Motofen Tablets
It is used to treat diarrhea.
Drug Class
Antidiarrheal
Pharmacologic Class
Opioid agonist (difenoxin), Anticholinergic (atropine)
Pregnancy Category
Category C
FDA Approved
Mar 1982
DEA Schedule
Schedule IV
Overview
What is this medicine?
Motofen is a medication used to treat diarrhea. It works by slowing down your bowel movements. It contains two ingredients: difenoxin, which helps stop diarrhea, and a very small amount of atropine, which is added to prevent people from taking too much of the medication.
How to Use This Medicine
Taking Your Medication
To use this medication correctly, follow your doctor's instructions and read all the information provided to you. Take your medication as directed, with or without food.
Storing and Disposing of Your Medication
Keep your medication at room temperature in a dry location, avoiding storage in a bathroom.
Missing a Dose
Since this medication is taken as needed, do not take it more frequently than prescribed by your doctor. If you have any questions or concerns about missed doses, consult with your doctor for guidance.
To use this medication correctly, follow your doctor's instructions and read all the information provided to you. Take your medication as directed, with or without food.
Storing and Disposing of Your Medication
Keep your medication at room temperature in a dry location, avoiding storage in a bathroom.
Missing a Dose
Since this medication is taken as needed, do not take it more frequently than prescribed by your doctor. If you have any questions or concerns about missed doses, consult with your doctor for guidance.
Lifestyle & Tips
- Stay well-hydrated by drinking plenty of clear fluids (water, broth, electrolyte solutions) to prevent dehydration caused by diarrhea.
- Avoid alcohol and other CNS depressants (e.g., sedatives, tranquilizers, certain pain medications) as they can increase drowsiness and dizziness when taken with Motofen.
- Do not exceed the recommended dose, as taking too much can lead to serious side effects from the atropine component.
- Avoid driving or operating heavy machinery until you know how this medication affects you, as it may cause dizziness or drowsiness.
Available Forms & Alternatives
Available Strengths:
Dosing & Administration
Adult Dosing
Standard Dose:
Initial: 2 tablets (2 mg difenoxin / 0.05 mg atropine) once, then 1 tablet (1 mg difenoxin / 0.025 mg atropine) after each loose stool or every 3-4 hours as needed.
Dose Range:
1 - 8 mg
Condition-Specific Dosing:
maximumDailyDose:
8 tablets (8 mg difenoxin / 0.2 mg atropine) per 24 hours
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established (Contraindicated in children under 2 years)
Child:
Not established (Not recommended for children under 12 years due to risk of respiratory depression and atropine toxicity)
Adolescent:
Not established (Generally not recommended for children under 12 years)
Dose Adjustments
Renal Impairment:
Mild:
No specific adjustment provided; use with caution.
Moderate:
Use with caution; monitor for adverse effects.
Severe:
Use with caution; monitor for adverse effects.
Dialysis:
Considerations: Not well studied; use with caution and monitor closely.
Hepatic Impairment:
Mild:
No specific adjustment provided; use with caution.
Moderate:
Use with caution; monitor for increased systemic exposure and adverse effects.
Severe:
Contraindicated or not recommended due to risk of hepatic coma and increased systemic exposure.
Confidence:
Medium
Pharmacology
Mechanism of Action
Difenoxin is an opioid agonist that acts on mu-opioid receptors in the intestinal smooth muscle, inhibiting gastrointestinal motility and propulsion. It also increases the tone of the anal sphincter and enhances water and electrolyte absorption from the bowel lumen. Atropine is an anticholinergic agent added in subtherapeutic amounts to deter abuse by producing unpleasant side effects (e.g., dry mouth, blurred vision, nausea) at doses higher than recommended.
