Pharmacology / Stats Flashcards
Which PPI has least interaction with cytochrome p450
pantoprazole
Inducers of P450
Dexamethasone, PHB, phenytoin, rifampin
DR PHil
Inhibitors of cytochrome p450
Chloramphenicol, cimetidine, erythromycin, fluconazole, indomethacin, methadone, omeprazole, ranitidine
C(H2)EF MIO
Describe Phases 1-4 of clinical trials
Phase I: small cohort (safety, safe dosing, side effects)
Phase II: larger cohort (effectiveness and safety)
III: effectiveness, side effects, compare effectiveness against other treatment modalities, continued safety profiling
IV: post marketing tests to establish/document benefits/effectiveness, risks/side effects, appropriate use / indications
Difference between case-control and cohort
Case-control: defined by disease status
cohort: characterized by exposure status
Nominal/categorical
assigns numbers, labels, or codes to particular study group (34-36 weeks GA, gender, race)
Glucose is transported from GI tract by ________
facilitated diffusion
Volume of distribution equation
total amount of drug in body (mg) / [plasma concentration (mg/L) x weight (kg)]
L/kg
Drugs that are highly protein bound have a _______ volume of distribution
lower
Preterm have ______ protein binding ability compared to full term infants
LOWER
Decreased total protein, albumin, glycoprotein concentrations –> greater volume of distribution
How does ranitidine affect cytochrome P450
inhibit
Zero vs first order kinetics? How does it affect half life
Zero-order kinetics: excretion of constant amount of drug per unit time regardless of serum drug concentration. Half life is DEPENDENT on drug dosage (larger doses cleared more slowly and fraction that is eliminated is not constant)
First-order kinetics: excretion of certain percentage of drug per unit time; rate of drug elimination is directly proportional to serum drug concentration. Exponential decrease of drug concentration over time and half-life is INDEPENDENT of drug dosage. Fraction that is eliminated is constant.
How is gentamicin metabolized (zero or first)
first order kinetics
statistical power formula and how to increase it
power = 1 - beta
Increase sample size
Outcome with large effect size - more likely to see diff b/w groups if effect of intervention is large
Increase power by increasing type I error rate
Decreasing SD of outcome
Addition of covariates
—> Increasing heterogeneity will increase SD which will decrease power
To make a causal claim
- Exposure and outcome must be associated
- Exposure must occur before effect
- No other plausible explanation exists
don’t need RCT per se
