Two shapes of dose response in one cohort of 1066 patients
Two patients on the same drug at 4 mg and 15 mg face different problems, not smaller and larger versions of one problem.
Huscher and colleagues analysed self-reported health problems in 1066 unselected rheumatoid arthritis patients in routine German practice, comparing three dose bands - under 5 mg, 5 to 7.5 mg, and above 7.5 mg of prednisone equivalent - against patients off glucocorticoids for at least twelve months. Complaints rose with dose, which is unsurprising. What made the 2009 paper useful is that they rose in two different shapes.
The linear group climbs with each milligram and has no safe floor: cushingoid phenotype, ecchymosis, leg oedema, fungal infection, parchment-like skin, shortness of breath and sleep disturbance. The threshold group barely appears until a particular dose is crossed. Glaucoma, depression and rising blood pressure became noticeably more common above 7.5 mg a day. Weight gain and epistaxis started around 5 mg. Cataract sat lowest of all, showing a threshold below 5 mg.
The data are self-reported and cross-sectional, so they establish patterns rather than causal magnitudes. Read alongside guideline thresholds built from other evidence, the frame is still usable: at 20 mg the whole list is live, at 5 mg only part of it is, and the surviving part is what long-term monitoring should be built around.
Ulcer risk as a combination problem more than a steroid one
Most of the ulcer risk attributed to prednisone belongs to whatever is being swallowed alongside it.
What to declare before a long steroid course is written
- Non-selective NSAIDs, including over-the-counter ibuprofen and naproxen
- Low-dose aspirin taken for cardiovascular protection
- Paracetamol at 2 g a day or more
- Anticoagulants and SSRIs, which raise bleeding risk independently
- Alcohol, and any history of previous ulcer or gastrointestinal bleed
Corticosteroids alone carry a modest ulcer risk; corticosteroids with a non-steroidal anti-inflammatory carry a serious one. The Tennessee Medicaid case-control study found a relative risk of 2.0 for peptic ulcer disease among current oral corticosteroid users overall, but 4.4 in those also taking NSAIDs against 1.1 in those who were not. A Swiss claims analysis reproduced the asymmetry with smaller numbers: adjusted odds ratios of 1.63 for glucocorticoid alone and 4.80 for the combination.
The largest dataset makes the point most starkly. Across seven European databases covering about 20 million people, concomitant non-selective NSAID and corticosteroid therapy produced the highest incidence rate ratio for upper gastrointestinal bleeding of any combination examined, at 12.8, and the greatest excess risk beyond what the two drugs would cause independently.
The medication review therefore matters more than an acid-suppression reflex. Ibuprofen bought over the counter never reaches the prescribing record, and patients on long-term prednisone take it without mentioning it. Paracetamol is the safer analgesic here, though daily doses of 2 g and above carry a risk of their own, and low-dose aspirin adds to it.
Gastroprotection follows the combination and other ulcer risk factors rather than arriving automatically with every steroid prescription, and it rests with the prescriber who can see the full list.
The 2.5 to 7.5 mg band and its cardiovascular tail
Maintenance doses at the bottom of the range attract the least attention and the most complacency.
Low-dose maintenance treatment is described to patients as if it were free, and it is not. The Endocrine Society states that even low-dose glucocorticoid use, in the range of 2.5 to 7.5 mg a day, increases cardiovascular disease, severe infection and hypertension, raises the incidence of type 2 diabetes, and increases overall mortality. That is a strong claim about a dose many people take for years without a formal review.
The band should not therefore be avoided. Plenty of conditions require maintenance steroid, and uncontrolled disease has its own mortality. The point is that a small milligram figure is a poor proxy for reassurance, so monitoring here should be deliberate: fracture assessment because the ACR threshold sits below this band, ophthalmic review because the cataract threshold does too, blood pressure and glucose because both show up at these doses, and a periodic honest conversation about whether the dose is still needed.
The daily figure also hides cumulative exposure. Six years at 5 mg is far more glucocorticoid than two months at 20 mg, and bone, skin and lens track the total rather than today's tablet.
Blood pressure, mood and sleep in the band above 7.5 mg
The psychiatric side of steroids is discussed almost entirely in terms of its rarest presentation.
