The effect of food on the absorption of phenylbutazone from a commercial 100 mg enteric-coated tablet.

It is recommended that many drugs be taken with or after meals. Recently, however, food intake has been shown to alter significantly the rate and/or extent of absorption of many drugs. Such alterations may induce important changes in the clinical activity of these drugs. Enteric-coated phenylbutazone is recommended to be taken with food to minimize possible gastro-intestinal side-effects. The results of this study demonstrate that while food delays the onset of absorption from this formulation by 4-5 h, it has no significant effect on the peak concentration or area under the curve. Thus, some effect on fluctuation in plasma levels at steady-state would be expected, but the mean concentration over the recommended dosage interval would remain the same. Treatment efficacy should therefore be unaffected by food but the tolerability may be improved.