How can I get more practice in Pharmacology, in particular dosage calculations II?
Answer
1. A patient has an order for 500 mg of erythromycin IV. The pharmacy provides 500 mg of erythromycin in 50 mL of sterile water to be infused over 30 minutes. With no IV pump available, the nurse chooses a microdrip infusion set calibrated to 60 gtt/mL. Determine the drip rate of the erythromycin solution.
X = 50 mL / 30 min x 60 gtt / 1 mL
X = 100 gtt / min
2. The nurse needs to infuse 1500 mL of D5W over 10 hours. What flow rate will the nurse use to program an IC pump for this infusion?
Flow rate (mL /hr) = Total volume ordered (in mL) / Total time (in hours)
Flow rate = 1500 mL / 10 hours = 150 mL / hour
3. A patient has an order for an infusion of D5W at 75 mL/ hr. The tubing set available is calibrated at 20 gtt/ mL. What's the drip rate?
75 mL / 60 min x 20 gtt / 1 mL = drip rate
25 gtt / mL = drip rate
4. A patient is admitted with frequent ventricular dysrhythmias. The licensed practitioner orders procainamide hydrochloride 100 mg IVP every 5 minutes prn until dysrhythmias disappear. If the medication label lists the dose strength as 50 mg / mL, how many mL of procainamide should the nurse administer to the patient every 5 minutes?
100 mg procainamide hcl x 1 mL / 50 mg = 2 mL procainamide
5. A patient with a history of atrial fibrillation takes digoxin tablets at home but currently has an order to be NPO. The licensed practitioner prescribes 0.125 mg of digoxin IV once for an elevated heart rate. The available digoxin vial contains 0.25 mg / mL. How many mL will the nurse administer?
0.125 mg x 1 mL / 0.25 mg = 0.5 mL