Gavilax Powder
It is used to treat constipation.
Drug Class
Laxative
Pharmacologic Class
Osmotic Laxative
Pregnancy Category
Category C
FDA Approved
Jan 1970
DEA Schedule
Not Controlled
Overview
What is this medicine?
Polyethylene Glycol 3350 (PEG 3350) is an osmotic laxative that works by drawing water into your intestines. This helps to soften your stool and make it easier to have a bowel movement. It is used to treat occasional constipation.
How to Use This Medicine
Taking Your Medication
To use this medication correctly, follow your doctor's instructions and read all the information provided. When preparing your dose, mix the powder with 1/2 to 1 cup (120 to 240 ml) of a liquid, such as water, juice, soda, coffee, or tea. Stir well to ensure the powder is fully dissolved before drinking. Do not consume the mixture if you notice any clumps. Avoid mixing the powder with starch-based thickeners. Use only the dosing cap that comes with the powder to measure your dose accurately.
Storing and Disposing of Your Medication
Store your medication at room temperature in a dry location, avoiding the bathroom. Keep all medications in a safe place, out of the reach of children and pets. Dispose of unused or expired medications properly. Do not flush them down the toilet or pour them down the drain unless instructed to do so. If you have questions about disposing of your medication, consult your pharmacist. You may also want to explore drug take-back programs in your area.
Missing a Dose
If you take this medication on a regular schedule, take a missed dose as soon as you remember. However, if it's close to the time for your next dose, skip the missed dose and resume your normal dosing schedule. Do not take two doses at the same time or take extra doses. If you take this medication as needed, do not take it more frequently than directed by your doctor.
To use this medication correctly, follow your doctor's instructions and read all the information provided. When preparing your dose, mix the powder with 1/2 to 1 cup (120 to 240 ml) of a liquid, such as water, juice, soda, coffee, or tea. Stir well to ensure the powder is fully dissolved before drinking. Do not consume the mixture if you notice any clumps. Avoid mixing the powder with starch-based thickeners. Use only the dosing cap that comes with the powder to measure your dose accurately.
Storing and Disposing of Your Medication
Store your medication at room temperature in a dry location, avoiding the bathroom. Keep all medications in a safe place, out of the reach of children and pets. Dispose of unused or expired medications properly. Do not flush them down the toilet or pour them down the drain unless instructed to do so. If you have questions about disposing of your medication, consult your pharmacist. You may also want to explore drug take-back programs in your area.
Missing a Dose
If you take this medication on a regular schedule, take a missed dose as soon as you remember. However, if it's close to the time for your next dose, skip the missed dose and resume your normal dosing schedule. Do not take two doses at the same time or take extra doses. If you take this medication as needed, do not take it more frequently than directed by your doctor.
Lifestyle & Tips
- Increase fluid intake throughout the day.
- Increase dietary fiber intake (fruits, vegetables, whole grains) if appropriate.
- Engage in regular physical activity.
- Do not use for more than 7 days unless directed by a doctor.
Available Forms & Alternatives
Available Strengths:
Dosing & Administration
Adult Dosing
Standard Dose:
17 grams (one heaping capful) of powder dissolved in 4 to 8 ounces of water, juice, soda, coffee, or tea once daily.
Dose Range:
17 - 17 mg
Condition-Specific Dosing:
chronicConstipation:
17 grams once daily for up to 7 days, or as directed by a physician.
Pediatric Dosing
Neonatal:
Not established (use only under medical supervision)
Infant:
Not established (use only under medical supervision)
Child:
For children 6 months to 16 years, dosing is off-label and typically 0.4 to 0.8 grams/kg/day, not to exceed 17 grams/day. Consult a physician.
Adolescent:
For adolescents 17 years and older, same as adult dosing (17 grams once daily).
Dose Adjustments
Renal Impairment:
Mild:
No adjustment needed
Moderate:
No adjustment needed
Severe:
No adjustment needed (minimal systemic absorption)
Dialysis:
No adjustment needed (minimal systemic absorption)
Hepatic Impairment:
Mild:
No adjustment needed
Moderate:
No adjustment needed
Severe:
No adjustment needed
Pharmacology
Mechanism of Action
Polyethylene Glycol 3350 is an inert, non-absorbable, osmotically active polymer that causes water to be retained within the lumen of the colon. This increases the water content of the stool, leading to softer stool consistency and increased stool bulk, which in turn stimulates colonic peristalsis and facilitates bowel evacuation.
