Lange Q&A Calculations Flashcards
How much sodium chloride is needed to adjust the following prescription to isotonicity? (E value for sodium thiosulfate is 0.31.)
0.53 g
The adult IV dose of zidovudine is 2 mg/kg q4h six times daily. How many milligrams will a 180-lb patient receive daily?
980 mg
What does 100 μg equal? (select 1 or more)
I. 100,000 ng
II. 0.1 mg
III. 0.001 g
I and II only
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consider 1 μg as equaling 1,000 ng, thus 100 μg = 100,000 ng. Since 1 mg equals 1,000 μg, 100 μg equals 0.1 mg. If 1 mg equals 0.001 g, 0.1 mg or 100 μg equals 0.0001 g.
For how many days will a 20-mL vial of morphine injection (4 mg/mL) last if the home patient is ordered on 3 mg q6h ATC?
6 days
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Explanation:
The total content of the vial will be 20 mL (4 mg/mL) = 80 mg.
The total amount of morphine prescribed per day = 3 mg × 4 (every 6 hours around the clock) = 12 mg. 80 mg ÷ 12 mg = 6.67 days. The nearest answer is 6 whole days.
The hospital protocol calls for additional dosing when the trough level of tobramycin (mol. wt. = 470) approaches 2 μg/mL. The concentration may also be expressed as how many μmol/L?
4.2 μmol/L
A child’s dose of a drug is reported as 1.2 mg/kg body weight. What is the appropriate dose for a child weighing 60 lb?
32 mg
Available in the pharmacy are cefazolin sodium 1-g vials with reconstitution directions of “addition of 2.5 mL SWFI will give 3.0 mL of solution.”
What infusion rate in mL/min should the nurse establish for each bottle?
5 mL/min
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.The original order requested that the solution be infused over a 20-minute time span. Therefore, 100 mL divided by 20 minutes equals 5 mL/min.
How many milligrams of sodium chloride should be added to the following medication order to maintain isotonicity? “Atrovent Inhalation Solution 0.02% 5 mL + SWF Injection 25 mL. Place in nebulizer ut dict” (Note: Atrovent inhalation solution is isotonic.)
225 mg
The patient weighs 175 lb. An injection is labeled “20 mg/mL.” How many milliliters should be added to 50 mL D5W if the usual dose is 0.5 mg/kg?
2mL
What % v/v concentration of alcohol would be listed on the label?
15.8 v/v%
A hospital pharmacist adds 200 mL of alcohol USP to sufficient mouthwash formula to make 1 L of final product. What is the new percentage of ethanol present if the original mouthwash was labeled as 12% v/v ethanol?
An ICU medical order reads “KCl 40 mEq in 1 L normal saline. Infuse at 0.5 mEq/min.” How many minutes will this bottle last on the patient?
80 mins
A pharmacist in a clinical setting is asked to evaluate a new blood test that has been developed to detect a specific disease. Available data include the following:
.
.Based on the previous data, what is the prevalence of this disease in the population tested?
10%
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Prevalence = total “bad things” / total people
How many grams of 1% hydrocortisone (HC) cream must be mixed with 0.5% HC cream if one wishes to prepare 60 g of a 0.8% w/w preparation?
36 grams
Using the following data, what is the approximate mean diastolic blood pressure value?
The mean value of a series of numbers is obtained by adding all of the values and then dividing by the actual number of values. In this example, the diastolic readings were 70 + 84 + 88 + 90 + 70 = 402 divided by 5 = 80.4.
A total parenteral nutrition (TPN) order requires 500 mL of D30W. How many milliliters of D50W should be used if the D30W is not available?
A physician requests 1 lb of bacitracin ointment containing 200 U of bacitracin per gram. How many grams of bacitracin ointment (500 U/g) must be used to make this ointment?
182 grams
The adult dose of a drug is 200 mg. What is the appropriate dose for an 8-year-old child whose BSA is calculated to be 0.6 m^2
70 mg
The manufacturer decides to market an ointment that contains 2,000 units of an enzyme per gram at the higher strength of 4,000 units per gram. What is the approximate expiration date if a standard of “not less than 90% of labeled claim” is established?
Explanation:
The product will be considered expired when the drug level has decreased by 10% from the original 4,000 units. Since 4,000 units times 10% = 400 units, the stability limit is 4,000 minus 400 or 3,600 units. Since 50 units are lost every month, 400 units divided by 50 units/month = 8 months.
Dopamine (intropin) 200 mg in 500 mL normal saline at 5 g/kg/min is ordered for a 155-lb patient. At what rate (mL/min) should the solution be infused to deliver the desired dose of 5 g/kg/min?
0.88mL/min
The infusion rate of theophylline established for an infant is 0.08 mg/kg/h. How many milligrams of drug is needed for a 12-hour infusion bottle if the body weight is 16 lb?
7mg
A hospital clinic requests 2 lb of 2% HC ointment. How many grams of 5% HC ointment should be diluted with white petrolatum to prepare this order?
