Mineral oil is the main lubricant laxative currently in clinical use.
In its nonemulsified form, mineral oil is minimally
absorbed; the emulsified form is about half absorbed. Absorbed mineral oil is
distributed to the mesenteric lymph nodes, intestinal mucosa, liv-er, and
Mineral oil is metabolized by the liver and
excreted in stool.
Mineral oil lubricates stool and the intestinal
mucosa and prevents water reabsorption from the bowel lumen. The increased
fluid content of stool increases peristalsis. Administration by enema also
Mineral oil is used to treat constipation and
maintain soft stool when straining is contraindicated, such as after a recent
MI (to avoid Valsalva’s maneuver), eye surgery (to prevent increased pressure
in the eye), or cerebral aneurysm repair (to avoid in-creased ICP).
Administered orally or by enema, this lubricant
laxative is also used to treat the patient with fecal impaction.
Mineral oil can interact with other drugs.
Mineral oil may impair the absorption of many oral drugs, in-cluding
fat-soluble vitamins, hormonal contraceptives, and anti-coagulants.
Mineral oil may interfere with the antibacterial activity of
non-absorbable sulfonamides. To minimize drug interactions, adminis-ter mineral
oil at least 2 hours before these medications. (See Ad-verse reactions to mineral oil.)