Teduglutide

Introduction Overview

Generic Name

teduglutide

Brand Name

Gattex

Dosage Form

Kit for subcutaneous injection (5 mg)

Drug Class

Miscellaneous GI agents; Glucagon-like peptide-2 (GLP-2) analog

Pharmacokinetics

Absorption:
Teduglutide is administered subcutaneously, where it is absorbed into systemic circulation. Due to its nature as a peptide analog of GLP-2, it is not orally bioavailable. Subcutaneous administration results in relatively rapid absorption with measurable plasma concentrations within minutes post-injection. The absolute bioavailability following subcutaneous injection is high, though exact percentages vary across studies. Peak plasma concentrations typically occur approximately 3 to 5 hours after injection. Repeated daily dosing maintains steady-state levels without significant accumulation beyond dose-dependent kinetics.

Distribution:
Once absorbed, teduglutide distributes into extracellular fluids with a volume of distribution approximating total body water. It is largely confined to plasma and interstitial fluids as expected for peptide drugs. Binding to plasma proteins is minimal, facilitating its distribution to target tissues such as the gastrointestinal tract. GLP-2 receptors are predominantly located on enteric neurons and intestinal epithelial cells, consistent with teduglutide's targeted action. Studies in animal models and humans demonstrate distribution to the intestinal mucosa, where it exerts trophic effects. There is limited passage across the blood-brain barrier, minimizing central nervous system exposure.

Metabolism:
Teduglutide undergoes proteolytic cleavage by dipeptidyl peptidase-4 (DPP-4), an enzyme expressed widely in plasma and on endothelial surfaces, leading to its inactivation. The peptide is metabolized into smaller inactive peptides and amino acids by ubiquitous proteases. Hepatic metabolism is minimal since the molecule is primarily cleared by enzymatic degradation in plasma and kidney tissues. Its metabolic profile is consistent with other GLP-2 analogs, and metabolism is not subject to cytochrome P450 enzymatic pathways, reducing the risk of CYP-mediated drug-drug interactions.

Elimination:
The primary route of elimination for teduglutide is renal excretion of metabolites and unchanged peptide. The drug has an elimination half-life of approximately 3 to 5 hours, enabling once-daily dosing. In patients with moderate to severe renal impairment (eGFR <60 mL/min/1.73 m2), clearance is reduced, necessitating dosage adjustments to prevent drug accumulation. There is minimal biliary or fecal excretion. The pharmacokinetic profile supports dosing parenterally with monitoring in renal dysfunction. No significant accumulation occurs with chronic administration in patients with normal renal function.

Dosage Forms

Available Dosage Forms:
Gattex is available as a kit for subcutaneous injection containing 5 mg of teduglutide as a sterile lyophilized powder in a single-dose vial. The kit includes a prefilled syringe containing 0.5 mL of Sterile Water for Injection used as the diluent to reconstitute the powder before administration. Each vial and syringe set is designed for single use only and must be discarded if not used within 3 hours of reconstitution.

Dosages for Adults and Adolescents:
The recommended dose of Gattex for treating short bowel syndrome (SBS) in adults and children aged 1 year and older is 0.05 mg/kg once daily administered subcutaneously. It is critical to rotate injection sites among the four quadrants of the abdomen, the upper thighs, or upper arms to minimize injection site reactions. In patients with moderate to severe renal impairment or end-stage renal disease (eGFR less than 60 mL/min/1.73 m2), the dose should be reduced to 0.025 mg/kg once daily to compensate for decreased clearance.

Specific Patient Populations:
In pediatric patients weighing less than 22 pounds (10 kg), Gattex use is not recommended due to insufficient safety and efficacy data. Self-administration by children has not been studied and is not advised; administration should be performed by a caregiver or healthcare provider. Renal impairment necessitates dosage adjustments as described. There are no established dosing modifications for hepatic impairment. Due to potential risks and limited data, Gattex is not recommended for use in children under 1 year of age. Pregnant and breastfeeding women should use Gattex only if clearly needed, with close medical supervision.

Storage and Handling:
Gattex powder should be stored at room temperature up to 77°F (25°C) and must not be frozen. The reconstituted solution must be used within 3 hours and discarded if unused. Single-dose vials and syringes should never be reused to prevent contamination and infection risks.

Mechanism Of Action

Teduglutide, the active ingredient in Gattex, is a recombinant analog of human glucagon-like peptide-2 (GLP-2), a 33-amino acid peptide hormone produced by intestinal L-cells. GLP-2 is an endogenous trophic factor that influences intestinal growth and function. Teduglutide binds to and activates the GLP-2 receptor, a G protein-coupled receptor expressed primarily on enteroendocrine cells, enteric neurons, and various cells within the intestinal mucosa.