Pharmacokinetics
Absorption:
Bioavailability:
<0.2%
Tmax:
Not applicable (minimal systemic absorption)
FoodEffect:
No significant food effect
Distribution:
Vd:
Not applicable (minimal systemic absorption)
ProteinBinding:
Not applicable
CnssPenetration:
No
Elimination:
HalfLife:
Not applicable (minimal systemic absorption)
Clearance:
Not applicable
ExcretionRoute:
Fecal
Unchanged:
>99.8% (excreted unchanged in feces)
Pharmacodynamics
OnsetOfAction:
1 to 3 days
PeakEffect:
Not applicable (gradual effect)
DurationOfAction:
Effect persists as long as treatment continues
Safety & Warnings
Side Effects
Urgent Side Effects: Seek Medical Attention Immediately
While rare, some people may experience severe and potentially life-threatening side effects when taking this medication. If you notice any of the following symptoms, contact your doctor or seek medical help right away:
- Signs of an allergic reaction, such as rash, hives, itching, red, swollen, blistered, or peeling skin (with or without fever), wheezing, tightness in the chest or throat, trouble breathing, swallowing, or talking, unusual hoarseness, or swelling of the mouth, face, lips, tongue, or throat
- Severe dizziness or fainting
- Diarrhea
- Rectal bleeding or rectal pain
Other Possible Side Effects
Like all medications, this drug can cause side effects. Although many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other unusual symptoms that bother you or do not go away, contact your doctor for advice:
- Loose, watery, or more frequent stools
- Stomach pain or cramps
- Gas
- Bloating
- Upset stomach
Reporting Side Effects
This list does not include all possible side effects. If you have questions or concerns about side effects, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
While rare, some people may experience severe and potentially life-threatening side effects when taking this medication. If you notice any of the following symptoms, contact your doctor or seek medical help right away:
- Signs of an allergic reaction, such as rash, hives, itching, red, swollen, blistered, or peeling skin (with or without fever), wheezing, tightness in the chest or throat, trouble breathing, swallowing, or talking, unusual hoarseness, or swelling of the mouth, face, lips, tongue, or throat
- Severe dizziness or fainting
- Diarrhea
- Rectal bleeding or rectal pain
Other Possible Side Effects
Like all medications, this drug can cause side effects. Although many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other unusual symptoms that bother you or do not go away, contact your doctor for advice:
- Loose, watery, or more frequent stools
- Stomach pain or cramps
- Gas
- Bloating
- Upset stomach
Reporting Side Effects
This list does not include all possible side effects. If you have questions or concerns about side effects, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Severe abdominal pain or cramping
- Rectal bleeding
- Nausea or vomiting
- No bowel movement after 7 days of use (for self-treatment)
- Signs of an allergic reaction (rash, itching, swelling, severe dizziness, trouble breathing)
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction and its symptoms.
Certain health conditions, including:
+ Bowel obstruction
+ Abdominal pain
+ Upset stomach
+ Rectal bleeding
+ Vomiting
+ Changes in bowel habits that persist for more than 2 weeks
A diagnosis of irritable bowel syndrome
Kidney disease
This list is not exhaustive, and it is crucial to discuss all your health problems and medications with your doctor.
To ensure safe treatment, inform your doctor and pharmacist about:
All prescription and over-the-counter medications you are taking
Any natural products or vitamins you are using
* Your complete medical history
Do not initiate, discontinue, or modify the dosage of any medication without first consulting your doctor to confirm that it is safe to do so in conjunction with this medication.
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction and its symptoms.
Certain health conditions, including:
+ Bowel obstruction
+ Abdominal pain
+ Upset stomach
+ Rectal bleeding
+ Vomiting
+ Changes in bowel habits that persist for more than 2 weeks
A diagnosis of irritable bowel syndrome
Kidney disease
This list is not exhaustive, and it is crucial to discuss all your health problems and medications with your doctor.
To ensure safe treatment, inform your doctor and pharmacist about:
All prescription and over-the-counter medications you are taking
Any natural products or vitamins you are using
* Your complete medical history
Do not initiate, discontinue, or modify the dosage of any medication without first consulting your doctor to confirm that it is safe to do so in conjunction with this medication.