Pharmacokinetics
Absorption:
Bioavailability:
Well absorbed (specific percentage not readily available)
Tmax:
Approximately 40-60 minutes (difenoxin)
FoodEffect:
Not significantly affected by food
Distribution:
Vd:
Not readily available
ProteinBinding:
Not readily available
CnssPenetration:
Yes (difenoxin can cross the blood-brain barrier, atropine also)
Elimination:
HalfLife:
Approximately 10-12 hours (difenoxin)
Clearance:
Not readily available
ExcretionRoute:
Primarily feces (difenoxin and its metabolites), some renal excretion
Unchanged:
Less than 1% (difenoxin)
Pharmacodynamics
OnsetOfAction:
Within 45-60 minutes
PeakEffect:
Approximately 2-3 hours
DurationOfAction:
3-4 hours per dose, up to 8-12 hours with repeated dosing
Confidence:
Medium
Safety & Warnings
Side Effects
Urgent Side Effects: Seek Medical Help Right Away
Although rare, this medication can cause severe and potentially life-threatening side effects. If you experience any of the following symptoms, contact your doctor immediately or seek emergency medical attention:
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
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of pancreatitis (pancreas problem), such as:
+ Severe stomach pain
+ Severe back pain
+ Severe upset stomach or vomiting
Trouble breathing, slow breathing, or shallow breathing
Numbness or tingling in the hands or feet
Depression or other mood changes
Changes in behavior
Swollen or sore gums
Severe constipation or stomach pain, which may be signs of a severe bowel problem
Swelling of the abdomen
Other Possible Side Effects
Like all medications, this drug can cause side effects. While 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 symptoms that bother you or do not go away, contact your doctor:
Dizziness or drowsiness
* Upset stomach
Reporting Side Effects
This list is not exhaustive, and you may experience other side effects. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Although rare, this medication can cause severe and potentially life-threatening side effects. If you experience any of the following symptoms, contact your doctor immediately or seek emergency medical attention:
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
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of pancreatitis (pancreas problem), such as:
+ Severe stomach pain
+ Severe back pain
+ Severe upset stomach or vomiting
Trouble breathing, slow breathing, or shallow breathing
Numbness or tingling in the hands or feet
Depression or other mood changes
Changes in behavior
Swollen or sore gums
Severe constipation or stomach pain, which may be signs of a severe bowel problem
Swelling of the abdomen
Other Possible Side Effects
Like all medications, this drug can cause side effects. While 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 symptoms that bother you or do not go away, contact your doctor:
Dizziness or drowsiness
* Upset stomach
Reporting Side Effects
This list is not exhaustive, and you may experience other side effects. If you have questions or concerns about side effects, consult 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 constipation or abdominal pain that worsens
- Abdominal distension (bloating)
- Fever or chills
- Signs of dehydration (e.g., extreme thirst, decreased urination, dry mouth, lightheadedness)
- Severe drowsiness, dizziness, or confusion
- Blurred vision or difficulty seeing
- Difficulty urinating
- Signs of allergic reaction (rash, itching, swelling, severe dizziness, trouble breathing)
- If diarrhea worsens or does not improve within 48 hours
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 symptoms you experienced as a result of the allergy.
Certain health conditions, including:
+ Diarrhea caused by an infection
+ Diarrhea caused by a severe bowel problem (pseudomembranous colitis)
+ Yellowing of the skin or eyes (jaundice)
Special Considerations for Children:
If the patient is under 2 years of age, do not administer this medication. It is not recommended for children younger than 2 years old.
Additional Interactions and Precautions:
This list is not exhaustive, and it is crucial to discuss all your medications (prescription, over-the-counter, natural products, and vitamins) and health problems with your doctor and pharmacist. They will help determine whether it is safe to take this medication with your other medications and health conditions. Never start, stop, or change the dose of any medication without first consulting 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 symptoms you experienced as a result of the allergy.
Certain health conditions, including:
+ Diarrhea caused by an infection
+ Diarrhea caused by a severe bowel problem (pseudomembranous colitis)
+ Yellowing of the skin or eyes (jaundice)
Special Considerations for Children:
If the patient is under 2 years of age, do not administer this medication. It is not recommended for children younger than 2 years old.
Additional Interactions and Precautions:
This list is not exhaustive, and it is crucial to discuss all your medications (prescription, over-the-counter, natural products, and vitamins) and health problems with your doctor and pharmacist. They will help determine whether it is safe to take this medication with your other medications and health conditions. Never start, stop, or change the dose of any medication without first consulting your doctor.
Precautions & Cautions
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. Before engaging in activities that require alertness, such as driving, wait until you understand how this drug affects you. Long-term use of this medication may lead to dependence. Consult your doctor before consuming alcohol, marijuana, or other forms of cannabis, as well as prescription or over-the-counter (OTC) medications that can cause drowsiness.
