COLLEGE OF NURSING TIME OF ADMINISTRATION Abbreviation Derivation Meaning A.c. Alt. die. Alt. hor hours Alt. noct. A.m. B.i.d H. H.d. H.s. M. et N. night O.d O.n. P.c. P.m. Pp.r.n Q.h Q2h Q3h Q4h Q.i.d or 4 i. d. a day Stat T.i.d ante cibum Alternis diebus alternis horis before meals alternate days alternate Alternis noctes ante miridiem bis in die hora hora decibitus hora somni mane at nocte alternate nights morning twice a day hour at bedtime at sleeping time morning and omni die omni nocte post cibum post miridiem pro re nata quaque hora quarter in die daily each night after meals afternoon when required every hour every 2 hours every 3 hours every 4 hours four times statim ter in die at once three times a day COMMON EQUIVALENT USED: 1 kg 1 kg 1 gram 500 cc 1 grain 1 gm 1 gallon 1 gallon 1 quart = 1000 grams = 2.2 lbs or pounds = 1000 mg 1 quart = 1 liter 1 pint 2 pints = 1000 cc = 1/2 liter or = = = = = 1 pint 1 ml 16 fluid ounces 15 gtts = 4 megtts 1 ml 1 gtt 60 mg 15 grains 4 liters or 4000 cc 4 quarts 1 liter = = 1 gtt 1 gm 1 gm = = HOUSEHOLD MEASURES: 1 table spoon 1 fluid ounce cc 1 fluid oz = cc 1 tbsp minims = = 15 ml or cc 30 ml or cc 1 tsp 1 cup = = 5 ml or cc 6 oz or 180 2 tbsp 1 glass = 8 oz or 240 = 1 ml = 15 to 16 3 tps Urios College COLLEGE OF NURSING Butuan City PREPARATION OF DRUGS Abbreviation Derivation Meaning Aq. q. dest. Comp. compound Conf. D. Dil. Empl. Et Fl. Inf. Lin. Liq. Lot. Mist. N.N.R. non-official Aqua Aqua destillata compositum water distilled water confection detur Dilutus Emplastrum et Fluidum Infusum Linimentum Liquor Lotio Mistura confection give dulute plaster and fluid infusion liniment liquid lotion mixture new and Ol. Pil. Pulv. S. fr. Sp. S. v. r. S.v.g. Syr. Tinct. Troch. Ung. Vin. remedy Oleum oil pilula pill Pulvis a powder Spiritus frumenti whisky spiritus spirit spiritus vini rectificatus alcohol Spiritus vini gallici brandy Syrupus syrup Tinetura tincture Trochiseum lozenge Unguentum ointment Vinum wine Urios College ABBREVIATIONS and SYMBOLS Abbreviation Derivation Meaning a. Add. Add part. Dol. part Ad. Lib desired C. C ć cc Cap. Contin. continued Dim. D. in p. aeq. divide in equal parts Ana Addle Adde partem dolente of each add to to the painful ad libitum as much as congius gallon Centigrade with cubic centimeter let him take let it be cum Capiat Continuator Dimidius one half Dividatur in partes Div. Dur. Dolor. Ft. gm gr. Garg. Kg L. lb M. m. ml. N. B. No. O Eart, vic. Q. s. Rx S S. or Sig. Aequales dividatus Duranted dolore fiat gram granum, grana Gargarisma kilogram liter libra misce minimus milliliter nota bene numero octarius Parttibus vicibus quantum sufficit recipe sine signa S. o. s. Ss Tsp Tbsp si opus sit semi teaspoon tablespoon divide while pain lasts let it or let tem be made gram, grams grains, grain gargle a thousand grams a liter a pound mix minim a thousandth of a liter note well number a pint in divided doses as much as is sufficient take without give the following Directions if necessary one half teaspoonful tablespoonful Urios College COLLEGE OF NURSING Butuan City DOSAGE CALCULATIONS Common Equivalents Used 1 kg = 2.2 lbs (pounds) 1 centimeters 1 kg = 1000 grams (gms) 1 gm = 1000 milligrams (mg) 1 1 gm = 15 grains (gr) 1 1 gr = 60 mg 1 mg = 1000 micrograms (mcg0 (fl oz) 1 gallon= 4 liters (L) 1 1 gal = 4 quarts (qts) 1 mcgtts gal = 4000 cubic 1 L L 1 1 qt =1L = 1000 cc or milliliters = 2 pints