Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
93 Cards in this Set
- Front
- Back
|
What is pharmacodynamics?
|
The study of the actions and effects of the drug IN the body
|
|
|
What is the effect of increasing the concentration of agonist in the presence of a non-competitive antagonist
|
No effect
|
|
|
What is Pharmacokinetics?
|
The study of the factors that affect concentration of drug in the body: absorption, distribution, metabolism, and elimination
|
|
|
What are the drug binding proteins in the blood?
|
Albumin
Alpha 1-acid glycoprotein |
|
|
What pathways of hepatic metabolism constitute Phase I reactions?
|
Oxidation, Reduction and Hydrolysis
|
|
|
Which pathway of hepatic metabolism constitutes Phase II reaction? What is its purpose
|
Conjugation. Another chemical group is added to the metabolite to increase polarity to allow subsequent elimination by the kidney
|
|
|
What common medication used to treat reflux is not to be given with Diazepam? Why?
|
Cimetidine (Tagamet) because cimetidine inhibits the hepatic enzymes that metabolize diazepam, prolonging its effects
|
|
|
What is Hofmann elimination?
|
Spontaneous degradation of drugs at physiologic pH and temperature
|
|
|
What is the alpha half-life of a drug?
|
The fall of 50% of the plasma concentration of a drug secondary to redistribution
|
|
|
What is the beta half-life of a drug?
|
The removal of 50% of the drug from the body via metabolism and/or elimination
|
|
|
What is the effect of Benzodiazepenes binding to GABA receptors?
|
binding to the GABA A subunit increases the inward flow of chloride ions, hyperpolarizing cell membranes and reducing neuronal transmission
|
|
|
If benzos don't produce analgesia, what good are they?
|
Sedation, anxiolysis, anterograde amnesia, muscle relaxation, anti-convulsant
|
|
|
What is the reversal agent for benzodiazepenes?
|
Flumazenil
|
|
|
Lingering sedative effects of diazepam is due to what?
|
1) active metabolites desmethyldiazepam and oxazepam
2) drug accumulation in fat tissues |
|
|
Is midazolam lipid or water soluble?
|
Both. Water soluble at pH <4 Lipid soluble at higher pH
This is due to an imidazole ring attached to chemical structure |
|
|
What is the dosing scheme for Midazolam?
|
IV: 0.05 to 0.15mg/kg (1-2 mg boluses every few mins)
IM: 0.5mg/kg (max 10-15mg) PO: 0.5-1mg/kg (max 15mg) |
|
|
Why is Lorazepam not used for IV sedation?
|
Slow onset and long-acting. Best used as a pre-op anxiolysis the night before
0.05mg/kg (not to exceed 4mg) |
|
|
What is the brand name of Triazolam?
|
Halcion (either 0.125mg or 0.25mg tablets)
|
|
|
How is triazolam different from lorazepam?
|
It is very short acting
|
|
|
What patients would you worry about giving Flumazenil to?
|
Epileptic patients (remember, benzos are anti-convulsants)
|
|
|
How is Flumazenil administered?
|
In emergency: 0.5 to 1mg bolus
Normally: 0.2mg initially folowed by 0.1 mg each minute for a total of 1mg |
|
|
Which opioid receptors are responsible for analgesia?
|
Mu and Kappa
|
|
|
What is the most common side effect of Mu receptor agonists?
|
Respiratory depression
|
|
|
Although most opioids are metabolized in the liver, remifentanil is metabolized where?
|
By plasma esterases
|
|
|
Which opioids do not cause histamine release?
|
Fentanyl, Remifentanil, Sufentanil, Alfentanil, Nalbuphine
|
|
|
What is the reason for the decrease in blood pressure seen with opioids?
|
Vasodilation.
|
|
|
Why is morphine preferred for post-operative pain management rather than IV sedation?
|
Slow onset and long duration of action
|
|
|
Which active metabolite of morphine is more potent than morphine and thus is a problem with patients with renal problems?
|
Morphine-6-glucuronide
|
|
|
What is the dosing for morphine?
|
1 to 2 mg IV in increments
|
|
|
What is the dosing for meperidine?
|
12.5mg to 25mg IV increments
|
|
|
What class of drugs when used in conjunction with meperidine produce an excitatory hyperthermic rxn?
|
MAOI's
|
|
|
What makes Meperidine different from the other opioids?
