NovoEight Side Effects: What to Expect and When to Call Your Doctor

NovoEight (turoctocog alfa) has been studied in large clinical trials involving more than 300 patients with hemophilia A, accumulating over 140,000 exposure days of data. Like all medications, NovoEight can cause side effects — most of which are mild and manageable, but some of which require immediate attention.

This guide explains what the FDA-approved label and clinical trial data tell us about NovoEight's side effect profile — in plain English.

Common Side Effects of NovoEight

The most frequently reported adverse reactions in clinical trials (occurring in 1% or more of patients) were:

Injection site reactions: Swelling, itching, pain, or redness at the site where the IV is given. These are typically mild and resolve on their own. Try alternating infusion sites to reduce local irritation.

Pyrexia (fever): Low-grade fever after infusion can occur. If fever is high (over 101°F/38.3°C) or persists, contact your healthcare provider.

Elevated liver enzymes: Some patients show temporary increases in liver function test values. Your HTC will monitor liver enzymes periodically.

Serious Side Effect #1: Factor VIII Inhibitor Development

The most clinically significant risk with NovoEight — and with all recombinant FVIII products — is the development of factor VIII inhibitors. Inhibitors are antibodies your immune system produces against factor VIII, which can render the treatment ineffective and cause loss of bleeding control.

In clinical trials of NovoEight in previously untreated patients (PUPs), 42.9% developed inhibitors — which is consistent with inhibitor rates seen across all recombinant FVIII products in this population. In previously treated patients (PTPs) with over 150 exposure days, no confirmed inhibitors were detected.

Signs that you may have developed an inhibitor:

Your normal dose of NovoEight is no longer controlling bleeding

You need larger doses than usual to stop a bleed

You are experiencing more frequent or harder-to-control bleeding episodes

If you suspect an inhibitor, contact your HTC immediately. Inhibitor testing (Bethesda assay) is done with a blood test. Inhibitor development is treatable — your hematologist will adjust your treatment plan.

Serious Side Effect #2: Allergic Reactions and Anaphylaxis

NovoEight is produced using Chinese hamster ovary (CHO) cells, and the product contains trace amounts of hamster proteins. Patients who are allergic to hamster proteins are contraindicated from using NovoEight.

Stop using NovoEight and get emergency help immediately if you experience any of these signs of a serious allergic reaction:

Rashes or hives

Difficulty breathing or swallowing, wheezing

Tightness of the chest

Swelling of the lips, tongue, or face

Light-headedness, dizziness, or fainting

Pale, cold skin or fast heartbeat

These symptoms require calling 911 or going to the nearest emergency room immediately.

Side Effects in Pediatric Patients

Clinical trials of NovoEight included 146 pediatric patients under 18 years of age, with the majority (62%) under 6 years old. The overall safety profile in children was consistent with that in adults. However, children typically have higher factor clearance rates and may need more frequent dosing than adults — requiring more infusions, which increases the overall exposure.

How to Monitor for Side Effects at Home

Keep a bleed diary noting how often you bleed and whether your NovoEight dose effectively stops each bleed

Attend all scheduled blood monitoring appointments at your HTC

Carry a medical ID card or wear a medical alert bracelet noting your hemophilia A diagnosis and current treatment

Report any new or unusual symptoms to your HTC promptly

Want to learn about drug interactions with NovoEight? Read: NovoEight Drug Interactions: What to Avoid and What to Tell Your Doctor.

If side effects prompt a prescription change and you need help finding an alternative medication in stock, medfinder can check pharmacies near you.