[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [JAK inhibitors](https://durgical.com/en/pharmacology/classes/jak-inhibitors/) › Upadacitinib

# Upadacitinib

## JAK inhibitors?

JAK inhibitors

## Pregnancy: contraindicated?

May harm the fetus: a pregnancy test is done before starting, and effective contraception is used during treatment and for at least 4 weeks after the last dose.

An oral JAK1 inhibitor for rheumatoid and psoriatic arthritis, atopic dermatitis, Crohn's disease, ulcerative colitis and spondyloarthritis.

Updated Nov 1, 2026

## Quick facts

**Group**
[JAK inhibitors](https://durgical.com/en/pharmacology/classes/jak-inhibitors/)

**Target**
Janus kinase 1 (JAK1)

**Used for**
Rheumatoid arthritis · Psoriatic arthritis

**Key effects**
Stuffy or runny nose · Nausea · Acne and folliculitis

**Monitor**
Latent tuberculosis · Cholesterol during treatment

**ATC**
L04AF03

No doses: the clinician sets them by the current guideline.

On this page

- The basics Mechanism of action
- Indications
- Adverse effects
- Pharmacokinetics
- Memory aid

- Clinical What the labels mean

- Safety Contraindications
- Key interactions
- What is monitored
- Administration and safety
- Pregnancy and breastfeeding
- Nursing care

- Study Test yourself

- Connections Connections

## Mechanism of action

✂**Janus kinase 1 (JAK1)**Upadacitinib

ⓘ The figure shows human JAK1 with abrocitinib, another JAK1 inhibitor that occupies the same ATP site; upadacitinib itself is not in this crystal.

**Target in 3D:** Janus kinase 1 (JAK1). PDB structure 6BBU (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/6BBU) · Drag to rotate · pinch to zoom

Upadacitinib is a Janus kinase inhibitor that acts mainly on JAK1. Many inflammatory cytokines signal through JAK–STAT: with JAK1 blocked, STAT proteins are not switched on and immune cells make fewer inflammatory signals, which calms joint, skin and bowel inflammation.

- Drug enters immune cells and blocks JAK1
- Cytokine receptors cannot switch on STAT proteins
- Fewer inflammatory genes are transcribed
- Joint, skin and bowel inflammation settles

## Indications

- Rheumatoid arthritis [Rheumatoid arthritis →](https://durgical.com/en/conditions/rheumatoid-arthritis/)
- Psoriatic arthritis [Psoriatic arthritis →](https://durgical.com/en/conditions/psoriatic-arthritis/)
- Atopic dermatitis [Atopic dermatitis →](https://durgical.com/en/conditions/atopic-dermatitis/)
- Ulcerative colitis [Ulcerative colitis →](https://durgical.com/en/conditions/ulcerative-colitis/)
- Crohn's disease [Crohn disease →](https://durgical.com/en/conditions/crohn-disease/)
- Ankylosing spondylitis and non-radiographic axial spondyloarthritis [Ankylosing spondylitis →](https://durgical.com/en/conditions/ankylosing-spondylitis/)
- Polyarticular juvenile idiopathic arthritis [Juvenile idiopathic arthritis →](https://durgical.com/en/conditions/juvenile-idiopathic-arthritis/)
- Giant cell arteritis [Giant cell arteritis →](https://durgical.com/en/conditions/giant-cell-arteritis/)

## Adverse effects

### Common

- Stuffy or runny nose
- Nausea
- Acne and folliculitis
- Headache
- Weight gain

### Serious (rare, important)

- Serious and opportunistic infections, including tuberculosis and hepatitis B or C reactivation
- Lymphoma and other cancers, such as skin and lung cancer
- Heart attack, stroke and blood clots in the legs or lungs
- Low blood counts and raised cholesterol

## Contraindications

- Hypersensitivity to upadacitinib
- Active serious infection, including active tuberculosis
- Pregnancy (may harm the fetus)

