- A patient on chronic glucocorticoid therapy develops hyperglycemia. This effect is a result of several metabolic actions of glucocorticoids. Which of the following mechanisms is the most significant contributor to steroid-induced hyperglycemia?
Answer: Stimulation of hepatic gluconeogenesis and decreased insulin sensitivity.
Glucocorticoids raise blood glucose levels through multiple mechanisms. The most significant are increasing hepatic glucose output via stimulation of gluconeogenesis (synthesis of glucose from non-carbohydrate precursors like amino acids) and inducing insulin resistance in peripheral tissues (skeletal muscle, adipose tissue), which decreases glucose uptake. They do not decrease glucagon secretion (they may increase it) and they do not inhibit glycogenolysis.
- A 48-year-old kidney transplant recipient is on a maintenance regimen including tacrolimus and prednisone. He presents with new-onset severe right hip pain, which is exacerbated by weight-bearing. An MRI of the hip is ordered. This patient's presentation is highly suspicious for which glucocorticoid-associated adverse effect?
Answer: Avascular necrosis of the femoral head.
Avascular necrosis (AVN), or osteonecrosis, is a serious complication of high-dose or long-term glucocorticoid therapy. The femoral head is the most commonly affected site. The mechanism is not fully understood but is thought to involve impaired blood supply to the bone, possibly due to microvascular occlusion by fat emboli, intravascular coagulation, or increased intraosseous pressure. The presentation of severe, localized joint pain, particularly in a weight-bearing joint like the hip, is characteristic of AVN.
- The anti-inflammatory effects of glucocorticoids are mediated by both genomic and non-genomic mechanisms. Which of the following is an example of a rapid, non-genomic action of glucocorticoids?
Answer: Interaction with membrane-bound receptors leading to altered ion fluxes.
When you encounter questions about glucocorticoid mechanisms, remember that these drugs work through two distinct pathways: slow genomic effects (involving gene transcription) and rapid non-genomic effects (occurring within minutes).
The correct answer is A because interaction with membrane-bound receptors leading to altered ion fluxes represents a classic non-genomic mechanism. These rapid effects occur within seconds to minutes through direct membrane interactions, bypassing the nuclear receptor pathway entirely. This can involve changes in calcium influx, potassium efflux, or other ion channel modifications that immediately affect cellular function.
Let's examine why the other options are incorrect. Option B (decreased IL-2 production) is wrong because this requires transcriptional suppression of the IL-2 gene, which is a genomic effect taking hours to develop. Option C (increased IκB-α transcription) is clearly genomic since it explicitly mentions gene transcription - this particular mechanism actually helps suppress NF-κB activity but requires new protein synthesis. Option D (COX-2 suppression) is also genomic because it involves inhibiting gene expression of the cyclooxygenase enzyme, again requiring transcriptional changes that take time to manifest.
Study tip: Remember the timing distinction - if a question asks about "rapid" or "immediate" glucocorticoid effects, look for membrane-related mechanisms. If it mentions gene names, protein synthesis, or transcription, those are genomic effects that take hours. This timing concept frequently appears on pharmacology exams when testing steroid hormone mechanisms.
- The redistribution of body fat, leading to central obesity, a 'moon face,' and a 'buffalo hump' in patients with chronic glucocorticoid excess, is a result of:
Answer: stimulation of lipolysis in the extremities and promotion of lipogenesis in central depots.
The characteristic fat redistribution of hypercortisolism is paradoxical. Glucocorticoids have complex, depot-specific effects on adipose tissue. They tend to promote lipolysis (breakdown of fat) in peripheral tissues like the arms and legs, contributing to the thin extremities seen in Cushing's syndrome. Simultaneously, they increase the differentiation of pre-adipocytes and promote lipogenesis (fat synthesis), particularly in central depots such as the face, supraclavicular area, dorsocervical region, and abdomen, leading to the classic central obesity pattern.
- A patient on chronic prednisone therapy for an autoimmune disorder develops hypertension. While glucocorticoids can increase vascular sensitivity to catecholamines, what is the principal mechanism by which they directly contribute to elevated blood pressure?
