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Collagenase Clostridium Histolyticum (Monograph)

Brand name: Xiaflex
Drug class: Enzymes
Chemical name: Collagenase (Clostridium histolyticum gene colG isoenzyme AUX-I
Molecular formula: C5632H8679N1481O1785S17C5220H7993N1353O1617S25
CAS number: 955089-04-0

Medically reviewed by on Mar 14, 2024. Written by ASHP.


Risk Evaluation and Mitigation Strategy (REMS):

FDA approved a REMS for collagenase clostridium histolyticum to ensure that the benefits outweigh the risk. The REMS may apply to one or more preparations of collagenase clostridium histolyticum and consists of the following: elements to assure safe use and implementation system. See


Enzymatic agent containing a mixture of 2 proteinases derived from Clostridium histolyticum that hydrolyze collagen, resulting in lysis of collagen deposits.

Uses for Collagenase Clostridium Histolyticum

Dupuytren’s Contracture

Treatment of Dupuytren’s contracture in adults having a palpable collagen cord. Designated an orphan drug by FDA for the treatment of advanced Dupuytren’s disease.

Dupuytren’s disease is a progressive fibroproliferative condition of the palmar fascia in the hand. Abnormal collagen deposition results in nodule and cord formation; may eventually limit hand movement by causing the affected fingers to chronically bend toward the palm with loss of ability to straighten these fingers resulting in contracture.

May be a useful alternative to surgery, particularly in patients reluctant to have surgical intervention or who desire minimal recovery time.

Collagenase Clostridium Histolyticum Dosage and Administration


Restricted Distribution Program


Intralesional Administration

Administer by intralesional injection.

Confirm collagen cord to be injected. Select injection site where cord is maximally separated from underlying flexor tendons and where skin is not closely adhered to cord. Apply antiseptic at injection site; allow skin to dry.

Place needle into collagen cord with caution. To minimize potential for injection into other tissues, avoid passing needle tip completely through the cord. (See Tendon Rupture, Ligament Damage, or Other Serious Injury under Cautions.) If needle insertion into a tendon is suspected or paresthesia is reported, withdraw and reposition needle into the cord.

After confirming proper needle position, inject approximately one-third of total dose into the collagen cord. Withdraw needle from cord and reposition in a slightly more distal location to initial injection site; inject another one-third of total dose within the cord. Repeat procedure a third time and reposition needle proximally to initial injection site; inject final portion of dose into the cord.

For injection of a collagen cord affecting a proximal interphalangeal (PIP) joint of the fifth finger, do not insert the needle >2–3 mm in depth; inject drug as close to the palmar digital crease as possible (not >4 mm distal to crease).

Following injection, advise patient to limit motion of treated finger, and to keep injected hand elevated until bedtime; also provide follow-up instructions for cord disruption. (See Advice to Patients.) If a joint contracture persists following initial injection, a finger extension procedure is recommended approximately 24 hours after administration to facilitate cord disruption. Local anesthesia may be used to control pain during finger extension procedure.

If cord disruption has not occurred after the first finger extension procedure, a second and third attempt may be performed at 5- to 10- minute intervals. However, >3 attempts per visit are not recommended. If cord disruption has not occurred after 3 attempts, a follow-up visit may be scheduled in approximately 4 weeks. If contracted cord persists after 4 weeks, an additional injection may be administered and finger extension procedure performed.

For full instructions on intralesional administration of collagenase clostridium histolyticum and on the finger extension procedure following injection, refer to prescribing information at [Web].


Before use, store vials of lyophilized powder and sterile diluent at 2–8°C. Prior to reconstitution, remove vials containing lyophilized powder and diluent from the refrigerator; allow to stand at room temperature at least 15 minutes but not >60 minutes. Only use diluent supplied by the manufacturer.

Swab rubber stopper and surrounding surface of vials containing lyophilized powder and diluent aseptically with sterile alcohol; other antiseptic agents should notbe used.

Using a 1 mL syringe with 0.01 mL graduations and a 27-gauge 0.5-inch needle, withdraw 0.39 or 0.31 mL of diluent for injection into collagen cords affecting a metacarpophalangeal (MP) or a PIP joint, respectively.

Inject diluent slowly toward sides of vial labeled as containing 0.9 mg of lyophilized powder. Swirl contents of vial slowly to ensure that powder is in solution; avoid shaking or inverting the vial. Discard syringe and needle used for reconstitution and diluent vial.

Prior to administration, reconstituted solution may be stored at room temperature for up to 1 hour or at 2–8°C for up to 4 hours. If reconstituted solution is stored at 2–8°C, allow solution to return to room temperature for approximately 15 minutes before use.

