(diphenoxylate HCl, atropine sulfate)
Cases of severe respiratory depression and coma, leading to permanent brain damage or death have been reported in patients less than 6 years of age who received Lomotil. Lomotil is contraindicated in patients less than 6 years of age due to these risks (see CONTRAINDICATIONS).
Toxicities associated with the atropine and diphenoxylate components of Lomotil have been reported. The initial presenting symptoms may be delayed by up to 30 hours due to prolonged gastric emptying time induced by diphenoxylate hydrochloride. Clinical presentations vary in terms of which toxicity (anticholinergic vs. opioid) will present first or predominate; non-specific findings have been reported and include symptoms such as drowsiness (see OVERDOSAGE).
The use of Lomotil should be accompanied by appropriate fluid and electrolyte therapy, when indicated. If severe dehydration or electrolyte imbalance is present, Lomotil should be withheld until appropriate corrective therapy has been initiated. Drug-induced inhibition of peristalsis may result in fluid retention in the intestine, which may further aggravate dehydration and electrolyte imbalance.
Lomotil is contraindicated in patients with diarrhea associated with organisms that penetrate the GI mucosa (toxigenic E. coli, Salmonella, Shigella), and pseudomembranous enterocolitis (Clostridium difficile) associated with broad-spectrum antibiotics (see CONTRAINDICATIONS). Antiperistaltic agents, including Lomotil, slow gastrointestinal motility and may enhance bacterial overgrowth and the release of bacterial exotoxins. Lomotil has been reported to result in serious GI complications in patients with infectious diarrhea, including sepsis, prolonged and/or worsened diarrhea. Prolonged fever and the delay in the resolution of stool pathogens were reported in study of Shigellosis in adults who used Lomotil vs. placebo.
In some patients with acute ulcerative colitis, agents that inhibit intestinal motility or prolong intestinal transit time have been reported to induce toxic megacolon. Consequently, patients with acute ulcerative colitis should be carefully observed and Lomotil therapy should be discontinued promptly if abdominal distention occurs or if other untoward symptoms develop.
Since the chemical structure of diphenoxylate hydrochloride is similar to that of meperidine hydrochloride, the concurrent use of Lomotil with monoamine oxidase (MAO) inhibitors may, in theory, precipitate hypertensive crisis.
Lomotil should be used with extreme caution in patients with advanced hepatorenal disease and in all patients with abnormal liver function since hepatic coma may be precipitated.
Diphenoxylate hydrochloride may potentiate the action of other drugs that cause dizziness or drowsiness, including barbiturates, benzodiazepines and other sedatives/hypnotics, anxiolytics, and tranquilizers, muscle relaxants, general anesthetics, antipsychotics, other opioids, and alcohol. Therefore, the patient should be closely observed when any of these are used concomitantly.
Since a subtherapeutic dose of atropine has been added to Lomotil, consideration should be given to the development of adverse reactions associated with atropine (see WARNINGS). Lomotil has caused atropinism (hyperthermia, tachycardia, urinary retention, flushing, dryness of the skin and mucous membranes) particularly in pediatric patients with Down's syndrome. Lomotil is not indicated for use in pediatric patients (see CONTRAINDICATIONS and WARNINGS). Monitor patients for signs of atropinism.
Advise patients:
Alcohol may increase the CNS depressant effects of Lomotil and may cause drowsiness (see WARNINGS). Avoid concomitant use of Lomotil with alcohol.
The concurrent use of Lomotil with other drugs that cause CNS depression (e.g., barbiturates, benzodiazepines, opioids, buspirone, antihistamines, muscle relaxants), may potentiate the effects of Lomotil (see WARNINGS). Either Lomotil or the other interacting drug should be chosen, depending on the importance of the drug to the patient. If CNS-acting drugs cannot be avoided, monitor patients for CNS adverse reactions.
No long-term study in animals has been performed to evaluate carcinogenic potential. Diphenoxylate hydrochloride was administered to male and female rats in their diets to provide dose levels of 4 and 20 mg/kg/day throughout a three-litter reproduction study. At 50 times the human dose (20 mg/kg/day), female weight gain was reduced and there was a marked effect on fertility as only 4 of 27 females became pregnant in three test breedings. The relevance of this finding to usage of Lomotil in humans is unknown.
Diphenoxylate hydrochloride has been shown to have an effect on fertility in rats when given in doses 50 times the human dose (see above discussion). Other findings in this study include a decrease in maternal weight gain of 30% at 20 mg/kg/day and of 10% at 4 mg/kg/day. At 10 times the human dose (4 mg/kg/day), average litter size was slightly reduced.
Teratology studies were conducted in rats, rabbits, and mice with diphenoxylate hydrochloride at oral doses of 0.4 to 20 mg/kg/day. Due to experimental design and small numbers of litters, embryotoxic, fetotoxic, or teratogenic effects cannot be adequately assessed. However, examination of the available fetuses did not reveal any indication of teratogenicity.
There are no adequate and well-controlled studies in pregnant women. Lomotil should be used during pregnancy only if the anticipated benefit justifies the potential risk to the fetus.
Caution should be exercised when Lomotil is administered to a nursing woman, since the physicochemical characteristics of the major metabolite, diphenoxylic acid, are such that it may be excreted in breast milk and since it is known that atropine is excreted in breast milk.
The safety and effectiveness of Lomotil have been established in pediatric patients 13 years of age and older as adjunctive therapy in the management of diarrhea. The safety and effectiveness of Lomotil have not been established in pediatric patients less than 13 years of age.
Lomotil is contraindicated in pediatric patients less than 6 years of age due to the risks of severe respiratory depression and coma, possibly resulting in permanent brain damage or death (see CONTRAINDICATIONS).
Lomotil has caused atropinism, particularly in pediatric patients with Down's syndrome (see PRECAUTIONS).
In case of accidental ingestion of Lomotil by pediatric patients, see OVERDOSAGE for recommended treatment.
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