Answer: Binding to and activation of mineralocorticoid receptors in the renal distal tubules.
At supraphysiologic doses, glucocorticoids like prednisone can cross-react and bind to mineralocorticoid receptors (MR) in the kidney. The natural ligand for the MR is aldosterone. Activation of the MR promotes sodium and water reabsorption in the distal convoluted tubule and collecting duct, leading to volume expansion and hypertension. This effect is independent of the renin-angiotensin-aldosterone system, which is actually suppressed by the volume expansion.
- A major concern with long-term glucocorticoid therapy in children is growth suppression. What is the primary mechanism underlying this adverse effect?
Answer: Direct inhibition of chondrocyte proliferation and function in the epiphyseal growth plates.
Glucocorticoids suppress linear growth in children through multiple mechanisms. The most important is a direct inhibitory effect on the epiphyseal growth plates, where they suppress the proliferation and differentiation of chondrocytes, the cells responsible for cartilage formation and longitudinal bone growth. They also suppress the secretion of growth hormone (GH) from the pituitary and reduce the synthesis of IGF-1, further contributing to growth retardation.
- A 65-year-old woman with polymyalgia rheumatica on long-term, low-dose prednisone complains of progressive, painless blurring of her vision and increased glare from headlights at night. An ophthalmologic examination is most likely to reveal which of the following findings?
Answer: Posterior subcapsular cataracts.
Long-term systemic glucocorticoid use is a significant risk factor for the development of posterior subcapsular cataracts. This type of cataract is characterized by opacities on the back surface of the lens, which can cause symptoms of glare (especially at night) and a gradual, painless decrease in visual acuity. While increased intraocular pressure (glaucoma) is another potential ocular side effect, the patient's specific symptoms are more classic for cataracts.
- A 58-year-old male with rheumatoid arthritis has been managed with long-term, high-dose prednisone. He presents with gradually worsening dull pain in his upper back and a noticeable loss of height. An X-ray reveals a vertebral compression fracture. This adverse effect is primarily a consequence of glucocorticoid-mediated:
Answer: inhibition of osteoblast function and promotion of osteoclast survival.
Glucocorticoid-induced osteoporosis is a major adverse effect. The primary mechanism involves direct effects on bone cells: glucocorticoids inhibit the function and differentiation of osteoblasts (bone-forming cells) and promote the apoptosis of osteoblasts and osteocytes. They also enhance the survival and activity of osteoclasts (bone-resorbing cells) by increasing the expression of RANKL and decreasing the expression of its decoy receptor, osteoprotegerin (OPG). This combination shifts bone remodeling in favor of resorption, leading to bone loss and increased fracture risk.
- A 25-year-old patient with asthma uses a high-dose inhaled corticosteroid (fluticasone) daily. She presents with a white, curd-like coating on her tongue and buccal mucosa that can be scraped off, revealing an erythematous base. This complication is a direct result of:
Answer: localized immunosuppression in the oropharynx promoting fungal overgrowth.
When you encounter oral lesions in patients using inhaled corticosteroids, think about the local effects of these medications in the oropharynx. The white, curd-like coating that scrapes off to reveal red tissue beneath is classic for oral thrush (candidiasis).
Inhaled corticosteroids like fluticasone work by suppressing local inflammatory responses in the airways. However, when these drugs deposit in the mouth and throat during inhalation, they create localized immunosuppression in the oropharynx. This suppresses the normal immune surveillance that keeps opportunistic fungi like Candida albicans in check, allowing fungal overgrowth and the characteristic thrush presentation. This makes option A correct.
Option B is wrong because this isn't a hypersensitivity reaction—there's no immune system overactivity here. The lesions are infectious, not allergic. Option C incorrectly suggests systemic immunosuppression and viral infection. High-dose inhaled corticosteroids primarily cause local effects, and the described lesions are fungal (candidiasis), not viral. Option D misidentifies the mechanism—while corticosteroids can affect cell proliferation, the white coating isn't mucosal atrophy but rather fungal overgrowth on top of inflamed tissue.
