You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Budesonide and explain in detail?
Budesonide, sold under the brand name Pulmicort among others, is a medication of the corticosteroid type. It is available as an inhaler, nebulization solution, pill, nasal spray, and rectal forms. The inhaled form is used in the long-term management of asthma and chronic obstructive pulmonary disease (COPD). The nasal spray is used for allergic rhinitis and nasal polyps. The pills in a delayed release form and rectal forms may be used for inflammatory bowel disease including Crohns disease, ulcerative colitis, and microscopic colitis.Common side effects with the inhaled form include respiratory infections, cough, and headaches. Common side effects with the pills include feeling tired, vomiting, and joint pains. Serious side effects include an increased risk of infection, loss of bone strength, and cataracts. Long-term use of the pill form may cause adrenal insufficiency. Stopping the pills suddenly following long-term use may therefore be dangerous. The inhaled form is generally safe in pregnancy. Budesonide chiefly acts as a glucocorticoid.Budesonide was initially patented in 1973. Commercial use as an asthma medication began in 1981. It is on the World Health Organizations List of Essential Medicines. Some forms are available as a generic medication. In 2019, generic budesonide was listed as involved in Tevas price fixing scheme in the United States. In 2019, it was the 201st most commonly prescribed medication in the United States, with more than 2 million prescriptions.

Medical uses
Asthma
Budesonide is given by metered-dose inhaler or nebulizer for maintenance and prophylactic treatment of asthma, including patients who require oral corticosteroids and those who may benefit from a systemic dose reduction.

Inflammatory bowel disease
Formulations of delayed-release budesonide are an effective treatment for mild-to-moderately active Crohns disease involving the ileum and/or ascending colon.  A Cochrane review found evidence for up to three months (but not longer) of maintenance of remission in Crohns disease.Budesonide assists in the induction of remission in people with active ulcerative colitis.Budesonide is highly effective and recommended as the drug of choice in microscopic colitis, for induction and maintenance of remission, and for both the lymphocytic colitis and collagenous colitis forms.

Allergic rhinitis
Budesonide in the form of nasal sprays is a treatment for allergic rhinitis.

Eosinophilic esophagitis
Topical budesonide has considerable effects in eosinophilic esophagitis. For this use, it is formulated as a tablet that disperses in the mouth, and sold under the trade name Jorveza.

Bergers disease
Budesonide (Tarpeyo) is indicated to reduce proteinuria (increased protein levels in the urine) in adults with primary immunoglobulin A (IgA) nephropathy (Bergers disease) at risk of rapid disease progression.

Side effects
Nasal budesonide inhalers have been associated with a number of side effects.  These include nose irritation or burning, bleeding or sores in the nose, lightheadedness, upset stomach, cough, hoarseness, dry mouth, rash, sore throat, bad taste in mouth, change in mucus, and blurred vision.  Other symptoms which should be reported immediately include difficulty in breathing, swelling of the face, white patches in the throat, mouth, or nose, irregular menstrual periods, severe acne, and on rare occasions, behavioral changes (mostly affecting children)

Contraindications
Budesonide is contraindicated as a primary treatment of status asthmaticus or other acute episode of asthma where intensive measures are required.  It is also contraindicated for patients who have hypersensitivity to budesonide.

Interactions
Those taking tablets or capsules orally should avoid grapefruit and grapefruit juice and echinacea.: 160 
Grapefruit juice may double bioavailability of oral budesonide.
Echinacea diminishes bioavailability.Also, high-fat meals delay absorption but do not impede absorption.

Pharmacology
Budesonide is an agonist of glucocorticoid receptors. Among its effects are:

Controls the rate of protein synthesis.
Depresses the migration of polymorphonuclear leukocytes and fibroblasts.
Reverses capillary permeability and lysosomal stabilization at the cellular level to prevent or control inflammation.
Has a potent glucocorticoid activity and weak mineralocorticoid activity.

Pharmacokinetics
Onset of action: Nebulization: 2–8 days; Inhalation: 24 hours; Nasal: 10 hours
Peak effect: Nebulization: 4–6 weeks; Inhalation: 1–2 weeks
Distribution: 2.2-3.9 L/kg
Protein binding: 85% to 90%
Metabolism: Hepatic via CYP3A4 to two metabolites: 16 alpha-hydroxyprednisolone and 6 beta-hydroxybudesonide; minor activity
Budesonide is extensively metabolized in first pass, resulting in a low bioavailability and systemic effects
Bioavailability: Capsule: 9% to 21%; Nebulization: 6%; Inhalation: 6% to 13%
Half-life elimination: 2–3.6 hours
Time to peak: Capsule: 0.5–10 hours (variable in Crohns disease); Nebulization: 10–30 minutes; Inhalation: 1–2 hours; Tablet: 7.4-19.2 hours
Excretion: urine (60%) and feces as metabolites.

Chemistry
Budesonide, also known as 11β,21-dihydroxy-16α,17α-(butylidenebis(oxy))pregna-1,4-diene-3,20-dione, is a synthetic pregnane steroid and non-halogenated cyclic ketal corticosteroid. It is the C16α hydroxyl, C16α,17α cyclic ketal with butyraldehyde derivative of prednisolone (11β,17α,21-trihydroxypregna-1,4-diene-3,20-dione).

Stereoisomerism
Society and culture
Legal status
On 19 May 2022, the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) adopted a positive opinion, recommending the granting of a conditional marketing authorization for the medicinal product Kinpeygo, intended for the treatment of primary immunoglobulin A nephropathy. The applicant for this medicinal product is Calliditas Therapeutics AB