castor oil
Emulsoil, Neoloid, Purge

Pharmacologic classification: glyceride, Ricinus communis derivative
Therapeutic classification: stimulant laxative
Pregnancy risk category X


Available forms
Available without a prescription
Liquid: 60 ml, 120 ml, 480 ml
Liquid (95%): 30 ml, 60 ml
Liquid emulsion: 63 ml (95%), 118 ml (36.4%)

Indications and dosages
 Preparation for rectal or bowel examination or surgery, acute constipation. Liquid. Adults: 15 to 60 ml (or 30 to 60 ml, 95%) P.O.
Children ages 2 to 12: 5 to 15 ml to 30 ml P.O.
Children younger than age 2: 1 to 5 ml P.O.
Liquid emulsion
Adults: 45 ml to 60 ml (36.4%) or 15 to 60 ml (95%) P.O. mixed with 4 to 8 oz (120 to 240 ml) water, milk, fruit juice, or soft drink.
Children ages 2 to 12: 15 ml to 30 ml (36.4%) or 5 to 15 ml (95%) P.O. mixed with 4 to 8 oz (120 to 240 ml) water, milk, fruit juice, or soft drink.

Pharmacodynamics
Laxative action: Castor oil acts primarily in the small intestine, where it’s metabolized to ricinoleic acid, which stimulates the intestine, promoting peristalsis and bowel motility.

Pharmacokinetics
Absorption: Unknown.
Distribution: Distributed locally, primarily in the small intestine.
Metabolism: Like other fatty acids, castor oil is metabolized by intestinal enzymes into its active form, ricinoleic acid.
Excretion: Excreted in feces.

Route Onset Peak Duration
P.O. 2-6 hr Variable Variable


Contraindications and precautions
Contraindicated in pregnant women; menstruating women; patients with ulcerative bowel lesions; and patients with abdominal pain, nausea, vomiting, or other symptoms of appendicitis or acute surgical abdomen. Also contraindicated in patients with anal or rectal fissures, fecal impaction, or intestinal obstruction or perforation. Use cautiously in patients with rectal bleeding.

Interactions
Drug-drug. Intestinally absorbed drugs: Decreases absorption of these drugs. Monitor patient closely.
Drug-herb. Male fern: Increases absorption and risk of toxicity. Discourage use together.

Adverse reactions
GI: nausea; vomiting; diarrhea; loss of normal bowel function with excessive use; abdominal cramps, especially in severe constipation; malabsorption of nutrients; cathartic colon (syndrome resembling ulcerative colitis radiologically and pathologically) with long-term misuse; laxative dependence with long-term or excessive use; constipation after catharsis.
Metabolic: hypokalemia, other electrolyte imbalances (with excessive use).
Other: protein-losing enteropathy.

Effects on lab test results
None reported.

Overdose and treatment
No information available.

Special considerations
• Failure to respond to drug may indicate an acute condition that needs surgery.
• Castor oil isn’t recommended for routine use in constipation; it’s commonly used to evacuate the bowel before diagnostic or surgical procedures.
• Because of rapid onset of action, drug shouldn’t be given at bedtime.
• Drug is most effective when taken on an empty stomach; shake it well before giving it.
• Flavored preparations are available.
• Observe patient for signs and symptoms of dehydration.
Pregnant patients
• Drug shouldn’t be used in pregnant women because of possible fetal abnormalities.
Breast-feeding patients
• Breast-feeding women should seek medical approval before using castor oil.
Geriatric patients
• With prolonged use, geriatric patients may experience electrolyte depletion, resulting in weakness, incoordination, and orthostatic hypotension.

Patient education
• Advise pregnant women not to use castor oil.
• Recommend that drug be chilled or taken with juice or carbonated beverage to improve palatability.
• Instruct patient to shake emulsion well before taking it.
• Reassure patient that after response to drug he may not need to move his bowels again for up to a few days.

Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE THREATENING.
◆ Canada only
◇ Unlabeled clinical use