|
It is not associated with bradycardia
|
|
|
Partial agonist activity at the kappa receptor means that meperidine is useful for what postoperatively?
|
Reduces shivering post-op
|
|
|
Why is Fentanyl the drug of choice for IV sedation?
|
Fast onset and short duration
|
|
|
What is the dosing for Fentanyl?
|
25 to 50 ug increments towards a total of ~1-2ug/kg
|
|
|
What is a dangerous effect of large bolus administration of fentanyl?
|
Chest wall rigidity (can't ventilate)
|
|
|
What property of remifentanil make it ideal for use in an infusion technique?
|
Very short half time, no cumulative effects
|
|
|
What type of opioid is nalbuphine?
|
It is an agonist-antagonist opioid.
|
|
|
What is a bad side effect of Naloxone use in patients taking opioids chronically?
|
Withdrawal and acute congestive heart failure
|
|
|
What is the dosing for Naloxone?
|
Initially 0.4 to 2mg IV for acute reversal
0.04 mg increments for gradual withdrawal |
|
|
Which barbiturates are used as anticonvulsants? What route?
|
Pentobarbital (IV)
Phenobarbital (Oral) |
|
|
Barbiturates are contraindicated in people with what rare blood disease?
|
Porphyria
|
|
|
What is the dosage of thiopental adminstered by IV for GA induction?
|
3 to 5 mg/kg
|
|
|
What is the preparation for methohexital?
|
1% solution given at 1.5 to 2mg/kg
|
|
|
Which patients should you not use methohexital on?
|
Patients with seizures. Interesting that you use barbs with patients with seizures
|
|
|
What would be a reason to use pentobarbital for IV sedation?
|
The cardiovascular effects of low BP and tachycardia are more modest.
|
|
|
What is the dosage used for propofol for deep sedation vs. General anesthesia?
|
75-150ug/kg/min vs. 100-300ug/kg/minute.
Lots of overlap indicates lower margin of safety of drug |
|
|
How does propofol reduce blood pressure?
|
Centrally mediated vasodilation
Blocks sympathetic tone and blunts the reflex tachycardia that wouldnormally occur |
|
|
Why would propofol be good for asthmatics?
|
It has bronchodilatory properties
|
|
|
Why is an egg allergy not necessarily a contraindication for propofol?
|
Because the egg protein is Lecithin and most egg allergies are to egg albumin
|
|
|
How is etomidate like midazolam?
|
Both contain an imidazole ring and are thus both water and lipid soluble depending on the pH of the solution.
|
|
|
How is etomidate administered?
|
At an IV does of 0.2 to 0.4 mg/kg
|
|
|
What are the main advantages of etomidate has as a sedative?
|
Cardiovascular stability (less decrease in BP) and spontaneous respiration is maintained.
|
|
|
What medical condition is associated with etomidate i continuous infusion doses?
|
adrendocortical suppression
|
|
|
When they describe ketamine as a dissociative anesthetic, what is it dissociating?
|
The thalamocortical and limbic systems
|
|
|
What is the MOA of ketamine?
|
non-selective antagonist of N-MDA receptors. These deal with the excitatory neurotransmitter glutamate
|
|
|
How is ketamine administered?
|
1 to 2mg/kg IV
3 to 7mg/kg IM (for GA) or 2 to 3mg/kg IM for sedation |
|
|
Why would you consider using glycopyrrolate if administering ketamine?
|
Ketamine increases salivary secretions
|
|
|
What is the blood:gas coefficient?
|
The exten to which the anesthetic gas molecules from the alveolar spaces will dissolve into plasma bfore the plasma is saturated
|
|
|
Which has a faster onset, a gas with a low or high blood:gas coefficient
|
Low. Because once the plasma is saturated, extra gas is free to move across the blood/brain barrier
|
|
|
What is the equivalent of the ED50 when talking about inhaled anesthetics?
|
The MAC. This is the inhaled concentration of the agent required to prevent movement in 50% of patients to a surgical stimulus
|
|
|
How does halothane differ from the other halogenated agents with respect to the heart?
|
Blocks the baroreceptor reflex leading to steep drop in BP at higher doses.
|
|
|
How does halothane cause cardiac dysrhythmias?
|
It suprresses the SA node activity, sensitizes the myocardium to catecholamine (epi) related ventricular dysrhythmias
|
|
|
Why should fresh gas flows of sevoflurane in particular be kept to at least 2L/min?
