ATROPINE Drug Interactions: What You Need to Know

Drug interactions: Alcohol Alcohol may increase the CNS depressant effects of diphenoxylate hydrochloride and atropine sulfate tablets and may cause drowsiness (see WARNINGS ). Avoid concomitant use of diphenoxylate hydrochloride and atropine sulfate tablets with alcohol.

Other

Drugs that Cause CNS Depression The concurrent use of diphenoxylate hydrochloride and atropine sulfate tablets with other drugs that cause CNS depression (e.g., barbiturates, benzodiazepines, opioids, buspirone, antihistamines, muscle relaxants), may potentiate the effects of diphenoxylate hydrochloride and atropine sulfate tablets (see WARNINGS ). Either diphenoxylate hydrochloride and atropine sulfate tablets 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.

Mao

Inhibitors Diphenoxylate may interact with monoamine oxidase inhibitors (MAOIs) and precipitate a hypertensive crisis . Avoid use of diphenoxylate hydrochloride and atropine sulfate tablets in patients who take MAOIs and monitor for signs and symptoms of hypertensive crisis (headache, hyperthermia, hypertension).

CONTRAINDICATIONS Phenohytro™ Tablets are contraindicated in patients with glaucoma; obstructive uropathy (for example, bladder neck obstruction due to prostatic hypertrophy); obstructive disease of the gastrointestinal tract (as in achalasia, pyloroduodenal stenosis, etc.); paralytic ileus, intestinal atony of the elderly or debilitated patient; unstable cardiovascular status in acute hemorrhage; severe ulcerative colitis especially if complicated by toxic megacolon; myasthenia gravis; hiatal hernia associated with reflux esophagitis. Phenohytro™ Tablets are contraindicated in patients with known hypersensitivity to any of the ingredients. Phenobarbital is contraindicated in acute intermittent porphyria and in those patients in whom phenobarbital produces restlessness and/or excitement.

WARNINGS Respiratory and/or CNS Depression in Pediatric Patients Less Than 6 Years of Age 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 diphenoxylate hydrochloride and atropine sulfate tablets . Diphenoxylate hydrochloride and atropine sulfate tablets are contraindicated in patients less than 6 years of age due to these risks (see CONTRAINDICATIONS ). Anticholinergic and Opioid-Toxicities Toxicities associated with the atropine and diphenoxylate components of diphenoxylate hydrochloride and atropine sulfate tablets 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 ). Dehydration and Electrolyte Imbalance The use of diphenoxylate hydrochloride and atropine sulfate tablets should be accompanied by appropriate fluid and electrolyte therapy, when indicated. If severe dehydration or electrolyte imbalance is present, diphenoxylate hydrochloride and atropine sulfate tablets 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.

Gastrointestinal

Complications in Patients with Infectious Diarrhea Diphenoxylate hydrochloride and atropine sulfate tablets are 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 diphenoxylate hydrochloride and atropine sulfate tablets, slow gastrointestinal motility and may enhance bacterial overgrowth and the release of bacterial exotoxins. Diphenoxylate hydrochloride and atropine sulfate tablets have 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 diphenoxylate hydrochloride and atropine sulfate tablets vs. placebo.

Toxic

Megacolon in Patients with Acute Ulcerative Colitis 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 diphenoxylate hydrochloride and atropine sulfate tablets therapy should be discontinued promptly if abdominal distention occurs or if other untoward symptoms develop. Interaction with Meperidine Hydrochloride Since the chemical structure of diphenoxylate hydrochloride is similar to that of meperidine hydrochloride, the concurrent use of diphenoxylate hydrochloride and atropine sulfate tablets with monoamine oxidase (MAO) inhibitors may, in theory, precipitate hypertensive crisis.

Hepatorenal Disease

Diphenoxylate hydrochloride and atropine sulfate tablets 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. Interaction with CNS Depressants Diphenoxylate hydrochloride and atropine sulfate tablets 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.