400 likes | 1.6k Vues
PEDIATRIC PRESCRIBING. By Dr. M. RAMESH M. Pharm, PhD, DipClinPharm, FICP (Australia) Professor Department of Pharmacy Practice JSS College of Pharmacy, Mysore. Introduction. Use of medicines in children is a challenge They react differently from adults to drugs
E N D
PEDIATRIC PRESCRIBING By Dr. M. RAMESH M. Pharm, PhD, DipClinPharm, FICP (Australia) Professor Department of Pharmacy Practice JSS College of Pharmacy, Mysore
Introduction Use of medicines in children is a challenge • They react differently from adults to drugs • Pharmacokinetic variation -- Change in body compartments -- Vd is high for neonates and infants -- Protein binding is less in neonates and infants • Lack of clinical trials
Pediatric age group • Neonates -- Birth to 1 month • Infants -- 1 month to 1 year • Children -- 1 year to 12 years • Adolescent -- 12 to 18 years
Prescription writing • Should be written according to prescription writing guidelines • Should state age, dose, frequency, route of administration and duration • Body wt and height should be stated
Prescription writing • Prefer oral route where possible • Should state the strength of cap/tab and concentration of oral liquids • Do not prescribe oral liquids in teaspoon measurement
Prescription writing • Where possible reduce the dosing frequency • Use inhaler aids and spacers for inhaled drugs • Do not mix the drug with food /infants feed
Prescription writing • Advice parents about child’s medication • Advise the parents to keep the medicines out of reach of children
Factors to be considered • Age • Dose • Dosing frequency • Routes of administration
Age • Variable in kinetics Neonates -- Decrease in clearance Infants -- Increase in clearance Children -- Decrease to reach adult rate of clearance • Neonatal skin is highly permeable • IM injection is painful (less muscle mass)
DoseDosing methods • Body surface area (BSA) • Body weight (mg/kg) • Percentage of adult dose (based on age)
Dosing method Body surface area (BSA) More accurate method • BSA (m2) = Ht (cm) X Wt (kg) 3600 or Ht (in) X Wt (lb) 3131 • Child’s dose = BSA 1.73 X Adult dose
Dosing method Body weight (mg/kg) Most commonly approached method i) Augsberger’s rule: Child’s approximate dose = (1.5 X Wt in Kg + 10) % of adult dose
Dosing method Body weight (mg/kg) ii) Clark’s rule: Child’s approximate dose = Wt (in pounds) 150 X Adult dose
Dosing method Ideal body weight (mg/kg) Useful in patients with large variations from ideal body weight Children 1 to 18 years: IBW (kg) = (Ht2 (cm) X 1.65) 1000
Dosing method Ideal body weight (mg/kg) • Children 5 feet and taller Male = 39 + (2.27 X Ht in inches) Female = 42. 2 + (2.27 X Ht in inches) • Use adult dose if -- Dose exceeds adult dose -- Child weighs >40 Kg or >12 years
Percentage of adult dose (based on age) Age % of adult dose New born 12.5 1 month 14.5 3 months 18
Percentage of adult dose (based on age) Age % of adult dose 6 months 22 1 year 25 3 years 33
Percentage of adult dose (based on age) Age % of adult dose 5 years 40 7 years 50 12 years 75
Dose calculation • Never guess or roughly estimate • Consider BSA where possible • Adjust the dose according to body weight
Dose calculation • Individualize the dose • Consider other factors (renal/hepatic status)
Dosing frequency • Reduce the dosing frequency when possible • Consider some flexibility in frequency
Routes of administrationOral • Preferred method unless other specific indication • Liquid preparations are most preferred • In prolonged therapy sugar free preparation should be used (to avoid tooth decay)
Routes of administrationOral • If the dose is <5ml, dilute it with suitable vehicle to 5ml • Do not prescribe teaspoon doses (dose may vary) • Do not prescribe 1 or 2 tab (mention the strength) • Do not mix it up with food/milk
Routes of administrationRectal • Absorption is erratic • Not preferred method
Routes of administrationTopical • Care should be taken as the drug may be absorbed in significant quantity • Avoid use of topical antibiotics due to danger of sensitization
Routes of administrationParenteral • IM is not preferred -- if necessary outer aspect of thigh is preferred • During IM/IV administration second person should be present to hold the child • Syringe should be prepared out of the child’s sight
Routes of administrationParenteral • Should be prepared for anaphylactic / other untoward reaction • Sterile technique is needed • Alcohol used for cleaning should be allowed to dry before injecting to avoid burning pain
Routes of administrationParenteral • Choose different sites if repeated injections are required • Other than IM/IV, intradermal injection can be considered