Psyllium is a polysaccharide bulk-forming fiber obtained from the seeds of Plantago psyllium. Bulk-forming fiber laxatives are among the agents of choice as initial therapy for most forms of occasional or idiopathic constipation and are also considered to be some of the safest laxative agents. Certain psyllium products may be used in adult and pediatric patients 6 years of age and older; the fiber wafers may be used in children as young as 4 years of age. However, fiber supplements are not routinely recommended in the treatment of childhood functional constipation due to a lack of evidence that supports their use over a healthy diet. Also, patients with chronic constipation may need other strategies to treat their condition. Guidelines strongly recommend soluble fiber (e.g., psyllium) to treat global symptoms of irritable bowel syndrome (IBS), regardless of subtype. Unlike methylcellulose and calcium polycarbophil, fiber supplementation with psyllium has been shown to reduce serum cholesterol in patients with hypercholesterolemia. Psyllium products have also been reported to be an effective fiber adjunct to help with satiety and to assist promotion of healthy weight and blood sugar. Flatulence and bloating are the most common side effects; psyllium has rarely caused more severe side effects such as allergy or mechanical obstruction of the esophagus or colon.
General Administration Information
For storage information, see the specific product information within the How Supplied section.
Route-Specific Administration
Oral Administration
-Take psyllium orally as directed at least 2 hours before or 2 hours after other oral medications.
-Administer each dosage with the recommended amount of fluid. It is advised that the patient drink another glass of water after consumption of the dose.
Oral Solid Formulations
Chewable Wafers (Fiber thins):
-Chew and swallow as directed. Administer with a full glass (240 mL) of water or other fluid to prevent choking.
Capsules:
-Swallow capsules whole. Swallow 1 capsule at a time and have patient take in an upright position. Administer dose with a full glass (240 mL) of water.
Oral Liquid Formulations
Granules or powders:
-Mix dosage with a full glass (240 mL) of water or other cool liquid prior to administration. Stir briskly and administer promptly.
Troublesome adverse effects associated with psyllium are uncommon and include abdominal pain or cramps, bloating, increased flatulence, and infrequently nausea or vomiting. Discontinue use if abdominal pain or vomiting occurs. Choking or asphyxia can occur if insufficient liquid is administered with psyllium; each dose should be administered with the proper amount of fluid. Patients should be aware of the signs/symptoms of choking or esophageal GI obstruction and should notify their physician immediately if they experience chest pain (unspecified), regurgitation, vomiting, or difficulty swallowing (dysphagia) or difficulty breathing.
Psyllium rarely causes hypersensitivity reactions, including anaphylaxis and dyspnea. Anaphylactoid reactions and other hypersensitivity may occur. Accidental inhalation of psyllium dust particles may cause anaphylaxis, dyspnea, and acute bronchospasm, particularly in sensitive individuals.
Psyllium products may cause allergic reactions in people sensitive to inhaled or ingested psyllium.
Bulk-forming laxatives should not be used in patients with symptoms of acute abdomen or appendicitis, esophageal stricture or perforation, or GI obstruction or ileus. Patients should be advised to consult with their healthcare professional before using psyllium products if unexplained/undiagnosed abdominal pain or nausea or vomiting are present or if they have noticed a sudden change in bowel habits that persists for 2 weeks. Patients should be advised to discontinue this product and to consult their health care professional if they experience rectal GI bleeding or failure to produce a bowel movement occurs. Patients should not use this product for a period more than 1 week for constipation without first consulting their provider.
Psyllium is contraindicated in patients with dysphagia. Use of psyllium products without adequate fluid intake may cause the dosage form to swell and block the throat or esophagus, which may cause choking. Advise patients to discontinue use of this product and seek immediate medical attention if they experience signs or symptoms of choking or esophageal blockage, such as chest pain, vomiting, dysphagia, or difficulty breathing after taking this product.
Patients with phenylketonuria should be aware that the sugar-free preparations of psyllium contain aspartame, a compound that is metabolized in the body and provides a source of phenylalanine.
