M Toronto Myositis Centreat St. Michael's Hospital
← All medications Medication guide

Upadacitinib

Rinvoq · say “oo-pa-da-SIT-in-ib”
JAK inhibitor
iUsed in myositis based on specialist experience and evidence, not a formal Canadian myositis approval.
i
Screened before you start.

You are checked for tuberculosis and shingles risk before starting, and your cholesterol and blood counts are monitored while you take it.

Print this guide ↗
What it is

A once-daily targeted pill.

Upadacitinib belongs to a class of medications called JAK inhibitors. It works by blocking specific enzymes (Janus kinases) inside immune cells that drive the inflammation behind joint and muscle disease. It is a small once-daily tablet taken by mouth, rather than an injection, and at the Centre it may be used in inflammatory arthritis and in selected autoimmune muscle disease where other treatments have not been enough.

How to take it
  • Take one 15 mg tablet once daily, with or without food, at about the same time each day.
  • Swallow the tablet whole; do not crush, split, or chew it.
  • If you miss a dose, take it when you remember unless the next dose is near; never double up.
  • Store at room temperature and keep it in its original packaging until you use it.
What to expect
  • Some people improve within days to weeks; for others it takes 8 to 12 weeks.
  • Early signs include less morning stiffness, less swelling, and better energy.
  • Do not stop because it seems slow; the effect builds over time.
  • It works best taken consistently every day.
Benefits

How it helps you.

Reduces pain and swelling

In trials, significant reductions in tender and swollen joints, with many reaching low disease activity.

Less morning stiffness

Marked improvement in the duration and severity of morning stiffness.

Slows structural damage

Shown to slow the progression of joint damage on X-ray.

Convenient once-daily pill

No needles, no refrigeration, and no injection-site reactions.

Improves daily function

Better ability to dress, cook, walk, grip, and climb stairs.

Fast onset for many

Some people notice improvement within the first 1 to 2 weeks.

Risks & side effects

What you should know.

Your doctor prescribed this because the expected benefits outweigh the risks for your situation. Here is the honest, full picture.

Common side effects
Cold symptoms
Upper respiratory infections (runny nose, sore throat, cough) are most common. Call if they worsen or persist.
Nausea
Some mild nausea, especially early. Taking with food may help.
Higher cholesterol
Cholesterol can rise, monitored with blood tests and treated if needed.
Acne or breakouts
Some new acne, usually mild and manageable.
Serious but uncommon
Serious infections
It calms the immune system, so infections including tuberculosis can occur. You are screened for TB before starting.
Shingles
Risk is higher than with some other treatments. Vaccination before or early in treatment is strongly recommended.
Blood clots
Very rarely, clots in the legs or lungs. Report new leg swelling, calf or chest pain, or breathlessness immediately.
Bowel injury
Very rarely, a tear in the intestine, especially with diverticulitis. Report severe stomach pain. There is also a small increase in cardiovascular and cancer risk in people over 50, so screening continues.
Staying safe

Monitoring and precautions.

Regular monitoring
  • Blood tests for blood counts, liver function, and cholesterol.
  • TB screening (skin test and chest X-ray) before starting, since TB can reactivate.
  • Cholesterol is followed and treated if it rises.
  • Cancer screening stays current (skin checks, mammograms, colonoscopies) as directed.
Daily precautions
  • Get the shingles vaccine before or soon after starting, since shingles risk is higher.
  • Avoid live vaccines. Flu and COVID vaccines are safe.
  • Do not smoke, since smoking adds to cardiovascular and cancer risk with JAK inhibitors.
  • Practice food safety and use sun protection, and report new or changing skin spots.
  • Tell your doctor about any new medication, since some interact with upadacitinib.
When to call your doctor

Contact the clinic if you notice:

Fever or signs of infection
Any fever, chills, cough, body aches, or painful urination that needs prompt treatment.
Shingles symptoms
A painful, blistering rash, often on one side of the body or face. Report promptly.
Breathlessness or leg swelling
New swelling in one leg, sudden chest pain, or trouble breathing may signal a clot.
Severe or persistent stomach pain
Rarely a sign of a bowel injury, especially with diverticulitis. Report it.
Before any new medication
Some drugs interact with upadacitinib. Check first, including antibiotics.
Planning pregnancy
It may harm an unborn baby. Talk to your doctor before planning a family.

Pregnancy & breastfeeding

Upadacitinib may harm an unborn baby. Do not take it if you are pregnant or planning to become pregnant, and use effective contraception while on it. Do not breastfeed while taking it. Talk with your doctor before planning a family.

!

This guide is for education, not medical advice. Myositis treatment is individual, and many of these medications are used based on specialist experience and research rather than a single approval for myositis. Never start, stop, or change a medication without your own doctor. Your doses and choices are decided with your care team at the Centre.

Print this guide ↗