Anti-inflammatory Drugs and Their Mechanisms - Glucocorticoids

Anti-inflammatory drugs are pharmacological agents that decrease inflammation and are categorized primarily into:

Corticosteroids (glucocorticoids):
- Powerful anti-inflammatory agents such as cortisol and hydrocortisone.
- Act through genomic and non-genomic mechanisms to modulate the immune response.
Non-steroidal anti-inflammatory drugs (NSAIDs):
- Include non-selective COX inhibitors (e.g., ibuprofen) and selective COX-2 inhibitors (e.g., celecoxib).
- Reduce inflammation by inhibiting the production of prostanoids, key mediators in the inflammatory process.

The immune system is a complex network of cells, tissues, and organs responsible for defending the body against harmful pathogens.
Focus on inflammatory processes and the mediators involved in these responses through lectures and tutorials.

Classification and Mechanism of Action of Anti-inflammatory Drugs:
- Corticosteroids are potent drugs with glucocorticoid activity that significantly reduce inflammation.
- NSAIDs act by inhibiting COX enzymes, leading to decreased prostanoid synthesis.
Clinical Indications for Use:
- Utilized in managing conditions such as rheumatoid arthritis, osteoarthritis, asthma, and inflammatory bowel disease.
Side Effects and Safety Issues:
- Corticosteroids can cause side effects such as weight gain, hypertension, and increased infection risk.
- NSAIDs may lead to gastrointestinal complications and cardiovascular risks, necessitating careful patient monitoring.

Corticosteroids:
- Mimic adrenal hormones and are effective in managing acute inflammation.
NSAIDs:
- Broad category of medications that inhibit cyclooxygenase enzymes, including:
- Aspirin: Irreversibly inhibits COX-1 and COX-2, effective for pain relief.
- Ibuprofen: Popular OTC option with lower GI toxicity.
- Celecoxib: Selective COX-2 inhibitor, reducing gastrointestinal side effects compared to non-selective NSAIDs.

Steroid hormones derived from cholesterol, with cortisol as the most notable.
Synthetic glucocorticoids (like dexamethasone) offer enhanced potency and longer action.
Mechanism involves binding to glucocorticoid receptors (GCRs) that lead to biological effects relevant to inflammation control.

Intracellular Mechanism:
- Genomic Actions:
- Involving transactivation of genes that promote anti-inflammatory proteins and transrepression of genes that produce inflammatory mediators.
- Non-Genomic Actions:
- Modulation of enzyme-linked pathways that decrease arachidonic acid, diminishing pro-inflammatory mediators.

Target Sites for Action:
- Inflammatory Cells: Reduces accumulation and cytokine production (IL-1, TNF) leading to decreased inflammation.
- Chemical Mediators: Lower prostanoid production causes less vascular permeability and vasodilation.
- Blood Vessels: Induces vasoconstriction and reduces vessel permeability to minimize swelling.

Drugs and Route of Administration (RoA):
- Hydrocortisone (topical):
  - Indicated for skin inflammation (eczema, dermatitis).
  - Side effects include local irritation and skin thinning.
- Dexamethasone (oral/injection):
  - Used for rheumatoid arthritis, asthma/COPD, CNS swelling, and TB.
  - Side effects include oral thrush, bruising, and risk of osteoporosis.
- Budesonide (inhalation):
  - Effective for respiratory inflammation.
  - Side effects may involve local irritation and mood changes.

Strategies include:
- Use topical applications to minimize systemic effects, important for treating children.
- Select less potent steroids to reduce risks compared to stronger options.
- Limit duration of high-potency steroid use to decrease side effects.

The serious side effects of corticosteroid therapy require careful evaluation against their benefits.
In many instances, NSAIDs such as aspirin, ibuprofen, or newer COX-2 selective drugs like celecoxib may provide safer alternatives with lower side effect profiles.