Psyllium, as a fiber laxative, is not absorbed systemically and is generally considered safe and effective by the American Gastroenterological Association (AGA) for use as directed during pregnancy for the purpose of treating occasional constipation; fiber supplements along with adequate water intake are first line therapies. To avoid impaction, psyllium should be taken with plenty of fluids. The AGA also recommends PEG 3350 as a first-choice laxative in pregnancy when non-pharmacologic methods (e.g., fluids, dietary fiber such as psyllium) are ineffective or inadequate for preventing or treating constipation. A stool softener such as docusate sodium is also considered low risk. As with other populations, cholesterol levels may decrease in some pregnant women using psyllium.
Psyllium use during breast-feeding is compatible. Because psyllium is not absorbed systemically by the mother, there is a lack of worry about excretion in breast milk. Adequate fluid intake and adequate fiber supplementation in the diet are first-line therapies for constipation during lactation. Adequate fluid intake is especially important to avoid impaction and straining following childbirth. The American Gastroenterological Association (AGA) also recommends PEG 3350 as a first-choice laxative when non-pharmacologic methods (e.g., fluids, dietary fiber such as psyllium) are ineffective or inadequate for preventing or treating constipation. A stool softener such as docusate sodium is also compatible with lactation.
The federal Omnibus Budget Reconciliation Act (OBRA) regulates the use of medications in residents (e.g., geriatric adults) of long-term care facilities. The OBRA guidelines caution that bulk forming laxatives, such as psyllium, may cause accumulation of stool and possible bowel obstruction if not used with a sufficient amount of fluid or in patients with other causes of impaired bowel motility.
Psyllium products are generally avoided in neonates, infants, and children 3 years and younger due to the potential choking hazard of the available dosage forms.
For use as a dietary fiber supplement to support digestive health and ease occasional constipation:
Oral dosage (psyllium granules or powders, e.g., Metamucil Dietary Fiber Supplement):
Adults: 1 rounded teaspoonful, tablespoonful, or premeasured packet in 240 mL of fluid PO, 1 to 3 times per day (see specific product chosen - all contain 2 grams of soluble dietary fiber per dose).
Children and Adolescents 12 to 17 years: 1 rounded teaspoonful, tablespoonful, or premeasured packet in 240 mL of fluid PO, 1 to 3 times per day (see specific product chosen - all contain at least 2.4 grams of soluble dietary fiber per dose).
Children 6 to 11 years: One-half of a rounded teaspoonful, tablespoonful, or premeasured packet (1.2 grams soluble dietary fiber per dose) in 240 mL of fluid PO, 1 to 3 times per day (see specific product chosen).
Oral dosage (chewable wafers; e.g., Metamucil Fiber Thins):
Adults: 2 wafers PO 1 to 3 times per day with 240 mL of fluid. Each serving provides 5 grams of dietary fiber.
Children and Adolescents 4 to 17 years: 2 wafers PO 1 to 3 times per day with 240 mL of fluid. Each serving provides 5 grams of dietary fiber.
Oral dosage (psyllium fiber capsules; e.g., Metamucil Fiber Capsules):
Adults: 2 to 5 capsules PO once daily initially; gradually increase to desired daily intake. May take up to 4 times daily. Each 5 capsule dose contains at least 1.8 grams of soluble dietary fiber.
Children and Adolescents 12 to 17 years: 2 to 5 capsules PO once daily initially; gradually increase to desired daily intake. May take up to 4 times daily. Each 5 capsule dose contains at least 1.8 grams of soluble dietary fiber.
For the adjunct treatment of hypercholesterolemia to lower cholesterol to promote heart health:
Oral dosage (psyllium granules or powders, e.g., Metamucil Dietary Fiber Supplement):
Adults: 1 rounded teaspoonful, tablespoonful or premeasured packet in 240 mL of fluid, given PO 3 times daily (see specific product chosen - all contain at least 2.4 grams of soluble dietary fiber per dose). Psyllium, in doses providing roughly 7 grams/day PO of soluble dietary fiber, may reduce the risk of heart disease when part of a diet low in saturated fat and cholesterol.
Children and Adolescents 12 to 17 years: 1 rounded teaspoonful, tablespoonful or premeasured packet in 240 mL of fluid, given PO 3 times daily (see specific product chosen - all contain at least 2.4 grams of soluble dietary fiber per dose). Psyllium, in doses providing roughly 7 grams/day PO of soluble dietary fiber, may reduce the risk of heart disease when part of a diet low in saturated fat and cholesterol.
