Why Combining Prednisone and Tysabri Is Risky
Both prednisone and Tysabri (natalizumab) are potent medications that work by affecting the immune system, but in different ways that create a synergistic effect when combined. Prednisone is a corticosteroid that globally suppresses the immune system's activity to reduce inflammation. Tysabri is a monoclonal antibody that prevents specific immune cells from entering the central nervous system, also acting as an immunosuppressant. The combined immunosuppressive effect is the primary reason why simultaneous use carries a heightened risk of opportunistic infections.
The Increased Risk of Progressive Multifocal Leukoencephalopathy (PML)
One of the most serious risks is the potential for developing Progressive Multifocal Leukoencephalopathy (PML), a severe brain infection caused by the John Cunningham (JC) virus. While Tysabri alone carries a boxed warning from the FDA regarding PML risk, concurrent or recent use of other immunosuppressants, including corticosteroids like prednisone, can further increase this danger. The JC virus is common, but only causes problems in individuals with compromised immune systems. By suppressing the immune system from two different fronts, the combination of prednisone and Tysabri can create an environment where the JC virus is more likely to become active and cause PML.
Other Potential Infections
Beyond PML, the combination of these two drugs can make a patient more susceptible to a wide range of other infections. These can include herpes infections, respiratory infections, urinary tract infections, and infections that typically do not cause severe illness in people with healthy immune systems. The risk of developing these infections is particularly elevated in patients on chronic or high-dose corticosteroid therapy.
Medical Management of Prednisone and Tysabri
Due to the significant safety concerns, medical professionals follow specific protocols when a patient needs to be treated with both prednisone and Tysabri. The goal is to minimize immunosuppression and the associated risks while effectively managing the patient's underlying condition, such as Multiple Sclerosis (MS) or Crohn's Disease.
Tapering Off Chronic Steroids
For patients with Crohn's disease who are on chronic oral corticosteroids, official prescribing information mandates a specific tapering schedule. A doctor will begin to slowly reduce the prednisone dose as soon as the Tysabri therapy shows therapeutic benefit. If the patient cannot be successfully tapered off oral corticosteroids within six months of starting Tysabri, the Tysabri treatment should be discontinued. This strategy is designed to limit the duration of concurrent, high-risk immunosuppression.
Acute vs. Chronic Use
It is important to differentiate between chronic and short-term use. While long-term combined use is strongly discouraged, short, high-dose courses of corticosteroids are often used to treat MS relapses. In clinical trials for MS, concurrent treatment of relapses with short-course corticosteroids was associated with an increased rate of infection, but the increase was similar to placebo-treated patients who also received steroids. This suggests that short-term use during a flare might be managed differently, but careful consideration and monitoring by a physician are still paramount.
Comparison of Prednisone and Tysabri Use
| Feature | Prednisone (Corticosteroid) | Tysabri (Natalizumab) |
|---|---|---|
| Mechanism | General immunosuppressant and anti-inflammatory agent. | Selective immunosuppressant; blocks immune cells from crossing the blood-brain barrier. |
| Use in Flares | Commonly used for short-term, high-dose treatment of acute flares. | Long-term maintenance therapy for chronic conditions. |
| Risk of PML | Increased risk when combined with other immunosuppressants. | Carries a boxed warning for PML risk; risk increases over time. |
| Administration | Oral tablets or intravenous (IV) infusion. | Intravenous (IV) infusion administered every four weeks. |
| Co-Administration | Chronic use is typically tapered off before or shortly after starting Tysabri. | Concurrent use with other immunosuppressants is generally contraindicated. |
Monitoring and Precautions
For patients receiving Tysabri, especially those with prior immunosuppressant use, strict monitoring is essential. This includes regular check-ups and watching for symptoms of infection. If you have been treated with prednisone recently or are on a tapering schedule, your doctor will need to closely monitor your immune status.
Symptoms of PML to be aware of include:
- Changes in thinking, memory, and orientation
- Progressive weakness or clumsiness
- Changes in vision
- Speech and walking difficulties
Any of these new or worsening neurological symptoms warrant immediate medical attention. The Tysabri TOUCH prescribing program is in place to manage these risks and requires patient registration and regular monitoring. For more detailed information on Tysabri's safety profile, review the Tysabri Prescribing Information.
Conclusion
While a physician may prescribe a short course of prednisone to manage a disease flare, taking prednisone with Tysabri, particularly on a chronic basis, is generally avoided due to the compounded risk of serious infections. This is especially true for the rare but dangerous brain infection, PML. The standard medical practice is to taper and discontinue chronic corticosteroids before initiating Tysabri therapy. It is imperative that patients discuss their full medication history with their healthcare team and never alter their treatment plan without professional guidance. The decision to use these medications concurrently, even for a short time, must be made with a clear understanding of the risks and under strict medical supervision.
