As a disease-modifying anti-rheumatic drug (DMARD), methotrexate is a cornerstone treatment for various autoimmune conditions, including rheumatoid arthritis, psoriatic arthritis, and severe psoriasis. It works by modulating the immune system to reduce inflammation, which can effectively manage symptoms and slow disease progression. However, this immune-modulating effect means patients may have a reduced ability to fight infections. This creates a critical consideration for what to do when you feel unwell, a decision encapsulated by the important "sick day" rule.
The Critical Link Between Methotrexate and Your Immune System
Methotrexate's therapeutic effects stem from its ability to suppress certain immune system activities. While beneficial for controlling autoimmune diseases, this suppression also weakens the body's natural defenses against pathogens. As a result, patients taking methotrexate are at a higher risk of developing infections and experiencing more severe complications from otherwise common illnesses. This risk, though modest for the low doses used in rheumatology, is the primary reason for caution when illness strikes.
The "Sick Day" Rule: Pausing Your Weekly Dose
The general recommendation for anyone taking low-dose methotrexate who falls ill is to temporarily stop taking their medication. This is not a decision to be made lightly, and it should always be accompanied by a call to your rheumatology specialist or GP. However, stopping the dose is a crucial safety measure to prevent complications.
Reasons to pause your weekly methotrexate dose include:
- Fever: A raised temperature is a common sign of infection, which can be a serious concern for immunocompromised individuals.
- Signs of Infection: This includes chills, severe sore throat, or a persistent cough. In rare cases, more serious opportunistic infections can occur.
- Vomiting and Diarrhea: Severe or persistent gastrointestinal symptoms can lead to dehydration. Dehydration can impair kidney function, which is necessary for the body to properly clear methotrexate. This can lead to a buildup of the drug to toxic levels.
- Before Surgery: It is standard practice to temporarily stop methotrexate before a surgical procedure to minimize the risk of infection and allow for proper wound healing. Your surgeon and rheumatologist will provide specific guidance on timing.
- Contact with Contagious Illnesses: If you have been exposed to a severe, contagious illness like chickenpox or shingles, contact your doctor immediately, as methotrexate can make these infections very serious.
Signs of Infection vs. Methotrexate Toxicity
One of the most difficult challenges for patients is distinguishing symptoms of a new infection from potential side effects or toxicity of the drug itself. Fever, for instance, can be a sign of both.
- Signs of infection may include fever, chills, a productive cough, and sore throat.
- Signs of methotrexate toxicity can include fever, mouth sores, fatigue, nausea, unexplained bruising, or a serious skin rash.
Because these signs can overlap, it is absolutely critical to contact a healthcare professional immediately. Do not attempt to guess the cause of your symptoms, and do not self-treat. Only a doctor can evaluate your condition and determine the appropriate steps.
What to Do If You've Already Taken Your Dose
If you have already taken your weekly dose and then become unwell, do not take another dose. Instead, monitor your symptoms and contact your doctor for advice, especially if your symptoms are severe or concerning. If you vomit within a few hours of taking your dose, you may be instructed to take another dose or wait until the following week, but this decision must come from a doctor.
The Process of Restarting Methotrexate
Do not resume your medication without clearance from your doctor. Generally, you should wait until you have fully recovered from the infection, all symptoms have resolved, and you have completed any course of antibiotics. Your doctor will ensure that resuming treatment is safe and will provide a specific timeline. While there is no withdrawal syndrome associated with stopping methotrexate abruptly, stopping for longer periods (four weeks or more) can increase the risk of a disease flare. For short, temporary pauses due to illness, this risk is minimal, but it is a balance that must be managed by your medical team.
Comparing Illness Scenarios with Methotrexate
Not all illnesses require the same approach when it comes to pausing medication. The decision depends on the severity and type of infection. Consult with your healthcare provider for an individualized plan.
| Scenario | Action to Take | Typical Duration of Pause |
|---|---|---|
| Mild cold (no fever) | Contact your doctor. Some may advise continuing if symptoms are very mild. | May not need a pause; dependent on doctor's advice. |
| Influenza, COVID-19, or High Fever | Hold your dose immediately. Contact your doctor immediately. | Until fully recovered and cleared by a doctor; often 1-2 weeks or more. |
| Stomach Bug (severe vomiting/diarrhea) | Hold your dose. Contact your doctor due to dehydration risk. | Until symptoms resolve and cleared by a doctor. |
| Upcoming Minor Surgery (e.g., dental) | Discuss with your doctor and surgeon. | Typically pause one week before and resume when wounds are healed. |
| Severe Infection (e.g., pneumonia) | Stop immediately. Seek urgent medical care. | As guided by the doctor managing the infection and your rheumatologist. |
Your Action Plan: What to Discuss with Your Doctor
When you call your healthcare team to report feeling unwell, be prepared to provide the following information:
- Your methotrexate dose and the date you last took it.
- A clear description of your symptoms, including your temperature.
- Whether you have been in contact with anyone with a known infectious disease.
- The name and dose of any antibiotics or other medications you are taking.
Conclusion
The simple answer to whether you should you take methotrexate if you're unwell is no, you should not, without explicit instruction from your healthcare provider. The immunosuppressive nature of methotrexate requires a cautious approach during any illness, especially one involving fever or symptoms of infection. Pausing the medication is a critical safety measure to protect your body from harm. The most important action is to communicate with your medical team. They will guide you through the process of safely holding your dose, managing your illness, and determining the appropriate time to resume your treatment. For more comprehensive information on managing your condition, the Versus Arthritis website offers reliable patient resources.