Upon binding to the GLP-2 receptor, teduglutide stimulates adenylate cyclase activity leading to an increase in intracellular cyclic AMP levels. This activation promotes mucosal epithelial cell proliferation, inhibits apoptosis, and enhances barrier function in the small intestine. Teduglutide also enhances intestinal blood flow by stimulating mesenteric vasodilation, which supports nutrient absorption and tissue repair.

The drug's trophic effect leads to increased villus height and crypt depth, augmenting the absorptive surface area of the remaining intestine in patients with short bowel syndrome (SBS). This enhanced absorptive capacity reduces dependence on parenteral nutrition or fluid support. Teduglutide also promotes the expression of nutrient transporters and enzymes, further optimizing intestinal functionality.

Compared to endogenous GLP-2, teduglutide has a single amino acid substitution rendering it resistant to degradation by dipeptidyl peptidase-4 (DPP-4), resulting in a longer half-life and improved pharmacodynamic profile. Clinical studies have confirmed that teduglutide significantly improves intestinal adaptation and reduces parenteral support in SBS patients, reflecting its mechanism of augmenting mucosal growth and repair processes.

Pharmacological Actions

Acts as a glucagon-like peptide-2 (GLP-2) receptor agonist promoting intestinal growth.
Stimulates proliferation of intestinal epithelial cells, increasing absorptive surface area.
Enhances mesenteric blood flow through vasodilation, improving nutrient absorption.
Inhibits apoptosis in gastrointestinal mucosal cells, supporting intestinal integrity.
Augments the expression of nutrient transporters and digestive enzymes in enterocytes.
Promotes mucosal barrier function and reduces intestinal permeability.
Resistant to DPP-4 enzymatic degradation, prolonging pharmacologic activity.
Facilitates intestinal adaptation in patients with short bowel syndrome.
Reduces dependence on parenteral nutrition and intravenous fluids.
Improves intestinal function by increasing villus height and crypt depth.
Modulates gut hormone secretion indirectly through receptor activation.
Delays gastric emptying and intestinal transit to increase nutrient absorption time.
Enhances overall gastrointestinal homeostasis and repair mechanisms.
May influence intestinal motility through enteric nervous system pathways.
Potential to improve quality of life in patients with chronic intestinal insufficiency.

Therapeutic Or Clinical Uses

Treatment of short bowel syndrome (SBS) in adults requiring parenteral support.
Management of SBS in children aged 1 year and older dependent on intravenous nutrition or fluids.
Adjunct therapy to reduce parenteral nutrition volume and frequency in SBS.
Improvement of intestinal absorption capacity post extensive bowel resection.
Support of intestinal adaptation processes after surgical bowel shortening.
Reduction of complications associated with long-term parenteral nutrition such as catheter-related infections and liver disease.
Potential use in patients with intestinal failure syndrome to enhance enteral autonomy.
Therapeutic option for patients with insufficient absorptive mucosa due to disease or surgery.
May aid in decreasing hospitalization duration related to parenteral nutrition dependency.
Used in patients who cannot fully sustain nutrition and hydration via oral or enteral routes.
Improvement of fluid and electrolyte absorption in SBS patients.
Facilitation of nutritional rehabilitation in gastrointestinal insufficiency.
Supportive therapy in chronic intestinal diseases with mucosal atrophy or damage.
Potential off-label investigational use for enhancing intestinal dysfunction recovery.
Considered when conventional nutritional support therapies are inadequate or cause significant morbidity.

Side Or Adverse Effects

Abdominal pain and bloating (distension).
Nausea and vomiting.
Upper respiratory tract infections, including common cold and influenza.
Injection site reactions such as redness, swelling, or itching.
Fluid overload leading to edema in extremities.
Hypersensitivity reactions including rash and urticaria.
Potential accelerated growth of pre-existing neoplastic or dysplastic cells.
Development of intestinal polyps requiring surveillance and removal.
Risk of bowel obstruction manifesting as abdominal pain, distension, vomiting, and constipation.
Inflammation or blockage of the gallbladder or pancreas, with associated symptoms.
Allergic reactions, including anaphylaxis with signs of facial swelling and breathing difficulty.
Weight gain due to fluid retention in susceptible individuals.
Electrolyte imbalances secondary to changes in fluid absorption.
Injection site lipodystrophy in cases of repeated injections at the same site.
Potential exacerbation of underlying heart failure due to fluid retention.

