Module 4 - glucocorticoids Flashcards
How do glucocorticoids differ in their molecular mechanism of action from most drugs?
Glucocorticoids differ in two ways: their receptors are located inside the cell rather than on the cell surface, and they modulate the production of regulatory proteins rather than affecting signaling pathways.
What happens when glucocorticoids penetrate the cell membrane and bind with receptors in the cytoplasm?
When glucocorticoids bind with receptors in the cytoplasm, they convert the receptor from an inactive form to an active form.
What is the next step in the molecular mechanism of glucocorticoids after the receptor becomes active in the cytoplasm?
After becoming active in the cytoplasm, the receptor-steroid complex migrates to the cell nucleus.
What does the receptor-steroid complex do in the cell nucleus?
In the cell nucleus, the receptor-steroid complex binds to chromatin in DNA, which alters the activity of target genes.
In most cases, how do glucocorticoids affect the activity of target genes?
In most cases, glucocorticoids increase the activity of target genes, leading to increased transcription of messenger RNA molecules for specific regulatory proteins.
Are there situations where glucocorticoids suppress the activity of target genes, and if so, what is the outcome?
Yes, in some cases, glucocorticoids suppress the activity of the target gene, leading to decreased synthesis of certain regulatory proteins.
How do glucocorticoids differ in their molecular mechanism of action from most drugs?
Glucocorticoids differ in two ways: their receptors are located inside the cell rather than on the cell surface, and they modulate the production of regulatory proteins rather than affecting signaling pathways.
What happens when glucocorticoids penetrate the cell membrane and bind with receptors in the cytoplasm?
When glucocorticoids bind with receptors in the cytoplasm, they convert the receptor from an inactive form to an active form.
What is the next step in the molecular mechanism of glucocorticoids after the receptor becomes active in the cytoplasm?
After becoming active in the cytoplasm, the receptor-steroid complex migrates to the cell nucleus.
What are the pharmacologic effects of glucocorticoids when administered in high doses for nonendocrine disorders?
High doses of glucocorticoids produce anti-inflammatory and immunosuppressive effects that are not seen at physiologic doses.
Are there any physiologic effects associated with high-dose glucocorticoid administration?
Yes, in addition to their pharmacologic effects, high doses of glucocorticoids also produce the physiologic effects observed at low doses.
What are the metabolic effects of high-dose glucocorticoid therapy compared to physiologic doses?
High-dose glucocorticoid therapy intensifies metabolic effects, including elevated glucose levels, suppressed protein synthesis, and increased mobilization of fat deposits.
Do most glucocorticoids have significant mineralocorticoid activity?
No, most glucocorticoids have very little mineralocorticoid activity, which generally results in limited sodium retention and potassium loss.
Is sodium retention and potassium loss completely absent with high-dose glucocorticoid therapy?
No, although most glucocorticoids have minimal mineralocorticoid activity, sodium retention and potassium loss can still occur in some patients and may pose risks.
What effect does high-dose glucocorticoid therapy have on the intestinal absorption of calcium?
High-dose glucocorticoid therapy can inhibit the intestinal absorption of calcium, an effect not observed at physiologic doses.
What are the major clinical applications of glucocorticoids primarily related to?
The major clinical applications of glucocorticoids stem from their ability to suppress immune responses and inflammation.
What are the characteristic symptoms of inflammation, and what initiates them?
The characteristic symptoms of inflammation are pain, swelling, redness, and warmth, initiated by chemical mediators such as prostaglandins, histamine, and leukotrienes.
How do prostaglandins and histamine contribute to inflammation symptoms, particularly pain and swelling?
Prostaglandins and histamine promote inflammation symptoms by causing vasodilation and increasing capillary permeability. They contribute to pain, with histamine directly stimulating pain receptors, and prostaglandins sensitizing pain receptors.
How do neutrophils and macrophages intensify inflammation, and what damage can they cause?
Neutrophils and macrophages heighten inflammation by releasing lysosomal enzymes that cause tissue injury.
What role do lymphocytes play in amplifying inflammation, and how do they do it?
Lymphocytes, crucial elements of the immune system, amplify inflammation by causing direct cell injury and promoting antibody formation, which helps perpetuate the inflammatory response.