Three threshold effects cluster at the same point. Rising blood pressure, depression or listlessness, and glaucoma all became noticeably more frequent above 7.5 mg a day in the German cohort. Blood pressure has the clearest mechanism - sodium and fluid retention, potassium loss and hypokalaemic alkalosis all appear in the label - and it is the easiest of the three to monitor, which makes home readings early in a course a reasonable ask.
Sleep behaves differently from mood and belongs in the linear group, which fits what patients report: broken sleep starts early and at low doses. Morning dosing helps and evening dosing makes it worse, since a dose taken late suppresses the hours when adrenal activity would normally be highest. Moving a split dose to a single morning one, before 9 am, is the first intervention to try.
The psychiatric conversation is usually pitched at the wrong end. Steroid psychosis and mania are real, dose-related and rare. The common problem is the one the cohort measured: flattened mood and listlessness at doses people consider modest, often unrecognised because nobody connects it to the tablet. Irritability, tearfulness and a sense of being unlike oneself at 10 mg are worth naming out loud.
Severe mood disturbance counts as a glucocorticoid complication justifying a more rapid reduction towards physiological dosing, alongside uncontrolled hyperglycaemia and fracture. The reduction itself is covered in the taper briefing.
Bone: fracture assessment from 2.5 mg a day beyond three months
The number that surprises people is 2.5. Not 5, not 10.
The lowest formal trigger in corticosteroid practice belongs to bone. The 2022 American College of Rheumatology guideline on glucocorticoid-induced osteoporosis covers anyone taking 2.5 mg a day or more for longer than three months, and strongly recommends fracture risk assessment as soon as possible after starting, in practice within six months: a history covering symptomatic and silent fractures, FRAX from age 40, and bone density with vertebral fracture assessment or spine radiographs.
Two details in that recommendation are missed routinely. FRAX is not validated below age 40, so younger patients are assessed on history and density rather than on a score. And above 7.5 mg a day the FRAX result needs a glucocorticoid correction, which the guideline notes may still understate the true risk.
Bone loss is fastest in the first months, which is why the assessment belongs early rather than at the first annual review. Calcium, vitamin D and lifestyle measures are recommended for everyone in this group; at medium, high or very high fracture risk, pharmacological treatment is strongly recommended, with the choice between bisphosphonates, denosumab and parathyroid hormone analogues made jointly. Anyone continuing between 2.5 and 7.5 mg a day at low or moderate risk is reassessed every one to two years.
A common misreading deserves a direct answer: 5 mg is not below the threshold. It is twice the threshold.
Glucose: the afternoon reading rather than the fasting one
A normal fasting glucose on a steroid course is not evidence of anything much.
Steroid hyperglycaemia has a shape ordinary diabetes monitoring is built to miss. Prednisolone taken once in the morning pushes glucose up through the afternoon and evening, and overnight values drift back towards normal. The fasting morning test therefore reads reassuringly while post-lunch readings sit well above target, and patients are declared fine on the one measurement least likely to detect the problem.
The Joint British Diabetes Societies guidance is specific about where to look. Capillary glucose is checked once daily, before or after lunch or the evening meal, or one to two hours after those meals, since that is when the effect of morning steroid dosing peaks. A reading above 12.0 mmol/L moves testing to four times a day. Two readings above 12.0 mmol/L within 24 hours moves the patient into the treatment algorithm, where gliclazide starting at 40 mg in the morning and titrated upward is a common first step. Consistent values under 10 mmol/L allow testing to stop.
HbA1c is useful before starting and unreliable during. It averages months, so it lags a rise that develops in days, and a normal result three weeks into treatment means little. Check it before the first dose if the purpose is to exclude pre-existing type 2 diabetes.
The way down is the other half. Glucose falls as the steroid falls, and treatment appropriate at 30 mg produces hypoglycaemia at 10. One published rule of thumb reduces insulin by 20 to 25 per cent, or gliclazide by 40 mg, for each 5 mg reduction in prednisolone from 20 mg. Patients started on glucose-lowering treatment during a course and never reviewed afterwards are a recognisable and avoidable group.
Cataract with almost no floor, glaucoma above 7.5 mg
Of everything on the harm list, the eyes have the lowest entry dose and the least warning.
Prolonged corticosteroid use produces posterior subcapsular cataract and raised intraocular pressure with possible optic nerve damage; the label lists both, along with a raised risk of secondary fungal and viral ocular infection. What the label does not supply is a dose at which either becomes likely, and that gap is where the cohort data earn their place.
