[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [PDE4 inhibitors](https://durgical.com/en/pharmacology/classes/pde4-inhibitors/) › Apremilast # Apremilast ## PDE4 inhibitors? PDE4 inhibitors An oral PDE4 inhibitor that calms immune cells, used in psoriatic arthritis, plaque psoriasis and the mouth ulcers of Behçet disease. Updated Nov 1, 2026 ## Quick facts **Group** [PDE4 inhibitors](https://durgical.com/en/pharmacology/classes/pde4-inhibitors/) **Target** Phosphodiesterase 4 (cAMP-specific) **Used for** Active psoriatic arthritis · Plaque psoriasis **Key effects** Diarrhoea and nausea · Headache **Monitor** Weight · Mood · Diarrhoea **ATC** L04AA32 No doses: the clinician sets them by the current guideline. On this page - The basics Mechanism of action - Indications - Adverse effects - Pharmacokinetics - Memory aid - Safety Contraindications - Key interactions - What is monitored - Administration and safety - Pregnancy and breastfeeding - Nursing care - Study Test yourself - Connections Connections ## Mechanism of action ✂**Phosphodiesterase 4 (cAMP-specific)**Apremilast ⓘ The figure shows apremilast in the catalytic site of human PDE4D (crystal structure). **Target in 3D:** Phosphodiesterase 4 (cAMP-specific). PDB structure 7CBQ (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/7CBQ) · Drag to rotate · pinch to zoom Apremilast is a small-molecule inhibitor of phosphodiesterase 4, the main enzyme that breaks down cyclic AMP in immune cells. Higher intracellular cAMP lowers the expression of pro-inflammatory cytokines such as TNF, interferon-gamma, IL-17 and IL-23. This damps the immune pathway that drives psoriasis and psoriatic arthritis. Exactly how this produces the clinical effect is not fully defined. - Apremilast blocks PDE4 inside immune cells - Cyclic AMP is no longer broken down and rises - Pro-inflammatory cytokines (TNF, IL-17, IL-23) fall - Skin plaques, joint inflammation and oral ulcers improve ## Indications - Active psoriatic arthritis [Psoriatic arthritis →](https://durgical.com/en/conditions/psoriatic-arthritis/) - Plaque psoriasis [Psoriasis →](https://durgical.com/en/conditions/psoriasis/) - Oral ulcers of Behçet disease [Behçet disease →](https://durgical.com/en/conditions/behcet-disease/) ## Adverse effects ### Common - Diarrhoea and nausea (most common) - Headache - Abdominal pain and vomiting - Upper respiratory infections, sore throat and nasal congestion ### Serious (rare, important) - Severe diarrhoea, nausea and vomiting with dehydration, especially in older adults - Depression, mood changes and suicidal thoughts - Weight loss - Hypersensitivity, including angioedema and anaphylaxis ## Contraindications - Hypersensitivity to apremilast - Caution with a history of depression or suicidal thoughts - Caution in older adults prone to dehydration or low blood pressure ## Key interactions **St John's wort and other strong enzyme inducers** May lower apremilast levels and its effect ## What is monitored - Weight, regularly - Mood, depression and suicidal thoughts - Diarrhoea, vomiting and hydration - Kidney disease, noted before starting ## Administration and safety - Oral tablets swallowed whole, not split, chewed or crushed - The dose is built up gradually over the first days to lessen stomach upset ## Pregnancy and breastfeeding Human data are very limited; animal studies suggested a possible higher risk of fetal loss, so the potential risk is explained. ## Nursing care - Ask about depression or suicidal thoughts before starting and at each visit - Weigh the patient regularly - Teach to report severe diarrhoea or vomiting - Review the medicine list and supplements, including St John's wort ## Pharmacokinetics **Absorption** Oral tablet, with or without food ## Memory aid APREmilast: A PDE4 Reducer of Eruptions; watch the 3 Ds: Diarrhoea, Depression, Dropping weight. ## Test yourself Think of the answer, then tap the question to see it. ## Which enzyme does apremilast inhibit, and which messenger rises? Phosphodiesterase 4; cyclic AMP rises. ## What are three indications of apremilast? Psoriatic arthritis, plaque psoriasis and the oral ulcers of Behçet disease. ## Which psychiatric adverse effect is checked during apremilast treatment? Depression and suicidal thoughts. [Add to my cards (3)](https://durgical.app/estudiar/?add=/en/pharmacology/apremilast/) [More Pharmacology questions →](https://durgical.com/en/practice/?f=pharmacology) ## Connections ## Related drugs 2 - [Roflumilast](https://durgical.com/en/pharmacology/roflumilast/) - [Methotrexate](https://durgical.com/en/pharmacology/methotrexate/) ## Related conditions 3 - [Psoriatic arthritis](https://durgical.com/en/conditions/psoriatic-arthritis/) - [Psoriasis](https://durgical.com/en/conditions/psoriasis/) - [Behçet disease](https://durgical.com/en/conditions/behcet-disease/) [← Back to the class: PDE4 inhibitors](https://durgical.com/en/pharmacology/classes/pde4-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: [Apremilast: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a614022.html) (MedlinePlus (U.S. National Library of Medicine), 2026); [RCSB PDB - 7CBQ: Crystal structure of PDE4D catalytic domain in complex with Apremilast](https://www.rcsb.org/structure/7CBQ) (RCSB Protein Data Bank, 2021); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=L04AA32) (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. --- Source: https://durgical.com/en/pharmacology/apremilast/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/apremilast/