Pharm Calculations
The practical nurse (PN) is preparing the change-of-shift report for a client who has a 265 ml secondary infusion that was started 2 hours ago at a rate of 85 ml/hour via an infusion pump. How many ml remaining to be infused should the PN report to the on-coming nurse? (Enter numeric value only.)
Rationale 85 ml x 2 hours = 170 ml has infused. 265 ml (total amount to be infused) - 170 ml (amount infused) = 95 ml remain to be infused.
A child who weighs 55 pounds receives a prescription for atovaquone with proguanil (Malarone Pediatric) 125 mg/50 mg PO daily. A drug reference states that children 11 to 20 kg should receive 1 pediatric tablet daily; 21 to 30 kg should receive 2 pediatric tablets daily; 31 to 40 kg should receive 3 pediatric tablets daily; and greater than 40 kg should receive 1 adult tablet daily with food. The drug is available as atovaquone 62.5 mg/proguanil 25 mg pediatric tablets. How many tablets should the practical nurse administer?
Rationale Calculate each drug component dose, using the formula, D/H 125 mg / 62.5 mg (atovaquone) = 2 combined with 50 mg / 25 mg (proguanil) = 2 The child should receive 2 tablets.
The healthcare provider prescribes diltiazem (Cardizem) 0.87 mg PO four times daily for an infant who weighs 22 pounds. The recommended maximum dose is 3.5 mg/kg/day.What action should the practical nurse take?
Rationale Calculate the recommended maximum dose, 22 pounds = 10 kg, so 3.5 mg x 10 kg = 35 mg. Calculate the prescribed daily dose. 0.87 mg x 4 doses = 3.48 = 3.5 mg/day. The prescribed daily dose 3.5 mg/day is below the recommended dose of 35 mg, which may be a misplaced decimal in the prescription, so the healthcare provider should be notified (D) for clarification of the dosage. (A, C, and D) are inaccurate actions.
A client receives a prescription for an intravenous infusion 0.45% sodium chloride 500 ml to be infused over 6 hours. The practical nurse should program the infusion pump to deliver how many ml/hour? (Enter numeric value only. If rounding is required, round to the nearest whole number.)
Rationale Calculate using Volume/Time: 500 ml/6 hours = 83.3 ml/hour 83!!!!!
A client scheduled for surgery is to receive an IV infusion of 0.9% sodium chloride with prochlorperazine edisylate (Compazine) 10 mg/50 ml over 30 minutes. The practical nurse should program the infusion pump to deliver how many ml/hour? (Enter numeric value only.)
Rationale Calculate: 50 ml : 30 minutes :: X ml : 60 minutes 50/X :: 30/60 3000 = 15X X = 100 ml
A client with Mycobacterium avium complex (MAC) is receiving an infusion of 5 % dextrose in water with amikacin (Amikin) 0.572 grams/100 ml every 12 hours. The practical nurse prepares the dose of amikacin using a vial labeled, " 250 mg/ml." How many ml should the practical nurse add to the infusion? (Enter numeric value only. If rounding is required, round to the nearest tenth.)
Rationale First convert gram to milligram: 1 gm = 1000mg .572 gram x 1000 = 572 mg Next use the formula D/H x Q: 572/250 x 1 = 2.288 (rounded to) 2.3 ml Fill in the blank
The practical nurse plans to administer labetalol hydrochloride (Trandate) 0.3 grams PO to a client with hypertension. Trandate is available in 200 mg scored tablets. How many tablets should the practical nurse administer? (Enter numeric value only.)
Rationale First convert grams to milligrams using the known conversion: 1 gram = 1000 mg. 0.1 gram = 100 mg as 0.3 gram = 300 mg Next using the formula, Desired/Available x 1 tablet = 300 mg/200 mg x 1 = 1.5 tablets Fill in the blank
A client receives a prescription for tobramycin sulfate (Nebcin) 0.128 grams IV q8 hours. Tobramycin is available in liquid concentration of 40 mg/ml. How many ml should the practical nurse administer? (Enter numeric value only. If rounding is required, round to the nearest tenth.)