Cataract had the lowest threshold of any effect measured in the 1066-patient dataset, appearing below 5 mg a day. A later systematic review in rheumatoid arthritis put both cataract and glaucoma in the threshold category, cataract around 5 mg daily and glaucoma around 7.5 mg in patients treated beyond six months. Older cross-sectional series found posterior subcapsular opacities almost exclusively in steroid-exposed patients.
Two behaviours follow. Long-term users need periodic ophthalmic review however modest the dose looks. And gradual blurring, glare around headlights or worsening night vision calls for an eye examination rather than a new spectacle prescription, since posterior subcapsular cataract hits near vision and glare disproportionately and is easily blamed on age.
Steroid-induced ocular hypertension stays silent until damage is done, which is the argument for scheduled pressure checks rather than symptom-triggered ones.
Live vaccines: 20 mg a day for fourteen days as the cut-off
Twenty milligrams for fourteen days is the line that decides vaccination, and it is applied wrongly in both directions.
| Harm | Pattern | Where it starts | Source of the number |
|---|---|---|---|
| Fracture risk assessment | Formal trigger | 2.5 mg daily beyond 3 months | ACR 2022 GIOP guideline |
| Cataract | Threshold, very low | Under 5 mg daily | Huscher 2009 cohort |
| Weight gain, epistaxis | Threshold | From 5 mg daily | Huscher 2009 cohort |
| Glaucoma, low mood, raised BP | Threshold | Above 7.5 mg daily | Huscher 2009 cohort |
| Cushingoid change, bruising, thin skin | Linear | No floor identified | Huscher 2009 cohort |
| Live vaccine deferral | Hard cut-off | 20 mg daily for 14 days | CDC altered immunocompetence guidance |
The threshold governing immunisation is one of the few hard numbers here. CDC guidance codifies the consensus: 20 mg or more of prednisone daily, or 2 mg/kg for someone under 10 kg, given for 14 or more consecutive days counts as high-dose corticosteroid therapy and raises safety concerns about live-virus vaccination. Live vaccines are deferred until at least a month after it stops.
Below the line the answer is permissive, and patients are wrongly refused every winter. Steroid therapy is not considered sufficiently immunosuppressive when it runs under 14 days, when the dose is below 20 mg a day, when it is long-term alternate-day treatment with short-acting preparations, when it is physiological replacement, or when it is topical, inhaled, intra-articular, bursal or intra-tendinous.
Timing runs the other way too. Immunosuppressive therapy is ideally begun four weeks after a live vaccine and two weeks after a non-live one, though treatment for an active inflammatory condition is not delayed on that account. Above physiological doses glucocorticoids also blunt the response to non-live vaccines, which affects effectiveness rather than safety.
Infection risk more broadly does not wait for 20 mg. The label warns that corticosteroids may mask signs of infection and that new infections may appear during use. Fever can be blunted and abdominal signs can be absent in a perforation, so a soft abdomen reassures less than usual.
Monitoring worth the trouble, and the parts built on habit
Some of the surveillance around long-term steroids is evidence. Some of it is inherited practice.
Not all of the standard surveillance rests on the same quality of evidence. Fracture assessment at 2.5 mg beyond three months carries a strong recommendation from a panel that graded its own evidence. The glucose monitoring window has a clear physiological rationale and consistent observational support. The vaccine threshold is a consensus figure the CDC candidly calls not well defined, adopted because a line has to sit somewhere. Cohort thresholds for cataract and glaucoma come from self-reported cross-sectional data and read as patterns rather than precise cut-offs.
That produces a hierarchy rather than a checklist. Bone assessment, blood pressure and afternoon glucose earn their place at almost any long-term dose; annual bloods ordered without a question attached mostly do not. Above all of them sits an accurate record of dose and duration, short courses included, since nearly every threshold described here is defined by the two together.
One further point prescribers sometimes dodge. Most of these effects reverse on stopping, but not all of them and not at the same rate. Cushingoid change, weight and mood recover over months. Lens opacities do not reverse. Bone density recovers partially and slowly. Describing the harm list as uniformly reversible is a kindness that misleads. The mechanics of coming off are in the taper briefing, and the drug itself is on the prednisone page.