## Key interactions

**Strong CYP3A4 inhibitors (such as ketoconazole)**
Higher JAK-inhibitor levels and more adverse effects.

**Other strong immunosuppressants and biologics**
Combination is generally not recommended: added infection risk.

**Live vaccines**
Avoided during treatment; vaccines, including herpes zoster vaccine, are given before starting.

**Grapefruit and grapefruit juice**
Avoided during treatment.

## What is monitored

- Latent tuberculosis, hepatitis B and C, and pregnancy test before starting
- Cholesterol during treatment
- Blood counts and other laboratory tests ordered by the team
- Signs of infection, chest pain, stroke or blood clots

## Administration and safety

- Tablets are swallowed whole, not split, crushed or chewed.
- Whole tablets or pieces seen in the stool are reported to the team.
- Grapefruit is avoided while on treatment.
- Vaccines, including herpes zoster vaccine, are brought up to date before starting.

## Pregnancy and breastfeeding

May harm the fetus: a pregnancy test is done before starting, and effective contraception is used during treatment and for at least 4 weeks after the last dose.

## Nursing care

- Before starting, confirm tuberculosis, hepatitis and pregnancy tests and ask about smoking, heart disease, clots and cancer.
- Teach to report fever, cough or painful skin, and to seek urgent care for chest pain, sudden breathlessness, leg swelling or stroke signs.
- Teach to report sudden vision changes and severe abdominal pain with fever.
- Remind about effective contraception and no breastfeeding during treatment and for a short time after the last dose.

## Pharmacokinetics

**Absorption**
Oral, as an extended-release tablet or an oral solution

**Metabolism**
Strong CYP3A4 inhibitors raise its levels, as with most JAK inhibitors

## Memory aid

UPAdacitinib turns the JAK warning UP: Infection, Cancer, Heart attack and stroke, Clots (I-C-H-C).

## Test yourself

Think of the answer, then tap the question to see it.

## Which Janus kinase does upadacitinib mainly block?

JAK1.

## What four groups of risks are in the boxed warning for oral JAK inhibitors such as upadacitinib?

Serious infections, cancers (including lymphoma), major heart events and stroke, and blood clots.

## Which food is avoided during upadacitinib treatment?

Grapefruit and grapefruit juice.

[Add to my cards (3)](https://durgical.app/estudiar/?add=/en/pharmacology/upadacitinib/)

[More Pharmacology questions →](https://durgical.com/en/practice/?f=pharmacology)

## What the labels mean

**Pregnancy: contraindicated**
May harm the fetus: a pregnancy test is done before starting, and effective contraception is used during treatment and for at least 4 weeks after the last dose.

## Connections

## Related drugs 3

- [Tofacitinib](https://durgical.com/en/pharmacology/tofacitinib/)
- [Baricitinib](https://durgical.com/en/pharmacology/baricitinib/)
- [Abrocitinib](https://durgical.com/en/pharmacology/abrocitinib/)

## Related conditions 8

- [Rheumatoid arthritis](https://durgical.com/en/conditions/rheumatoid-arthritis/)
- [Psoriatic arthritis](https://durgical.com/en/conditions/psoriatic-arthritis/)
- [Atopic dermatitis](https://durgical.com/en/conditions/atopic-dermatitis/)
- [Ulcerative colitis](https://durgical.com/en/conditions/ulcerative-colitis/)
- [Crohn disease](https://durgical.com/en/conditions/crohn-disease/)
- [Ankylosing spondylitis](https://durgical.com/en/conditions/ankylosing-spondylitis/)
- [Juvenile idiopathic arthritis](https://durgical.com/en/conditions/juvenile-idiopathic-arthritis/)
- [Giant cell arteritis](https://durgical.com/en/conditions/giant-cell-arteritis/)

[← Back to the class: JAK inhibitors](https://durgical.com/en/pharmacology/classes/jak-inhibitors/)

Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: [Upadacitinib: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a619051.html) (MedlinePlus (U.S. National Library of Medicine), 2026); [RCSB PDB - 6BBU: Crystal Structure of JAK1 in complex with compound 25](https://www.rcsb.org/structure/6BBU) (RCSB Protein Data Bank, 2018); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=L04AF03) (WHO Collaborating Centre for Drug Statistics Methodology, 2026).

## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake

Representative model, for educational purposes only.

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License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/upadacitinib/