agonists (agonist/antagonists) at a high enough dose as long as they are not irreversible B - partially correct/partially incorrect; "Naloxone is a pure opioid antagonist and will reverse opioid effects at mu, kappa and delta receptors" (Peck, Hill and Williams p. 135); as for sigma receptors, "they are not reversed by naloxone" and are no longer considered opioid receptors. (Peck, Hill and Williams p. 125) C - correct; may precipitate pulmonary oedema (morphine is used to treat, therefore naloxone can potentially precipitate) D - incorrect; naloxone has previously been tried in shock states to reverse hypotension E - correct; will increase sympathetic tone depending on circumstance as opioid receptors decrease sympathetic tone. |
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OP03b [Mar97] Naloxone:
A. Is effective at antagonising a full agonist but not a partial agonist B. Causes pulmonary oedema C. Is an agonist at sigma-opioid receptors D. Does not reverse opioid-induced spasm of sphincter of oddi E. Used to treat withdrawal in opiate addicts |
ANSWER B
A. FALSE B. TRUE C. FALSE: competitive antagonist at mu, delta, kappa and sigma D. FALSE E. FALSE: can precipitate withdrawal |
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OP04 [Mar96] [Jul99] {Diagram of numbered structure of morphine}
Which substitutions correct? A. N17 substitution gives antagonist activity B. C6 methylation produces codeine C. Glucuronidation occurs at C2 D. Diacetylation decreases lipid solubility |
ANSWER A
A. TRUE N17 substitution does give anatagonist activity. E.g. naloxone has CH2CHCH2 (as opposed to the CH3 in morphine. Naloxone is an oxymorphone derivative. B. false, C3 O-methylation produces codeine. C. false, Glucuronidation occurs at C3 and C6 (hence Morphine-3-glucuronide is the major metabolite, M6G the minor metabolite). D. false, Diacetylation (as in C3 and C6 for diacetylmorphine = heroin) increases lipid solubility. |
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Also remembered as:
Morphine base structure with questions about substitutions A. C3 and C6 increase lipid solubility B. Acetyl group on ?C3 gives heroine C. N- substitution gives antagonist D. C5 glucuronidation site E. C3 methyl gives codeine |
ANSWER C
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OP05 [Mar96] [Jul98] [Jul00] Pethidine in doses of 2 to 2.5 mg/kg causes all of the following EXCEPT:
A. Bradycardia B. Decreased systemic vascular resistance C. ?Normal arterial BP / ?decreased BP D. Increased cardiac output |
ANSWER A
A: true, pethidine has atropine like properties which causes a tachycardia B: false : Therapeutic doses of morphine-like opioids in therapeutic doses produce vasodilation, decreased peripheral resistance, and inhibition of baroreceptor reflexes C: false, n supine position and at therapeutic dose, opioids have no major effect on BP, HR, rhythm. When the patient sits up, however orthostatic hypotension can occur. D: false, There is no great demonstrated effect on cardiac output by pethidine. Pethidine can cause tachycardia, in which case if stroke volume is constant, cardiac output could increase |
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OP06 [Mar96] Regarding the clearance of morphine:
A. Affected by cirrhosis B. Affected by hepatic blood flow C. Shows low hepatic extraction ratio D. ? E. ? |
ANSWER B
morphine "undergoes extensive first-pass metabolism and only 25-30% reaches the systemic circulation" (Peck Hill and Williams p.127) suggesting high hepatic extraction ratio |
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OP07 [Jul97] [Mar99] [Jul99] [Jul00] [Feb04] [Jul04] Fentanyl:
A. With pKa 8.4 is 90% ionised at physiological pH B. Has an octanol coefficient of 10 C. Is 1,000 times more potent than morphine D. Has first-pass lung uptake reduced to 20% by propranolol E. Has up to 50% uptake in the lung |
ANSWER A
A: true ; pKa is around 8.4 and thus at physiological pH 90% will be ionised B: false, octane coeff 510 C: false, 100x potent D: ??? E: false, 75% uptake lung |
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OP08 [Jul97] An opioid which can be used for TIVA:
A. Morphine B. Pethidine C. Fentanyl D. Sufentanil E. Alfentanil |
ANSWER B
Pethidine accumulates therefore is not suitable. Theoretically any combination of intravenous hypnotic and opioid agents can be used in a synergistic/additive manner to achieve general anaesthesia. |