|
To minimize compound A accumulation in the CO2 absorber
|
|
|
What color is the N2O gas tank?
|
Blue
|
|
|
What patients should Nitrous use be avoided in due to its ability to enter closed spaces
|
Otitis Media, Sinus Infections, Emphysema
|
|
|
What is the predecessor inhalation agent of the halogenated gases?
|
Diethyl Ether
|
|
|
What is the halogen side chain of the newer gases?
|
Fluorine! Does that mean these gases are good for the teeth?
|
|
|
Where is halothane partially metabolized in the body?
|
In the liver
|
|
|
Coronary steal phenomenon is associated with which gas?
|
Isoflurane
|
|
|
How is the only depolarizing agent administered?
|
1-1.5mg/kg IV for induction of anesthesia
|
|
|
Succinylcholine can cause a rise in what chemical element?
|
Potassium, therefore it should be avoided in certain patients
|
|
|
Which patients should not be administered succinylcholine?
|
certain neuromuscular disorders, especially those with pseudocholinesterase abnormalities.
|
|
|
Which non-depolarizing agent has the fastest onset?
|
Rocuronium. Occurs in ~1minute
|
|
|
Which of the non-depolarizing agents has the 1) longest duration of action? 2) the shortest?
|
1) Pancuronium (longest)
2) Mivacurium (shortest) |
|
|
There are 2 classes of non-depolarizing agents. What are they and what is their associated suffix?
|
1) Aminosteroids: CURONIUM
2) Benzylisoquinoline:CURIUM |
|
|
Why is the use of atracurium a problem with asthmatic patients?
|
Because benzylisoquinolines cause histamine release, with flushing and peripheral vasodilation
|
|
|
Which class of non-depolarizing agents are associated with increased heart rate?
|
The aminosteroids. Bad for people with cardiac problems...
|
|
|
Which non-depolarizing agent is like succinylcholine and affected by deficiency in pseudocholinesterase?
|
Mivacurium (interesting that it also has a shortened duration like Sch)
|
|
|
AmiNOsteroids and
|
CurONium (just flipped backwards. grabbing at straws, but whatever works)
|
|
|
Which of the non-depolarizing agents are eliminated by Hofmann elimination? What class of drugs do they belong to?
|
Atracurium and Cistracurium
Benzylisoquinolines |
|
|
What drugs do you use to reverse the muscle relaxants?
|
Cholinesterases paired with anticholinergics to temper the bad side effects of increased ACh
|
|
|
What are the common cholinesterase/anticholinergic pairings? How are they administered
|
1. Neostigimine 0.4-0.8mg/kg with Glycopyrrolate 0.2mg/MG
2. Edrophonium 0.5-1.0mg/kg with atropine 0.014mg/MG |
|
|
What are the 2 types of receptors bound by ACh?
|
Nicotinic and Muscarinic
|
|
|
Anticholinergics specifically block which of the receptors?
|
Muscarinic
|
|
|
Where are the muscarinic receptors found?
|
At postganglionic sites of the PARAsympathetic system at the HEART, SALIVARY GLANDS, SMOOTH MUSCLE
|
|
|
Where are the Nicotinic receptors found?
|
At autonomic ganglia and neuromuscular junctions of skeletal muscle
|
|
|
What is the benefit of using glycopyrrolate instead of atropine or scopalamine?
|
Glycopyrrolate cannot cross the blood-brain barrier and thus does not cause sedation
|
|
|
Central anticholinergic syndrome caused by high doses of the anticholinergics that can cross the blood-brain barrier can be reversed by what?
|
The anticholinesterase Physostigmine because it can cross the blood brain barrier?
|
|
|
Why would anticholinergic system not be a problem with glycopyrrolate?
|
Because it cannot cross the blood brain barrier, atropine and scopalamine can though.
|
|
|
Centrally medicaated nausea is in which part of the brain?
|
The medulla, specifically at the chemoreceptor trigger zone
|
|
|
What drugs beling to the 5-HT3 antagonists? What are they used for?
|
Ondansetron and Dolasetron. These are centrally acting anti-nausea medications
|
|
|
In addition to using dexamethasone as a post-operative anti-inflammatory agent, it can also be used for?
|
Antinausea when administered at at least 8mg IV
|