Remember that inhaled corticosteroids commonly cause oral thrush through local immunosuppression, which is why patients should rinse their mouths after each use. On pharmacology exams, connect medication side effects to their mechanisms of action—corticosteroids suppress immunity, so think about what infections might occur when that protection is reduced.
- A patient with a history of latent tuberculosis infection (positive PPD, negative chest X-ray) is being considered for a long-term course of high-dose glucocorticoids for a severe autoimmune disease. The physician's primary concern regarding the latent infection is that glucocorticoids may cause reactivation by primarily impairing the function of:
Answer: macrophages and CD4+ T-helper cells that form and maintain granulomas.
Control of latent tuberculosis infection relies on cell-mediated immunity, specifically the formation of granulomas that 'wall off' the mycobacteria. These granulomas are maintained by a complex interplay between activated macrophages and cytokine-producing T-lymphocytes, particularly CD4+ T-helper 1 (Th1) cells. Glucocorticoids are potent suppressors of cell-mediated immunity. They inhibit macrophage activation and function, and they suppress the production of key cytokines (like IFN-γ and TNF-α) by T-cells, which can lead to the breakdown of granulomas and reactivation of the latent infection.
- A key molecular action of the activated glucocorticoid receptor (GR) is transrepression, where it decreases the synthesis of inflammatory proteins. This is mechanistically distinct from transactivation. Which of the following describes a primary mechanism of transrepression by the GR?
Answer: The GR directly binds to and sequesters pro-inflammatory transcription factors like AP-1 and NF-κB.
When you encounter questions about glucocorticoid receptor mechanisms, focus on distinguishing between transactivation (turning genes on) and transrepression (turning genes off). These represent fundamentally different molecular pathways for how steroids exert their effects.
Transrepression occurs when the activated glucocorticoid receptor directly interferes with pro-inflammatory transcription factors rather than binding to DNA itself. The GR physically binds to and sequesters key inflammatory mediators like AP-1 and NF-κB, preventing them from activating their target genes. This protein-protein interaction effectively "ties up" these transcription factors, blocking the synthesis of inflammatory cytokines, chemokines, and other pro-inflammatory proteins. This mechanism explains why glucocorticoids are such potent anti-inflammatory drugs.
Choice A describes transactivation, not transrepression - this is when GR binds to glucocorticoid response elements to activate gene transcription. Choice B incorrectly assigns histone methyltransferase activity to the GR; while chromatin modification is important in gene regulation, the GR doesn't function as this type of enzyme. Choice C describes a form of transactivation where the GR would activate genes encoding repressor proteins like IκB-α, which is actually how some anti-inflammatory effects occur, but this isn't the primary transrepression mechanism being asked about.
Remember that transrepression is about direct protein-protein interactions that sequester transcription factors, while transactivation involves DNA binding and gene activation. This distinction is crucial for understanding how glucocorticoids can simultaneously suppress inflammatory genes and activate metabolic genes.
- A patient receiving long-term prednisone therapy for sarcoidosis presents for a routine check-up. A complete blood count (CBC) with differential is ordered. Which of the following patterns is most expected due to the pharmacological effects of the glucocorticoid?
Answer: Leukocytosis with neutrophilia and lymphopenia.
Glucocorticoids have profound effects on circulating white blood cells. They cause an increase in neutrophils (neutrophilia) by increasing their release from the bone marrow and, more importantly, by decreasing their migration out of the vasculature (demargination). Conversely, they cause a decrease in lymphocytes, eosinophils, monocytes, and basophils by inducing their sequestration in lymphoid tissues and promoting apoptosis. Therefore, the classic picture is an elevated total WBC count (leukocytosis) driven by neutrophilia, with accompanying lymphopenia and eosinopenia.
- A patient is prescribed a short course of high-dose dexamethasone to manage cerebral edema associated with a brain tumor. Which of the following adverse effects is most likely to manifest within the first few days of therapy?
