Simplifying drug regimens is 1 method of improving patient compliance. Medications originally administered several times a day are now reported to maintain 24 h effectiveness on once-daily administration. In many cases this technique of administration results in the use of less expensive medication, an improvement in compliance, and even decreased side effects. All patients may not be controlled or tolerate increased intervals between drug doses. Interpatient variation dictates that physicians closely monitor their patients when prescribing new or unapproved regimens of drug therapy.