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OP10 [Mar98] Pethidine
A. 100mg is equal to 10mg morphine in effect B. decreases heart rate C. No effect on cardiac output D. Is preferred to morphine for analgesia E. ? |
ANSWER A
A: true, pethidine is 1/10th as potent as morphine B: true, has atropine like effects, tachycardia is common C:False: it has direct negative inotropic effect at high doses. D: False Morphine is widely used for acute and chronic pain, and more commonly than pethidine. Pethidine is not suitable for long term use due to accumulation of toxic metabolities which can effect the CNS |
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OP10b [Mar98] Pethidine produces:
A. Miosis B. More severe hypotension with comparable dose of morphine C. More biliary spasm than morphine D. more histamine release than morphine |
ANSWER B
A: false, all opiods do cause miosis but pethidine has atropine like structure which cause mydriasis B: TRUE despite the tachycardia, pethidine causes more orthostatic hypotension, Stoelting 104 C: false, all opioids cause a degree of SM spasm, pethidine and fentanyl have less than morphine D: false, evokes less histamine release than morphine |
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OP11 [Mar98] TIVA with morphine causes the following EXCEPT:
A. Mydriasis B. Muscle rigidity C. Respiratory depression D. ? |
ANSWER A
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OP12 [Mar98] [Jul98] [Jul02] [Mar03] Codeine:
A. Substitution at C6 position of morphine B. 10% of codeine is metabolised to diacetyl morphine C. IM 100mg is equivalent to 10 mg morphine D. Methyl substitution at the ?C5/?C6 position of morphine E. Can be safely given IV because causes no histamine release F. Has higher first pass effect than morphine |
ANSWER A C D
A. true. Substitution of a methyl group for the hydroxyl group on C3 of morphine. B. False 10% is metabolised via demethylation in the liver to morphine. C.true, IM 120mg of codeine is equivalent in analgesic effect to 10 mg of morphine D. see A E. false, IV codeine not reccommended because of histamine release - hypotension, angioedema, pul oedema F. FALSE, Presence of methyl group on C3 limits first pass hepatic metabolism |
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OP13 [Jul98] Morphine metabolism:
A. Principally metabolised to morphine-6-glucuronide B. Metabolites have shorter half-life C. Found in extrahepatic sites D. Metabolites freely cross the blood-brain barrier E. In neonates, predominantly by sulphation |
ANSWER C
A: false, Morphine is primarily conjugated to morphine-3-glucuronide (which has neuroexcitatory properties). Approximately 10% is metabolised to morphine-6-glucuronide (an active metabolite with a much greater analgesic potency than morphine, especially when the blood brain barrier is bypassed -eg. for intrathecal of intraventricular administration in animal models there is 100 times greater potency for M6G) B: false C: true, Stoelting says that morphine is metabolised principally by conjugation to glucuronic acid, in hepatic and extrahepatic sites, primarily the kidney D: false E: false |
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OP15 [Mar99] [Feb00] [Jul02] Sufentanil:
A. 30 times as potent as fentanyl B. < 7% excreted unchanged in urine C. Greater protein binding than fentanyl D. Half-life of elimination between fentanyl & alfentanil E. Predominantly bound by ?albumin/ ? alpha1-acid glycoprotein |
ANSWER C D E
A: false, 5-10 times potent B: less than 1% excreted unchanged C: true, sufent 90%, fent 80% D: true, fent 5, sufent 3, alf 1.5 E: true, alpha1acid bind bases, sufent 90% PPB |
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OP16 [Mar99] [Jul00]
Pethidine is the traditionally favoured opioid in obstetrics because: A. Norpethidine does not cross the placenta B. Does not undergo ion trapping C. Causes less neonatal depression D. It does not cross the placenta E. It is thought to cause less respiratory depression in the neonate. |
ANSWER E
Meperidine is the most commonly used parenteral opioid analgesic during labor. Meperidine is thought to cause less respiratory depression in the neonate than morphine does; therefore, it is more commonly used.[73] It may, however, cause loss of beat-to-beat variability of FHR tracings |
