Pediatric Informatics: Computer Applications in Child Health (Health ...

27 Dispensing: Pharmacy Information Systems 351
be missed). Rules and data across the clinical systems within an institution (such as
CPOE and PharmIS) should be as consistent as possible. Differences in tolerances
for errors or flexibility may lead to conflicting alerts (such as a situation where a
CPOE system that does not display a dosage warning to a prescriber, but for which
the linked PharmIS provides a dosage error to the pharmacist.
Example of dose range check:
Drug “X” has the following dose limits
Pediatric limits:
Per Dose: 25–50 mg/kg
Per Day: 50–100 mg/kg [daily dose usually divided twice per day (every 12 h)]
Adult limits:
Per Dose: 1,000–2,000 mg
Per Day: 2,000–4,000 mg [daily dose usually divided twice per day
(every 12 h)]
In a 12 kg pediatric patient – if the prescriber orders 300 mg per dose every
12 h, the 300 mg value is the one needed by most PharmIS, as it reflect the
final dose to be compounded, labeled, dispensed, and administered. For Dose
Screening, however, the 300 mg value must be divided by the weight in order
to check it against the above parameters (i.e. 300 mg per dose/12 kg = 25
mg/kg/dose; 25 mg/kg/dose × 2 doses per day = 50 mg/kg/day). It should also be
checked against maximum adult doses to assure that, in an example of a larger
adolescent pediatric patient, the correct mg/kg dose is not in excess of the adult
maximum doses.
27.3.3.2 Detecting Known Allergy and Drug Interactions
Another essential PharmIS CDS function is allergy checking/screening, 8 which
requires linkage to an accurate and current patient allergy profile (which must be
maintained and available to the PharmIS). Although drug allergy checks should
be comprehensive and include chemically related drugs with known cross-reactive
potential (such as is known penicillin with piperacillin or cefotaxime), this is challenging
because of the lack of an available evidence-based standard coding scheme
of cross-reactivity potentials and an effective method to distinguish (or notate a
distinction) between true allergy (such as anaphylaxis) and individual intolerance
(such as nausea to narcotics) to a medication. Most systems do not differentiate
these two phenomena, and it is unknown if doing so would improve safety in this
area.
As with automated dose checking, allergy screening rules may be provided by
an interfaced third party CDS system or may be configured locally. Allergy checking
functionality is currently available on many PharmIS. The same advantages and