Get your patient on Diphenoxylate Hydrochloride And Atropine Sulfate - Diphenoxylate Hydrochloride And Atropine Sulfate tablet (Diphenoxylate Hydrochloride And Atropine Sulfate)

Diphenoxylate hydrochloride and atropine sulfate tablets are indicated as adjunctive therapy in the management of diarrhea in patients 13 years of age and older.

Diphenoxylate hydrochloride and atropine sulfate tablets are contraindicated in:

• Pediatric patients less than 6 years of age due to the risks of respiratory and central nervous system (CNS) depression ( see WARNINGS ).
• Patients with diarrhea associated with pseudomembranous enterocolitis ( Clostridium difficile ) or other enterotoxin-producing bacteria due to the risk of gastrointestinal (GI) complications, including sepsis ( see WARNINGS ).
• Patients with known hypersensitivity to diphenoxylate or atropine.
• Patients with obstructive jaundice.

The following serious adverse reactions are described elsewhere in labeling:

• Respiratory and/or CNS depression ( see WARNINGS )
• Anticholinergic and opioid-toxicities, including atroponism ( see WARNINGS and PRECAUTIONS )
• Dehydration and electrolyte imbalance ( see WARNINGS )
• GI complications in patients with infectious diarrhea ( see WARNINGS )
• Toxic megacolon in patients with acute ulcerative colitis ( see WARNINGS )

At therapeutic doses of diphenoxylate hydrochloride and atropine sulfate tablets, the following other adverse reactions have been reported; they are listed in decreasing order of severity, but not of frequency:

Nervous system: numbness of extremities, euphoria, depression, malaise/lethargy, confusion, sedation/drowsiness, dizziness, restlessness, headache, hallucination

Allergic: anaphylaxis, angioneurotic edema, urticaria, swelling of the gums, pruritus

Gastrointestinal system: megacolon, paralytic ileus, pancreatitis, vomiting, nausea, anorexia, abdominal discomfort

The following adverse reactions related to atropine sulfate are listed in decreasing order of severity, but not of frequency: hyperthermia, tachycardia, urinary retention, flushing, dryness of the skin and mucous membranes.

Each Diphenoxylate Hydrochloride and Atropine Sulfate Tablet contains:
2.5 mg of diphenoxylate hydrochloride USP (equivalent to 2.3 mg of diphenoxylate) and 0.025 mg of atropine sulfate USP (equivalent to 0.01 mg of atropine).
Diphenoxylate hydrochloride, an antidiarrheal, is ethyl 1-(3-cyano-3,3-diphenylpropyl)-4-phenylisonipecotate monohydrochloride and has the following structural formula:

Atropine sulfate, an anticholinergic, is endo-(±)-α-(hydroxymethyl) benzeneacetic acid 8-methyl-8-azabicyclo[3.2.1] oct-3-yl ester sulfate (2:1) (salt) monohydrate and has the following structural formula:

A subtherapeutic amount of atropine sulfate is present to discourage deliberate overdosage.

Inactive ingredients of diphenoxylate hydrochloride and atropine sulfate tablets include silicified microcrystalline cellulose, pregelatinized starch, and magnesium stearate.

Diphenoxylate is rapidly and extensively metabolized in man by ester hydrolysis to diphenoxylic acid (difenoxine), which is biologically active and the major metabolite in the blood. After a 5 mg oral dose of carbon-14 labeled diphenoxylate hydrochloride in ethanolic solution was given to three healthy volunteers, an average of 14% of the drug plus its metabolites was excreted in the urine and 49% in the feces over a four-day period. Urinary excretion of the unmetabolized drug constituted less than 1% of the dose, and diphenoxylic acid plus its glucuronide conjugate constituted about 6% of the dose. In a 16-subject crossover bioavailability study, a linear relationship in the dose range of 2.5 to 10 mg was found between the dose of diphenoxylate hydrochloride (given as diphenoxylate hydrochloride and atropine sulfate liquid) and the peak plasma concentration, the area under the plasma concentration-time curve, and the amount of diphenoxylic acid excreted in the urine. In the same study the bioavailability of the tablet compared with an equal dose of the liquid was approximately 90%. The average peak plasma concentration of diphenoxylic acid following ingestion of four 2.5 mg tablets was 163 ng/mL at about 2 hours, and the elimination half-life of diphenoxylic acid was approximately 12 to 14 hours.

In dogs, diphenoxylate hydrochloride has a direct effect on circular smooth muscle of the bowel that conceivably results in segmentation and prolongation of gastrointestinal transit time. The clinical antidiarrheal action of diphenoxylate hydrochloride may thus be a consequence of enhanced segmentation that allows increased contact of the intraluminal contents with the intestinal mucosa.

Tablets — round, flat-faced radius-edged, white tablet with M in a box on one side and containing 2.5 mg of diphenoxylate hydrochloride USP and 0.025 mg of atropine sulfate USP, supplied as: