ESCAPE PHENOMENON WITH PRAVASTATIN DURING LONG-TERM TREATMENT OF PATIENTS WITH HYPERLIPIDEMIA ASSOCIATED WITH DIABETES-MELLITUS

The escape phenomenon is considered to be a type of drug resistance ca used by an increase in drug metabolism or an induction of enzymes or f unctional proteins toward which the drug is targeted. In practice, how ever, little evidence supports the actual occurrence of the escape phe nomenon; rather, deterioration of compliance may be a more plausible c ause. To address this issue, we compared changes in serum lipids in tn o groups of patients with diabetes mellitus during long-term treatment of hyperlipidemia with pravastatin sodium, a soluble 3-hydroxy-3-meth ylglutaryl coenzyme A reductase inhibitor. Sixteen male and female pat ients with non-insulin-dependent diabetes mellitus and hyperlipidemia were enrolled in this study. All 16 patients had maintained decreased serum total cholesterol (TC) levels of 15% or more (from 261.5 +/- 5.6 mg/dL to 195.6 +/- 2.1 mg/dL, mean +/- SE) for 3 months or longer aft er beginning pravastatin therapy. Their serum TC levels had then incre ased by 10% or more from the reduced levels (from 195.6 +/- 2.1 mg/dL to 231.6 +/- 3.3 mg/dL, mean +/- SE). At this point, patients were ran domly separated into two groups-group A receiving reinforcement of dru g compliance and diet therapy and group B receiving no reinforcement. Changes in serum Lipids, plasma glucose, glycated hemoglobin A(1c) (Hb A(1c)), and body weight were studied. Serum TC levels decreased signi ficantly (234.4 +/- 4.3 mg/dL to 205.6 +/- 4.3 mg/dL) in serum group A , but remained unchanged (228.4 +/- 4.6 mg/dL to 230.1 +/- 2.9 mg/dL) in group B. No significant changes were observed in the levels of plas ma glucose, Hb A(1c), or body weight. Results of this study suggest th at insufficient diet therapy and poor drug compliance, rather than the escape phenomenon, account for a re-increase in serum TC levels after an initial decrease in levels with pravastatin therapy.