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Treatment Name: Diphenoxylate and atropine (Lomotil®)

Diphenoxylate and atropine (Lomotil®) is a Supportive Care Therapy to treat Diarrhea

How does diphenoxylate and atropine (Lomotil®) work?
Diphenoxylate is designed to slow down the movement of the intestines and increase the time it takes for food and liquids to move through the digestive tract. This gives the intestines more time to absorb liquids, which helps to make stools more solid. Atropine may slow down intestinal movement.

Goals of therapy:
Diphenoxylate and atropine (Lomotil®) is taken to resolve or decrease episodes of diarrhea (watery bowel movements) and is commonly taken on an as needed basis with the goal of treating diarrhea.

Diphenoxylate and atropine may also help to decrease bloating, cramping, or stomach pain associated with diarrhea, as well as pain around the rectum resulting from frequent loose stools.


Create your own Treatment Tracker

Diphenoxylate and atropine (Lomotil®) is a prescription medication and is usually taken at home or given in a hospital to treat diarrhea.

  • Usual starting dose: Lomotil® 5 mg (two 2.5 mg/0.025mg tablets = 5mg/0.05mg) by mouth every six hours as needed
  • Usual starting dose: Lomotil® 2 teaspoonfuls (10 mL = 5mg/0.05mg) by mouth every six hours as needed

Improvement in symptoms should occur within 48 hours. Once control of diarrhea is obtained, the dosage may be decreased to meet individual needs. If improvement is not seen within 2 days, contact your doctor or go to the nearest emergency department.

Keep a journal and track the days and times when your bowel movements are:

  • Watery
  • Loose
  • Soft
  • Formed
  • Hard

A journal documenting bowel movement frequency and consistency will help you know whether diphenoxylate and atropine is working and help you and your doctor manage the diarrhea.

Store diphenoxylate and atropine at room temperature (77°F).

Side Effects

In the prescribing label information (diphenoxylate and atropine package insert), the most commonly reported side effects from diphenoxylate and atropine (Lomotil®) are shown here:

  • Drowsiness
  • Confusion
  • Fatigue
  • Headache
  • Itching
  • Nausea and vomiting
  • Fast heart rate
  • Stomach discomfort
  • Flushing
  • Dry skin or itching
  • Dry mouth
  • Dizziness
  • Trouble urinating
  • Inflammation of the pancreas
  • Numbness in arms or legs

Diphenoxylate and atropine should be used in pregnant women and women who are breast-feeding only if the potential benefits to the mother outweigh the potential risks to the unborn baby. There are no well-controlled studies in pregnant women.

Note: The exact percentage of patients that will experience diphenoxylate and atropine (Lomotil®) side effects is unknown because it has been used under widely varying patient populations in a variety of clinical trials.

Side effect videos Side Effect Videos
DiarrheaDiarrheaFatigue Fatigue Nausea and VomitingNausea and Vomiting


How often is monitoring needed?
Labs (blood tests) may be checked if you are experiencing significant diarrhea. Labs often include: Comprehensive Metabolic Panel (CMP), magnesium, plus any others your doctor may order. If diarrhea lasts for more than 2 days or gets worse while taking diphenoxylate and atropine (Lomotil®), or you have abdominal swelling, call your doctor as these may be signs of a more serious condition. Diarrhea can quickly cause dehydration and electrolyte problems, especially when severe. It is important to stay hydrated to keep up with fluid that is lost through bowel movements.

How often is imaging needed?
Imaging may be checked if there is any concern of any serious abdominal problems. Imaging may include: X-rays or computerized tomography (CT) scans.

How might blood test results/imaging affect treatment?
Depending upon the results, your doctor may advise continuing diphenoxylate and atropine (Lomotil®) as planned, add additional medicines to treat diarrhea, switch to an alternative therapy, or for severe cases, recommend hospitalization to manage diarrhea, dehydration, and electrolytes.

Questions to Ask Your...