Be aware that dehydration and electrolyte imbalances, which can occur with diarrhea, may increase the risk of side effects associated with this medication. Discuss with your doctor ways to prevent or manage dehydration and electrolyte problems.
Keep this medication out of reach of children, as accidental ingestion can lead to severe respiratory problems or coma, potentially resulting in long-term brain damage or death. If a child accidentally takes this medication, seek immediate medical attention.
When administering this medication to children, exercise caution, as the risk of certain side effects may be higher in this population. Note that this medication is not approved for use in children under 12 years old; consult with your doctor to discuss the potential risks and benefits. If you are pregnant, planning to become pregnant, or breastfeeding, inform your doctor to weigh the benefits and risks of this medication for both you and your baby.
Be aware that dehydration and electrolyte imbalances, which can occur with diarrhea, may increase the risk of side effects associated with this medication. Discuss with your doctor ways to prevent or manage dehydration and electrolyte problems.
Keep this medication out of reach of children, as accidental ingestion can lead to severe respiratory problems or coma, potentially resulting in long-term brain damage or death. If a child accidentally takes this medication, seek immediate medical attention.
When administering this medication to children, exercise caution, as the risk of certain side effects may be higher in this population. Note that this medication is not approved for use in children under 12 years old; consult with your doctor to discuss the potential risks and benefits. If you are pregnant, planning to become pregnant, or breastfeeding, inform your doctor to weigh the benefits and risks of this medication for both you and your baby.
Overdose Information
Overdose Symptoms:
- Severe drowsiness or coma
- Respiratory depression (slow, shallow breathing)
- Pinpoint pupils (initially, then dilated with atropine toxicity)
- Flushing of the skin
- Dry mouth and skin
- Blurred vision, dilated pupils
- Urinary retention
- Severe constipation or paralytic ileus
- Tachycardia (rapid heart rate)
- Hypertension (high blood pressure)
- Hallucinations, agitation, delirium (due to atropine toxicity)
What to Do:
Seek immediate medical attention. Call 911 or your local emergency number. For poison control, call 1-800-222-1222. Treatment may include supportive care, activated charcoal, and naloxone for opioid effects, or physostigmine for severe anticholinergic effects.
Drug Interactions
Contraindicated Interactions
- Monoamine Oxidase Inhibitors (MAOIs) - risk of hypertensive crisis (theoretical with atropine)
- Patients with pseudomembranous colitis associated with broad-spectrum antibiotics
- Patients with diarrhea associated with enterotoxin-producing bacteria or Salmonella, Shigella, or Campylobacter infections (risk of toxic megacolon)
Major Interactions
- CNS depressants (e.g., alcohol, barbiturates, benzodiazepines, other opioids, sedatives, hypnotics, tricyclic antidepressants) - additive CNS depression, respiratory depression.
- Anticholinergic agents (e.g., tricyclic antidepressants, phenothiazines, antihistamines, other antispasmodics) - additive anticholinergic effects (e.g., urinary retention, severe constipation, paralytic ileus, blurred vision).
- MAOIs - potential for hypertensive crisis (due to atropine's effects on catecholamines, though less common with low dose).
Moderate Interactions
- Drugs that prolong QT interval (atropine can have minor effects on cardiac conduction at higher doses).
- Drugs that affect gastrointestinal motility (e.g., metoclopramide, erythromycin) - may alter absorption or effect.
- Opioid antagonists (e.g., naloxone) - may precipitate withdrawal symptoms if patient is opioid-dependent.
Minor Interactions
- Not typically listed for this drug combination.
Monitoring
Baseline Monitoring
Hydration status
Rationale: To assess baseline fluid balance and guide rehydration therapy.
Timing: Prior to initiation of therapy
Electrolyte levels (Na, K, Cl, Bicarbonate)
Rationale: To assess baseline electrolyte balance, especially in patients with severe diarrhea.
Timing: Prior to initiation of therapy
Bowel function and characteristics of diarrhea
Rationale: To establish baseline and monitor treatment effectiveness.
Timing: Prior to initiation of therapy
Routine Monitoring
Stool frequency and consistency
Frequency: Daily or as needed
Target: Reduction in frequency, improved consistency
Action Threshold: If no improvement within 48 hours, discontinue and re-evaluate; if worsening, discontinue immediately.
