Med Chem Tutoring - Anesthesia By Alaina Darby adarby1@uthsc.edu

Local Anesthesia

Which of the following is not true of local anesthesia? Reversible loss of sensation Includes loss of consciousness Does not affect pain mechanisms Interferes with sodium permeability B

Which of the following is not properly paired? Unionized binding site: internal membrane Ionized binding site: hydrophobic pathway Unionized binding site: hydrophobic pathway Ionized binding site: external membrane B

Which of the following is responsible for cocaine’s addictive liability? Tropine moiety Benzoyl group Carbomethoxy group Benzoic acid group C

Which of the following is an undesirable property of cocaine that is not true of tetracaine? Low potency Short duration of action Addiction liability Tissue irritation C

Removing which of the following groups is essential for activity? Aromatic group Aromatic substitution Alkyl substitutions on intermediate chain Terminal amino functionality A

Which of the following substitutions decreases activity? Para- Cl Ortho- NH2 Meta- NHR Ortho- NO2 D

Which of the following LA’s would have faster onset and lower toxicity? Lower pKa and lower lipophilicity Higher pKa and lower lipophilicity Lower pKa and higher lipophilicity Higher pKa and higher lipohilicity C

Which of the following is most likely to antagonize sulfonamide antibiotics? Benzocaine Lidocaine Bupivicaine Prilocaine A Ester will break down into PABA metabolite via ester bond hydrolysis and this antagonizes the sulfas Remember the trick that if “i“ comes before the –caine, it is an amide.

Which of the following can prilocaine cause? Increased toxicity of anticholinergics Hypersensitivity reaction Convulsions Methemoblobinemia D

Which of the following reactions can produce CNS toxicity? N-dealkylation of lidocaine N-alkylation of lidocaine N-demethylation of lidocaine N-methylation of lidocaine A

Remember the mechanisms that you can use to prevent CNS toxicity!! Prevent generation of acetaldehyde… e.g. tocainide Prevent CNS entry… e.g. tolycaine There was a question about this last year!!

General Anesthesia

Which of the following stages of anesthesia is optimal for surgery due to relaxation of the skeletal muscles? Stage I Stage II Stage III Stage IV C

Which of the following has the fastest induction and recovery? Methoxyflurane N2O Halothane Desflurane D

Which of the following has the Slowest induction and recovery? Methoxyflurane N2O Halothane Desflurane A

Remember!! High blood solubility: Low blood solubility: Slow induction Slow recovery Fast induction Fast recovery Therefore: MAC (potency) is roughly inversely proportional to partition coefficient (solubility)… If they are very soluble (slow induction/recovery) then they are usually not as potent

How much of the MAC is required for surgery? 0.7 1 1.3 1.5 C MAC is only calculated for 50% of patients… need more for the other 50%

Which of the following can increase MAC? Hyperthermia Alcohol ingestion Increased age Opioids A Think of it as “revving up” for increased MAC HYPER states (natremia/thermia) and increased catecholamines Decreased MAC (makes anesthesia more effective) is due to decreases in things HYPO states (natremia/tension/thermia/oxia), drugs that can cause these states, and decreased catecholamines

Which of the following has no effect on MAC? Pregnancy Lidocaine Hypertension Alcohol C

Which of the following theories is properly matched? Meyer-Overton: stereoselective effects Meyer-Overton: squeezing of nerves impedes conduction Receptor theory: expansion of membranes plays a role Receptor theory: correlation between lipid solubility and MAC B

Which of the following receptors/channels is not involved in the receptor theory? GABA Chloride channels NMDA receptors Beta receptors D

Which of the following has the highest risk of hepatotoxicity? Isoflurane Enflurane Methoxyflurane Halothane D

Which of the following ions contributes to nephrotoxicity? Cl Br Ca A

Which of the following is most likely to cause seizures? Isoflurane Enflurane Methoxyflurane Halothane B

Which has the least toxicity? Isoflurane Enflurane Methoxyflurane Halothane A

Which of the following is the drug of choice for induction of anesthesia? Ketamine Propofol Etomidate Thiopental B

Which of the following has an active metabolite? Ketamine Propofol Etomidate Thiopental A

Which of the following has an advantage in elderly and shock patients? Ketamine Propofol Etomidate Thiopental A

Which of the following puts patients at increased risk for 30 day mortality? Ketamine Propofol Etomidate Thiopental C

Midazolam can prevent the side effects of which of the following? Ketamine Propofol Etomidate Thiopental A

I made these last year to study… http://www.flashcardmachine.com/3221961/x7p2 This is helpful for getting familiar with the structures!!