Polyethylene Glycol 3350, Sodium and Potassium Salts (Oral)

Polyethylene glycol 3350, potassium salts, and sodium in combination are used as a laxative treatment to cleanse the colon in preparation for certain medical tests.


In the US, polyethylene glycol 3350, potassium salts, and sodium in combination are sold under the brand names TriLyte wFlavor Packs, GaviLyte-N with Flavor Pack, and Nulytely. The drug comes in powder form for conversion into a solution or suspension and can only be obtained on prescription from your physician.

Polyethylene glycol 3350, potassium salts, and sodium in combination is used in a hospital or clinical setting to cleanse the patient's bowel prior to medical tests such as a colonoscopy. The drug is a laxative that works by triggering diarrhea, which effectively cleans out the colon. The procedure is necessary in order to allow your physician to view the inside of your colon more clearly during the procedure.

Conditions treated

  • Preparatory for certain medical diagnostic procedures

Type of medicine

  • Laxative
  • Hyperosmotic

Side effects

In addition to the effects it is meant to have, some medications can cause unwanted side effects in some patients. You may not notice any ill effects while taking polyethylene glycol 3350, potassium salts, and sodium in combination, but if you do, you may need further medical attention.

Talk to your treating physician immediately if you notice any of the effects listed below:

  • Vomiting of blood or material that resembles coffee grounds
  • Vomiting
  • Feeling unusually tired or weak
  • Sudden feeling of tightness in the chest
  • Swelling in the ankles and legs
  • Skin rash, itching, hives or welts
  • Shortness of breath
  • Severe stomach pains
  • Reddened skin
  • Puffiness or swelling around the eyes, eyelids, lips, tongue, or mouth
  • Pale skin
  • Increased sweating
  • Rapid heartbeat
  • Dizziness
  • Problems swallowing
  • Difficult, rapid, or noisy breathing, sometimes accompanies by wheezing
  • Sudden onset of difficult or labored breathing
  • Coughing producing a pink frothy sputum
  • Cough
  • Constipation
  • Chest pain
  • Cyanosis
  • Black or bloody, tarry stools

In some patients, polyethylene glycol 3350, potassium salts, and sodium in combination causes unwanted effects that go away by themselves. Your physician may be able to suggest ways of managing your side effects, but if they do not resolve by themselves within a day or so following treatment, you should consult your GP.

  • Swelling
  • Runny nose
  • Nausea
  • Cracked, dry, or scaly skin
  • Burning or itching around the anus
  • Bloating
  • Blistering, crusting, irritation, itching, or reddening of the skin
  • Abdominal or stomach fullness
  • Abdominal or stomach cramps

The side effects that are mentioned here are not necessarily the only ones that affect patients who have taken polyethylene glycol 3350, potassium salts, and sodium in combination. If you notice any other odd or bothersome effects, you should speak to your physician.


Your colonoscopy will be scheduled in advance. Because of this, you will probably be given specific instructions as to when you should use the medicine, based on the time of your procedure. If you do not receive any such instructions, or if you do not understand what to do, have a chat with your physician.

You must use the medication exactly as you are instructed to by your physician or nurse. If you do not use the drug properly, your test may not work and you might have to have it done again.

When you are given your prescription, you will also be given a medication guide. Be sure to read the guide right through so that you understand the instructions it contains. If you do not understand the information in the guide, you should check with your physician.

It is important that you have nothing solid to eat for at least two hours prior to using the medication. In addition, you must not eat solid food once you have taken your first dose of medicine, until after your colonoscopy. However, you may drink clear liquid or water up till two hours before your test, provided that it is not colored purple or red.

You must not take any other oral medication for up to one hour prior to taking this medicine. This is because oral medication may not have chance to get into your body before being removed by the laxative effect of the medicine. Ask your physician for advice if you are taking any other form of medicines.

Usage guidelines

1. The medication comes in powder form for mixing with water. Do not take the powder undiluted.

2. One flavor pack should be added to the bottle provided, before adding water. Do not add extra flavoring, and discard any unused flavor packs.