Precautions

Perform colonoscopy and upper intestinal endoscopy to check for polyps before initiating therapy in adults.
Screen children for blood in stool and evaluate for polyps prior to initiation.
Monitor for new or recurring polyps during long-term treatment with regular surveillance.
Avoid use in patients with active malignancy of the gastrointestinal tract or related organs.
Exercise caution in patients with history of bowel obstruction or stenotic lesions.
Closely monitor patients with cardiac or renal impairment for signs of fluid overload.
Reduce dose in patients with moderate to severe renal impairment.
Educate patients about rotating injection sites to minimize local reactions.
Do not use Gattex in pediatric patients under 1 year of age due to lack of safety data.
Advise patients to report any signs of bowel obstruction or abdominal pain promptly.
Screen patients for gallbladder and pancreatic disease before and during treatment.
Avoid abrupt discontinuation without consulting healthcare provider.
Pregnant or breastfeeding women should use Gattex only if clearly needed, with close supervision.
Advise patients to inform all healthcare providers about Gattex use when new medications are prescribed.
Regularly evaluate electrolyte, fluid status, and kidney function during treatment.

Warnings

May accelerate growth of pre-existing abnormal or cancerous cells.
Intestinal polyps can develop or enlarge; surveillance colonoscopy is mandatory.
Risk of bowel obstruction requiring temporary discontinuation of therapy.
Potential for inflammation or blockage of gallbladder and pancreas; monitor diligently.
Fluid overload may precipitate or worsen congestive heart failure.
Allergic and hypersensitivity reactions including anaphylaxis have been reported.
Use with caution in patients with a history of gastrointestinal malignancies.
Self-administration by children is not recommended due to limited safety data.
Not established for efficacy and safety in children under 1 year of age.
May increase absorption of concomitant oral medications, necessitating dose adjustments.
Discontinue therapy if cancer is detected during treatment.
Injection site infections or reactions may occur; proper injection technique is critical.
Careful monitoring advised in patients with renal impairment due to altered clearance.
Pregnancy safety has not been established; potential fetal risk cannot be excluded.
Breastfeeding during treatment is not recommended.

Contraindication

Known hypersensitivity to teduglutide or any component of Gattex.
Active malignancy involving the stomach, intestines, liver, gallbladder, or pancreas.
History of gastrointestinal polyps that cannot be removed or monitored.
Patients with a known or suspected bowel obstruction.
Use in pediatric patients under 1 year of age due to insufficient data.
Concurrent use in patients with severe hypersensitivity reactions to GLP-2 analogs.
Pregnancy, unless potential benefit outweighs risk (relative contraindication).
Breastfeeding women due to lack of safety information.
Severe renal impairment without appropriate dose adjustment and monitoring.
Patients unable to comply with recommended monitoring for polyps and neoplasia.

Drug Interactions

May increase absorption of concurrently administered oral medications such as benzodiazepines.
Potentially necessitates dose adjustment of oral drugs due to enhanced bioavailability.
No significant interactions with cytochrome P450 substrates as teduglutide is not metabolized by CYP enzymes.
Concomitant use with other gastrointestinal growth factors or trophic agents has not been studied.
Interactions with drugs affecting intestinal motility have not been well characterized.
No major interactions reported with common cardiovascular or antihypertensive agents.
Close monitoring recommended when initiating or discontinuing medications metabolized in the gut.
No known interaction with parenteral nutrition components.
Reduced absorption of certain oral medications is not expected owing to the drug’s mode of action.
Caution when initiating Gattex with drugs that have narrow therapeutic indices requiring steady absorption.
Possible alteration in effectiveness of immunosuppressants taken orally due to altered absorption.
Inform all healthcare providers of Gattex therapy due to potential effects on oral drug pharmacokinetics.
No clinically significant interaction with over-the-counter medications or herbal supplements currently reported.
Clinical vigilance advised when starting new oral medications during Gattex therapy.
Pharmacodynamic interactions with agents affecting intestinal blood flow or absorption may theoretically occur.

Preparations Of The Drug

Gattex is supplied as a single-dose vial containing 5 mg of teduglutide powder.
Each kit includes a sterile single-dose prefilled syringe containing 0.5 mL of Sterile Water for Injection as a diluent.
The powder and diluent must be reconstituted immediately before use and administered within 3 hours.
The kit is intended for subcutaneous injection once daily, ideally at the same time each day.
Preparation involves mixing the lyophilized powder with the diluent in the vial using aseptic technique.
After reconstitution, the solution should be inspected for particulate matter and discoloration before use.
Any unused portion of the reconstituted solution must be discarded; it is not suitable for storage.
Kits must be stored at room temperature, avoiding freezing or excessive heat exposure.
The drug preparation supplies are designed for single use; never reuse needles or syringes.
Patients should receive education on safe preparation, injection technique, and disposal of materials.
Instructions for use are provided within the package insert emphasizing correct dosing and handling.
Healthcare providers or caregivers should initially supervise administration to ensure proper technique.
The inclusion of a sterile water syringe helps ensure dosing accuracy and ease of preparation.
Proper disposal of needles, syringes, and vials should follow local regulations for biohazard waste.
No generic versions are currently available; the brand Gattex is proprietary to Takeda Pharmaceutical Company.