Oral dosage (psyllium fiber capsules; e.g., Metamucil Fiber Capsules):
Adults: Start with 5 capsules PO once per day; gradually increase to desired daily intake. Recommended cholesterol-lowering and Max dose: 5 capsules PO 4 times daily. Each 5 capsule dose contains at least 1.8 grams of soluble dietary fiber. Psyllium, in doses providing roughly 7 grams/day PO of soluble dietary fiber, may reduce the risk of heart disease when part of a diet low in saturated fat and cholesterol.
Children and Adolescents 12 to 17 years: Start with 5 capsules PO once per day; gradually increase to desired daily intake. Recommended cholesterol-lowering and Max dose: 5 capsules PO 4 times daily. Each 5 capsule dose contains at least 1.8 grams of soluble dietary fiber. Psyllium, in doses providing roughly 7 grams/day PO of soluble dietary fiber, may reduce the risk of heart disease when part of a diet low in saturated fat and cholesterol.
For control of diarrhea* secondary to AIDS-associated enteropathy*:
Oral dosage (psyllium capsules, wafers, granules, or powders):
Adults: Adding fiber may be a useful adjunct in treating AIDS- or protease inhibitor-associated noninfectious diarrhea to promote less watery stools. 1.8 to 2.4 grams of soluble dietary fiber (usually 1 wafer, 5 capsules, or 1 rounded teaspoon, tablespoon or premixed packet for suspension in 240 mL or fluid, depending on product chosen) PO twice daily has been recommended.
For the adjunct treatment of irritable bowel syndrome*:
Oral dosage:
Adults: 3.5 grams PO per day. Guidelines strongly recommend soluble fiber, like psyllium, to treat global symptoms of IBS.
Maximum Dosage Limits:
The below are general guidelines for constipation and lowering of cholesterol; see specific product directions for maximum dosages that may differ for other uses or nutritional supplementation of fiber.
-Adults
7.2 grams (as soluble dietary fiber)/day PO for granules or powders; 6 wafer thins/day PO; 20 fiber capsules/day PO.
-Geriatric
7.2 grams (as soluble dietary fiber)/day PO for granules or powders; 6 wafer thins/day PO; 20 fiber capsules/day PO.
-Adolescents
7.2 grams (as soluble dietary fiber)/day PO for granules or powders; 6 wafer thins/day PO; 20 fiber capsules/day PO.
-Children
12 years: 7.2 grams (as soluble dietary fiber)/day PO for granules or powders; 6 wafer thins/day PO; 20 fiber capsules/day PO.
6 to 11 years: 3.4 grams (as soluble dietary fiber)/day PO for granules or powders; 6 wafer thins/day PO.
4 to 6 years: 6 wafer thins/day PO.
Less than 4 years: Safety and efficacy have not been established (choking hazard).
-Infants
Do not use (choking hazard).
Patients with Hepatic Impairment Dosing
Specific guidelines for dosage adjustments in hepatic impairment are not available; it appears that no dosage adjustments are needed.
Patients with Renal Impairment Dosing
Specific guidelines for dosage adjustments in renal impairment are not available; it appears that no dosage adjustments are needed.
*non-FDA-approved indication
Acetaminophen; Aspirin, ASA; Caffeine: (Moderate) Psyllium can interfere with the absorption of certain oral drugs if administered concomitantly. For example, psyllium fiber can adsorb salicylates. Per the psyllium manufacturers, administration of other prescribed oral drugs should be separated from the administration of psyllium by at least 2 hours.
Acetaminophen; Aspirin, ASA; Caffeine: (Moderate) Psyllium can interfere with the absorption of certain oral drugs if administered concomitantly. For example, psyllium fiber can adsorb salicylates. Per the psyllium manufacturers, administration of other prescribed oral drugs should be separated from the administration of psyllium by at least 2 hours.
