Corticosteroids Overview

Corticosteroids

• Hormones produced by the adrenal cortex.
• Affect almost all body organs.
• Maintain homeostasis when secreted normally.
• Disease results from inadequate or excessive secretion.
• Exogenous corticosteroids: Prednisone is a prototype.
• Other drugs include: beclomethasone, betamethasone, budesonide, cortisone, dexamethasone, flunisolide, fluticasone, hydrocortisone, methylprednisolone, prednisolone, triamcinolone.
• Action: bind drug receptors on target cells, increase or decrease protein synthesis.
• Result: decreased inflammatory response (less edema), decreased chemicals causing dilation and tissue irritation, immunosuppression, inhibition of phagocytosis and tissue repair.
• Uses: control symptoms (do not cure disease processes).
  • Allergic or hypersensitivity disorders
  • Collagen disorders (Lupus)
  • Dermatologic disorders (dermatitis)
  • Endocrine disorders (adrenocortical insufficiency)
  • Gastrointestinal disorders (ulcerative colitis & Crohn's)
  • Hematologic disorders (idiopathic thrombocytopenic purpura)
  • Hepatic disorders with edema
  • Neoplastic disease (leukemia, Hodgkin's lymphoma)
  • Neurologic conditions (cerebral edema, spinal cord injury, nausea & vomiting)
  • Ophthalmic disorders (optic neuritis)

Other Drugs for Glaucoma

• Prostaglandin analogs: Most widely prescribed glaucoma drugs.
  • Prototype: bimatoprost (Latisse, Lumigan).
  • Used for open-angle glaucoma and ocular hypertension.
  • Action: ocular hypotension.

Beta-adrenergic blockers

• Prototype: timolol maleate.
• Used for chronic open-angle glaucoma, aphakic glaucoma, secondary glaucoma, and for ocular hypertension.
• Action: blocks beta1 & beta2 to reduce intraocular pressure.

Alpha2-adrenergic agonists

• Prototype: brimonidine.
• Used for open-angle glaucoma and ocular hypertension.
• Action: reduces aqueous humor production.
• Use: lowers intraocular pressure.

Cholinergic drugs

• Prototype: pilocarpine.
• Used for chronic simple glaucoma, chronic and acute angle-closure glaucoma.
• Action: stimulates cholinergic receptors inside the eye.
• Use: reduce accommodation to lower intraocular pressure.
• Adverse effects: burning, conjunctival vascular congestion, headache, cardiopulmonary (hypertension, tachycardia, bronchial spasm), GI (nausea and vomiting, diarrhea)

Carbonic anhydrase inhibitors

• Prototype: acetazolamide (oral), brinzolamide, dorzolamide.
• Used for open-angle and secondary glaucoma.
• Action: inhibits carbonic anhydrase, reducing the rate of aqueous humor formation and lowering intraocular pressure.
• Use: open-angle glaucoma.
• Adverse effects: Stevens-Johnson syndrome, agranulocytosis, anemia, metabolic acidosis

Osmotic Drugs

• Prototype: mannitol.
• Temporarily reduces IOP (intraocular pressure) in acute glaucoma attacks and before surgery.
• Used for corneal ulcers and bacterial conjunctivitis.
• Prototype: fluoroquinolone (ciprofloxacin).

Antiviral drugs

• Prototype: trifluridine.
• Used for primary keratoconjunctivitis and recurrent epithelial keratitis.

Antifungal drugs

• Prototype: natamycin.
• Used for fungal blepharitis, conjunctivitis, and keratitis.

Antiallergic drugs

• Prototype: cromolyn sodium.
• Used for vernal keratitis, vernal conjunctivitis, and vernal keratoconjunctivitis.
• Decreases or stops the body's reaction to an allergen.

H1-receptor antagonists

• Prototype: emedastine difumarate.
• Treatment for ocular pruritus.
• Adverse effect: headache in 11% of cases

Corticosteroids

• Prototype: dexamethasone.
• Decreases inflammation after cataract extraction and corneal refractive surgery.
• Used with anti-inflammatory drugs.

