Patient Medication Information: uses, side effects, how to take - Riva-Magnesium Oxide, Citric Acid and Sodium Picosulfate
ABOUT THIS MEDICATION
What the medication is used for:
RIVA-MAGNESIUM OXIDE, CITRIC ACID AND SODIUM PICOSULFATE is a white powder. It is a very strong purgative (i.e. to empty bowels). RIVA-MAGNESIUM OXIDE, CITRIC ACID AND SODIUM PICOSULFATE is used to cleanse the bowel of faecal matter and secretions prior to x-ray examination, endoscopy or surgery. This product is not intended for routine use as a laxative.
When it should not be used:
- 1. If you are allergic to any of the ingredients (see above).
- 2. If you have any of the following; gastric retention (reduced ability of the stomach to empty), gastric or intestinal ulcers, appendicitis, gastrointestinal blockage or perforation.
- 3. If you have ileus (intestinal blockage or failure of normal movements), toxic colitis (damage to intestinal wall) or toxic megacolon (acute dilatation of the large bowel). In these conditions, transit of the contents of the bowel may be impaired or prevented. Symptoms include nausea, vomiting, diarrhoea, abdominal pain, tenderness or swelling, colicky pain and fever.
- 4. If you have congestive cardiac failure (the heart is unable to pump blood efficiently around the body).
- 5. If you have severely reduced kidney function.
What it does:
Magnesium oxide and citric acid combine together (chemical reaction) in water to form magnesium citrate, which works as an osmotic laxative drawing water into the bowel to help make the stool soft and more watery. Sodium picosulfate works as a stimulant laxative to increase the bowel movements to move- the contents along. Together they work to empty the bowel prior to medical procedures.
What the medicinal ingredient is:
Each sachet contains 16.1 g of powder which has three active ingredients: sodium picosulfate 10 mg, magnesium oxide 3.5 g and citric acid 12 g; the latter two form magnesium citrate in
solution.
What the important nonmedicinal ingredients are:
Lactose anhydrous, natural orange flavour, potassium bicarbonate and saccharin sodium
What dosage forms it comes in:
Powder
WARNINGS AND PRECAUTIONS
Please consult your doctor before taking RIVA-MAGNESIUM OXIDE, CITRIC ACID AND SODIUM PICOSULFATE if you:
- Have recently had gastrointestinal surgery,
- Have a medical condition affecting the heart or kidneys,
- Have inflammatory bowel disease such as ulcerative colitis or Crohn’s disease,
- Are using bulk forming laxatives e.g. bran.
- Have heart problems such as a recent heart attack, irregular or fast heartbeat (arrhythmia), lengthened heart beat (QT prolongation) or angina
- Have a history of seizures
- Have an impaired gag reflex
Pregnancy or Breast-Feeding: If you are pregnant or are breast-feeding, ask your doctor or pharmacist for advice before taking RIVA-MAGNESIUM OXIDE, CITRIC ACID AND SODIUM PICOSULFATE.
INTERACTIONS WITH THIS MEDICATION
Taking Other Medicines:
Please inform your doctor or pharmacist:
- If you are taking or have recently taken or used any other medicines – even those that are available without a prescription.
- If you are taking anti-epileptics, contraceptives, antibiotics, diabetes medications and cardiac glycosides as they may be affected during treatment with RIVA-MAGNESIUM OXIDE, CITRIC ACID AND SODIUM PICOSULFATE.
- If you are taking diuretics, corticosteroids and lithium as these drugs may affect electrolyte balance.
- If you are taking nonsteroidal anti-inflammatory drugs (NSAIDS), tricyclic antidepressants, antipsychotic drugs or carbamazapine as these drugs may add to the electrolyte imbalance.
- If you are taking oral iron preparations for a week before colonoscopy.
- If you are taking constipating drugs (e.g. cholinergics, opioids); they should be temporarily discontinued for a few days before the procedure.
- If you are taking Tetracycline and fluoroquinolone antibiotics, digoxin, chlorpromazine and penicillamine they should be taken 2 hours before or not less than 6 hours after taking RIVA-MAGNESIUM OXIDE, CITRIC ACID AND SODIUM PICOSULFATE, to avoid loss of effectiveness of these other medications.
PROPER USE OF THIS MEDICATION
PRE-DOSING INSTRUCTIONS:
If you have special dietary requirements, please discuss this with your doctor.
At least 3 days prior to your procedure:
- Do not consume seeds or nuts due to digestive residue
- Do not consume any fresh fruits or raw vegetables (i.e. no salads) and no multigrain bread
ADULT DOSING INSTRUCTIONS:
Fill a mug with 150 ml (5 oz) of cold water. Empty contents of one sachet in the mug (rarely, mixture may heat up - allow to cool before drinking). Stir for 2-3 minutes until completely dissolved before you drink. The solution should now become an off-white, cloudy liquid. Following each sachet, drink 1.5 to 2 Litres of a variety of clear fluids over 4 hours.
DO NOT DRINK JUST WATER ALONE. Drinking only water to replace the fluid losses may lead to electrolyte imbalance, particularly to hyponatremia and possibly seizures. A good option is to also drink a balanced electrolyte solution (e.g. Gastrolyte†, Pedialyte†) as recommended by a health professional to replace fluid losses.
Recommended clear fluids include any fluid that you can see through, that is not red or purple; such as sports drinks (e.g. Gatorade†), Gastrolyte†, Pedialyte†, Kool-Aid†, clear broth (chicken, vegetable or beef stock with no noodles, meat or vegetables), fruit juices (e.g. apple, white (not red) cranberry, white (not purple) grape), tea or coffee (black, sweetened to taste, no milk, cream or soy), clear sodas (e.g. ginger ale), plain Jell-O† (not red or purple), Popsicles† (not red or purple) and water.
Diabetics can use a fibre-free supplement/meal replacement.
One day before your procedure you should have clear fluids ONLY and no solid food. See list above.
Morning colonoscopy - before 12:00 pm (noon);
One day before your procedure: Take 1 sachet (first dose) at 5:00 pm followed by 1.5 to 2 Litres of a variety of clear fluids.
Six (6) hours before your procedure: Take 1 sachet (second dose) followed by 1.5 to 2 Litres of a variety of clear fluids.
No fluid should be taken at least 2 hours prior to your procedure.
Afternoon colonoscopy - 12:00 pm (noon) or later:
One day before your procedure: Take 1 sachet (first dose) at 7:00 pm followed by 1.5 to 2 Litres of a variety of clear fluids.
On the same day as your procedure: Take 1 sachet (second dose) in the morning, 6 hours before your procedure (time to be confirmed by the physician), followed by 1.5 to 2 Litres of a variety of clear fluids.
In order to replace fluid lost from the body, it is important to drink plenty of clear fluids throughout the treatment with RIVA-MAGNESIUM OXIDE, CITRIC ACID AND SODIUM PICOSULFATE until bowel movements have ceased.
No fluid should be taken at least 2 hours prior to your procedure.
PEDIATRIC DOSING INSTRUCTIONS:
Fill a mug with 150 ml (5 oz) of cold water. Empty contents of one sachet in the mug (rarely, mixture may heat up - allow to cool before drinking). Stir for 2-3 minutes until completely dissolved before you drink.
If possible, it is recommended that RIVA-MAGNESIUM OXIDE, CITRIC ACID AND SODIUM PICOSULFATE should be given at least 5-6 hours before bedtime to avoid interference with sleep. Therefore, splitting the dose over two days is recommended for children as follows:
(1 to 6 years old):
One day before your procedure: Take ¼ of the prepared solution as per DOSING INSTRUCTIONS (first dose) at 6:00 pm followed by one cup of clear liquid (250 mL, 8 oz) every hour while the child is awake. No solid food should be taken after 6:00 PM.
On the same day as your procedure: Take ¼ of the prepared solution as per DOSING INSTRUCTIONS (second dose) at 8:00 am, followed by one cup of clear liquid (250 mL, 8 oz) every hour up to 2 hours prior to your child’s procedure.
(6-12 years old):
One day before your procedure: Take ½ of the prepared solution as per DOSING INSTRUCTIONS (first dose) at 6:00 pm followed by one cup of clear liquid (250 mL, 8 oz) every hour while the child is awake. No solid food should be taken after 6:00 PM.