pint = 500 cc or ½ L pint = 16 fluid ounces ml gtt = 15 gtts or drops = 4 microdrops or Household Measures 1 tbsp 1 fl oz cc 1 fl oz 240 cc 1 tbsp minims or = = 15 ml or cc 30 ml or cc = 2 tbsp = mx 1 1 3 tsp 1 tsp cup = 5 ml or cc = 6 fl oz or 180 1 glass = 8 fl oz or ml = 15 to 16 Conversion 0 0 Cto 0 F = 0 Cx9 / 5 + 32 Fto 0 C = 0 F − 32(5 / 9) Computation of pediatric Doses using: A. CLARK’S RULE Average adult dose safe dose 150 Example x weight of child in pounds = estimated : How much Aspirin should a one-year-old child weighing 21 lbs. receive if the average adult dose is 10 grains? 10 grains B. YOUNG’S RULE x 150 21 lbs = grain 1 2/5 or 1.4 grains Average adult dose safe dose Age of child + x age of child in years = estimated 12 Example: How much Atropine Sulfate should an eight year old child received if adult dose is grain 1/150 8 1 xgrain = grain1 / 375 8 + 12 150 C. FRIEDMAN’S RULE Average adult dose 150 x age in months = estimated safe dose Example : The adult dose of atropine sulfate is 0.6 mg. How much should a 2month-old child receive? 0.6 x 2 1.2 = = 0.008mg 150 150 D. BODY WEIGHT The body weight method of calculating allows for individualizing the drug dose and involves three steps as follows: 1. Convert pounds to kilograms if necessary. 2. Determine drug dose per body weight by multiplying: Drug dose x body weight = client’s dose per day 3. Follow the basic formula to calculate drug dosage: D q = H Q Example: order – Cefaclor (Ceclor) 20 mg/kg/day in three divided doses . Child’s weight – 31 lbs Drug label – Cefaclor (Ceclor) 125 mg / 5 ml a. Convert pounds to kilograms 31 divided by 2.2 = 14 kg. b. drug dose x body weight 20 x 14 = 280 mg / day 280 mg divided by 3 divided doses in a day = 93 mg / dose c. Calculate drug dosage 93mg x = cross multiply 125mg 5ml Answer: 3.7 ml is to be given per dose Practice Problems: 1. Order:Flurouracil (5-Ft) 12 mg/kg/day intravenously not to exceed. Weight: 132 lbs 2. Order:Phenytoin (Dilantin) 5mg/kg/day in two divided doses Weight: 55 lbs. 3. Order: sulfisoxazole (Gantrisin) 50 mg/kg/day in four divided doses Weight: 44 lbs 4. Order:albuterol (Provenuil) 0.1 mg/kg/day in four divided doses Weight: 86 lbs 5. Order:oxacillin (Prostaphlin) 40 mg/kg/day in four divided doses Weight: 33 lbs Stock: 250 mg / 5 ml How many milligrams should be given per day? How many milliliters should the child received per dose? Dosage Problems for Medications in the Same System Example: Order: 0.250 Digoxin Stock: 0.125 mg Digoxin per tablet Give: ______ tablet (s) 0.250mg D q x − , therefore, = cross multiply H Q 0.125mg 1tablet 0.125mg ( x) 0.250mg (1tablet ) = 0.125 0.125mg x = 2tablets Practice Problems: 1. furosemide (Lasix) 160 mg daily as prescribed. Lasix 40 mg tablets are “on hand” Give ____ tablets 2. Allopurinol 150 mg is prescribed Allopurinol 250 mg tablets are “on hand” Give ____ tablets 3. Codeine elixir 20 mg is prescribed Codeine elixir is labeled 10 mg per 5 ml Give _____ mg Dosage Problems for Medications in Different Systems Whenever the desired and on-hand drug dosages are in different systems, you would: 1. Choose the approximate equivalent. 