Acetaminophen; Aspirin: (Moderate) Psyllium can interfere with the absorption of certain oral drugs if administered concomitantly. For example, psyllium fiber can adsorb salicylates. Per the psyllium manufacturers, administration of other prescribed oral drugs should be separated from the administration of psyllium by at least 2 hours.
Acetaminophen; Aspirin; Diphenhydramine: (Moderate) Psyllium can interfere with the absorption of certain oral drugs if administered concomitantly. For example, psyllium fiber can adsorb salicylates. Per the psyllium manufacturers, administration of other prescribed oral drugs should be separated from the administration of psyllium by at least 2 hours.
Aminosalicylate sodium, Aminosalicylic acid: (Moderate) Psyllium can interfere with the absorption of certain oral drugs if administered concomitantly. For example, psyllium fiber can adsorb salicylates. Per the psyllium manufacturers, administration of other prescribed oral drugs should be separated from the administration of psyllium by at least 2 hours.
Aspirin, ASA: (Moderate) Psyllium can interfere with the absorption of certain oral drugs if administered concomitantly. For example, psyllium fiber can adsorb salicylates. Per the psyllium manufacturers, administration of other prescribed oral drugs should be separated from the administration of psyllium by at least 2 hours.
Aspirin, ASA; Butalbital; Caffeine: (Moderate) Psyllium can interfere with the absorption of certain oral drugs if administered concomitantly. For example, psyllium fiber can adsorb salicylates. Per the psyllium manufacturers, administration of other prescribed oral drugs should be separated from the administration of psyllium by at least 2 hours.
Aspirin, ASA; Caffeine: (Moderate) Psyllium can interfere with the absorption of certain oral drugs if administered concomitantly. For example, psyllium fiber can adsorb salicylates. Per the psyllium manufacturers, administration of other prescribed oral drugs should be separated from the administration of psyllium by at least 2 hours.
Aspirin, ASA; Caffeine; Orphenadrine: (Moderate) Psyllium can interfere with the absorption of certain oral drugs if administered concomitantly. For example, psyllium fiber can adsorb salicylates. Per the psyllium manufacturers, administration of other prescribed oral drugs should be separated from the administration of psyllium by at least 2 hours.
Aspirin, ASA; Carisoprodol; Codeine: (Moderate) Psyllium can interfere with the absorption of certain oral drugs if administered concomitantly. For example, psyllium fiber can adsorb salicylates. Per the psyllium manufacturers, administration of other prescribed oral drugs should be separated from the administration of psyllium by at least 2 hours.
Aspirin, ASA; Citric Acid; Sodium Bicarbonate: (Moderate) Psyllium can interfere with the absorption of certain oral drugs if administered concomitantly. For example, psyllium fiber can adsorb salicylates. Per the psyllium manufacturers, administration of other prescribed oral drugs should be separated from the administration of psyllium by at least 2 hours.
Aspirin, ASA; Dipyridamole: (Moderate) Psyllium can interfere with the absorption of certain oral drugs if administered concomitantly. For example, psyllium fiber can adsorb salicylates. Per the psyllium manufacturers, administration of other prescribed oral drugs should be separated from the administration of psyllium by at least 2 hours.
Aspirin, ASA; Omeprazole: (Moderate) Psyllium can interfere with the absorption of certain oral drugs if administered concomitantly. For example, psyllium fiber can adsorb salicylates. Per the psyllium manufacturers, administration of other prescribed oral drugs should be separated from the administration of psyllium by at least 2 hours.
Aspirin, ASA; Oxycodone: (Moderate) Psyllium can interfere with the absorption of certain oral drugs if administered concomitantly. For example, psyllium fiber can adsorb salicylates. Per the psyllium manufacturers, administration of other prescribed oral drugs should be separated from the administration of psyllium by at least 2 hours.
Atropine; Difenoxin: (Moderate) Diphenoxylate can decrease GI motility. Drugs used to treat constipation, such as laxatives, would counteract the effect of antidiarrheals. In general, it would be illogical to concurrently administer these drugs at the same time. If an antidiarrheal medication is needed, it would be wise to temporarily discontinue use of agents with laxative effects.
Benzoic Acid; Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate: (Moderate) Psyllium can interfere with the absorption of certain oral drugs if administered concomitantly. For example, psyllium fiber can adsorb salicylates. Per the psyllium manufacturers, administration of other prescribed oral drugs should be separated from the administration of psyllium by at least 2 hours.
