4 tablets.
To determine how many 12.5-mg tablets are needed to administer a total of 50 mg of medication, you can use the following equation:
(Number of tablets) x (Strength per tablet) = Total medication strength
Let's solve for the number of tablets:
(Number of tablets) x (12.5 mg) = 50 mg
Divide both sides by 12.5 mg:
Number of tablets = 50 mg / 12.5 mg
Number of tablets = 4
The nurse should give the patient 4 tablets of 12.5 mg each to administer a total of 50 mg of the medication.