Precautions & Cautions
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. To avoid potential risks, do not use this drug for more than 7 days without explicit instructions from your doctor. Additionally, refrain from using other laxatives or stool softeners unless your doctor advises you to do so. You may not experience the full effects of this medication immediately, as it may take a few days to become fully effective. If you are pregnant, planning to become pregnant, or are currently breast-feeding, it is crucial to discuss this with your doctor, as you will need to carefully weigh the benefits and risks of this medication to both you and your baby.
Overdose Information
Overdose Symptoms:
- Severe diarrhea
- Excessive fluid loss
- Abdominal cramping
- Electrolyte imbalances (e.g., low potassium, low sodium)
What to Do:
Discontinue use. Rehydrate with fluids and electrolytes. Seek medical attention if symptoms are severe or persistent. Call 1-800-222-1222 (Poison Control).
Drug Interactions
Moderate Interactions
- Other oral medications (theoretical decrease in absorption if taken simultaneously; separate administration by 2 hours)
Monitoring
Baseline Monitoring
Assessment of constipation severity and duration
Rationale: To determine appropriate use and rule out underlying conditions (e.g., bowel obstruction)
Timing: Prior to initiation of therapy
Routine Monitoring
Bowel movement frequency and consistency
Frequency: Daily
Target: Regular, soft, formed stools
Action Threshold: No bowel movement after 7 days of use (for self-treatment), or persistent diarrhea/abdominal pain
Abdominal discomfort (bloating, cramping)
Frequency: Daily
Target: Minimal to none
Action Threshold: Severe or worsening abdominal pain
Symptom Monitoring
- Abdominal pain
- Bloating
- Nausea
- Diarrhea
- Rectal bleeding
- Signs of electrolyte imbalance (e.g., muscle weakness, irregular heartbeat, confusion - rare with normal use)
Special Patient Groups
Pregnancy
Generally considered low risk and often recommended for constipation during pregnancy due to minimal systemic absorption. Consult a healthcare provider.
Trimester-Specific Risks:
First Trimester:
Low risk
Second Trimester:
Low risk
Third Trimester:
Low risk
Lactation
Considered safe for use during breastfeeding due to minimal systemic absorption and lack of excretion into breast milk. L1 (safest) lactation risk category.
Infant Risk:
Low risk
Pediatric Use
Commonly used off-label for chronic constipation in children, but dosing should be determined by a healthcare professional, especially for infants and young children. Ensure adequate fluid intake to prevent dehydration.
Geriatric Use
Generally safe for elderly patients. However, monitor for potential electrolyte imbalances, especially in those with pre-existing renal impairment or those taking diuretics, though this is rare with normal use due to minimal absorption.
Clinical Information
Clinical Pearls
- Polyethylene Glycol 3350 is not for immediate relief; it typically takes 1 to 3 days to produce a bowel movement.
- Ensure the powder is completely dissolved in the liquid before consumption.
- It can be mixed with various liquids (water, juice, soda, coffee, tea) without affecting its efficacy.
- Encourage adequate daily fluid intake to maximize effectiveness and prevent dehydration.
- It is generally well-tolerated with a low incidence of side effects compared to stimulant laxatives.
Alternative Therapies
- Bulk-forming laxatives (e.g., psyllium, methylcellulose)
- Stool softeners (e.g., docusate sodium)
- Stimulant laxatives (e.g., senna, bisacodyl - for short-term use)
- Saline laxatives (e.g., magnesium hydroxide)
- Lubricant laxatives (e.g., mineral oil)
- Prescription osmotic laxatives (e.g., lactulose)
- Chloride channel activators (e.g., lubiprostone)
- Guanylate cyclase-C agonists (e.g., linaclotide, plecanatide)
Cost & Coverage
Average Cost:
$10 - $30 per 255g bottle (14 doses)
Generic Available:
Yes
Insurance Coverage:
Often covered by insurance as a Tier 1 or Tier 2 medication, or available OTC.
General Drug Facts
If your symptoms or health issues persist or worsen, it's essential to contact your doctor for further guidance. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so be sure to check with your pharmacist for more information. If you have any questions or concerns about your medication, don't hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek emergency medical attention. When seeking help, be prepared to provide details about the medication taken, the amount, and the time it happened.