Indications
Monobasic Sodium Phosphate is a saline laxative. It is usually combined with Dibasic Sodium Phosphate in a ready-to-use enema that is given into the rectum. It is used for short-term relief of occasional constipation and to empty the lower bowel before examinations, surgery or childbirth, or as directed by a doctor.
How It Works
The phosphate salts draw water into the bowel by osmosis. This softens and increases the volume of stool and stimulates the bowel to empty, usually within 2 to 5 minutes of giving the enema.
Dosage and Administration
Adults and children aged 12 years and over: one adult-size enema given rectally as a single dose, not more than once in 24 hours, or as directed on the label or by your doctor. Lie on your left side with knees bent, gently insert the lubricated nozzle into the rectum, squeeze the bottle slowly, then remove it. Hold the liquid in until you feel a strong urge to empty the bowel. Children’s enemas and doses are smaller and should be used only on a doctor’s advice. Do not use for more than 3 days in a row.
Interactions
- Diuretics (water tablets), ACE inhibitors, angiotensin receptor blockers and NSAIDs: higher risk of kidney damage and salt imbalance.
- Medicines that affect heart rhythm or lower calcium or potassium: use with care.
- Lithium: levels may change.
- Do not use with other sodium phosphate laxatives.
Contraindications
- Bowel blockage, bowel perforation, inflammatory bowel disease or undiagnosed stomach pain, nausea or vomiting.
- Kidney failure or significant kidney disease.
- Congestive heart failure, dehydration, or high sodium or phosphate levels.
- Megacolon (enlarged colon) or Hirschsprung’s disease.
- Children under 2 years.
Side Effects
Common effects include bloating, cramping, a burning feeling in the rectum and a strong urge to pass stool. Rarely, it can cause dehydration and changes in blood salts (high phosphate, high sodium, low calcium, low potassium), especially if it is held in too long, used too often, or given to older people or those with kidney problems.
Get urgent medical help if there is no bowel movement within 30 minutes and you feel unwell, or if you have rectal bleeding, severe stomach pain, dizziness, confusion, muscle cramps or twitching, a seizure, or very reduced urine.
Pregnancy and Lactation
Use in pregnancy and breastfeeding only on a doctor’s or midwife’s advice. A single dose before childbirth is commonly used under supervision.
Precautions and Warnings
Use only once in 24 hours. If the enema liquid does not come out, contact a doctor because the salts can be absorbed. Take care in older adults, people with heart, kidney or liver disease, or those on a salt-restricted diet. Drink enough fluids. Stop and get advice if constipation lasts more than a week or there is a sudden change in bowel habit.
Overdose
Using too much, or more often than advised, can cause serious dehydration and dangerous salt changes, which may lead to kidney damage, heart rhythm problems and seizures. Seek emergency medical help.
Therapeutic Class
Osmotic (saline) laxative, rectal enema.
Storage
Store below 30°C in a dry place, away from light and out of the reach of children. Do not freeze.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.