Pharmacology Exam 2 Flashcards
Let's get it ladies! I feel the A!
Brand Name For:
Midazolam
Diazepam
Lorazepam
Dexmedetomidine
Midazolam (Versed)
Dizepam (Valium)
Lorazepam (Ativan)
Dexmedetomidine (Precedex)
How does the GABAA Receptor work?
- Ligand gated ion channel (Cys- loop Family)
- Cl selective channel allows influx into cell or hyperpolarization.
What is the action of GABAA?
Inhibitory neurotransmitter when stimulated induces unconsciousness, depression of spinal reflexes & amnesia
Alpha1 and Alpha5 containing GABAA receptors are important for _____.
Alpha 2 and Alpha 5 containing GABA A receptors are important for _____.
Alpha 1 & 5: Sedation
Alpha 2 & 5: Anxiolytic
What is the most abundant GABAAreceptor subunit, and where is it located?
Alpha 1 subunit accounts for approximately 60% of GABAAreceptors in the brain.
Where are 2subunits located?
Principally in the hippocampus and amygdala
What is one of the most important advantages of Propofol compared with other sedative hypnotics?
More rapid return of consciousness with minimal residual CNS effects.
What is the uniqueness is shape about Propofol compared to thiopental, etomidate, and ketamine?
It is not a chiral compound
How does Diprivan and generic Propofol differ?
- Diprivan uses the preservative disodium edetate with sodium hydroxide to adjust the pH to 7 to 8.5
- Generic formulation of Propofol uses the preservative sodium metabisulfite and has a lower pH (4.5 to 6.4).
Though Propofol is not recommended with any other drug lidocaine has been frequently added to Propofol to prevent pain, mixing these two puts your patient at risk of?
A fat emboli leading to a pulmonary embolism. Mixing lidocaine with Propofol may result in coalescence of oil droplets.
How does the prodrug Aquavan compare with Propofol?
- Slower onset
- Large volume of distribution
- Higher potency
- Increased water solubility
- The formaldehyde byproduct causes and unpleasant dysesthesia (burning) sensation in the genital area.
Which receptors do Propofol work on?
GABAA receptors although it has activity at glycine receptors. Ligand gated channels.
True/False, spinal motor neuron excitability is altered by Propofol?
False, spinal motor neuron is not altered by Propofol, suggesting that immobility during Propofol anesthesia is not caused by drug-induced spinal cord depression.
What enzyme is important in the metabolism of Propofol?
cytochrome P450
Elimination half-time and the context sensitive half time for Propofol infusion lasting up to 8 hours.
- Elimination half time = 0.5-1.5 hours
- Context-sensitive half-time after 8 hours= less than 40 minutes.
True/False Pulmonary uptake of Propofol is significant and influences the initial availability of Propofol, and most of the drug that undergoes pulmonary uptake during the first pass is released bake into the circulation.
True
What is the major metabolic pathway for Propofol?
Glucuronidation
True/False. Patients with cirrhosis of the liver have impaired elimination of Propofol?
-False, there is no evidence of impaired elimination in patients with cirrhosis of the liver.
Concentration of Propofol at the time of awakening are similar in alcoholic and normal patients.
True/False. Renal dysfunction influences the clearance of Propofol.
False
How does Propofol in older adults compare to younger adults?
Patients older than 60 years of age have decreased rate of plasma clearance
True/False Propofol crosses the placenta?
True. Propofol readily crosses the placenta but is rapidly cleared from the neonatal circulation.
What are the blood levels needed for unconsciousness and awakening with Propofol.
- Unconsciousness = 2 to 6 mcg/mL
- Awakening = 1 to 1.5 mcg/mL
How do induction doses for the elderly patient and children compare with young adults?
- Children require higher induction doses of Propofol on a mg/kg basis (due to larger central distribution volume and increased clearance rate.
- Elderly patients require a lower induction dose (25 to 50% decrease) due to a smaller central distribution volume, decreased clearance rate, and increased pharmacodynamic activity.
What makes Propofol a readily titratable drug for IV sedation?
The short context-sensitive half time and the short effect-site equilibration time.
