Absorption of paracetamol from suppositories in geriatric patients with fecal accumulation in the rectum.

The bioavailability of paracetamol from suppositories was studied in 16 geriatric in-patients in stable clinical condition; 9 had significant amounts of feces in the rectum. Rectal accumulation of feces reduced the peak plasma paracetamol concentration by 32% (p = 0.05) and the AUC0-8h by 27% (p = 0.04). The peak concentration, however, appeared earlier among patients with rectal accumulation of feces. Compared to findings in 6 healthy young controls, geriatric patients had higher plasma concentrations of the main paracetamol metabolites.