Answer: Insomnia, euphoria, or mood lability.
Neuropsychiatric effects of glucocorticoids can occur acutely, often within days of starting high-dose therapy. These can range from mild effects like insomnia and anxiety to more severe reactions such as euphoria, depression, mania, or psychosis ('steroid psychosis'). The other listed effects—osteoporosis, cataracts, and clinically significant HPA axis suppression requiring a taper—are all complications of chronic, long-term glucocorticoid use.
- The anti-inflammatory properties of glucocorticoids include the suppression of arachidonic acid metabolites. The primary mechanism for reducing the synthesis of both prostaglandins and leukotrienes is:
Answer: upregulation of the synthesis of annexin A1, which in turn inhibits phospholipase A2.
Glucocorticoids inhibit the entire arachidonic acid cascade at its origin. They do this indirectly by inducing the synthesis of a protein called annexin A1 (also known as lipocortin-1). Annexin A1 inhibits the activity of phospholipase A2 (PLA2), the enzyme responsible for liberating arachidonic acid from membrane phospholipids. By reducing the availability of the precursor, arachidonic acid, glucocorticoids decrease the production of all its downstream metabolites, including prostaglandins (via the COX pathway) and leukotrienes (via the lipoxygenase pathway).
- A patient treated with oral prednisone and naproxen for a rheumatoid arthritis flare develops epigastric pain. Endoscopy reveals a gastric ulcer. The synergistic risk of peptic ulcer disease with combined glucocorticoid and NSAID use is primarily due to:
Answer: both agents impairing mucosal defense mechanisms through the inhibition of prostaglandin synthesis.
When you encounter questions about drug combinations causing GI toxicity, focus on how different medications can work together to overwhelm the stomach's natural protective mechanisms.
Both glucocorticoids and NSAIDs independently increase peptic ulcer risk by impairing mucosal defense, but through slightly different pathways. NSAIDs like naproxen block cyclooxygenase (COX) enzymes, which dramatically reduces protective prostaglandin E₂ (PGE₂) synthesis. PGE₂ normally stimulates mucus and bicarbonate production while promoting mucosal blood flow. Glucocorticoids also suppress prostaglandin synthesis, but additionally impair other mucosal defense mechanisms including cellular repair and immune responses. When combined, these drugs create a synergistic effect—the total damage exceeds what you'd expect from simply adding their individual effects.
Option A incorrectly suggests glucocorticoids directly increase acid secretion, but their primary ulcerogenic effect is through mucosal defense impairment, not acid hypersecretion. Option B wrongly attributes platelet aggregation impairment to glucocorticoids—this is actually an NSAID effect through COX-1 inhibition, and while NSAIDs do cause direct mucosal injury, this misses the key prostaglandin connection. Option C about delayed gastric emptying is not a significant mechanism for either drug class in ulcer formation.
The correct answer is D because both drug classes ultimately converge on the same critical pathway: prostaglandin synthesis inhibition, which devastates the stomach's ability to protect itself.
Remember: when you see combination GI toxicity questions, look for shared mechanisms rather than completely different pathways—drugs often synergize by hitting the same protective system from multiple angles.
- A 30-year-old male with ulcerative colitis is treated with high-dose oral methylprednisolone. After two weeks, he complains of proximal muscle weakness, making it difficult to climb stairs. A serum creatine kinase (CK) level is normal. This finding is most consistent with which glucocorticoid-induced adverse effect?
Answer: Steroid-induced myopathy
Steroid-induced myopathy is a well-known adverse effect of glucocorticoids, particularly potent fluorinated steroids. It characteristically presents as painless proximal muscle weakness. The underlying mechanism is primarily protein catabolism, leading to atrophy of type IIb muscle fibers. Unlike inflammatory myopathies or rhabdomyolysis, muscle enzyme levels like CK are typically normal or only mildly elevated.
- A patient with a skin wound is treated with a potent topical glucocorticoid. The surgeon notes that the wound healing process is significantly delayed. This impairment is most directly related to the glucocorticoid's inhibitory effects on:
Answer: fibroblast proliferation and collagen synthesis.