Signs of CNS depression (drowsiness, dizziness, confusion)
Frequency: Regularly, especially during initial therapy or dose adjustments
Target: Absence of significant CNS depression
Action Threshold: If significant CNS depression occurs, reduce dose or discontinue.
Signs of anticholinergic effects (dry mouth, blurred vision, urinary retention, constipation, abdominal distension)
Frequency: Regularly
Target: Absence of severe anticholinergic symptoms
Action Threshold: If severe symptoms occur, reduce dose or discontinue. Monitor for paralytic ileus.
Fluid and electrolyte balance
Frequency: As clinically indicated, especially in severe diarrhea or prolonged use
Target: Normal hydration and electrolyte levels
Action Threshold: If dehydration or electrolyte imbalance occurs, initiate appropriate rehydration/replacement therapy.
Symptom Monitoring
- Constipation (especially severe or prolonged)
- Abdominal pain or distension
- Fever
- Signs of dehydration (decreased urination, dry mouth, excessive thirst, lightheadedness)
- Drowsiness or dizziness
- Blurred vision
- Urinary retention
- Nausea or vomiting
- Signs of toxic megacolon (severe abdominal distension, fever, rapid heart rate, altered mental status)
Special Patient Groups
Pregnancy
Category C. Use only if the potential benefit justifies the potential risk to the fetus. Difenoxin and atropine can cross the placenta.
Trimester-Specific Risks:
First Trimester:
Potential for fetal harm, especially with opioid exposure. Use only if clearly needed.
Second Trimester:
Similar considerations as first trimester. Monitor for fetal effects.
Third Trimester:
Risk of neonatal opioid withdrawal syndrome if used chronically. Risk of respiratory depression in neonate if used near term. Atropine may cause fetal tachycardia.
Lactation
L3 (Moderate risk). Both difenoxin and atropine are excreted in breast milk. Potential for CNS depression (drowsiness, poor feeding) and anticholinergic effects (dry mouth, constipation) in the infant. Use with caution; monitor infant closely for adverse effects.
Infant Risk:
Risk of CNS depression, respiratory depression, and anticholinergic effects (e.g., constipation, urinary retention, tachycardia) in the breastfed infant. Avoid if possible, especially in preterm or neonates.
Pediatric Use
Contraindicated in children under 2 years of age due to the risk of respiratory depression and atropine toxicity. Not recommended for children under 12 years of age due to increased sensitivity to opioid and anticholinergic effects. Safety and efficacy have not been established in this population.
Geriatric Use
Use with caution in elderly patients due to increased sensitivity to CNS depressant and anticholinergic effects (e.g., drowsiness, confusion, urinary retention, constipation). Start with lower doses and titrate slowly. Monitor closely for adverse effects.
Clinical Information
Clinical Pearls
- Motofen is a Schedule IV controlled substance due to its opioid component (difenoxin).
- The atropine component is subtherapeutic for antidiarrheal effect but is included to discourage abuse by causing unpleasant anticholinergic side effects at higher doses.
- Not recommended for diarrhea caused by bacterial infections (e.g., Salmonella, Shigella, E. coli) or pseudomembranous colitis, as it may prolong the illness or lead to toxic megacolon.
- Discontinue if no improvement in diarrhea is seen within 48 hours or if abdominal distension or other adverse effects develop.
- Ensure adequate rehydration and electrolyte replacement, as this medication only treats symptoms, not the underlying cause of diarrhea.
Alternative Therapies
- Loperamide (Imodium)
- Bismuth subsalicylate (Pepto-Bismol, Kaopectate)
- Racecadotril (not available in US)
- Oral rehydration solutions (primary treatment for dehydration)
Cost & Coverage
Average Cost:
$30 - $100+ per 30 tablets
Generic Available:
Yes
Insurance Coverage:
Tier 2 or Tier 3 (depends on insurance plan and formulary)
General Drug Facts
If your symptoms or health issues persist or worsen, it is 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 it is a good idea to check with your pharmacist. If you have any questions or concerns about this medication, do not hesitate to discuss them with 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 detailed information about the overdose, including the medication taken, the amount, and the time it occurred.