What are the mechanisms through which glucocorticoids interrupt the inflammatory process?
Glucocorticoids interrupt inflammation through multiple mechanisms, including the inhibition of chemical mediator synthesis, suppression of phagocyte infiltration, and reduction of lymphocyte proliferation.
How do the mechanisms by which glucocorticoids suppress inflammation compare to those of nonsteroidal anti-inflammatory drugs (NSAIDs)?
The mechanisms by which glucocorticoids suppress inflammation are more diverse than those of NSAIDs, which primarily inhibit prostaglandin production. Glucocorticoids act through multiple pathways, resulting in more potent anti-inflammatory effects.
For what purpose are glucocorticoids indicated in rheumatoid arthritis?
Glucocorticoids are indicated for adjunctive treatment of acute exacerbations of rheumatoid arthritis.
What is the primary effect of glucocorticoids in rheumatoid arthritis?
Glucocorticoids can reduce inflammation and pain but do not alter the course of the disease.
Why is prolonged systemic use of glucocorticoids in rheumatoid arthritis generally avoided?
Prolonged systemic use of glucocorticoids is avoided due to the risk of serious complications.
Under what circumstances may intra-articular injections of glucocorticoids be advantageous in rheumatoid arthritis?
Intra-articular injections may be advantageous when arthritis affects only a few joints.
What are the advantages of using local injections of glucocorticoids in rheumatoid arthritis?
Local injections can be highly effective and have less toxicity compared to systemic therapy.
What can be the result of intra-articular injections of glucocorticoids in terms of pain and joint mobility?
Intra-articular injections can lead to significant reductions in pain and inflammation and may prompt increased joint mobility.
What precaution should be given to patients who have received intra-articular glucocorticoid injections for rheumatoid arthritis?
Patients should be cautioned against excessive use of the treated joints, even if their symptoms have improved.
What concern is associated with the long-term use of glucocorticoids in children?
Long-term use of glucocorticoids in children can inhibit bone growth and potentially result in decreased stature.
How does glucocorticoid use during periods of increased bone growth in children affect the risk of osteoporosis?
Glucocorticoid use during periods of increased bone growth increases the risk of lifetime osteoporosis.
What are the patient care concerns regarding the use of glucocorticoids in pregnant women?
Inadequate studies in pregnant women.
Teratogenic and physiologic effects observed in animal studies.
Possible contribution to cleft palate if used during the first trimester.
Risk of neonatal hypoadrenalism if used later in pregnancy.
Benefits versus risks assessment needed.
Smallest effective dose and non-systemic formulations preferred.
Hydrocortisone preferred for systemic use.
What advice is given regarding breastfeeding for women taking glucocorticoids?
Low doses likely have minimal impact on nursing infants.
High pharmacologic doses can lead to growth delay and adverse effects in nursing infants.
Breastfeeding is not recommended for women taking high doses of glucocorticoids.
What concerns may affect older adults who use glucocorticoids long-term?
Long-term glucocorticoid use in older adults can lead to osteoporosis, adrenal insufficiency, and gastrointestinal (GI) ulceration, which may affect them disproportionately.
What type of doses of glucocorticoids are associated with adverse effects?
Adverse effects of glucocorticoids occur in response to pharmacologic doses, not physiologic doses.
How does the intensity of adverse effects change with dosage size and treatment duration?
The intensity of adverse effects increases with higher doses and longer treatment duration of glucocorticoids.
Are most adverse effects of glucocorticoids observed when treatment is brief (a few days or less)?
No, most adverse effects are not observed when treatment is brief, even at high doses of glucocorticoids.
What is a common and serious complication of prolonged systemic glucocorticoid therapy?
Osteoporosis with fractures is a common and serious complication of prolonged systemic glucocorticoid therapy.
Is osteoporosis a common complication when glucocorticoids are administered via inhalation or topically?
No, it is uncommon when glucocorticoids are inhaled or administered topically, even with prolonged use.
Which bones are most affected by glucocorticoid-induced osteoporosis?
The ribs and vertebrae are the bones most affected by glucocorticoid-induced osteoporosis.