2. Use the formula D/H =q/Q Example: Order: 500 mg Gentrisin QID Stock: 0.5 grams tablets Give ______ tablet (s) Change: To convert 500 milligrams to grams divide 500 milligrams by 1000 (1 gram = 1000 milligrams) or move the decimal point of 500 mg three places to the left – 500 mg = 0.500 grams. Use the formula: 0.5 grams D q x = , therefore, = cross multiply H Q 0.5 grams 1tablet x = 1tablet Practice Problems: 1. Thorazine hydrochloride is available in a syrup (3 mg/ml). the prescribed does is 3 teaspoons. You will give _____ ml which is equal to _____ mg. 2. Aspirin is available in 0.5 gram tablets. The prescribed does is grains 30 OD. Give _____ tablet (s) OD. 3. Phenobarbital ¼ grain is ordered q 6h PO. The stock available contains ½ grain per tablet. You would give _____ tablet (s). Dication Package as Powder. The available amount of drug is in a solute form (dry powder) and needs to be reconstituted by adding a diluent (solvent). The label on the available drug well give directions for adding the diluent. There are three common diluents that must always be sterile when added to the drug powder. Use either on of the three. a. Bacteriostatic water b. Sodium chloride (0.9%) c. Sterile distilled water for injection Read the directions for reconstitution at the label for the: a. recommended diluent b. quantity of diluent c. ratio of solute to solvent after reconstitution Use the usual formula to calculate drug dosage required. Example: The physician prescribed 250 mg of Amoxycillin IM q 8h. The medication was available as a powder in a 1 gram vial. Directions for reconstitution: Reconstitute with 2.5 ml of sterile water for injection. Shake well unit dissolved. Solution concentration ---------equal 330 mg/ml. fluid volume will equal 3.0 ml. Use the formula: D q 250 mg x _____ = _____, therefore, _______ = _____ cross multiply H Q 1000 mg 3 ml 1000 mg (x) = 250 mg (3ml) ___________ ____________ 1000 mg 1000 mg X = 0.75 ml will be given IM every 8 hours Practice Problems: 1. The physician ordered that a patient receive 1.5 mg Stadol IM q 3-4 hours as needs for pain. The medication was available for injection as 2.0 mg/ml. the nurse would give _____ ml every 3 to 4 hours prn. 2. The physician prescribed 500 mg of Velosef IM every 12 hours for the patients genitourinary infection. The medication available was a powder form in a 2gram vial. Directions at the label of the container read: reconstitute with 6.0 ml of sterile water for injection, shake well. Solution concentration will yield 270 mg/ml. fluid volume will equal to 7.4 ml. Use approximate quantities for dosage calculations. You will give _____ of the drug IM every 12 hours. Drugs Measured in Units: 1. PENICILLIN – some preparations penicillin come in units / ml, whereas other come in milligrams / ml. you can use the formula D/H = q/Q. Rule: To prepare Penicillin for injection, follow these steps: Read the medication order noting the number of units to be given. For example, a patch is prescribed 300,000 units of Penicillin G Procaine to be administered IVTT every 12 hours. Penicillin G Procaine is available as 600,000/1.2 ml. Therefore, you would use the formula: D/H =q/Q 300,000 units 600,000 units = x = cross multiply 1.2 ml 600,000 units (x) = 600,000 units 300,000 units (1.2 ml) 600,000 units x = 0.6 ml of the drug will be given IVTT every 12 hours 2. INSULIN – Frequently, you will it necessary to mix two types of insulin, usually regular insulin and NPH insulin. When you have to mix insulin, there are two important guidelines that you must remember: a. Do no contaminate the contents of one vial with the contente of the other vial. b. Always draw up the NPH insulin, which is a turbid preparation, last because chemically, it has a protein substance in it that the clear Regular insulin does not have. Drawing up the NPH insulin last helps prevent contamination of the regular insulin. Example: The doctor’s order reads as follow: Urine sugar q 6 hours (6 AM – 12 NN – 6 PM – 12 MN) Give Regular insulin subcutaneously for the following urine sugar result. 0 Trace 1+ 2+ 3+ 4+ - none none 5 units 10 units 15 units 20 units Stock: Regular insulin 40 units / ml. At 6 AM, the Regular insulin result was 2+. a. How many ml will you give using a tuberculin syringe? Use the formula: D/H =q/Q, 10 40 40 40 units = units units (x) = units x = x cross multiply 1 ml 10 units (1 ml) 40 units 0.25 x b. How many units will you give using a : (1) u-40 insulin syringe 10 units = x cross multiply 40 units 40 units 40 units (x) = 10 units (40 units) 40 units = 40 units x = 10 units (2) u-80 insulin syringe? 10 units = x cross multiply 40 units 80 units 40 units (x) = 10 units (80 units) 40 units = 40 units x = 20 units (3) u-100 insulin syringe? 10 units = x cross multiply 40 units 100 units 40 units (x) = 10 units (100 units) 40 units = 40 units x = 25 units Practice Problems: 1. The physician prescribed Penicillin G 125,000 units IM q 12 h. The medication is available in solution as 250,000 units/5 ml. The nurse would give _____ every 12 hours. 2. The physician prescribed 15 units of U=100 Regular insulin subcutaneously at 11 AM to cover a sugar and acetone reading of 3+. The nurse had a u-100 insulin syringe. She would draw up into the syringe ___Units. Intravenous Fluids 1. Calculating rate of flow per minute – Use the formula: Total amount of volume in ml x drop factor Drops per minute = ___________________________________ OR number of hours to last x 60 minutes/hour = total volume to infuse in ml x drop factor 60 minutes / hour Example: Administer 1000 ml of DW every 8 hours. The drop factor is 15 gtts/ml Use hour total volume to infuse in ml x drop factor : Drops per minute =number of hours to last x 60 minutes per = 1000 ml (15 gtts/ml) = 15 000 gtts = 125 gtts 8 hours (60 mins/hr) 480 mins 4 mins = 31.25 gtts/min or 31 to 32 gtts/min 2. Calculating amount to infuse ml per hour – Use the formula: Hourly volume = Amount of solution to infuse in ml Number pf hours to infuse solution Example period. : A patient is to receive 1000 ml of D LR over a 6-hour The patient will receive _____ ml/5hour hourly volume = in ml Use : amount of solution to infuse Number of hours to infuse solution = 1000 m = 6 hours 166.66 ml per hour or 167 ml per hour 3. Calculating duration of infusion – Use the formula: Total of hours to infuse in ml factor Number of hours to last hour x drop = rate of flow per minute x 60 minutes per Example : How long will an intravenous infusion of D5NM 1000 cc running at 20 gtts/min last when the drop factor of the delivery system is 15 gtts/ml? Use : number of hours to last = total volume in ml x drop factor gtts / min x 60 mins / hr = 1000 ml (15 gtts/ml) 20 gtts/min (60 mins/hr) = 15000 = 12.5 hours Or 1200 / hr 12 hours and 30 minutes = 2. To make 1.5 liters of a 5% solution from a stock of 25% solution, you would need ____ml of solute. Add _____ ml of water to make 1.5 liters of the solution. 3. To prepare 400 ml of 20% sodium bicarbonate solution form a pure drug, you would need _____ grams of solute. Add _____ ml of water to make 400 ml.