Rationale First using the known conversion: 1 gram = 1000 mg = 0.128 gram = 128 mg Next use the Desired/Have x 1 ml = 128 mg/40 mg x 1ml = 3.2 ml
A child who weighs 32 pounds receives a prescription for a moxicillin with clavulanate (Augmentin) 194 mg PO every 8 hours. The recommended dose is 40 mg/kg/day, and the bottle contains 125 mg/5ml. How many mg should the child receive in a 24-hour period? (Enter numeric value only. If rounding is required, round to the nearest tenth.)
Rationale The child's weight in kg (2.2 : 1 kg :: 32 pounds : X kg = 14.54 kg) is used to calculate the recommended dose (40 mg x 14.54 kg/day = 581.81 = 582 mg). The prescribed dose in 24 hours is 194 mg x 3 doses = 582 mg.
A client with multiple sclerosis and muscle spasms receives a prescription for baclofen (Kemstro) 30 mg PO daily. The medication is supplied from the pharmacy in 20 mg scored tablets. How many tablets should the practical nurse administer? (Enter numeric value only.)
Rationale Use ratio and proportion, 30 mg : X tablets = 20 mg : 1 tablet 20X = 30 X = 1.5
The nurse is preparing to administer Hepatitis B Vaccine, Recombinant (Energix-B) 5 mcg IM to a school-aged child. The vaccine is labeled, 10 mcg/ml. How many ml should the practical nurse administer? (Enter numeric value only. If rounding is required, round to the nearest tenth).
Rationale Use ratio and proportion, 5 mcg : X ml :: 10 mcg : 1ml 10X = 5 X = 0.5 ml
The nurse needs to calculate a client's oral temperature of 99.2 Fahrenheit to Celsius. What temperature in Celsius (C) should the practical nurse document? (Enter numeric value only. Round to the nearest tenth.)
Rationale Use the formula to convert Fahrenheit to Celsius (C), Fahrenheit temperature (99.2) minus 32 divided by 1.8 = 37.3 degrees C.
A client with multiple sclerosis is prescribed Dantrolene (Dantrium) 0.1 grams PO bid for spasticity. Dantrolene is available in 100 mg capsules. How many capsules should the practical nurse administer? (Enter numeric value only.)
Rationale Using the conversion of 1 gram = 1000 mg: 0.1 gram = 100 mg 100 mg = 1 capsule
The healthcare provider prescribes a continuous intravenous infusion of dextrose 5% and 0.45% sodium chloride witth KCl 20 mEq/1000 ml to be delivered over 8 hours. The practical nurse should program the infusion pump to deliver how many ml/hour? (Enter numeric value only. If rounding is required, round to the nearest whole number.)
Rationale Using the formula volume/time: 1000 ml/8 hours = 125 ml/hour
Promazine 0.1 grams PO is prescribed for an older client who is agitated. Promazine is labeled in 50 mg tablets. How many tablets should the PN administer to the client? (Enter numerical value only.)
Rationale 0.1 gram x 1000mg/1 gram = 0.1 x 1000 = 100 mgD./ H = 100 / 50 = 2 tablets
A client receives a prescription for retrovir (zidovudine) 0.15 grams PO BID PO. The dispensed medication is available in mg. How many mg should the practical nurse administer? (Enter numerical value only.)
Rationale 1 mg = 0.001 gram0.15 gram x 1 mg/0.001 gram = 150 mg
A client receives a prescription for scopolamine 300 mcg SUBQ. The dispensed medication is labeled in mg. How many mg should the practical nurse administer? (Enter numerical value only. If rounding is required, round to the nearest tenth.)
Rationale 1 mg = 1000 mcg300 mcg x 1 mg/1000 mcg = 0.3 mg
Mineral oil U.S.P 30 ml PO daily for 3 days is prescribed for a client who is experiencing severe constipation. The medication dose cup is marked in tablespoons. How many tablespoons should the practical nurse administer? (Enter numeric value only.)
Rationale 15 ml equals 1 Tablespoon. Use the ratio equation: 15 ml : 1 Tbs :: 30 ml : X 15 / 30 :: 1 / X 15X = 30 X = 2 Tablespoons Fill in the blank
A client with Parkinson's disease is receiving benztropine (Cogentin) 3.5 mg PO twice daily. The medication is available in 0.5 mg tablets. How many tablets should the practical nurse administer for each dose? (Enter numeric value only.)
