What the label lists and what reports show
Collagenase clostridium histolyticum side effects
Collagenase clostridium histolyticum's FDA label lists its adverse reactions in its own words. FAERS holds 7,032 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is contusion (678 reports).
- No generic listed
Check it at the source: the collagenase clostridium histolyticum FDA label on DailyMed (effective May 17, 2019); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of XIAFLEX?XIAFLEX may cause serious side effects, including: See “What is the most important information I should know about XIAFLEX for the treatment of Dupuytren’s contracture?” increased chance of bleeding. Bleeding or bruising at the injection site can happen in people who receive XIAFLEX. Talk to your healthcare provider if you have a problem with your blood clotting. XIAFLEX may not be right for you. The most common side effects with XIAFLEX for the treatment of Dupuytren’s contracture include: swelling of the injection site or the hand bruising or bleeding at the injection site pain or tenderness of the injection site or the hand swelling of the lymph nodes (glands) in the elbow or armpit (axilla) itching breaks in the skin redness or warmth of the skin pain in the armpit Tell your healthcare provider if you have any side effect that bothers you or does not go away. […]
Source: FDA drug label (XIAFLEX), Endo USA, Inc., effective April 22, 2026 (SPL set 805cecd0-fd1f-11dd-87af-0800200c9a66), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsNo allergic sensitivity or toxic reactions have been noted in clinical use when used as directed. However, one case of systemic manifestations of hypersensitivity to collagenase in a patient treated for more than one year with a combination of collagenase and cortisone has been reported.
Table 5. Adverse Reactions Occurring in ≥ 1% of XIAFLEX-Treated Patients with Peyronie’s disease and at a Greater Incidence than Placebo After Up to Four Treatment Cycles in Studies 1 and 2 Combined
This table is printed in the XIAFLEX label published by Endo USA, Inc. of April 22, 2026; the label quoted above does not print one.
| Adverse Reaction | XIAFLEX N=551 | Placebo N=281 |
|---|---|---|
| All Adverse Reactions | 84.2% | 36.3% |
| Penile hematoma a | 65.5% | 19.2% |
| Penile swelling b | 55.0% | 3.2% |
| Penile pain c | 45.4% | 9.3% |
| Penile ecchymoses d | 14.5% | 6.8% |
| Blood blister | 4.5% | 0 |
| Penile blister | 3.3% | 0 |
| Pruritus genital | 3.1% | 0 |
| Painful erection | 2.9% | 0 |
| Erectile dysfunction | 1.8% | 0.4% |
| Skin discoloration | 1.8% | 0 |
| Procedural pain | 1.6% | 0.7% |
| Injection site vesicles | 1.3% | 0 |
| Localized edema | 1.3% | 0 |
| Dyspareunia | 1.1% | 0 |
| Injection site pruritus | 1.1% | 0 |
| Nodule | 1.1% | 0 |
| Suprapubic pain | 1.1% | 0 |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
Source: FDA drug label, SMITH & NEPHEW, INC, effective May 17, 2019 (SPL set 6b6fbfc6-98fa-46aa-88ef-ab00fbb08ffd), via openFDA; the full label on DailyMed
What do FAERS reports show?
7,032 reports list collagenase clostridium histolyticum among the medicines taken, each a report of something that happened, not proof the medicine caused it; 494 are coded as a death and 634 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 19 reactions below, 6 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Collagenase clostridium histolyticum: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions