Pharmacy Orientation PDF

Pharmacy Orientation For First level Pharmacy students By Dr. Germeen N. S. Girgis Lecture 3 Handling of the prescription  Handling of the prescription The pharmacist is responsible for proper handling of the prescription including receiving, c...

Pharmacy Orientation For First level Pharmacy students By Dr. Germeen N. S. Girgis Lecture 3 Handling of the prescription  Handling of the prescription The pharmacist is responsible for proper handling of the prescription including receiving, checking, compounding, finishing and delivery. I- Receiving the prescription The pharmacist personally must receive the prescription from the patient, or the person who represents the prescription for the patient.  A- If the patient's name does not appear in the prescription, the pharmacist should obtain this information. B- If the prescription is intended for a child, the age for whom the medicine is intended should be recorded in the prescription. C- If there is any doubt concerning reading of the prescription ingredients or directions or if it appears that an error has been made in writing it, the pharmacist must consult other pharmacists or the prescriber without arousing fear of doubt on the part of the customer. II- Checking the prescription for safety The pharmacist should understand it very well. Must be sure that is no dangerous overdose or incompatibilities, otherwise he should consult the physician who wrote it. All the following should be checked: Dose based on age, weight, or body surface area. Route of administration. Pharmaceutical dosage form. Frequency of administration III- Compounding the prescription Check any calculation and storage requirement. Collect the container. Write the label. Prepare the medicine. Pack the medicine into the container. Fix the label. Check the finished preparation Methods for calculating the dose for child or infant Based on age Age is important because infants, children and old people require smaller dose than that of adults. There are a number of methods for calculating the fractional part of the average adult dose which an infant or child can take safely.  Fried's rule (for infants younger than 2 years) This rule is rarely used and should be limited to patients under 2 years of age. It is based on the assumption that an adult dose of a drug can be tolerated safely by a child when he reaches the age of 150 months [ 12.5 years ] Infant dose = Age (in months) / 150 X Adult dose Example  Example 1: Physician orders ciprofloxacin for a 6- month-old infant, the usual adult dose is 500 mg. what is the infant's dose? Infant dose = Age (in months) / 150 X Adult dose Infant dose = (6 months / 150) X 500 mg = 20 mg Example 2  Young's rule This formula is seen more frequently than Fried's Rule. Young's rule may be used for child age 1 to 12 years. Child's dose = Age in Years / (Age in Years + 12) X Adult dose  Example: Physician orders ciprofloxacin for a 5- years-old child, the usual adult dose is 500 mg. what is the Child's dose? Child's dose = Age in Years / (Age in Years + 12) X Adult dose Child's dose = 5 / (5 + 12) X 500 mg Child's dose = 5 / (17) X 500 = 150 mg (rounded from 147 mg)  Cowling's rule Is based on age in years at next birthday [ present age + 1 ] Child's dose = (Age in Years + 1) / 24 X Adult dose Methods for calculating the dose Based on weight As a general rule, a naturally heavy individuals can withstand larger doses of medicines than a person of less weight.  Clark's rule For weight in pounds Child's dose = Weight of child in pounds (lb) / 150 (average weight of adult in Ib) X Adult dose For weight in Kg Child's dose = Weight of child in Kg / 68.2 Kg X Adult dose N.B : 1 pound (lb) is equal to 0.453 Kg  Example: A 10 years-old, 68 Ib child is to receive Carbamazepine for seizure disorder. The usual adult dose is 300 mg. what is the Child's dose? Child's dose = (68/ 150) x 300 mg Child's dose = 0.45 x 300 ≈ 135 mg Methods for calculating the dose Based on body surface area rule (BSA) Body surface area (BSA) is the total area exposed to the environment in m2. Child's dose = BSA in m2 of child / BSA in m2 of adult x adult dose The average BSA for adult is 1.73 m2 Child's dose = BSA in m2 of child / 1.73 x adult dose  Calculating dose using body surface area The most accurate way of determining pediatric dosages. The BSA of a patient takes into consideration both the height and weight of the patient. BSA may be calculated using a chart called a nomogram. A BSA is found on a nomogram by using a straight edge to draw a line between the patient's height (in cm or inch) and weight (in Ib or Kg). The BSA can be found where the line intersects the BSA column in the middle. BSA is measured in units of meters squared  BSA has been determined for child who is 24 inches tall and weighs 37 pounds. By positioning a straight edge at 24 inches on the left column and 37 pounds on the right column, we are able to draw a straight line between the two points. The line drew intersects the middle column at a BSA of 0.44 m2.  Example 1: A ten month old infant weighs 10 Kg and 27 inches tall. Using the BSA, calculate a dose for this patient if the usual adult dose is 750 mg. Step 1: write out the formula that you'll need to solve the problem Child's BSA (in m2) / BSA in m2 of adult x adult dose = child's dose Step 2: Use the BSA nomogram and the child's height and weight to determine the child's BSA. Child's dose = 0.41m2 / 1.73 m2 x 750 mg Child's dose = 0.41 m2 x 750 ≈ 180 mg 1.73 m2  Example 2: If the adult dose of drug is 75 mg, what would be the dose of a child weighing 40 lb. and measuring 32 inch. in height ? use the BSA. Solution From the nomogram, the BSA = 0.60 m2 Child's dose = 0.60 (m2) / 1.73 (m2) X 75 mg = 26 m