You won’t find “sensitive teeth” in the list of side effects for methotrexate (Rheumatrex), a common treatment for lupus. However, several MyLupusTeam members have described experiencing sudden, sharp tooth pain while taking this drug.

“I’ve been taking methotrexate for a few months now, and my molars have been hurting,” shared one member. “I’ve changed my brushing routine, toothpaste, toothbrush, and nothing helps. I know methotrexate causes mouth issues like thrush, but I wasn’t sure about tooth pain.”

Keep reading to learn more about how methotrexate may cause tooth pain and sensitivity.

What Is Methotrexate?

Methotrexate is a disease-modifying antirheumatic drug (DMARD) and immunosuppressive medication. This medication can treat people with mild to moderate systemic lupus erythematosus — the most common form of the condition— as well as cutaneous lupus erythematosus, lupus affecting the skin. The medication can also help with joint pain and swelling (arthritis) associated with lupus.

Methotrexate can also be used to treat other diseases, such as rheumatoid arthritis, psoriasis, and certain forms of cancer. Most people take methotrexate once a week, usually by mouth, but it can also be injected into muscle.

Methotrexate works by decreasing immune system activity. It interferes with the way your body makes folic acid, a B vitamin that is an important building block for your cells. Without folic acid, cell growth slows down, especially in tissues that usually grow quickly, such as your immune system.

Methotrexate Side Effects

Your likelihood of developing side effects while taking methotrexate increases with a higher dose. If you are older or have kidney disease, you may be more likely to have more severe side effects.

Common side effects of methotrexate include:

• Nausea and upset stomach
• Oral ulcers (mouth sores)
• Sore gums
• Diarrhea
• Dizziness
• Tiredness
• Hair loss
• Decreased appetite
• Headache

Many side effects are related to the fact that methotrexate slows tissue growth. Your digestive tract has many fast-growing tissues, including the inner lining of your cheeks and lips — the buccal mucosa — so lesions (sores) can form in your mouth.

What Causes Sensitive Teeth?

Your teeth can become sensitive when the inner layer, called dentin, gets exposed. This can happen when the protective outer layer — the enamel — is worn down. Enamel wear and tear can occur for many reasons, including:

• Brushing too hard
• Grinding your teeth
• Consuming acidic food and drinks

You might also experience tooth sensitivity if your gums expose your teeth’s roots, which aren’t covered in enamel. Your roots might become exposed because of:

• Recessed gums
• Excessive brushing
• Periodontal (gum) disease
• Plaque buildup

Other common causes of sensitive teeth include having damaged or cracked teeth and undergoing dental procedures. Interestingly, tooth sensitivity may be worse between the ages of 25 and 30 years.

Common triggers of tooth sensitivity include:

• Cold or hot food or drinks
• Sour or acidic food or drinks
• Cold air
• Toothbrushing
• Over-the-counter (OTC) mouthwash containing acids

Triggers can differ for everyone. A MyLupusTeam member shared, “I have pain in my molars also. For several months, my upper teeth on one side were sensitive to heat but not cold.”

Can Methotrexate Affect Your Mouth?

Methotrexate most commonly affects your oral health by leading to mouth sores. Between 11 percent and 17 percent of people taking a low dose of methotrexate develop oral ulcers, usually under the tongue or on the hard palate (the bony part of the roof of your mouth) or gums. If you have a methotrexate-related sore on your gums, it could cause tooth sensitivity in that area.

One MyLupusTeam member taking methotrexate noted, “I also have experienced sensitivity with teeth and have had a lot of mouth ulcers.”

Because methotrexate suppresses your immune system, it may make you more susceptible to infections, such as oral thrush. This fungal infection can cause inflammation in your mouth and gums, leading to tooth pain and sensitivity.

Does Lupus Cause Sensitive Teeth?

People with lupus have a high risk of periodontal disease, which can cause gum recession and irritation that lead to tooth sensitivity.

Disorders involving the jaw joint — also called the temporomandibular joint (TMJ) — are common in people with lupus. TMJ disorders can develop from long-term teeth grinding and clenching, which can wear away enamel and cause tooth sensitivity.

Medications and conditions associated with lupus, such as Sjögren’s syndrome, can cause dry mouth from decreased saliva production. Dry mouth can increase the acid level in your mouth and damage tooth enamel.

A MyLupusTeam member who hasn’t taken methotrexate shared that they also experience tooth sensitivity: “I have these incidences with an upper and a bottom jaw tooth (always the same ones) that just hurt sometimes. It’s like they are even sensitive to touch. I know I’ve talked to other team members that have tooth pain due to lupus.”

Managing Sensitive Teeth and Oral Health While Taking Methotrexate

A key way to help prevent mouth sores is to take your medication exactly as directed by your doctor. Most cases of oral ulcers in people taking methotrexate occur because of either an error in dosing, which increases drug exposure, or an interaction with another drug.

Some OTC medications, such as ibuprofen (Motrin) and omeprazole (Prilosec), can interact with methotrexate and increase your risk of oral ulcers, as can certain antibiotics, such as ciprofloxacin. If you’re on methotrexate, it’s important not to take any OTC medicines or start a new prescription without first talking to your doctor or pharmacist.

Maintaining good overall oral health is also important. Regular dental checkups and cleanings can help stave off many problems that could cause tooth sensitivity.

If you experience sensitive teeth, you can try strategies such as these:

• Use a desensitizing toothpaste regularly.
• Brush gently with a soft-bristled toothbrush to help protect your gums and enamel.
• Avoid triggers of pain, such as hot, cold, or sour foods.
• Wear a mouth guard at night to keep you from grinding your teeth.

A MyLupusTeam member with tooth sensitivity shared this tip: “I usually just put some sensitive toothpaste on my teeth and leave it there.”

If you experience sensitive teeth or other side effects of methotrexate, seek medical advice from a health care professional. You can also talk to your doctor about taking a folate supplement to help with methotrexate side effects. They can help you find the best regimen to manage your lupus symptoms and minimize tooth sensitivity and other unwanted effects of treatment.

Talk With Others Who Understand

On MyLupusTeam — the social network for people with lupus and their loved ones — more than 223,000 members come together to ask questions, give advice, and share their stories with others who understand life with lupus.

Have you experienced tooth sensitivity while taking methotrexate? What strategies helped your symptoms? Share your experience in the comments below, or start a conversation by posting on your Activities page.