psyllium (Metamucil, Fiberall)

Introduction

Tradenames: Metamucil, Fiberall. (from plantago seed)

Indications

• relief of constipation
• may aid in the management of diarrhea
• bowel preparation
• irritable bowel syndrome

Contraindications

• fecal impactation
• GI obstruction

pregnancy-category B

safety in lactation ?

Dosage

• 1 to 2 tablespoons PO QD/BID/TID, mixed with at least 8 oz of fluid

Pharmacokinetics

• elimination: not absorbed
• some effect may be seen in 12-24 hours
• full effect may not be apparent for 2-3 days

Adverse effects

• gastrointestinal
  • gaseous abdominal distension
  • abdominal cramping
  • belching
  • diarrhea
  • constipation
  • intestinal obstruction
  • flatulence
• aerosolization of powder
  • bronchospasm
  • anaphylaxis on inhalation in susceptible individuals
  • rhinoconjunctivitis

Drug interactions

• binds to many medications decreasing absorption
  • give other medications 1 hour before or 3-4 hours after psyllium
• specific medications affected include:
  • warfarin
  • digoxin
  • K+ sparing diuretics
  • salicylates
  • tetracyclines
  • nitrofurantoin

Mechanism of action

• adds bulk in the form of insoluble fiber to the stool
• bulk promotes peristalsis & reduces fecal transit time

More general terms

• laxative

Component of

• cortisol/lidocaine/psyllium
• polycarbophil/psyllium/senna
• cortisol/lidocaine/polycarbophil/psyllium
• psyllium/senna