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OP18 [Jul99] Pethidine:
A. Norpethidine metabolite B. Pethidine 6-glucuronide C. Better bioavailability than codeine |
ANSWER A
Norpethidine is a major metabolite which contributes to pethidine's toxicity. Pethidine BA=50%, Codiene=60% |
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OP19b [Jul01] [Jul04] Alfentanil works faster than fentanyl because:
A. More lipid soluble B. Higher concentration unbound, unionised at physiological pH C. Decreased protein binding D. Larger volume of distribution E. ? |
ANSWER B
Correct, pKa is approx 6.4 – 90% unionised at physiological pH |
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OP20 [Jul00] [Apr01] Methadone:
A. Phenanthrene derivative B. ?metabolism C. Peak plasma levels at 3 hours D. Used in chronic cancer pain due to non addictive potential E. ? d & l isomers |
ANSWER C
A: false, Methadone is a potent synthetic opiate agonist of the phenylheptylamine class and is structurally unrelated to morphine. Phenanthrenes consist of morphine, hydromorphone, oxymorphone and codeine and its relations B?? C: true, time from admin to peak plasma conc : epidural 15-20mins, intrathecal 30mins, nasal inhalation .12 hours, oral 2-4 hours D - false. Significant incidence of dependence and addiction with definite withdrawal reaction E - methadone is marketed as the racemic mixture. l-isomer is responsible for analgesic effects and d-isomer has less analgesic, resp depression activity or addiction, but does have antitussive effects |
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OP21 [Apr01] Tramadol:
A. Has beta blocking properties B. Blocks noradrenaline reuptake C. Has greater opioid activity than morphine (OR: As potent a mu agonist as morphine) D. Is directly inhibited by yohimbine E. Only the +ve enantiomer is active |
ANSWER B
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OP22 [Jul01] The most unlikely thing to occur with morphine administered in recovery is:
A. Constipation B. Respiratory depression C. Sedation D. Nausea and vomiting E. Physical dependance |
ANSWER E
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OP24 [Jul01] Extrahepatic de-esterfication of Remifentanil
A Occurs in RBC B By Plasma Cholinesterase C NOT in incubated blood D Has (?mean) clearance less than 1L/min E Has an active metabolite |
ANSWER A
tissue and non specific esterases (also in RBC) |
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OP25 [Jul01] The following are metabolites of morphine except:
A. Morphine-6-glucuronide B. Morphine-3-glucuronide C. Normorphone D. Codeine E. Hydromorphine |
ANSWER E
# Morphine-3-glucuronide - 75-85% # Morphine-6-glucuronide - 5-10% # Normorphine - 5% # Codeine - Small amount |
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OP26 [Jul01] Fentanyl given at dose of 50-150 mcg/kg:
A. Causes potent cardiac depression B. Does not cause muscle rigidity C. Has an elimination half-time of more than 3 hours D. Not enough to relieve the stress response to surgery E. Preserve cardiac output |
ANSWER C
A: false, it does not cause direct cardiac depression B: false, all opioids administered at high enough doses will cause muscle ridigity C: true, E1/2 5 hours D: false, it does relieve the stress response E: false, although there is no direct effect of myocardial contractility, but cardiac output is decreased |
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OP27 [Jul04] Prolonged duration of action of morphine in renal failure is due to
A. Morphine 3-glucuronide B. Morphine 6-glucuronide C. Metabolism of morphine D. Methyl-O-morphine E. Normorphine |
ANSWER B
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OP28 [Jul-06] Which is NOT a side effect of morphine:
A. Seizures B. Mydriasis C. Respiratory depression D. Histamine release E. Constipation |
ANSWER B
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OP07 [Jul97] [Mar99] [Jul99] [Jul00] [Feb04] [Jul04] Fentanyl:
A. Elimination half-life < 2 hour B. Carried on albumin mostly C. Carried on alpha-1 acid glycoprotein mostly D. Can cause hypertension with MAOI E. Alfentanil acts faster as it has a higher unionised, unbound fraction |
ANSWER C
A: false, false; elimination half-time 3.1-6.6hr B: false; albumin carries acid drugs C. true D: false, pethidine cause hypertension when given in combination with MAOI, via serotoninergic syndrome E: false |
