Dosing and uses of Bentyl (dicyclomine)
Adult dosage forms and strengths
capsule
- 10mg
injectable solution
- 10mg/mL
syrup
- 10mg/5mL
tablet
- 20mg
Irritable Bowel Syndrome
20 mg PO q6hr; may increase up to 40 mg q6hr; if efficacy not achieved in 2 weeks or adverse effects require dose <80 mg/day, therapy should be discontinued; safety data not available for doses > 80 mg/day for periods > 2 weeks
10-20 mg IM q6hr; not to exceed 80 mg/day Im
Dosing considerations
- IM use should not be longer than 1-2 days; replace IM with PO as soon as possible
- Do not use IV
Administration
Take 30-60 minutes before a meaL
Pediatric dosage forms and strengths
capsule
- 10mg
injectable solution
- 10mg/mL
syrup
- 10mg/5mL
tablet
- 20mg
Irritable Bowel Syndrome (Off-label)
Infants >6 months: 5 mg PO q6-8hr; not to exceed 20 mg/day PO
Children: 10 mg PO q6-8hr; not to exceed 40 mg/day PO
Administration
Take 30-60 minutes before a meaL
Geriatric dosage forms and strengths
Irritable bowel syndrome
10-20 mg PO q6hr; may gradually increase PRN; not to exceed 160 mg/day
Dosing considerations
High incidence of anticholinergic effects; avoid except in short-term situations to decrease secretions (Beers Criteria)
Do not use IM in geriatric patients
Bentyl (dicyclomine) adverse (side) effects
>10%
Dizziness (40%)
Xerostomia (33%)
Blurred vision (27%)
1-10%
Somnolence (9%)
Nervousness (6%)
Weakness (7%)
Frequency not defined
Abdominal distension
Confusional state
Cycloplegia
Delirium
Dermatitis
Erythema
Fatigue
Hallucinations
Insomnia
Malaise
Palpitation
Rash
Syncope
Warnings
Contraindications
Hypersensitivity to dicyclomine or any anticholinergic drugs
Closed-angle glaucoma
Myasthenia gravis
Hemorrhage with cardiovascular instability
Paralytic ileus
Breast feeding
Intestinal atony of elderly/debilitated patients
Toxic megacolon
GI obstruction
Obstructive uropathy
Severe ulcerative colitis
Reflux esophagitis
Infants aged <6 months (reports of seizure, respiratory failure, death)
Cautions
Caution in renal/hepatic impairment
Caution in benign prostatic hyperplasia
Caution in congestive heart failure
Caution in tachycardia secondary to cardiac insufficiency or thyrotoxicosis, hypertension, coronary artery disease, chronic obstructive pulmonary disease, hiatal hernia, mitral stenosis, brain damage or spastic paralysis in children, salivary secretion disorder, down syndrome, autonimic neuropathy, hyperthyroidism
Tachyarrhythmia; assess before administration
Toxin-mediated diarrhea
Elderly (Beers Criteria)
May cause drowsiness; avoid alcohoL
For IM injection only; IV injection may result in thrombosis or thrombophlebitis and injection-site reactions
Heat prostration can occur (fever and heat stroke due to decreased sweating)
Psychosis in patients sensitive to anticholinergic drugs reported (eg, elderly, mentally ill individuals); signs and symptoms resolve within 12-24 hr after discontinuation
Incomplete intestinal obstruction: Diarrhea may be an early symptom, especially in patients with ileostomy or colostomy
Salmonella dysenteric patients: Due to risk of toxic megacolon
Use caution in patients with mild-moderate ulcerative colitis
Effects may be potentiated when used with other sedative drugs or ethanoL
Serious respiratory reactions, CNS symptoms, and deaths reported following administration to infants
Pregnancy and lactation
Pregnancy category: B
Lactation: Enters breast milk; contraindicated
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 Bentyl (dicyclomine)
Mechanism of action
Anticholinergic/antispasmodic; no effect on acid secretion, but direct smooth muscle relaxant effects; blocks the action of ACh at parasympathetic sites in smooth muscle, secretory glands, and CNs
Absorption
Bioavailability: PO (67% of IM)
Onset: 1-2 hr
Duration: <4 hr
Peak plasma time: PO (60-90 min)
Distribution
Vd: 3.65 L/kg
Metabolism
Metabolites: Ranitidine N-oxide, desmethylranitidine, ranitidine
Elimination
Half-life: 1.8 hr
Excretion: Urine (80%); feces (8%)