3. Fill the bottle with lukewarm water, up to the fill mark.

4. Shake the bottle thoroughly until all the powder is gone.

5. The mixture can be stored in the fridge but you must use it within 48 hours.

6. Take the medication in accordance with your physician's instructions.

7. Do not sip the mixture; try to drink it quickly.

8. If it is not possible for you to swallow the mixture, your physician or nurse may administer it to you via a nasal tube.

9. The medicine takes about an hour to become effective after you have drunk the first dose. Initially, you will have diarrhea, followed by loose and watery matter.

10. You must continue to take the medication until your stools are free from solids and appear clear.

11. Do not keep any unused mixture.

The dose of the medication that you are told to take will vary between patients. You should take the medicine in accordance with the instructions you are given by your nurse or physician, or you can follow the directions on the product dispensary label. The information that follows is based on the average dose. If your dose is at variance with this, do not change it unless you are told to by your physician.

The number of doses that you will take of polyethylene glycol 3350, potassium salts, and sodium in combination will depend on how your body reacts to the drug. This factor will also determine the frequency of doses you need to take and how long you need to use the medicine for.

For colon cleansing, oral dosage format:

  • Adults: Take 240 ml at 10 minute intervals.
  • Children aged six months and over: The dose is based on the child's body weight. The dose is usually 25 ml per kg, per hour. However, your child's treating physician will determine the use and dose rates.
  • Children aged six months and under: Your child's treating physician will determine the use and dose rates.


You should not use some forms of medication with other drugs, as doing so could cause the two to interact, causing unpleasant or dangerous side effects. If this applies in your case, your physician may change one of your medicines or alter the dose until you have finished using polyethylene glycol 3350, potassium salts, and sodium in combination. If you are already taking any other medicines, including over the counter products, vitamins, herbal remedies, and diet pills, you must tell your physician.

It is not recommended that you use this medicine with any of the following drugs. Your physician may elect not to use polyethylene glycol 3350, potassium salts, and sodium in combination, or may change some of the other drugs you usually use:

  • Trospium
  • Trihexyphenidyl
  • Tolterodine
  • Solifenacin
  • Scopolamine
  • Procyclidine
  • Oxybutynin
  • Methscopolamine
  • Hyoscyamine
  • Glycopyrrolate
  • Fesoterodine
  • Eplerenone
  • Dicyclomine
  • Darifenacin
  • Clidinium
  • Biperiden
  • Benztropine
  • Belladonna Alkaloids
  • Belladonna
  • Atropine
  • Amantadine

It is not generally recommended to take any of the following drugs with polyethylene glycol 3350, potassium salts, and sodium in combination. However, this may be appropriate in some cases. Your physician may adjust the dose of one of your medications or the frequency of their use in order to mitigate or manage possible side effects:

  • Zofenopril
  • Triamterene
  • Trandolapril
  • Temocapril
  • Spironolactone
  • Spirapril
  • Ramipril
  • Quinapril
  • Perindopril
  • Pentopril
  • Pazopanib
  • Moexipril
  • Memantine
  • Mefenamic Acid
  • Lisinopril
  • Licorice
  • Ledipasvir
  • Ketoconazole
  • Indomethacin
  • Imidapril
  • Gefitinib
  • Fosinopril
  • Enalaprilat
  • Enalapril Maleate
  • Elvitegravir
  • Digoxin
  • Delapril
  • Cilazapril
  • Captopril
  • Canrenoate
  • Benazepril
  • Amphetamine
  • Amiloride
  • Alacepril
  • Licorice
  • Dasatinib

Some medication should not be used with tobacco, alcohol, or certain food groups. You should discuss this aspect of your treatment with your physician before using polyethylene glycol 3350, potassium salts, and sodium in combination.

