Section VIII. PEDIATRIC DOSE CALCULATIONS
a. Premature babies and other very young infants may be unusually responsive
to many drugs because of the immaturity of the following.
(1) Renal function.
(2) Enzymatic mechanisms for drug inactivation.
(3) The blood-brain barrier.
(4) The brain.
NOTE: Children are often more sensitive than adults to drugs which alter the acid-base
metabolism or the water-and-electrolyte balance.
b. Pediatric doses based on formal experiments or the experience of the
prescriber are better than those calculated according to a general rule or formula.
Unfortunately, optimal pediatric doses have not been established for most drugs. Thus,
where possible, doses for younger children, and especially for infants, should be
learned as such and not based merely on a formula; doses calculated with a formula (as
a fraction of the adult dose based on the body weight or body surface area) are very
unreliable for premature infants, but more reliable for children at least 2 years old.
1-23. DOSAGE RULES INVOLVING A FRACTION OF THE ADULT DOSE
a. A General Rule of Dosage.
AGE (IN YEARS)
20 or older
the adult dose
1/2 the average adult dose
1/4 the average adult dose
1/8 the average adult dose
1/12 the average adult dose