A better understanding of your treatments will allow you to ask more questions of your healthcare team. We then hope that with the answers, you will get better results and have greater satisfaction with your care. Because we know it's not always easy to know what questions to ask, we've tried to make it easy for you!

Choose any healthcare provider below to see common questions that you may want to ask of this person. Then, either print each list to bring to your clinic visits, or copy the questions and send them as a message to your healthcare team through your electronic medical record.

ChemoExperts Tips

  • Although atropine may help treat diarrhea, atropine is also added to Lomotil® to prevent taking too much lomotil® (signs of overdosage include: drying of skin or mouth, large pupils, restlessness, flushing, fast heart rate, nausea, slow breath rate, or confusion. Take only as prescribed and record the time that each dose is taken to prevent taking too much
  • Do not take diphenoxylate and atropine (Lomotil®) if you have an active intestinal infection with a certain type of bacteria known as Clostridium difficile, or “C. diff”
  • Drowsiness is a possible side effect of diphenoxylate and may increase your risk of falling down and getting injured. Do NOT operate vehicles or machinery after taking a dose of diphenoxylate and atropine until you know how your body reacts to the medication. (Lomotil®) should not be taken with alcohol
  • If you notice blood in your stool, are experiencing severe stomach cramps, feel dizzy, have chills or a fever (100.4°F), contact your doctor immediately or go to the nearest emergency department
  • If you notice stomach cramping with diarrhea, especially after eating dairy products such as milk, cheese, or yogurt, or when taking antibiotics, consider changing your diet to the “B.R.A.T. diet = B = Bananas, R = Rice, A = Applesauce, T = Toast” until your symptoms from diarrhea resolve
  • If you are taking antibiotics, ask your doctor or pharmacist before you start taking diphenoxylate and atropine to make sure it is safe to do so
  • A pharmacist should ALWAYS review your medication list to ensure that drug interactions are prevented or managed appropriately

Patient Assistance & Co-payment Coverage

Patients under the age of 65 years, or those with private insurance plans:
If you have insurance and are looking for patient assistance or copay assistance for Diphenoxylate and atropine (Lomotil®), we have provided links that may help.

Visit our Patient Assistance page and click the links to various patient assistance programs for help paying for Diphenoxylate and atropine (Lomotil®). Depending upon your income, they may be able to help cover the cost of:

  • Diphenoxylate and atropine (Lomotil®)

For Branded medications (may be available for generic medications too), check with the manufacturer to determine if a co-pay card is offered and if it could reduce your monthly copay.

  • If you are uninsured, check with the manufacturer to determine if you are eligible to receive medication at no cost.

Medicare and Medicaid patients (Patients 65 years or older):
The clinic providing treatment will likely pre-authorize medications and immune therapies such as Diphenoxylate and atropine (Lomotil®) and are the best source to help you understand drug cost.

  • Ask to speak with a patient assistance technician or financial counselor at the clinic or hospital administering this therapy.

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Diphenoxylate and atropine (Lomotil®) package insert.

Created: November 24, 2017 Updated: November 13, 2018

What is Diarrhea?

Many diarrhea treatment options exist. Watch our diarrhea side effect effect video to learn more about diarrhea and available treatments, many of which are available over-the-counter.

What is a CMP?

A Comprehensive Metabolic Panel (CMP) is a frequently ordered blood test that tells clinicians the status of your: 1) Electrolytes & Acid/Base status2) Kidney function, 3) Liver function, 4) Blood sugar, and 5) Calcium at the time the test was taken. It is commonly used to monitor liver and kidney function when beginning new medications such as chemotherapy. A total of 14 tests are run simultaneously and are shown below.

Electrolytes & Acid/Base status:
1) Sodium, 2) Potassium, 3) Carbon dioxide, 4) Chloride

Kidney Function:
5) BUN (blood urea nitrogen), 6) Serum creatinine (Scr)

Liver Function:
7) AST, 8) ALT, 9) Total bilirubin, 10) Alk Phos, 11) Albumin, 12) Total protein

Blood sugar:
13) Serum glucose

14) Serum calcium