Question | Answer |
goal range for flucytosine | 50-100 mcg/ml |
goal range for digoxin | 0.8-2.0 mcg/L [typically 1.2 is the upper limit] |
goal range for valproic acid | 50-100 mg/L |
Formula for loading dose | [Peak] * Vd / bioavailability |
formula for the elimination rate constant or slope | [ln (y1)- ln (y2)] / x1-x2 |
formula for volume of distribution | dose/change in concentration = bioavailability * dose / peak conc (bolus) = rate of infusion / k* Css |
formula for peak concentration | peak conc = concentration / e^kt
t=time from peak for concentration. |
formula for bioavailability | F= [DOSEiv * AUCpo] / [DOSEpo * AUCiv] |
relationship between the elimination constant k, VD and clearance | Cl=k*VD |
formula for half life | t1/2=0.693/k |
in what way do isozymes affect fluconazole | at doses above 400 mg/day you get 3A4 inhibition but lower doses only have 2C9 |
Cockcroft -Gault formula for CrCl | CrCl=[(140-age)*TBW]/Scr*72
Women get 80% of total
AdjBW if BMI >25
actualBW if BMI <18.5
all others use IBW |
formula for IBW | men=50+2.3 for each inch over 5 ft
women 45.5 +2.3 for each inch over 5 ft |
what population is the schwartz eqn designed for | peds |
what GFR equations work for pts with renal dysfunction | MDRD and CKDepi. MDRD is limited to pts with CrCl < 60 only. |
drugs that compete with creatinine for secretion in pts resulting in false elevations in Creatinine clearance | trimethoprim, cimetidine, fibric acid derivatives OTHER than gemfibrozil, dronedarone |
what does the hill eqn measure | relationship btn drug response and concentration |
hysteresis | conc late after dose has diff effect than early with same conc |
causes of counterclockwise hysteresis loop | delayed equilibrium between plasma and site of action, active metabolite, sensitization, Ex: digoxin |
causes of clockwise hysteresis loop | tolerance, formation of inhibitory metabolite, faster equilibrium between arterial blood supply and site of action than venous and site of action. Ex: cocaine and pseudoephedrine |
goal ranges, free and total for phenytoin | free=1-2
total=10-20 |
calculation for phenytoin adjustment in changing albumin | Cp=[Cp' / (0.9*Alb/4.4)]+1 |
calculation for phenytoin adjustment in CKD AND changing albumin | Cp=Cp' / [(0.48*0.9*Alb/4.4)+1] |
calculation for phenytoin adjustment in CKD | Cp=Cp'/0.5 |
what is the effect on digoxin in pts with renal insufficiency | Vd decreases. need to decrease BOTH loading dose and maintenance dose. typically loading doses ok to keep same but not in this case due to lower VD for digoxin. |
therapeutic range for aminoglycosides | peak 4-10, trough <2
amikacin 20-30
trough amikacin <10 |
phenobarbital therapeutic range | 15-40 mg/L |
therapeutic range for lithium | 0.3-1.3 mmol/L |
therapeutic range for carbamazepine | 4-12 mg/L |
therapeutic range for cyclosporine | 100-250 mcg/L |
theophylline therapeutic range | 10-20 mg/L |
concentration or time dependent killing for aminoglycosides | concentration |
concentration or time dependent killing for vancomycin | time dependent though some concentration dependence as well |