Anti-inflammatory drugs

• Prototype: diclofenac.
• Used for reducing inflammation after cataract extraction or corneal refractive surgery.

Immunosuppressants

• Prototype: cyclosporine emulsion.
• Used to increase tear production.

General Guidelines for Ophthalmic Drug Therapy

• Topical administration is common.
• Effective administration essential for therapeutic effects.
• Systemic absorption is decreased by occluding the lacrimal duct.
• Multiple drops require intervals of 5 to 10 minutes.

Otitis Externa (Swimmer's ear)

• Inflammation of the external ear canal.
• Caused by moisture, allergies, or trauma.
• Topical agents are common for high drug concentration in the infected tissue.
• Systemic medications may be required for deep tissue infections, or if immunocompromised.

Otitis Media

• More common in children.
• Bacteria or pathogens enter the middle ear from the nasopharynx or from the tympanic membrane.
• Oral amoxicillin is the typical treatment.

Anti-infective, antiseptic, glucocorticoid, and acidifying agents.

• Combination drug prototype: neomycin - polymyxin B-hydrocortisone.
• Treats acute external otitis media.
• Action: each drug in the combined formula has its own mechanism to inhibit bacterial growth or limit the inflammatory processes.
• Fluoroquinolone prototype: ciprofloxacin, used for necrotizing otitis externa.
• Action: inhibits bacterial growth.

Antibacterial agent

• Prototype: amoxicillin (a penicillin).
• Inhibits cell wall synthesis in sensitive organisms.
• Result: cell death.
• For acute otitis media.
• Adverse effects: include hypersensitivity to drugs, GI effects, and development of superinfections.

Guidelines for Dermatologic Drug Therapy

• Drug selection depends on the condition and factors (acuity, severity, location, area, and method of application).
• Agent choice depends on patient response.

Antimicrobials (topical)

• Includes:
  • Bacitracin, benzoyl peroxide, clindamycin, erythromycin, metronidazole, mupirocin, silver sulfadiazine
  • Butenafine, ciclopirox, clotrimazole, ketoconazole, nystatin
  • Acyclovir

Antiseptics

• Kill or inhibit bacteria, viruses, or fungi.
• Prevent infection.

Corticosteroids

• Topical use decreases inflammation.

Emollients and moisturizers

• Used as lubricants.

Enzymes

• Trypsin
• Debrides wounds

Immunosuppressants

• Pimecrolimus and tacrolimus (both topical).
• Treatment of inflammatory skin conditions (e.g., psoriasis).

Keratolytics

• Used for treating keratin-containing skin conditions.

Retinoids (isotretinoin)

• Suppresses sebum production.
• Used for acne treatment.
• Adverse effects: strictly regulated by FDA due to reproductive and psychiatric risks.
• Common side effects: dryness, arthralgia, hyperlipidemia.
• Contraindication: pregnancy category X (black box warning).

Sunscreens

• Used to protect from UV exposure.

Hyperthyroidism

• Excessive thyroid hormone secretion.
• Causes: Problems with thyroid, or elevated TSH (thyroid stimulating hormone).
• Graves' disease is a common cause.

Hypothyroidism

• Inadequate production of thyroid hormones
• Causes: Thyroiditis or decreased TSH/TRH.

Antidiuretic hormone (ADH)

• Resorbs water into tubules; regulates urine volume.

Diabetes Insipidus

• Associated with posterior pituitary dysfunction.
• Characterized by large urine output.
• Lack of ADH inhibits the kidney's ability to reabsorb water.

Calcium and Bone Metabolism

• Three main hormones are involved:
  • Parathyroid hormone (PTH)
  • Calcitonin
  • Vitamin D
• Hypocalcemia and hypercalcemia are significant.
• Hypocalcemia is characterized by increased calcium resorption and bone loss; conditions include weaken bones and fractures leading to pain and disability.

Vitamin D

• Increases calcium and phosphorus absorption in the GI tract.
• Adverse effect: hypercalcemia.

