Lomotil (Diphenoxylate and atropine) at a glance: schedule, half-life, and class
- Generic name
- Diphenoxylate hydrochloride and atropine sulfate
- Brand names
- Lomotil, Lonox
- Drug class
- Opioid-related antidiarrheal (diphenoxylate) with an anticholinergic (atropine)
- US legal status
- Schedule V, prescription only
- Approved uses
- Additional treatment of diarrhea in people 13 and older
- Forms
- Tablets (2.5 mg diphenoxylate, 0.025 mg atropine); liquid
- Onset
- 45 to 60 minutes
- Half-life
- About 2.5 hours; difenoxin 12 to 14 hours
- Reversal agent
- Naloxone (repeated or prolonged dosing may be needed)
Lomotil uses: what diphenoxylate and atropine is prescribed for
Diphenoxylate slows the muscle contractions of the gut and is used, alongside fluids and treating the cause, for diarrhea in adults and children 13 and older.[1]
The tiny dose of atropine has no effect at normal doses but causes unpleasant effects, such as dry mouth, flushing, and a fast heartbeat, at high doses, which discourages misuse.[1]
Lomotil dosage: how diphenoxylate and atropine is usually prescribed
The figures below come from the FDA-approved label and describe how prescribers typically use diphenoxylate and atropine. They are not personal dosing advice. A prescriber sets the dose for each person and adjusts it over time.[1]
| Product | Typical adult dose | Notes from the label |
|---|---|---|
| Adults, starting | 5 mg (2 tablets) four times a day | Maximum 20 mg of diphenoxylate a day |
| Once diarrhea is controlled | As little as 5 mg a day | Stop if no improvement within 10 days of maximum dosing |
| Children under 6 | Contraindicated | Risk of severe, delayed breathing depression |
Lomotil (diphenoxylate and atropine) side effects and risks
Common side effects include dizziness, drowsiness, dry mouth, nausea, and constipation.[1]
Children: accidental ingestion of even one or two tablets by a young child can cause breathing problems that appear up to 30 hours later. Keep it locked away.[1]
Infections and colitis: slowing the gut in diarrhea caused by toxin-producing bacteria, such as C. difficile, or in ulcerative colitis can lead to toxic megacolon. It should not be used for these conditions.[1]
Lomotil interactions: what not to mix with diphenoxylate and atropine
Choose what it would be combined with:
| Combined with | What happens | Label guidance |
|---|---|---|
| MAO inhibitors | Possible hypertensive crisis | Avoid |
| Alcohol, benzodiazepines, sleep medicines, opioids | Additive sedation and slowed breathing | Use caution |
| Other anticholinergics (antihistamines, tricyclics, bladder medicines) | Dry mouth, urinary retention, confusion, overheating | Use caution |
This is not a full list. A pharmacist can check a complete medication list, including supplements and over-the-counter products.[1]
Lomotil overdose: signs of diphenoxylate and atropine overdose and what to do
Overdose causes atropine effects first, flushing, dry skin and mouth, high temperature, and a fast heartbeat, followed by sleepiness, pinpoint pupils, and slowed breathing that can be delayed and prolonged.[1]
If someone may have overdosed
- Call 911 if the person is unresponsive, cannot be woken, has blue or gray lips, or is breathing slowly or not at all.
- Give naloxone (Narcan or a generic nasal spray, sold without a prescription) into one nostril. If there is no response after 2 to 3 minutes, give another dose.
- If you are trained, give rescue breaths. Otherwise place the person on their side so they do not choke.
- Stay with them. Naloxone can wear off before diphenoxylate and atropine does, so the overdose can return even after the person wakes up.
- Most states have Good Samaritan laws that protect people who call 911 for an overdose from some drug charges.
Lomotil withdrawal timeline: how long diphenoxylate and atropine withdrawal lasts
Physical dependence is rare at recommended doses for short periods. Long-term, high-dose use can cause opioid-like dependence.[1]
- 12 to 24 hoursEarly symptomsRestlessness, sweating, runny nose, and stomach cramps after long-term high-dose use.
- Days 1 to 3PeakDiarrhea, nausea, aches, and poor sleep.
- Within 1 weekResolvesSymptoms usually fade over several days.
How to get prescribed Lomotil (diphenoxylate and atropine) legally in the US
In the United States, diphenoxylate and atropine is a Schedule V controlled substance. The only legal way to get it is with a prescription from a clinician registered with the Drug Enforcement Administration (DEA), filled by a licensed pharmacy. Depending on state law, that can be a physician, nurse practitioner, or physician assistant.[2]
- Refills: Schedule V prescriptions can be refilled as the prescriber authorizes, subject to state law.[2]
- Telehealth: federal flexibilities let DEA-registered clinicians prescribe Schedule II to V medicines after a telemedicine visit, without a prior in-person exam, through December 31, 2026. A permanent DEA rule was under final review in late 2026. State rules can be stricter.[3]
- Monitoring: prescribers and pharmacists in most states check a prescription drug monitoring program, a database of controlled-substance prescriptions, before prescribing or dispensing.
