Castor oil, 30 g

Pharmacokinetics

After oral administration in the alkaline environment of the duodenum in the presence of bile, ricinoleic acid is formed from the oil under the influence of lipase. Absorption of ricinoleic acid is inversely proportional to the dose taken. When oil is administered in a dose of 4 g, the absorption of ricinolic acid is about 100%; when it is administered in a dose of 50 g, only 36% is absorbed (the rest of the acid is excreted in the feces within 24 hours); when it is administered in a dose of 60 g, the percentage of absorbed acid is only 10%. The absorption rate of ricinoleic acid is half the absorption rate of oleic acid. At least 10 g of oil should be taken to develop a loosening effect.

The absorbed portion of ricinolic acid undergoes β-oxidation in the liver and skeletal muscles and is included in metabolic processes.

Pharmacodynamics

Castor oil is a laxative of vegetable origin.

The mechanism of action of castor oil is due to the ricinolic acid released from it in the duodenal lumen. At concentrations of 0.5 mmol/L, ricinolic acid irritates receptors throughout the intestine and inhibits Na+/K+/2Cl–transporters, resulting in loss of electrolyte absorption and a secondary delay in water absorption. In concentrations greater than 2 mmol/L ricinoleic acid increases water secretion into the intestinal lumen.

The volume of intestinal contents increases under the influence of castor oil, increases intestinal motility and accelerates its emptying. The oil remaining in the intestine facilitates the movement of feces through the large intestine. The laxative effect develops 2-6 hours after taking the oil and weakens after emptying the bowels.

When irritating the intestinal receptors, castor oil reflexively stimulates the centers of the spinal cord which coordinate the contractile activity of the myometrium. As a result, castor oil increases uterine contractions during pregnancy.

Indications

Active ingredient

Composition

active ingredient:

Castor oil – 30 g.

How to take, the dosage

As a laxative administered to adults 15 – 30 g once a day. When cleansing bowels before diagnostic procedures it is taken 2 – 6 hours before the study. Children at the age of 12-14 years old are prescribed 5 – 15 g once a day.

In case of weakness of labor strength and in order to stimulate labor activity the castor oil is administered in dose of 40-50 g once against the background of using medicines stimulating uterine contractility.

In dermatological practice to soften the skin and remove scales from excessive keratinization it is used topically in the form of boltushka in ethyl alcohol in 1:10 ratio with 2% salicylic acid added (10 g of castor oil, 2 g of salicylic acid, ethyl alcohol up to 100 ml). Boltushka shall be rubbed into the lesion once a day for 4 – 7 days, after which mechanical cleaning of the lesion shall be carried out and treatment shall be continued.

In the treatment of burns, skin wounds it is prescribed topically in the form of boltushkas and emulsions in distilled water 1 – 2 times a day under a bandage.

For strengthening hair growth a solution of 10 g castor oil and 100 ml of 96% ethyl alcohol is prepared and rubbed into the scalp.

Interaction

In concomitant use reduces absorption of fat-soluble vitamins A, D and K. In doses up to 4 g / day increases absorption of fat-soluble drugs – male fern extract, mebendazole, griseofulvin, probucol.

In concomitant use with saline laxatives a sharp increase in the laxative effect is possible.

M-cholinoblocking agents (atropine sulfate, platifiline, pirenzepine), antispasmodics (papaverine, drotaverine) weaken the effect of castor oil.

The anticholinesterase agents (neostigmine, pyridostigmine, rivastigmine) and glycerol increase the laxative effect of castor oil.

It enhances the effect of agents that stimulate myometrial contractile activity (methylergometrine, ergometrine, oxytocin, prostaglandins) up to the threat of uterine rupture in labor.

When used topically, it increases the transcutaneous absorption of drugs applied together with it on the skin.

Special Instructions

Impact on driving and operating machinery. During administration of castor oil it is not recommended to drive a motor vehicle, you should refrain from other operator’s activities due to possible impairment of concentration during the onset of the effect.

Caution when using. Castor oil should not be used as a laxative for more than 3 days because it may interfere with digestion and absorption of vitamins A and D, and cause hypovitaminosis. Castor oil should not be used with medicinal products derived from the male fern because this could lead to systemic absorption and neurotoxic effects.

Contraindications

Side effects

Overdose

It develops when ingestion of castor oil in a dose greater than 7 g/kg body weight. Diarrhea, abdominal cramps, impaired renal function, dizziness, hallucinations, loss of consciousness are characteristic.

The specific antidotes are atropine sulfate and loperamide. Measures of care include withdrawal of the drug, replenishment of fluid and electrolyte losses (combined oral and intravenous administration is preferred), supportive and symptomatic therapy aimed at elimination of the resulting disorders. If neurotoxic effects develop, diazepam 5 – 10 mg intravenously is administered.

Pregnancy use

The use of castor oil is contraindicated in pregnancy due to the possibility of premature termination. Use in the third trimester of pregnancy is possible only under vital signs. If it is necessary to use during lactation, breastfeeding must be stopped for the duration of the treatment.

Pediatric use. The use of castor oil in children under 12 years of age is not recommended because of the high sensitivity of the intestines of children to irritants and the risk of dehydration.