Bisphosphonates

• Inhibits calcium resorption from bone.
• Prototype: alendronate (Fosamax) - Treats osteoporosis in post-menopausal women and men.
• Adverse effects are limited when taken as ordered.
• Treatment is required upon waking with 6-8 ounces of water, 30 minutes before eating or drinking. Remain upright for at least 30 minutes following administration.

Calcitonin

• Used for hypercalcemia, Paget's disease, and postmenopausal osteoporosis.

Myasthenia Gravis

• Neuromuscular condition characterized by disruptions in neurologic and autoimmune processes

Acetylcholinesterase inhibitors

• Prototype: neostigmine (IV use only) - used as an antidote for certain surgical treatments (tubocurarine, skeletal muscle relaxants).
• More commonly prescribed: pyridostigmine.
• Use: treatment and diagnosis of Myasthenia Gravis.

Alzheimer's Disease

• Most common form of dementia.
• Deficiency in cholinergic function.
• Neurologic conditions including neuritic plaques and neurofibrillary tangles.
• Symptoms may include difficulty remembering new information; disorientation and mood changes; loss of memory, behavior problems and difficulty speaking or swallowing.

Cholinesterase inhibitors

• Prototype: donepezil (Aricept); rivastigmine (Exelon)
• Action: increases acetylcholine in the brain.
• Used to slow neuronal degradation and improves memory.
• Adverse effects include: headache, dizziness, depression, vertigo, and GI disturbances (depending on the individual).

N-methyl-d-aspartate receptor antagonist

• Prototype: memantine (Namenda).
• Action: antagonizes NMDA receptor.
• Slows progression of moderate to severe Alzheimer's disease.
• Contraindication: renal failure.

Urinary Retention

• Affects the bladder, and is related to general anesthesia, diabetes, prostate enlargement, neurologic disorders (sclerosis, Parkinson's), and surgery.

Cholinergic agonist

• Prototype: bethanechol chloride (Urecholine).
• Action: increases urinary and Gl muscle tone.
• Use: acute post-operative urinary retention.
• Adverse effects: heart block, orthostatic hypotension, GI symptoms, and urinary urgency.
• Contraindication: bladder neck surgery.

Dopamine receptor agonists

• Prototype: levodopa-carbidopa (Sinemet), amantadine, pramipexole, ropinirole.
• Action: increases dopamine in the synapse.
• Use: Parkinson's disease and Restless Leg Syndrome.
• Adverse effects: headache, anxiety, hallucinations, drowsiness, cardiac effects.
• Contraindications: individuals with glaucoma, severe hypertension, MAO inhibitors, severe cardiovascular, pulmonary, renal, hepatic or endocrine disorders.

Catechol-O-Methyltransferase Inhibitors

• Prototype: tolcapone.
• Increases dopamine levels in the brain.

Anticholinergics

• Examples: Atropine, benztropine mesylate (Cogentin), scopolamine, and ipratropium bromide.
• Actions: antispasmodic and antisecretory action.
• Used to reduce secondary symptoms of parkinsonism.
• Adverse effects: anticholinergic effects (depending on the individual).
• Contraindications: glaucoma, GI & GU obstruction, and cardiovascular disorders.

Gastrointestinal anticholinergics

Dicyclomine hydrochloride (Bentyl)

• Action: GI smooth muscle relaxant.
• Treatment of irritable bowel syndromes.
• Adverse effects: anticholinergic effects.
• Contraindication: glaucoma, asthma, and GI/GU obstruction.

Urinary antispasmodics

• Prototype: oxybutynin (Ditropan).
• Relaxes smooth muscles.
• Use: bladder instability.
• Adverse effects: anticholinergic effects.
• Contraindications: ulcers and obstructions.

Explore the essential functions and mechanisms of corticosteroids produced by the adrenal cortex. This quiz covers their role in maintaining homeostasis, their therapeutic uses, and examples of various corticosteroid medications. Test your knowledge on their effects on inflammatory responses and immunosuppression!