Trade/other name(s): Fleet Mineral Oil
Why would this drug be used?
Mineral oil is used to treat constipation. You can buy it over the counter, without a prescription.
How does this drug work?
Mineral oil coats the intestinal surface so that water isn't absorbed into the body. The extra water swells and softens the stool. This stimulates the normal forward movement of the intestines (peristalsis), which usually results in a bowel movement within 6 to 8 hours. The lubrication also eases passage of the stool.
Before taking this medicine
Tell your doctor…
- If you are allergic to anything, including medicines, dyes, additives, or foods.
- If you have any trouble swallowing, or if you are unable to sit or stand upright. Small amounts of mineral oil can accidentally be inhaled and cause pneumonia.
- If you have nausea, vomiting, rectal bleeding, unexplained abdominal pain, blocked intestine, or any disease of the stomach or intestine. Something other than constipation may be causing your problem, and mineral oil may worsen it.
- About any other prescription or over-the-counter medicines you are taking, including vitamins and herbs. In fact, keeping a written list of each of these medicines (including the doses of each and when you take them) with you in case of emergency may help prevent complications if you get sick.
Interactions with other drugs
Do not take mineral oil within 2 hours of taking other medicines or vitamins. It may interfere with their absorption into the body.
Do not take stool softeners such as docusate calcium, docusate potassium, or docusate sodium within 2 hours of mineral oil. These drugs can cause the mineral oil to be absorbed into the body.
Some sources report that the action of warfarin (blood thinners) and oral contraceptives (birth control pills) may be affected by mineral oil.
Check with your doctor, nurse, or pharmacist about other medicines, vitamins, herbs, and supplements, and whether alcohol can cause problems with this medicine.
Interactions with foods
Mineral oil should not be taken by mouth within 2 hours of meals because it may interfere with absorbing vitamins and other nutrients from food.
Tell all the doctors, dentists, nurses, and pharmacists you visit that you are taking this drug.
How is this drug taken or given?
Mineral oil is taken two ways. You can take it as a liquid by mouth on an empty stomach at bedtime or as a rectal enema. The dose is standard for all adults.
Take this drug exactly as prescribed by your doctor, or follow the directions on the label. If you have any questions or are confused by the instructions, talk to your doctor or nurse. Store the medicine in a tightly closed container out of the reach of children and pets.
Taking mineral oil may cause diarrhea in some people. If you have diarrhea, you should try to replace the fluid, nutrients, and minerals that you're losing. Drink 2 to 3 quarts of fluid a day, and try fluids with electrolytes, such as chicken broth or sports drinks, which are helpful in replacing potassium and salt lost in diarrhea.
If you are taking opioid pain relievers, you will need to take a laxative regularly. Mineral oil is not recommended for this use because of its unwanted effects over time.
Don't take mineral oil longer than a week. It blocks absorption of certain nutrients, including vitamins A, D, E, and K. It can also build up in the tissues and cause problems.
If you are not taking opioid pain medicine and you use laxatives all the time, your body may forget how to move your bowels normally and you come to depend on laxatives. Talk to your doctor if this is a problem for you.
To help avoid constipation, try to drink 2 to 3 quarts of fluid a day. Increase the amount of fiber you eat in foods by eating fruits, vegetables, beans, peas, and whole-grain breads and cereal. Talk to your doctor about what kind of exercise may help you.
Possible side effects
You will probably not have most of the following side effects, but if you have any talk to your doctor or nurse. They can help you understand the side effects and cope with them.
- loss of normal bowel responses when laxatives are used for a long time*
- leakage of oil from rectum (more common with larger doses)
- reduced absorption of nutrients from food*
There are some other side effects not listed above that can also occur in some patients. Tell your doctor or nurse if you develop these or any other problems.
This drug appears to pre-date the current FDA approval process, which would mean it was not required to get formal FDA approval.
Disclaimer: This information does not cover all possible uses, actions, precautions, side effects, or interactions. It is not intended as medical advice, and should not be relied upon as a substitute for talking with your doctor, who is familiar with your medical needs.
Last Revised: 11/17/2009