DOCUSATE ASCEND

Indications

• Constipation
• Prevention of straining during bowel movements
• Management of conditions such as hemorrhoids or anal fissures

Dosage

Children: Refer to the BNF for Children for appropriate dosing in children.

Adults: The usual oral dosage is 50 to 500 mg daily in divided doses, or 100 to 250 mg taken once daily. Rectal administration can involve 283 to 566 mg as a single dose.

Mechanism of action

Docusate exerts its effects primarily through its surfactant properties in the intestines. It allows for the incorporation of fat and water into the feces, which softens the stool. Studies have shown that docusate increases the secretion of water, sodium, chloride, and potassium while decreasing the absorption of glucose and bicarbonate. This mechanism may involve an increase in intracellular cyclic AMP, either directly by docusate or through E series prostaglandins.

Pharmacodynamics

As an anionic detergent and laxative, docusate promotes stool softening by reducing surface tension. Its onset of action varies, with oral administration taking 6 to 72 hours and rectal administration acting within 2 to 15 minutes. The effects are localized in the jejunum, aiding in the passage of feces.

Pharmacokinetics

Docusate is absorbed in the gastrointestinal tract, but its specific absorption and elimination characteristics are not well-documented. It is primarily metabolized in the intestines, and the active metabolites facilitate the stool softening effect. The pharmacokinetic profile indicates that its action can vary based on the route of administration and individual patient factors.

Adverse effects

• Abdominal cramping
• Diarrhea
• Nausea
• Throat irritation

Precautions

• Use with caution in patients with intestinal obstruction or abdominal pain of unknown origin
• Not recommended for long-term use

Pregnancy

Docusate is generally considered safe to use during pregnancy, but it is advisable to consult a healthcare provider before use.

Breast-feeding

Docusate is excreted in breast milk; however, it is considered safe to use while breastfeeding.

Storage

Store at room temperature, away from moisture and heat. Keep out of reach of children.

Formulations

• Oral capsules
• Oral liquid
• Rectal suppositories

Indications

• Constipation
• Softening of impacted feces
• Bowel cleansing prior to medical procedures

Dosage

Children: For children aged 2-11 years: 12.5 to 25 mg 3 times a day, adjusted according to response. For children aged 12-17 years: 120 mg for 1 dose.

Adults: For oral use: 50 to 500 mg daily in divided doses, adjusted according to response. For rectal use: 120 mg as a single dose.

Mechanism of action

Docusate sodium acts as a stool softener by increasing the wetting efficiency of the intestinal fluid, facilitating the mixing of aqueous and fatty substances, which leads to a reduction in stool hardness. It also promotes the secretion of intestinal fluids, which aids in the overall ease of bowel movements.

Pharmacodynamics

Docusate sodium works by altering the surface tension of the stool, making it easier for water to mix with the stool, thus softening it. Its effects are generally observed within 1 to 3 days of oral administration, while rectal administration can lead to a quicker response, typically within 20 minutes.

Pharmacokinetics

Docusate sodium is absorbed in the gastrointestinal tract, with a peak plasma concentration occurring approximately 1 to 2 hours after administration. The elimination half-life is not well-characterized, but the drug is excreted mainly in the urine. The onset of action varies depending on the route of administration; oral doses typically take 1-3 days to have an effect, whereas rectal doses have a faster onset.

Contra-indications

• Inflammatory bowel disease (except under medical supervision)
• Intestinal obstruction
• Hypersensitivity to soya
• History of hypersensitivity to arachis oil or peanuts

Adverse effects

• Anal irritation
• Contact dermatitis
• Granuloma pneumonia
• Lipoid pneumonia
• Rectal discharge

Interactions

• Avoid concurrent use with liquid paraffin
• Excessive use of stimulant laxatives may cause diarrhea and related effects such as hypokalemia

Precautions

• Prolonged use should be avoided
• Administered at night for optimal effect
• Rectal preparations not indicated if hemorrhoids or anal fissure are present

Pregnancy

Manufacturer advises caution; consult a healthcare professional before use during pregnancy.

Breast-feeding

Manufacturer advises caution; present in small amounts in milk following oral administration.

Storage

Store in a cool, dry place away from direct sunlight. Keep out of reach of children.

Formulations

• Docusate sodium 2.5 mg per 1 ml oral solution
• Docusate sodium 10 mg per 1 ml oral solution
• Docusate sodium 12.5 mg/5 ml oral solution
• Docusate sodium 100 mg capsules
• Docusate sodium 120 mg enema

Mechanism of action

Recent studies suggest that docusate's mechanism of action is due largely to it's surfactant effect in the intestines, which allow fat and water into the feces to soften the stool. Docusate’s mechanism of action was investigated in 1985 on healthy patients. Docusate was added directly to the jejunum based on calculated concentrations of docusate in the jejunum. At this concentration, there was an increase in secretion of water, sodium, chloride, and potassium as well as a decrease in absorption of glucose and bicarbonate. Based on in vitro data, the authors suggested this effect was due to an increase in intracellular cyclic AMP either directly through docusate or E series prostaglandins.

Pharmacodynamics

Docusate sodium is a laxative and an anionic detergent that supposedly promotes incorporation of water and fats into stool through a reduction in surface tension, resulting in softer fecal mass. Docusate's onset of action is 6-72 hours orally and 2-15 minutes rectally. The effects of docusate are thought to be exerted locally in the jejunum.