Dosing and uses of Motofen (difenoxin-hcl-atropine)
Adult dosage forms and strengths
difenoxin hcl/atropine
tablets: Schedule IV
- 1 mg/0.025 mg
Diarrhea
Initially 2 mg (2 tab) PO then 1 mg (1 tab) q3-4hr PRN loose stool; no more than 8 mg/day
Pediatric dosage forms and strengths
Safety & efficacy not established
Geriatric dosage forms and strengths
Diarrhea
Initially 2 mg (2 tab) PO then 1 mg (1 tab) q3-4hr PRN loose stool; no more than 8 mg/day
Motofen (difenoxin-hcl-atropine) adverse (side) effects
1-10%
Nausea (6.7%)
Somnolence (4%)
Vomiting (3.3%)
Xerostomia (3.3%)
Headache (2.5%)
Frequency not defined
Dizziness
Lightheadedness
Abdominal discomfort
Anticholinergic effects
Warnings
Contraindications
<2 years old
Hypersensitivity, infectious diarrhea, jaundice
GI obstruction, hemorrhage, intestinal atony, myasthenia gravis, obstructive uropathy, reflux esophagitis, ulcerative colitis
Cautions
Closed-angle glaucoma, esophageal achalasia
Hepatorenal disease, abnormal liver function
Improvement of symptoms within 48 hr, if not, unlikely to be effective
Do not exceed recommended dosage; reduce initial dosage for maintenance
Pregnancy, breastfeeding
Pregnancy and lactation
Pregnancy category: C
Lactation: enters breast milk/not recommended
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Motofen (difenoxin-hcl-atropine)
Mechanism of action
Difenoxin: Acts on smooth muscle of intestinal tract, inhibiting GI motility & excessive GI propulsion
Atropine: Subtherapeutic quantity of atropine is added to discourage deliberate overdose of diphenoxylate
Pharmacokinetics
Half-life elimination: 4.4 hr
Onset: 45 min-1 hr
Duration: 3-4 hr
Peak Plasma Time: 40-60 min
Excretion: Feces and urine as conjugates
