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Pharmaceutical Calculations Finals Study Guide Chapter 1: Dimensional Analysis, Ratios, Proportions, Percentage and Estimation -

C 1 V 1 = C2 V 2

Chapter 2: International System of Units -

Conversions o 1 inch = 2.54 cm o 1 fl. Oz = 29.57 mL o 1 cup (8 oz) = 240 mL o 1 pint (16 oz) = 473 mL o 1 quart (32 oz) = 946mL o 1 gallon (128 oz) = 3785 mL o 1 fl oz = 2 tbsp

o o o o o o o

1 tbsp = 3 tsp 1 mile = 1.6 km 1 lb = 16 oz 1 lb = 454 g 1 kg = 2.2 lb 1 gr = 64.8 mg 1 oz = 28 g

Chapter 3: Measurement of Weight and Volume -

LWQ (mg) = SR (mg) X 100 Acceptable error % % error = SR (mg) X 100 Quantity desired The least measurable quantity in liquids 20% of the available measuring cylinder.

Chapter 5: Density and Specific Gravity -

Density = g/ml Specific gravity = density of substance Density of water Specific gravity: the ratio of the density of a substance compared to the density of a reference material, usually water.

Chapter 4: Interpretations of Prescriptions and Med Medications ications and Orders -

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Parts of a Prescription o Superscription – meaning you take o Inscription – medication prescribed o Signa – directions to the patient Doses: the quantity of prescribed dose, number of doses, number of days Medication Concentrations: The quantity of an active therapeutic ingredient to use to achieve the desired drug concentration Rate of Drug Administration: the quantity of drug administered per unit of time to meet prescribed dosing schedule (mg/min, drops/min, ml/hr) Medication Adherence: Patient’s adherence or compliance with all aspects of medication treatment Compounding: the quantities of active and inactive ingredients to use in the compounding of a prescription or medication order Chemical-Physical Factors: calculations to make solution isotonic, iso-osmotic, equimolar or buffered Pharmacoeconomics: including Medications cost, cost-benefit analysis, cost-effectiveness analysis, and medication pricing Signa Abbreviations: o Aa - of each o Dtd – give such o Non rep. – do not o Ad - up to make doses repeat o Disp. – dispense o Ft – make o Qs – sufficient o Div. – divide o M. – mix quantity o No. – number

Qs. ad. – sufficient o Ncv – nausea and o IV - intravenous quantity to make vomiting o IVB – intravenous o F – fluid o Noct – night bolus o G – gram o NPO – nothing by o IV drip – o Gal – gallon mouth intravenous drip o Gtt – drop o Pc – after meals o IVP – intravenous o IU – units o Pm – afternoon push o Lb – pound o Po – by mouth o Od – right eye o Kg – kilogram o Prn – as needed o Os – left eye o L – liter o qAM – every o Ou – both eyes o Mcg – microgram morning o Rect. – rectal o Ac – before meals o q4h – every 4 o SL – sublingual o Ad lib – at hours o Top. – topically pleasure o qid – four times a o V – vaginally o Admin – day o In pulv – into administer o rep – repeat powders o Am – morning o sid – once a day - Roman Numerals o Aq – water o stat – o Ss= ½ o Bid – twice a day immediately o i/j = 1 o C – with o at dict – as o v=5 o D – day directed o X = 10 o Dil – dilute o wk – week o L = 50 o Et – and o ad – right ear o C = 100 o Hs – at bedtime o as – left ear o D = 500 o Lc – between o au – each ear o M = 1000 meals o ID – intradermal - Medication Scheduling: frequency and duration Frequency of medication scheduling: depends on drug’s characteristics, patient’s condition, nature and severity of illness Once daily vs multiple daily for days or weeks or for life Medication Adherence (Compliance): patient’s following of the instructions for taking the medication prescribed, including the correct dose, dosing frequency, and duration of treatment Medication nonadherence: patient’s failure to adhere or comply with instructions Compliance: # of Days Supply of Medication X 100 # of Days since last refill o

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Chapter 7: Calculation of Doses: General Considerations -

# of doses = total quantity Size of dose

Chapter 8: Calculation of Doses: Patient Parameters

Chapter 16: Reducing and Enlarging Formulas -

Ratio and Proportion Dimensional Analysis Factor Method

Chapter 6: Percentage, Ratio Strength, and Other Expressions of Concentrations -

Percent weight-in-volume: o No. of g of solute in 100 mL of solution % w/v Percent volume-in-volume: o No. of mL of solute in 100 mL of solution % v/v Percent weight-in-weight: o No. of g of solute in 100 g of solution % w/w

Milligrams % -

Express the number of mg of substances in 100 mL of liquid It is used to express the conc. of drug in plasma Nonprotein N in blood: 30 mg % means that each 100 mL of blood contains 30 mg of nonprotein nitrogen The conc. of substances in biological fluids are more often expressed in mg% or mg/dL

PPM and PPB -

PPM – parts per million 1:1000000 PPB – parts per billion1:1000000000

Chapter 15: Altering Strength – Stock Solution and Allegation -

Q1 X V1 = Q2 X V2 o 1st quantity x 1st concentration = 2nd quantity x 2nd concentration C1 x V1 = C2 x V2 o 1st volume x 1st concentration = 2nd volume x 2nd concentration A preparation can be strengthened by addition of active ingredient, by admixture with a like preparation of greater strength or through the evaporation of the vehicle (if liquid) The strength of a preparation may be decreased or diluted by the addition of diluent or by the admixture with a like preparation of lesser strength

Chapter 11: Isotonic and Buffer Solutions II Equivalent of Na (not Na) X E-Value = Amt of Na pH = pka + log

[𝒔𝒂𝒍𝒕] [𝒂𝒄𝒊𝒅]

pH = pKa + log

[𝑩𝒂𝒔𝒆] [𝒔𝒂𝒍𝒕]

E = (MW/i)/(MW/i) E = 32.5/(MW/i) Tf = (i) (m) (1.858)

Chapter 12: Electrolyte Solutions Molarity (M) = 𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑚𝑜𝑙𝑒𝑠 𝑜𝑓 𝑠𝑜𝑙𝑢𝑡𝑒 (n) / 𝑉𝑜𝑙𝑢𝑚𝑒 𝑜𝑓 𝑠𝑜𝑙𝑢𝑡𝑖𝑜𝑛 𝐿 (mwt of solute X volume of solution (L)) Molality (m) = 𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑚𝑜𝑙𝑒𝑠 𝑜𝑓 𝑠𝑜𝑙𝑢𝑡𝑒 (n) / 𝑤𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑠𝑜𝑙𝑣𝑒𝑛𝑡 (𝑘𝑔) Normality Definition: Normality is a measure of concentration equal to the gram equivalent weight per liter of solution. N = M X n (# of equivalents) -

A mole is the molecular weight of a substance in grams. A millimole is 1/1000 of the molecular weight in grams

1 mEq X charge = MW (mg) Normal osmolality = 275-295 mOsmol/kg Hypotonic  low concentration soln Hypertonic  high concentration soln Plasma osmolality (mOsmol/kg) = (2 (Na + K)) plasma + [BUN]/2.8 + [glucose]/18 Chapter 14: Assesment of Nutritional Statues, Enteral and Parenteral Nutrition, and the Food Nutrition L Label abel -

2-in-1 (CHO & AA)

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3-in-1 (CHO, AA & Lipid) Parenteral: Central (>900 mOmol/kg), Peripheral (...