Baricitinib is used to treat rheumatoid arthritis. It's a type of drug known as a Janus kinase JAK inhibitor. It works by blocking the action of Janus kinase enzymes, which are involved in the inflammation that causes the symptoms of rheumatoid arthritis.

Baricitinib can relieve the symptoms of pain, stiffness and swelling in your joints and slow the joint damage that rheumatoid arthritis can cause. Most people who benefit from this treatment will notice some improvement within the first 12 weeks of treatment.

Baricitinib is taken as a tablet once a day. In some circumstances, such as if you're over 75 or if you've had repeated infections, your doctor may decide to reduce the standard dose. 

If you take more than the recommended dose by mistake, contact your doctor straight away. If you miss a dose, carry on with the usual dose the next day – don't double it.

If you haven't noticed any improvement in your symptoms after six months, your doctor may decide to stop the baricitinib treatment.

Because it's a long-term treatment, it's important to keep taking baricitinib unless you have severe side effects, even if it doesn't seem to be working at first. You should still keep taking it even when your symptoms improve, to help keep your condition under control.