Bismuth Subsalicylate: (Moderate) Psyllium can interfere with the absorption of certain oral drugs if administered concomitantly. For example, psyllium fiber can adsorb salicylates. Per the psyllium manufacturers, administration of other prescribed oral drugs should be separated from the administration of psyllium by at least 2 hours.
Bismuth Subsalicylate; Metronidazole; Tetracycline: (Moderate) Psyllium can interfere with the absorption of certain oral drugs if administered concomitantly. For example, psyllium fiber can adsorb salicylates. Per the psyllium manufacturers, administration of other prescribed oral drugs should be separated from the administration of psyllium by at least 2 hours.
Bumetanide: (Moderate) Loop diuretics may increase the risk of hypokalemia especially in patients receiving prolonged therapy with laxatives. Monitor serum potassium levels to determine the need for potassium supplementation and/or alteration in drug therapy.
Butalbital; Aspirin; Caffeine; Codeine: (Moderate) Psyllium can interfere with the absorption of certain oral drugs if administered concomitantly. For example, psyllium fiber can adsorb salicylates. Per the psyllium manufacturers, administration of other prescribed oral drugs should be separated from the administration of psyllium by at least 2 hours.
Calcium Phosphate, Supersaturated: (Moderate) Sodium phosphate monobasic monohydrate; sodium phosphate dibasic anhydrous should not be combined with additional laxatives or purgatives when being used to evacuate the bowel prior to colonic radiologic examinations or surgery.
Cardiac glycosides: (Moderate) Psyllium can interfere with the absorption of certain oral drugs if administered together. Psyllium can adsorb cardiac glycosides. Per the manufacturer, administration of other oral drugs should be separated from the administration of psyllium by at least 2 hours.
Choline Salicylate; Magnesium Salicylate: (Moderate) Psyllium can interfere with the absorption of certain oral drugs if administered concomitantly. For example, psyllium fiber can adsorb salicylates. Per the psyllium manufacturers, administration of other prescribed oral drugs should be separated from the administration of psyllium by at least 2 hours.
Dichlorphenamide: (Moderate) Use dichlorphenamide and psyllium together with caution. Dichlorphenamide increases potassium excretion and can cause hypokalemia and should be used cautiously with other drugs that may cause hypokalemia including laxatives. Measure potassium concentrations at baseline and periodically during dichlorphenamide treatment. If hypokalemia occurs or persists, consider reducing the dichlorphenamide dose or discontinuing dichlorphenamide therapy.
Digoxin: (Moderate) Psyllium can interfere with the absorption of certain oral drugs if administered together. Psyllium can adsorb cardiac glycosides. Per the manufacturer, administration of other oral drugs should be separated from the administration of psyllium by at least 2 hours.
Diphenoxylate; Atropine: (Moderate) Diphenoxylate can decrease GI motility. Drugs used to treat constipation, such as laxatives, would counteract the effect of antidiarrheals. In general, it would be illogical to concurrently administer these drugs at the same time. If an antidiarrheal medication is needed, it would be wise to temporarily discontinue use of agents with laxative effects.
Droperidol: (Moderate) Caution is advised when using droperidol in combination with laxatives, which may lead to electrolyte abnormalities, especially hypokalemia or hypomagnesemia, as such abnormalities may increase the risk for QT prolongation or cardiac arrhythmias.
Enteral Feedings: (Minor) Ferrous sulfate elixir has an acidic pH and has been reported to form precipitates with enteral feedings and may clog feeding tubes.
Ethacrynic Acid: (Moderate) Loop diuretics may increase the risk of hypokalemia especially in patients receiving prolonged therapy with laxatives. Monitor serum potassium levels to determine the need for potassium supplementation and/or alteration in drug therapy.
Food: (Major) For better iron absorption, administer iron salts 1 hour before or 2 hours after meals. If GI irritation occurs, the iron supplement may be administered with meals. However, where possible, avoid administering coffee, tea, or dairy products within 1 hour before or 2 hours after giving iron.