While glucocorticoids affect all phases of wound healing, their most significant impact on the structural integrity and tensile strength of the healed wound is the inhibition of the proliferative phase. They directly inhibit the proliferation of fibroblasts and their synthesis of collagen and other extracellular matrix components. This leads to a weaker scar and delayed wound closure. While they also inhibit inflammation (C) and angiogenesis (part of B), the effect on fibroblasts and collagen is central to the poor healing quality.
- A 45-year-old woman with systemic lupus erythematosus has been on 40 mg of prednisone daily for 8 weeks. Her physician decides to slowly taper the dose over the next two months. The primary physiological reason for this gradual dose reduction is to:
Answer: allow the adrenal cortex to recover its ability to produce endogenous cortisol.
Prolonged administration of exogenous glucocorticoids suppresses the hypothalamic-pituitary-adrenal (HPA) axis. The hypothalamus reduces CRH release, and the pituitary reduces ACTH release, leading to atrophy of the adrenal cortex. If the exogenous steroid is withdrawn abruptly, the atrophied adrenal gland cannot produce sufficient cortisol to meet the body's needs, leading to a life-threatening adrenal crisis. Tapering the dose slowly allows the HPA axis to recover and endogenous cortisol production to resume.
- A patient is administered a high dose of intravenous hydrocortisone for septic shock. A key anti-inflammatory mechanism that contributes to vascular stabilization in this acute setting is the inhibition of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression. How do glucocorticoids primarily accomplish this effect?
Answer: By preventing the activation of transcription factors, such as NF-κB, that are required for iNOS and COX-2 gene expression.
Glucocorticoids exert their anti-inflammatory effects primarily through genomic mechanisms. The glucocorticoid-receptor complex can repress the expression of pro-inflammatory genes. A key mechanism is interfering with the activity of pro-inflammatory transcription factors like Nuclear Factor-kappa B (NF-κB) and Activator Protein-1 (AP-1). Since these transcription factors are essential for inducing the expression of genes like iNOS and COX-2 during an inflammatory response, their inhibition by glucocorticoids prevents the synthesis of these enzymes.
- A patient who was on 60 mg of prednisone daily for 3 months for giant cell arteritis is tapered to 5 mg daily. She now presents with diffuse muscle and joint pain, fatigue, and orthostatic hypotension. Laboratory results show hyponatremia and hyperkalemia. This clinical picture is most consistent with:
Answer: an unmasked secondary adrenal insufficiency.
When you encounter a patient who's been on high-dose corticosteroids for months and develops new symptoms after tapering, always consider adrenal suppression. Prolonged exogenous steroid use suppresses the hypothalamic-pituitary-adrenal (HPA) axis, preventing normal cortisol production.
This patient's presentation is classic for secondary adrenal insufficiency. The muscle/joint pain, fatigue, and orthostatic hypotension reflect cortisol deficiency, while hyponatremia and hyperkalemia indicate inadequate mineralocorticoid activity. After 3 months of high-dose prednisone, her adrenal glands stopped producing cortisol. The rapid taper from 60mg to 5mg didn't allow sufficient time for HPA axis recovery, unmasking the underlying adrenal insufficiency.
Choice B (steroid-induced Cushing's syndrome) would present with weight gain, moon facies, and hypertension—opposite of this patient's symptoms. Choice C (giant cell arteritis flare) might cause muscle pain but wouldn't explain the electrolyte abnormalities or orthostatic hypotension. Choice D (mineralocorticoid excess) would cause hypertension, hypokalemia, and hypernatremia—again, the opposite of what we see.
The key study tip: Remember that any patient on supraphysiologic steroids (>7.5mg prednisone equivalent) for more than 2-3 weeks risks HPA suppression. Watch for the triad of fatigue, hypotension, and electrolyte disturbances (low sodium, high potassium) when steroids are tapered too quickly. This requires either slower tapering or temporary increase in steroid dose.
