Lomogray (diphenoxylate + atropine): Uses, Dosage & Side Effects

What it's for (Indications)

Diphenoxylate + Atropine is indicated as adjunctive therapy in the management of diarrhea.
This medication is typically reserved for cases of acute or chronic diarrhea where the underlying cause has been identified and treated, or when non-pharmacological measures or other anti-diarrheal agents are insufficient or inappropriate.
It is crucial to note that this combination is not intended for the treatment of diarrhea caused by infectious organisms, such as *Clostridium difficile*, or other enterotoxin-producing bacteria, unless appropriate anti-infective treatment is concurrently administered.
Its primary role is to reduce the frequency and fluid content of stools, thereby alleviating symptomatic discomfort and preventing further dehydration.
It is not a substitute for fluid and electrolyte replacement therapy.

Dosage Information

Type	Guideline
Standard	For adults, the typical starting dosage of diphenoxylate + atropine is two tablets (containing 2.5 mg diphenoxylate hydrochloride and 0.025 mg atropine sulfate per tablet) four times daily, or as directed by a healthcare professional. The maximum recommended daily dosage should not exceed 20 mg of diphenoxylate (equivalent to 8 tablets) within a 24-hour period to minimize the risk of opioid-related central nervous system effects and atropine toxicity. Dosage should be adjusted based on the patient's response and tolerance. Once diarrhea is controlled, the dosage may be gradually reduced to the lowest effective level for maintenance therapy, often one tablet two to three times daily. This medication is absolutely contraindicated in children under 2 years of age due to the significant risk of respiratory depression and CNS toxicity, and extreme caution is warranted for pediatric patients up to 6 years of age, for whom alternative therapies are generally preferred. Prolonged use without medical supervision is strongly discouraged.

Type

Guideline

Standard

For adults, the typical starting dosage of diphenoxylate + atropine is two tablets (containing 2.5 mg diphenoxylate hydrochloride and 0.025 mg atropine sulfate per tablet) four times daily, or as directed by a healthcare professional. The maximum recommended daily dosage should not exceed 20 mg of diphenoxylate (equivalent to 8 tablets) within a 24-hour period to minimize the risk of opioid-related central nervous system effects and atropine toxicity. Dosage should be adjusted based on the patient's response and tolerance. Once diarrhea is controlled, the dosage may be gradually reduced to the lowest effective level for maintenance therapy, often one tablet two to three times daily. This medication is absolutely contraindicated in children under 2 years of age due to the significant risk of respiratory depression and CNS toxicity, and extreme caution is warranted for pediatric patients up to 6 years of age, for whom alternative therapies are generally preferred. Prolonged use without medical supervision is strongly discouraged.

Safety & Warnings

Common Side Effects

The use of diphenoxylate + atropine can be associated with a range of side effects, stemming from both its opioid and anticholinergic components.
Common adverse reactions primarily affect the gastrointestinal tract and central nervous system.
Gastrointestinal side effects may include constipation, nausea, vomiting, abdominal discomfort, and paralytic ileus, particularly with high doses or prolonged use.
Central nervous system effects can manifest as dizziness, drowsiness, headache, sedation, lightheadedness, and rarely, euphoria or depression.
Atropine-related anticholinergic effects, which are more pronounced with higher doses, include dry mouth, blurred vision, urinary retention, flushing, hyperthermia, and tachycardia.
Serious but less common adverse effects involve severe respiratory depression, especially in young children or those with compromised respiratory function, and toxic megacolon in patients with inflammatory bowel disease.
Allergic reactions such as rash or angioedema are also possible.
Patients should report any unusual or severe symptoms to their healthcare provider immediately, especially if they experience difficulty breathing, severe abdominal pain, or changes in mental status.

Serious Warnings

Black Box Warning: **WARNING: RESPIRATORY DEPRESSION AND CENTRAL NERVOUS SYSTEM (CNS) EFFECTS IN PEDIATRIC PATIENTS; RISK OF TOXIC MEGACOLON IN PATIENTS WITH INFLAMMATORY BOWEL DISEASE** Diphenoxylate + atropine is associated with a significant risk of respiratory depression and central nervous system (CNS) effects, particularly in young children. This medication is contraindicated in children younger than 2 years of age due to the documented risk of severe, life-threatening respiratory depression and other serious CNS adverse reactions, which have been fatal even at recommended doses. Cases of respiratory arrest and coma have been reported following the administration of diphenoxylate + atropine in this vulnerable population. Healthcare providers must exercise extreme caution when considering its use in pediatric patients up to 6 years of age, and it should only be used if there are no appropriate alternatives, with close monitoring for signs of CNS or respiratory depression. Furthermore, the use of anti-diarrheal agents like diphenoxylate can precipitate toxic megacolon in patients with inflammatory bowel disease (IBD), such as ulcerative colitis or Crohn's disease, especially during acute exacerbations. This severe complication can lead to colonic perforation, sepsis, and death. Therefore, diphenoxylate + atropine is contraindicated in patients with diarrhea associated with enterotoxin-producing bacteria or those with inflammatory bowel disease where toxic megacolon is a risk. Overdosage, even in adults, can lead to severe respiratory depression, coma, and death.
Diphenoxylate + atropine carries several important warnings.
Due to its opioid component, diphenoxylate, there is a risk of physical dependence and psychological addiction, particularly with prolonged use or at higher doses.
Concurrent use with other central nervous system (CNS) depressants, including alcohol, sedatives, tranquilizers, or other opioids, can significantly potentiate CNS depression, leading to severe drowsiness, respiratory depression, and potentially coma or death.
Patients should be advised against driving or operating heavy machinery until they know how the medication affects them.
This drug should be used with extreme caution in patients with hepatic impairment, as decreased metabolism can increase systemic exposure to diphenoxylate.
In patients with inflammatory bowel disease, the use of anti-diarrheal agents like diphenoxylate can precipitate toxic megacolon, a life-threatening complication characterized by dilation of the colon and systemic toxicity.
Fluid and electrolyte imbalances often accompany severe diarrhea, and these must be corrected prior to initiating therapy with diphenoxylate + atropine.
The atropine component can exacerbate conditions like acute narrow-angle glaucoma, prostatic hypertrophy, or bladder neck obstruction.
Pediatric patients, especially those under 6 years, are particularly vulnerable to respiratory depression and other CNS effects, making its use in this population highly restricted and often contraindicated.

How it Works (Mechanism of Action)

Diphenoxylate + atropine exerts its therapeutic effects through a dual mechanism involving its two active pharmaceutical ingredients. Diphenoxylate, a synthetic phenylpiperidine derivative, functions as an opioid receptor agonist, primarily targeting mu-opioid receptors located within the intestinal wall. By binding to these receptors, diphenoxylate effectively inhibits gastrointestinal motility, leading to a significant reduction in peristaltic movements. This action prolongs the transit time of intestinal contents, allowing for increased reabsorption of water and electrolytes from the gut lumen, which consequently reduces the frequency and improves the consistency of stools. While chemically related to meperidine, diphenoxylate does not cross the blood-brain barrier readily at therapeutic doses, minimizing central nervous system effects; however, at higher doses, it can produce opioid-like CNS depression and euphoria. Atropine sulfate is included in a subtherapeutic dose primarily to deter abuse of diphenoxylate. As an anticholinergic agent, atropine produces unpleasant peripheral effects such as dry mouth, blurred vision, and urinary retention when ingested in doses significantly higher than recommended, thereby discouraging intentional overdose. It does not substantially contribute to the anti-diarrheal action at the doses prescribed for therapeutic effect.