Furosemide: (Moderate) Loop diuretics may increase the risk of hypokalemia especially in patients receiving prolonged therapy with laxatives. Monitor serum potassium levels to determine the need for potassium supplementation and/or alteration in drug therapy.
Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate; Sodium Biphosphate: (Moderate) Psyllium can interfere with the absorption of certain oral drugs if administered concomitantly. For example, psyllium fiber can adsorb salicylates. Per the psyllium manufacturers, administration of other prescribed oral drugs should be separated from the administration of psyllium by at least 2 hours.
Lactulose: (Major) In general, other laxatives, such as psyllium, should not be used concurrently with lactulose, especially during the initial phase of therapy for portal-systemic encephalopathy. Although psyllium is a bulk-forming laxative, it can cause loose stools which may falsely suggest that adequate lactulose dosage has been achieved.
Loop diuretics: (Moderate) Loop diuretics may increase the risk of hypokalemia especially in patients receiving prolonged therapy with laxatives. Monitor serum potassium levels to determine the need for potassium supplementation and/or alteration in drug therapy.
Magnesium Salicylate: (Moderate) Psyllium can interfere with the absorption of certain oral drugs if administered concomitantly. For example, psyllium fiber can adsorb salicylates. Per the psyllium manufacturers, administration of other prescribed oral drugs should be separated from the administration of psyllium by at least 2 hours.
Methenamine; Sodium Salicylate: (Moderate) Psyllium can interfere with the absorption of certain oral drugs if administered concomitantly. For example, psyllium fiber can adsorb salicylates. Per the psyllium manufacturers, administration of other prescribed oral drugs should be separated from the administration of psyllium by at least 2 hours.
Salicylates: (Moderate) Psyllium can interfere with the absorption of certain oral drugs if administered concomitantly. For example, psyllium fiber can adsorb salicylates. Per the psyllium manufacturers, administration of other prescribed oral drugs should be separated from the administration of psyllium by at least 2 hours.
Salsalate: (Moderate) Psyllium can interfere with the absorption of certain oral drugs if administered concomitantly. For example, psyllium fiber can adsorb salicylates. Per the psyllium manufacturers, administration of other prescribed oral drugs should be separated from the administration of psyllium by at least 2 hours.
Sodium Phosphate Monobasic Monohydrate; Sodium Phosphate Dibasic Anhydrous: (Moderate) Sodium phosphate monobasic monohydrate; sodium phosphate dibasic anhydrous should not be combined with additional laxatives or purgatives when being used to evacuate the bowel prior to colonic radiologic examinations or surgery.
Torsemide: (Moderate) Loop diuretics may increase the risk of hypokalemia especially in patients receiving prolonged therapy with laxatives. Monitor serum potassium levels to determine the need for potassium supplementation and/or alteration in drug therapy.
Warfarin: (Moderate) Psyllium can interfere with the absorption of certain oral drugs if administered concomitantly. For example, psyllium fiber is theorized to adsorb oral anticoagulants (e.g., warfarin); although, response to a single dose of warfarin was not affected by repeated administration (every 2 hours) of psyllium in a group (n=6) of healthy subjects. Per the psyllium manufacturers, administration of other prescribed oral drugs should be separated from the administration of psyllium by at least 2 hours.
Psyllium fiber is a bulk-forming fiber laxative that increases the weight and water-absorbent properties of stool. By retaining water in stool, the fiber increases stool bulk and improving consistency of bowel movements. Psyllium produces a modest but significant improvement in total cholesterol and LDL cholesterol levels. Soluble fiber from the psyllium attaches to cholesterol in the intestine and reduces cholesterol absorption, thus allowing it to be excreted via the feces with the fiber. A diet rich in soluble fiber has long been known to help maintain healthy metabolic parameters, including cholesterol, body weight, and blood sugar; psyllium appears to show favorable effects on these parameters in patients with and without diabetes.
Pharmacokinetics:
Psyllium is administered orally. The drug distributes locally throughout the intestine, and the laxative effects are usually observed within 12 hours, although they may not be apparent for 3 days. Psyllium is not metabolized and is excreted in the feces.
-Route-Specific Pharmacokinetics
Oral Route
Psyllium is not absorbed into the circulation following oral administration.