docusate sodium
Brand: Colace, Surfak
Prototype Drug
Drug Class: stool softener / emollient laxative
Drug Family: GI agent
Subclass: anionic surfactant
Organ Systems: gastrointestinal
Mechanism of Action
Functions as a surfactant (detergent), lowering surface tension between the aqueous and fatty components of stool, allowing water and fat to penetrate and soften the stool. Does not stimulate peristalsis or increase bowel movements but allows easier passage of softer stool.
stool water content (surfactant action)
Indications
- constipation prevention (softening hard stools)
- anorectal conditions (hemorrhoids, anal fissure)
- opioid-induced constipation (combined with senna)
Contraindications
- intestinal obstruction
- concomitant mineral oil use (enhances absorption of mineral oil to toxic levels)
Adverse Effects
Common
- diarrhea
- abdominal cramping (mild)
- nausea
Serious
- hepatotoxicity (docusate calcium, rare)
- mineral oil toxicity (if co-administered)
Pharmacokinetics (ADME)
| Absorption | minimal systemic absorption |
| Distribution | acts locally in GI tract |
| Metabolism | minimal |
| Excretion | fecal |
| Half-life | not applicable |
| Onset | 12–72 hours |
| Peak | varies |
| Duration | varies |
| Protein Binding | minimal |
| Vd | minimal |
Drug Interactions
| Drug / Agent | Mechanism | Severity |
|---|---|---|
| mineral oil | docusate enhances intestinal absorption of mineral oil, causing lipoid pneumonia risk | major |
Nursing Considerations
- Docusate is primarily a preventive stool softener and should not be relied upon to treat established constipation; combine with senna for more effective relief.
- Administer with adequate fluids; the surfactant effect is enhanced by hydration.
- Do NOT administer with mineral oil; docusate increases mineral oil absorption, raising the risk of lipoid pneumonia.
- In the palliative care context, the standard prescription is senna 2 tablets + docusate 100 mg twice daily to prevent opioid-induced constipation.
Clinical Pearls
- Despite widespread use, clinical evidence supporting docusate's efficacy as a standalone laxative is weak; combination with senna is more evidence-based for opioid-induced constipation.
- Docusate is not absorbed systemically and has an excellent safety profile, making it appropriate for pregnant women with constipation.
Safety Profile
Pregnancy safe
Lactation generally-safe
Renal Adjustment Not required
Hepatic Adjustment Not required
TDM Not required
Concordance Terms
Cross-referenced clinical concepts — click any term to see all content where it appears.