Computerized drug therapy: application of the hand-held microcomputer to dosage regimen design.

For many drugs estimation of a safe and effective dosage regimen is difficult. Typically these drugs exhibit optimal therapeutic activity when drug concentrations in the blood are maintained within narrow limits and considerable intersubject variability exists in their rate of elimination from the body. Computer programs have been written to estimate the size and frequency of dose administration necessary to achieve therapeutic drug concentrations in the blood. The programs utilize pharmacokinetic equations and information on the individual patient's physiologic (e.g., age, weight, sex) and pathologic (e.g., existence of liver or renal disease) status. The drugs studied were gentamicin, theophylline, digoxin, phenytoin and warfarin. The programs were written using the hand-held TRS 80 Pocket Computer with an 8K memory module. These programs have been in use for 3 years and are currently involved in clinical consults approx. 100 times a month.