- Pharmacies: a legitimate pharmacy always requires a valid prescription, has a licensed pharmacist available, and is licensed in the state it ships to. The FDA's BeSafeRx tool and the NABP's safe pharmacy list help confirm a pharmacy is real.[4][5]
- Cost: generic diphenoxylate and atropine is inexpensive.
Traveling: keep the medicine in its original pharmacy container and carry a copy of the prescription. Check the rules of the destination country before travel, because many countries restrict controlled medicines or require a permit.
Can you order Lomotil (diphenoxylate and atropine) online legally?
Yes, but only with a valid prescription and only from a pharmacy licensed in your state. Many licensed pharmacies, including mail-order pharmacies run by insurers, fill diphenoxylate and atropine prescriptions online and ship them. Buying diphenoxylate and atropine from a website that does not require a prescription is illegal, and the product is often fake.[4][6]
- See a licensed clinicianA clinician evaluates you in person or by telemedicine and decides whether diphenoxylate and atropine is appropriate.
- The prescription goes to a pharmacyPrescriptions are usually sent electronically, straight from the prescriber to the pharmacy you choose.
- The pharmacy checks and fills itA pharmacist verifies the prescription and your identity, then dispenses the medicine in person or by mail.
Signs that an online seller is illegal:
- It sells diphenoxylate and atropine with no prescription, or after only a short online questionnaire.
- It takes orders through social media, messaging apps, or email.
- It asks for payment in cryptocurrency, gift cards, or money transfers.
- It has no US street address, no state pharmacy license, and no pharmacist to speak to.
- Its prices are far below those of ordinary pharmacies, or it ships from another country.
The FDA's BeSafeRx tool links to each state's license lookup, and the National Association of Boards of Pharmacy lists verified online pharmacies.[4][5]
Lomotil price: how much does Lomotil (diphenoxylate and atropine) cost without insurance?
Generic diphenoxylate and atropine is inexpensive.
What you pay depends on the strength, the number of doses, your insurance plan, and the pharmacy. Cash prices for the same prescription can differ several times over between pharmacies in the same town, so check current prices before you fill it.
Ways to pay less, legally:
- Ask the prescriber whether a generic diphenoxylate and atropine is available. FDA-approved generics work the same way as the brand and usually cost much less.
- Compare cash prices between pharmacies before you fill the prescription.
- Use a free prescription discount card, such as GoodRx or SingleCare, when you pay cash. These cards cannot be combined with insurance on the same fill.
- For brand-name medicines, check the manufacturer's savings program or patient assistance program.
- Ask about a 90-day supply or your insurer's mail-order pharmacy, which often lowers the cost per dose when your prescriber agrees it is appropriate.
Warning: A price far below what licensed pharmacies charge, especially with no prescription required, is a strong sign of an illegal seller and counterfeit medicine.[4]
Is Lomotil legal? Diphenoxylate and atropine legal status in other countries
| Country | Status |
|---|---|
| United Kingdom | Prescription-only medicine (co-phenotrope) |
| International | Diphenoxylate is in Schedule I of the 1961 Single Convention; low-dose preparations with atropine are exempted in Schedule III |
Laws change and differ in detail. Check current rules before carrying any controlled medicine across a border.[7]
Common questions about Lomotil (diphenoxylate and atropine)
Is Lomotil a narcotic?
Diphenoxylate is chemically related to meperidine and is a Schedule V controlled substance, the lowest federal schedule.
Why does Lomotil contain atropine?
To discourage misuse. Large doses cause unpleasant effects such as dry mouth, flushing, and a racing heart.
Can children take Lomotil?
No. It is contraindicated under age 6 and not recommended under 13, because it can cause severe, delayed breathing problems.
Is Lomotil stronger than Imodium?
Both slow the gut. Loperamide (Imodium) is available without a prescription and is usually tried first.
How long can I take Lomotil?
If diarrhea does not improve within 10 days at the maximum dose, it is unlikely to help; see a clinician.
Can you buy Lomotil (diphenoxylate and atropine) without a prescription?
No. Lomotil (diphenoxylate and atropine) is a Schedule V controlled substance in the US, so it is illegal to buy or possess it without a valid prescription. Websites and social media sellers that offer it without one are not legal pharmacies, and the DEA warns that pills sold this way are often counterfeit and can contain fentanyl. The legal route is a visit with a licensed clinician, in person or by telehealth, and a prescription filled at a state-licensed pharmacy. The FDA's BeSafeRx tool and the NABP's safe pharmacy list help confirm an online pharmacy is real.
Sources
- Lomotil (diphenoxylate and atropine) prescription information. DailyMed, US National Library of Medicine.
- Controlled Substance Schedules. DEA Diversion Control Division.
- Prescribing controlled substances via telehealth. US Department of Health and Human Services.
- BeSafeRx: Your Source for Online Pharmacy Information. US Food and Drug Administration.
- Safe Pharmacy. National Association of Boards of Pharmacy.
- One Pill Can Kill. US Drug Enforcement Administration.
- International drug control conventions. United Nations Office on Drugs and Crime.
