Introduction to Pharmaceutical Calculation

1. Introduction to Pharmaceutical Calculation

3. Pharmaceutical Calculation • application of basic mathematical calculations to ensure safe and effective pharmaceutical and medication preparation. • Accurate calculation of formulas and conversions are vital.

4. Application of Pharm Calc to Pharmacy Practice • Dose calculation • Temperature conversion • Flow Rates • Measurement conversion

5. Application of Pharm Calc to Pharmacy Practice • Dilution • Solution concentration • Ingredient calculation for compounds • Prescription quantity calculation

6. Importance of Pharmaceutical Calculation Skills • Ensure accuracy • Ensure patient safety by providing correct dose • May cause harm to patient if not done properly • To avoid under-dosing • To avoid overdosing

7. Review of Basic Algebraic Functions • Addition • Subtraction • Multiplication • Division

8. Addition • Component parts • Addends – two numbers that are added • Total – answer to an addition problem - also called sum

9. Addition • Addition Symbol: + • Total or Sum Symbol: = or ________

10. Subtraction • The difference between two numbers • Component parts • Difference – the answer to a subtraction problem • Minuend – upper number • Subtrahend – lower number • Ex: 702 - minuend - 512 - subtrahend 190 – difference Symbol : -

11. Multiplication • “repeated addition” • Component parts • Factors – numbers that are multiplied together • Product – result of multiplication problem • Symbol : x

12. Division • “separating into parts” • Prime number – number whose only factors are one and itself • Component parts of division • Dividend – number being divided • Divisor – number that is being used to divide • Quotient – the answer to a division problem • Symbol: ÷ or / or

13. Division • Expressed in several ways Ex: 100 / 20 = 5 dividend divisor quotient 100 ÷ 20 = 5 dividend divisor quotient 5 quotient 20 100 dividend divisor

14. Practice Problems • Mr. Haddad gave you a prescription for Metoprolol50mg two times daily. Compute the total amount of Metoprolol(in mg) he will consume in 7 days.

15. Solution Metoprolol 50mg x 2 ( times per day) 100mg per day total Then 100 mg per day x 7 days Answer: 700 mg per week of Metoprolol total

16. Practice problems • Pharmacy technician Omar Syed was instructed to repackage 920 milliliters (mls) bottle of wound care solution into 8 bottles. How many milliliters of wound care solution will each bottle contain?

17. Solution Divide the 920 mls solution bottle by 8 bottles 920ml ÷ 8 bottles = 115 mls per bottle answer

18. Arabic and Roman Numerals • Arabic numerals – used worldwide Ex: 0,1,2,3,4,5,6,7,8 and 9 • Roman numerals – commonly used to denote quantities in pharmacy practice • Also commonly used in writing prescriptions

19. Roman numerals Symbol Equivalent ½ or 0.5 1 5 10 50 100 500 1000 ss I V X L C D M

20. Roman numerals • Note: • When a smaller Roman numeral is placed before a larger Roman numeral, the smaller Roman numeral is subtracted from the larger Roman numeral. • When a smaller Roman numeral is placed after a large one, the value of smaller numeral is added to the larger. • Ex: IX = 9 ( 10 or X minus 1 or I) • Ex: XXII = 22 ( 2 times 10 or XX plus 2 times 1 or II)

21. Practice exercise Convert the following Roman numerals to Arabic numerals: IV = _______ DCV = ______ LXXIII = ______ VII = ________ XXXVII= ______ MCCCXLII = ______ XCI = _______ CDLV = _______

22. QUESTIONS ?