Clinical Pharmacy Calculations MCQs

A new cephalosporin antibiotic was given at a dose of 5 mg/kg by a single intravenous bolus injection to a 58-year-old man who weighed 75 kg. The antibiotic follows the pharmacokinetics of a one compartment model and has an elimination half-life of 2 hrs. Th e apparent volume of distribution is 0.28 L/kg, and the drug is 35% bound to plasma proteins.

What is the initial plasma drug concentration in this patient?

Calculate the daily infusion volume of D10W to be administered to a neonate weighing 3 lb. 8 oz. on the basis of 60 mL/kg/day.

If a patient is determined to have a serum cholesterol level of 200 mg/dL, what is the equivalent value expressed in terms of millimoles (mmol) per liter?

Determine the creatinine clearance rate for an 80-year-old male patient weighing 70 kg and having a serum creatinine of 2 mg/dL. [Use Cockcroft-Gault equations]

The usual initial dose of chlorambucil is 150 ug/kg of body weight once a day. How many milligrams should be administered to a person weighing 154 lb?

The adult dose of a drug is 500 mg. What is the dose for a 2 year old child as per young rule?

If a patient's mean pulmonary artery pressure is 14 mmHg, his left atrial pressure is 8 mmHg, and his cardiac output is 4.0 L/minute. What will be Pulmonary Vascular Resistance (PVR)?

With a normal tidal volume of 500 milliliters, a normal dead space of 150 milliliters, and a respiratory rate of 12 breaths per minute. What will be the alveolar ventilation rate?

A vancomycin solution containing 1000 mg of vancomycin hydrochloride diluted to 250 mL with D5W is to be infused at a constant rate with a continuous-drip intravenous infusion set that delivers 25 drops/mL. What flow rate (drops per minute) should be used to infuse all 250 mL of the
vancomycin hydrochloride solution in 2 hrs.?

If digoxin has a half-life of 35 hrs. how long will it take for a toxic plasma concentration of 8 ng/mL to decline to a therapeutic plasma concentration of 2 ng/mL?

A new cardiac glycoside is developed for oral and intravenous administration. The drug has an elimination half-life (t½) of 24 hrs. and an apparent volume of distribution (VD) of 3 L/kg. The effective drug concentration is 1.5 ng/mL. Toxic effects of the drug are observed at drug concentrations > 4 ng/mL. The drug is bound to plasma proteins at approximately 25%. The drug
is 75% bioavailable after an oral dose.

What is the loading dose (DL) for this patient?

A new cardiac glycoside is developed for oral and intravenous administration. The drug has an elimination half-life (t½) of 24 hrs. and an apparent volume of distribution (VD) of 3 L/kg. The effective drug concentration is 1.5 ng/mL. Toxic effects of the drug are observed at drug concentrations > 4 ng/mL. The drug is bound to plasma proteins at approximately 25%. The drug
is 75% bioavailable after an oral dose.

What is the oral maintenance dose, if given once a day, for a 68-year-old man who weighs 65 kg and has congestive heart failure (CHF) and normal renal function?

A 35-year-old man who weighs 70 kg and has normal renal function needs an intravenous infusion of the antibiotic carbenicillin. The desired steady state plasma drug concentration is 15 mg/dL. The physician wants the antibiotic to be infused into the patient for 10 hrs. Carbenicillin has an elimination half-life (t½) of 1 hr. and an apparent volume distribution (VD) of 9L in this patient.

If the patient’s renal clearance for carbenicillin is 86 mL/min, what is the hepatic clearance for carbenicillin?

A 35-year-old man who weighs 70 kg and has normal renal function needs an intravenous infusion of the antibiotic carbenicillin. The desired steady state plasma drug concentration is 15 mg/dL. The physician wants the antibiotic to be infused into the patient for 10 hrs. Carbenicillin has an elimination half-life (t½) of 1 hr. and an apparent volume distribution (VD) of 9L in this patient.

What is the total body clearance rate for carbenicillin in this patient?

A 35-year-old man who weighs 70 kg and has normal renal function needs an intravenous infusion of the antibiotic carbenicillin. The desired steady state plasma drug concentration is 15 mg/dL. The physician wants the antibiotic to be infused into the patient for 10 hrs. Carbenicillin has an elimination half-life (t½) of 1 hr. and an apparent volume distribution (VD) of 9L in this patient.

What is the recommended loading dose?

A 35-year-old man who weighs 70 kg and has normal renal function needs an intravenous infusion of the antibiotic carbenicillin. The desired steady state plasma drug concentration is 15 mg/dL. The physician wants the antibiotic to be infused into the patient for 10 hrs. Carbenicillin has an elimination half-life (t½) of 1 hr. and an apparent volume distribution (VD) of 9L in this patient.

Assuming that no loading intravenous dose was given, how long after the initiation of the intravenous infusion would the plasma drug concentration reach 95% of the theoretic steady-state drug concentration?

A 35-year-old man who weighs 70 kg and has normal renal function needs an intravenous infusion of the antibiotic carbenicillin. The desired steady state plasma drug concentration is 15 mg/dL. The physician wants the antibiotic to be infused into the patient for 10 hrs. Carbenicillin has an elimination half-life (t½) of 1 hr. and an apparent volume distribution (VD) of 9L in this patient.

Assuming that no loading dose was given, what rate of intravenous infusion is recommended for this patient?

A new cephalosporin antibiotic was given at a dose of 5 mg/kg by a single intravenous bolus injection to a 58-year-old man who weighed 75 kg. The antibiotic follows the pharmacokinetics of a one compartment model and has an elimination half-life of 2 hrs. Th e apparent volume of distribution is 0.28 L/kg, and the drug is 35% bound to plasma proteins.

How long after the dose is exactly 75% of the drug eliminated from the patient’s body?

A new cephalosporin antibiotic was given at a dose of 5 mg/kg by a single intravenous bolus injection to a 58-year-old man who weighed 75 kg. The antibiotic follows the pharmacokinetics of a one compartment model and has an elimination half-life of 2 hrs. Th e apparent volume of distribution is 0.28 L/kg, and the drug is 35% bound to plasma proteins.

How much drug remains in the patient’s body (DB) 8 hrs. after the dose?

A new cephalosporin antibiotic was given at a dose of 5 mg/kg by a single intravenous bolus injection to a 58-year-old man who weighed 75 kg. The antibiotic follows the pharmacokinetics of a one compartment model and has an elimination half-life of 2 hrs. Th e apparent volume of distribution is 0.28 L/kg, and the drug is 35% bound to plasma proteins.

What is the predicted plasma drug concentration (Cp) at 8 hr. after the dose?