Medical interactions

If you suffer from or have a history of other medical conditions, they may affect how this medication works. Be sure to discuss your medical history fully with your treating physician, before you use this medication:

Note that by using polyethylene glycol 3350, potassium salts, and sodium in combination with any of the medicines listed below, you may find that the side effects are made worse:

  • Trouble swallowing
  • Hyponatremia (low sodium in the blood)
  • Hypomagnesemia (low magnesium in the blood)
  • Hypokalemia (low potassium in the blood)
  • Hypocalcemia (low calcium in the blood)
  • Heart rhythm problems (such as prolonged QT interval)
  • Recent heart attack
  • Dehydration
  • Congestive heart failure
  • Cardiomyopathy
  • Poorly controlled angina

Polyethylene glycol 3350, potassium salts, and sodium in combination should never be used in patients who have any of the following complaints:

  • Toxic megacolon (very dilated or swollen intestine)
  • Toxic colitis (very inflamed intestine)
  • Ileus (intestine stops moving)
  • Gastric retention (problem with emptying the stomach)
  • Bowel perforation (hole in the intestine)
  • Bowel blockage

It should be noted that using this drug in patients with any of the following conditions can lead to a worsening of the illness:


Before you decide to use any medication, you should take into account the risks as well as the benefits of doing so. This is a decision that you should come to following discussions with your physician.

Be sure to mention any allergies or odd reactions that you have had to any form of medicines in the past, including over the counter products. Include food dyes, preservatives, animal by-products, and particular food groups in this list.

You will be required to attend regular check-up appointments with your physician throughout your treatment with this drug. It is important that you attend these appointments as they will be used to discuss the results of your tests. You will also be able to mention any side effects that you are suffering.

Pediatric patients

There is no evidence to suggest that using this medication in children over the age of six months would cause any problems. However, research has not been carried out on the safety and efficacy of using the medicine in children under six months of age.

Geriatric patients

Although there has been no research to suggest that using this drug in elderly patients could present any specific problems, this age group is more likely to have age-related complaints, including kidney disease. This medication should therefore be used with caution in geriatric patients.

Pregnancy and breastfeeding

There is no evidence that polyethylene glycol 3350, potassium salts, and sodium in combination can cause problems in the unborn baby. However, pregnant women should discuss the safety of using this drug with their treating physician.

It is not thought that this drug can pass into breast milk. You may therefore wish to discontinue doing so until the medication has left your system and your diagnostic tests are all complete. Discuss the implications of continuing to breastfeed your child while taking this medicine with your physician or midwife.

This medicine can cause dehydration. Tell your physician if you experience any of the following symptoms:

  • Decreased urine production
  • Feeling faint
  • Dizziness
  • Headache
  • Vomiting

If you begin to notice that your stomach is bloated, distended or painful after using this medication, tell your GP straight away.

Some patients suffer a severe allergic reaction to this drug. If you develop a skin reaction, including hives or a rash, you must stop using the medicine and seek immediate medical attention.

While you are using polyethylene glycol 3350, potassium salts, and sodium in combination, you must not take any additional forms of stimulant laxatives, including both non-prescription and prescription products.


You should store your prescription of polyethylene glycol 3350, potassium salts, and sodium in combination at room temperature and in a closed container. Make sure that the medicine does not get wet. Do not freeze the medicine or place it near direct sunlight or heat sources.

Once you have combined the powder with water to form a solution, you may keep the products in your refrigerator for up to 48 hours.

Always store your medicine in a place that is well out of the reach of children and pets. If a pet consumes your medication, contact your veterinary practice immediately. Do not try to make your pet vomit.

Do not keep any unwanted or out of date medicines. Take any unused product to your pharmacist or GP for safe disposal.


The drug polyethylene glycol 3350, potassium salts, and sodium in combination is a laxative that is used to prepare patients for diagnostic procedures, including colonoscopy. The medicine works by causing the patient to have diarrhea, leaving the colon clean for examination.

There are a number of medicines that should not be used at the same time as taking this drug. In addition, there are several medical conditions that could be made worse by using this medicine. For this reason, you must mention to your doctor any health conditions that you have, as well as any medication that you are using, prior to starting treatment with polyethylene glycol 3350, potassium salts, and sodium in combination.