Rationale Using D/H: 3.5 mg / 0.5 mg = 7 tablets Fill in the blank
A client who weighs 79 pounds is receiving clomipramine (Anafranil) PO. The practical nurse (PN) refers to the published drug literature which recommends the dose of 3 mg/kg/day. How many mg should the PN determine is the recommended dose for this client?
Rationale 2.2 pounds = 1 kg, so 79 pounds = 35.9090 kg35.9090 Kg x 3 mg = 107.7 or 108 mg/day 108!!
A client who weighs 79 pounds is receiving clomipramine (Anafranil) PO. The practical nurse (PN) refers to the published drug literature which recommends the dose of 3 mg/kg/day. How many mg should the PN determine is the recommended dose for this client? (Enter numerical value only.)
Rationale 2.2 pounds = 1 kg, so 79 pounds = 35.9090 kg35.9090 Kg x 3 mg = 107.7 or 108 mg/day only marks 108!!! correct
A client who weighs 40.6 kg is receiving ethacrynic acid (Edecrin) PO. The practical nurse (PN) refers to the published drug literature which recommends the dose of 1 mg/kg/dose. What dose in mg should the practical nurse (PN) determine is the recommended dose for this client? (Enter numerical value only. If rounding is required, round to the nearest whole number.)
Rationale 1 mg/kg/dose40.6 kg x 1 mg/1 kg/dose = 40.6 mg or 41 mg/dose 41!!
A child who weighs 17.1 kg is receiving chloral hydrate liquid. The practical nurse (PN) refers to the published drug literature which recommends the dose of 25 mg/kg/dose. What dose in mg should the practical nurse (PN) determine is the recommended dose for this child? (Enter numerical value only. If rounding is required, round to the nearest whole number.)
Rationale 17.1 kg x 25 mg/1kg/dose = 427.5 or 428 mg/dose 428!!!
A client who has a gastrostomy feeding tube is receiving 3/4 strength Ensure 240 ml every 6 hours. Full strength Ensure is available in a 240 ml can. The PN should use how many ml of Ensure to prepare the feeding? (Enter numeric value only. If needed, round to the nearest whole number.)
Rationale 240 ml Ensure : 1 :: X ml Ensure : 0.75 240/X : 1 / 0.75 X = 240 x 0.75 = 180 ml Ensure + 60 ml water = 240 ml 180!!! of ensure only
The practical nurse is administering a 250 milliliter (ml) intravenous solution to be infused over 2 hours. How many ml/hou r should the practical nurse program t he infusion pump? (Enter numeric value only.)
Rationale 250 ml : 2 hours = X ml : 1 hour 250 = 2X X = 250 divided by 2 = 125 ml/hr Fill in the blank
A loading dose of acetylcysteine (Mucomyst) 8 grams, which is available as a 20% solution (200 mg acetylcysteine per ml) is prescribed by nasogastric tube for a client with acetaminophen toxicity. How many ml of diluent should be added to the medication to obtain a 1:4 concentration? (Enter the numerical value only. If rounding is required, round to the whole number.)
Rationale 8 grams = 8,000 mg prescribed dose. Using the formula, D/H x Q, 8,000 mg / 200 mg x 1 ml = 40 ml of the 20% solution. Dilute the 40 ml to a 1:4 concentration for administration using ratio and proportion, 1 : 4 solution :: 40 ml : X X= 160 ml total volume to administer. Subtract total volume of 160 ml - 40 ml of 20% concentration = 120 ml diluent is added to obtain a 1:4 concentration.
A 49-year-old client with myasthenia gravis is receiving pyridostigmine (Mestinon) 126 mg PO every 4 hours. The available form is 60 mg in 5 ml syrup. How many ml should the practical nurse administer? (If rounding is required, round to the nearest tenth.) Rationale Fill in the blank
Using the formula, Desired dose / dose on Hand x Quantity of volume on hand (D/H x Q): 126 mg / 60 mg x 5 ml = 10.5 ml