On the same day as your procedure: Take ½ of the prepared solution as per DOSING INSTRUCTIONS (second dose) at 8:00 am, followed by one cup of clear liquid (250 mL, 8 oz) every hour up to 2 hours prior to your child’s procedure.
In order to replace fluid lost from the body, it is important to drink plenty of clear fluids throughout the treatment with RIVA-MAGNESIUM OXIDE, CITRIC ACID AND SODIUM PICOSULFATE until bowel movements have ceased. In general, patients should drink about 250 mL of water or clear fluid and/or a balanced electrolyte solution (e.g.: Gastrolyte†, Pedialyte†) as recommended by a health care professional, every hour while they feel the effects of RIVA-MAGNESIUM OXIDE, CITRIC ACID AND SODIUM PICOSULFATE.
No fluid should be taken at least 2 hours prior to your procedure.
Overdose:
If you think you, or a person you are caring for, have taken too much RIVA-MAGNESIUM OXIDE, CITRIC ACID AND SODIUM PICOSULFATE, contact a healthcare professional, hospital emergency department, regional poison control centre or Health Canada's toll-free number, 1-844 POISON-X (1-844-764-7669) immediately, even if there are no signs or symptoms.
Overdose would lead to profuse diarrhoea. Treatment is by general supportive measures and correction of fluid and electrolyte balance.
SIDE EFFECTS AND WHAT TO DO ABOUT THEM
Like all medicines, RIVA-MAGNESIUM OXIDE, CITRIC ACID AND SODIUM PICOSULFATE can cause side effects, although not everybody gets them. Adverse reactions to RIVA-MAGNESIUM OXIDE, CITRIC ACID AND SODIUM PICOSULFATE are very rare (< 1 in 10, 000). Some examples include: hyponatraemia, epilepsy, grand mal convulsions, nausea, rash, headache, anaphylactoid reaction, hypersensitivity.
If any side effects become serious or persist, or if you notice any side effects not listed in this leaflet, please tell your doctor or pharmacist.
| SERIOUS SIDE EFFECTS, HOW OFTEN THEY HAPPEN AND WHAT TO DO ABOUT THEM | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| SERIOUS SIDE EFFECTS, HOW OFTEN THEY HAPPEN AND WHAT TO DO ABOUT THEM | ||||||||||||
| Symptom / effect | Talk with your doctor or pharmacist | Stop taking drug and call your doctor or pharmacist | ||||||||||
| Symptom / effect | Talk with your doctor or pharmacist | Stop taking drug and call your doctor or pharmacist | ||||||||||
| Only if severe | In all cases | |||||||||||
| Only if severe | In all cases | |||||||||||
| Common | Hypermagnesemia (high level of magnesium in your blood): decrease to your reflex response (hyporeflexia), low blood pressure, difficulty breathing or shallow breathing and your heart stops beating (cardiac arrest). | ✓ | ||||||||||
| Uncommon | Hyponatremia (low level of sodium in your blood): Nausea and vomiting, confusion, drowsiness and fatigue, restlessness and irritability, muscle weakness, cramps, seizures, coma. | ✓ | ||||||||||
| Convulsion, epilepsy, confusional state, headache. | ✓ | |||||||||||
| Vomiting, diarrhea, abdominal pain, nausea. | ✓ | |||||||||||
This is not a complete list of side effects. For any unexpected effects while taking RIVA-MAGNESIUM OXIDE, CITRIC ACID AND SODIUM PICOSULFATE, contact your doctor or pharmacist.
HOW TO STORE IT
Store at room temperature (15°C to 30°C).
Keep out of reach of children.
Reporting Side Effects
You can report any suspected side effects associated with the use of health products to Health Canada by:
- Visiting the Web page on Adverse Reaction Reporting (canada.ca/drug-device-reporting) for information on how to report online, by mail or by fax; or
- Calling toll-free at 1-866-234-2345.
NOTE: Contact your health professional if you need information about how to manage your side effects. The Canada Vigilance Program does not provide medical advice.
MORE INFORMATION
This document plus the full product monograph, prepared for health professionals, can be provided by contacting the manufacturer, Laboratoire RIVA Inc., at: 1-800-363-7988. This leaflet was prepared by: Laboratoire RIVA Inc. 660 Boul. Industriel Blainville, Quebec J7C 3V4 www.labriva.com Last revised: JAN 08, 2026