363.2g
What % w/v of hydrated citric acid could be listed in a formula if the anhydrous citric acid is not available? The hydrated form of citric acid contains 10% water. (Mol. wt.: citric acid anhydrous = 192 g/mol; water = 18 g/mol)
A pharmacist adds 2 mL of tobramycin injection (40 mg/mL) to 4 mL of tobramycin ophthalmic solution 0.3%. What is the concentration of tobramycin in the final mixture?
The USP contains nomograms for estimating body surface area (BSA) for both children and adults. Which of the following measurements must be known in order to use these nomograms
height and weight
A pharmacist in a clinical setting is asked to evaluate a new blood test that has been developed to detect a specific disease. Available data include the following:
.
.
Based on the above values, what is the sensitivity of this test?
90%
A patient’s serum cholesterol value is reported as 4 mM/L. What is this concentration expressed in terms of mg/dL? (mol. wt. of cholesterol = 386)
Calcium chloride (CaCl2·2H2O) has a formula weight of 147. What weight of the chemical is needed to obtain 40 mEq of calcium? (Ca = 40.1; Cl = 35.5; H2O = 18)
A pharmacist dilutes 100 mL of Clorox with sufficient water to make 1 qt of solution. Commercial Clorox contains 5.25% w/v sodium hypochlorite. What is the concentration of sodium hypochlorite in the final dilution as a w/v ratio?
How many milligrams of codeine phosphate is being consumed daily by a patient taking the following prescription as directed?
33 ml
How many milligrams of a drug would be contained in a 10 mL container of a 0.65% w/v solution of a drug?
How much elemental iron is present in every 300 mg of ferrous sulfate (FeSO4·7H2O)? (Atomic wt.: Fe = 55.9, S = 32, O = 16, H = 1. Iron has valences of 2 and 3.)
After 1 month of therapy, all of the patients listed using the following data had a systolic blood pressure reduction of 10 mm with a standard deviation (SD) of ±5 mm. What percentage of patients had a reduction between 5 and 15 mm?
A SD is calculated mathematically for experimental data. It shows the dispersion of numbers around the mean (average value). One SD will include approximately 67% to 70% of all values, whereas two SDs will include approximately 97% to 98%.
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answer is 70%
A medication order in CCU reads “Heparin 20,000 units in normal saline 250 mL. Infuse at 20 units/min.” What flow rate in drops per minute should be established if a Buretrol delivering 60 drops per milliliter is used?
A nurse adds a 4-mL syringe unit of 2.4 M units penicillin suspension to a 20-mL vial containing 10 mL of normal saline. What is the new concentration of penicillin expressed as units/mL?
How many milliliters of triamcinolone acetonide aqueous injection (40 mg/mL) could be used to prepare 240 mL of the formula?
A nurse in a nursing home setting mixes 240 mL of a dietary supplement formula (400 mOsm/L) with 250 mL of D10W and 200 mL of water containing 5 g calcium chloride. What is the osmolarity of this solution? (mol. wt. = 111; mol. wt. of dextrose = 180.)
A hospital pharmacy technician adds by syringe 20 mL of a concentrated sterile 2% w/v dye solution to a 250-mL commercial bag of sterile normal saline. What is the concentration of the dye in the final solution
A 250-mL infusion container contains 5.86 g of potassium chloride (KCl). How many milliequivalents (mEq) of KCl is present? (Mol. wt. of KCl = 74.6)
mEq = mg * valance/ mw
How many milliliters of Epinephrine HCl solution (0.1%) may be used to prepare the solution?
How many milliliters of normal saline should be mixed in a syringe with 1 mL of a 1:1,000 strength solution in order to obtain a 1:2,500 dilution?
How many grams of magnesium is present in every 350 mL dose? (Mg = 24.3, carbonate = 60)
What is the estimate of the milliosmolarity (mOsm/L) for normal saline (Na = 23, Cl = 35.5)?
A nursing home patient is experiencing diarrhea from his enteral nutritional solution, which has an osmolarity of 520 mOsm/L. How many milliliters of purified water is needed to reduce 500 mL of this solution to an osmolarity of 300 mOsm/L?
The level of iron impurities in a water sample is 2 mg/L. How is this concentration in terms of ppm expressed?
What flow rate must be programmed into the PCA unit to obtain the desired amount of morphine per minute?
What is the minimum amount of a potent drug that may be weighed on a prescription balance with a sensitivity requirement of 6 mg if at least 95% accuracy is required?
A prescription calls for the dispensing of a 4% Pilocar solution with the directions of “gtt i OU TID.” Assume that the dropper is calibrated to deliver 20 drops per milliliter. How many milligrams of pilocarpine hydrochloride is being used per day?
A vial containing 1,000 units of an expensive drug powder is labeled “add 9 mL SWFI to obtain 100 units/mL.” How many milliliters of diluent is needed if the nursing staff requests a concentration of 120 units/mL?
Propylene glycol was purchased at a cost of $24.00 per pound. What is the cost of 100 mL of the liquid? (Specific gravity = 1.04)