Discard any unused portion of reconstituted solution after injection. Avoid use of reconstituted solution if it contains particulates, is cloudy, or discolored.



Dupuytren’s Contracture
Intralesional Injection

Initially, 0.58 mg. Using a 1 mL syringe, withdraw 0.25 or 0.2 mL of reconstituted solution from the single-dose vial for a cord associated with an MP or PIP joint contracture, respectively. Administer total dose of 0.58 mg in approximately 3 equally divided injections into different sites along the cord. (See Administration under Dosage and Administration.)

If an MP or PIP joint contracture persists 4 weeks following initial treatment and finger extension procedure, a single 0.58-mg dose injected into the cord and finger extension (approximately 24 hours following injection) may be repeated.

Intralesional injections of drug may be administered up to 3 times per cord at approximately 4-week intervals.

Inject one cord at a time. If a patient has multiple palpable cords with MP or PIP joint contractures, these cords may be injected one at a time in sequential order.

Special Populations

No special population dosage recommendations at this time.

Cautions for Collagenase Clostridium Histolyticum




Tendon Rupture, Ligament Damage, or Other Serious Injury

Injection into collagen structures of the hand may result in damage and possibly permanent injury (e.g., tendon rupture, ligament damage). Flexor tendon rupture, pulley rupture, ligament injury, complex regional pain syndrome (CRPS), tendinitis, and sensory abnormality of the hand also reported.

Inject only into a collagen cord associated with an MP or PIP joint contracture. Avoid injection into tendons, nerves, blood vessels, or other collagen-containing structures of the hand.

Use special care when treating the PIP joint of the fifth finger, since tendon ruptures reported near the digital PIP joint crease. For cord injection affecting the PIP joint, do not insert the needle >2–3 mm in depth; inject drug as close to the palmar digital crease as possible (not >4 mm distal to crease). (See Administration under Dosage and Administration.)

Sensitivity Reactions

Risk of severe hypersensitivity reactions (including anaphylaxis) following injection. Be prepared to manage severe allergic reactions. Severe allergic reactions not observed in clinical studies but patients developed increasing IgE-anti-drug antibody titers with successive injections; mild allergic reactions (e.g., pruritus) reported after up to 3 injections.

General Precautions

Coagulation Disorders

Use caution in patients with coagulation disorders including those receiving anticoagulants (except low-dose aspirin). Safety and efficacy in patients receiving anticoagulants (other than low-dose aspirin up to 150 mg daily) within 7 days prior to injection not known. (See Interactions.)

Specific Populations


Category B.


Not known whether drug is distributed into milk. Use caution.

Pediatric Use

Safety and efficacy not established in children <18 years of age.

Geriatric Use

No overall differences in safety and efficacy relative to younger adults.

Common Adverse Effects

Peripheral edema (e.g., swelling of injected hand), contusion, injection site reaction, injection site hemorrhage, pain in injected extremity.

Drug Interactions

Not a substrate for CYP isoenzymes or other drug metabolizing enzyme pathways. Pharmacokinetic drug interactions not evaluated.

Specific Drugs




Anticoagulants (e.g., aspirin, clopidogrel, prasugrel, warfarin)

Potential risk of abnormal coagulation

Safety and efficacy in patients receiving anticoagulants (other than low-dose aspirin up to 150 mg daily) within 7 days prior to injection not known

Use with caution

Collagenase Clostridium Histolyticum Pharmacokinetics



Following single-dose intralesional injection, no detectable plasma concentrations for up to 30 days.



May remain confined to tissues near injection site, but tissue distribution not evaluated to date.



Metabolism may occur at injection site from local synthesis and release of α-2-macroglobulin (α2M) by fibroblasts and tissue macrophages followed by endocytosis and lysosomal proteolysis, but elimination not evaluated to date.

Special Populations

Studies not performed to date to evaluate effects in patients with impaired hepatic or renal function.




Powder for Injection

2–8°C; do not freeze. Reconstituted solutions are stable at room temperature ≤1 hour or at 2–8°C ≤4 hours.


Advice to Patients


Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

Distribution of collagenase clostridium histolyticum is restricted. (See Restricted Distribution Program under Dosage and Administration.)

Collagenase Clostridium Histolyticum


Dosage Forms


Brand Names



For injection, for intralesional use

0.9 mg



AHFS DI Essentials™. © Copyright 2024, Selected Revisions March 24, 2017. American Society of Health-System Pharmacists, Inc., 4500 East-West Highway, Suite 900, Bethesda, Maryland 20814.

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