Pharmacokinetics Flashcards
Which kinetic model describes the process that metabolizes a constant amount of drug per unit time?
Zero order
What drugs follow zero order kinetics?
Aspirin, phenytoin, alcohol, warfarin, heparin, & theophylline
Which process is a phase 2 reaction? (Reduction, conjugation, oxidation, hydrolysis)
Conjugation
Adds electrons to a compound
Reduction
Removes electrons from a compound
Oxidation
Adds water to a compound to split it apart
Hydrolysis
What are the 3 phases of metabolism?
Modification
Conjugation
Elimination
What drugs undergo perfusion-dependent hepatic elimination?
Diazepam
Fentanyl
Rocuronium
Lidocaine
Propofol
Remifentanil
Fentanyl
Propofol
Lidocaine
What drugs undergo capacity-dependent hepatic elimination?
Diazepam
Fentanyl
Rocuronium
Lidocaine
Propofol
Remifentanil
Diazepam
Rocuronium
Measures how much drug is delivered to the liver vs how much drug is eliminated by the liver
Hepatic extraction ratio
Perfusion-dependent hepatic elimination is primarily determined by?
Liver blood flow
Capacity-dependent hepatic elimination is primarily determined by?
The liver’s ability to extract the drug from the blood
Co-administration of which drug reduces the observed potency of codeine?
Diltiazem
Fluoxetine
Phenytoin
Rifampin
Fluoxetine
Which P450 enzyme is the most important , metabolizing nearly 50% of the drugs we administer?
CYP 3A4
______ influences whether drugs are excreted in the urine or reabsorbed into the peri tubular calillaries
Urine pH
______ & ______ acidify the urine to help eliminate basic drugs
Ammonium chloride & cranberry juice
_____ & _____ will alkaline the urine to help eliminate acidic drugs
Sodium bicarbonate & acetazolamide
Identify the drugs that are metabolized by nonspecific plasma esterases (select 3)
Esmolol
Atracurium
Cocaine
Remifentanil
Succinylcholine
Fospropofol
Esmolol, atracurium, Remifentanil
Pseudocholinesterase deficiency extends the DOA of what drugs?
Succ
Mivacurium
Cocaine
Ester LAs
Which LA is least likely to accumulate in a hypoxia fetus?
Chloroprocaine
What is the equation for calculating loading dose?
(Vd x desired plasma concentration) / bioavailability
An oral drug has a volume of distribution of 0.5L/kg with a bioavailability of 50%. In a 70kg pt, what loading dose must be administered to achieve a plasma concentration of 10mg/L?
700mg
Drugs with an ester linkage are most susceptible to which type of metabolism?
Hydrolysis
Vd=
(Amount of drug)/ (desired Cp)
Steady state is achieved after how many half lives?
5
