Prednisone

Is prednisone safe?

For a short course it usually is, and for many serious conditions it is the right drug despite its downsides. Prednisone is a synthetic corticosteroid that damps down inflammation and the immune system within hours. It treats asthma flares, rheumatoid arthritis, lupus, severe allergic reactions, inflammatory bowel disease and dozens of other conditions.

Its risks come from the same power. Because it suppresses the immune system and touches almost every organ, side effects grow with the dose and the length of treatment. We score it 66, level with gabapentin (66) and below ibuprofen (74). Do not stop or cut prednisone without your prescriber; for many people the disease is the bigger danger.

Doses on the label

There is no single dose. The US label gives a starting range of 5 mg to 60 mg a day depending on the condition, then asks the prescriber to step down to the lowest dose that keeps it under control. For acute flares of multiple sclerosis it cites 200 mg of prednisolone a day for a week, then 80 mg every other day for a month. Some long-term patients take twice the daily dose every other morning (alternate-day therapy), which the label says can reduce adrenal suppression and growth effects in children.

The label notes that the adrenal glands are most active between 2 am and 8 am, and steroids given then suppress them least, which is why daily doses are usually taken in the morning. A delayed-release version starts releasing the drug about 4 hours after it is swallowed and is taken with food.

Even short courses carry some risk

A 2017 BMJ study of 1.5 million insured US adults found that 21.1% had at least one short course (under 30 days) in three years, often for respiratory infections, back pain and allergies. In the 30 days after starting, rates of sepsis were 5.3 times higher, blood clots 3.3 times and fractures 1.9 times higher than in the same people at other times. That trade-off matters most when the reason for the course is minor.

Day to day, people notice a bigger appetite, poor sleep, flushing, and mood changes from euphoria to irritability. The label also lists severe depression and psychosis, most often at high doses. In people with diabetes, blood sugar can climb within a day or two, so medicines such as metformin or insulin may need adjusting.

Long-term use: bones, eyes and infections

After months of treatment the list grows. The label warns of:

• Bone loss and fractures. Bone density should be monitored on long-term treatment. Ask your doctor whether you need calcium and vitamin D or a bone-protecting drug.
• Eye damage. Cataracts and glaucoma; eye pressure should be checked if treatment goes beyond 6 weeks.
• Infections. Chickenpox and measles can be severe or fatal in people who are not immune. Latent tuberculosis and hepatitis B can reactivate, so people are screened before long courses.
• Cushing's features. A rounder face, fat on the upper back, thin skin, bruising and stretch marks.
• Growth. Children on long-term treatment need their growth monitored.

Prednisone is contraindicatedContraindicationA situation in which a medicine should not be used, because the risk clearly outweighs any benefit, such as a known allergy to it.More in the glossary in systemic fungal infections.

Stopping safely: the adrenal glands

Taken for more than a few weeks, prednisone tells the adrenal glands to stop making cortisol. The label warns this suppression can last for months after the last dose, and that people may need extra steroid during illness, injury or surgery in that time. Stopping suddenly can trigger adrenal insufficiency and, at worst, adrenal crisis, a medical emergency.

In 2020 NHS England issued a National Patient Safety Alert introducing a Steroid Emergency Card for adults at risk of adrenal crisis. If you have been given one, carry it and show it to any doctor, dentist or paramedic.

Interactions to know

• Liver enzymes: ketoconazole and macrolide antibiotics raise steroid levels. The MHRA has warned that ritonavir and cobicistat, used in HIV treatment, can cause systemic steroid side effects. Rifampicin, phenytoin and carbamazepine lower them.
• Blood thinners: steroids usually blunt the effect of warfarin, so INR needs closer checks.
• Painkillers: NSAIDs such as ibuprofen and aspirin add to the risk of stomach ulcers and bleeding.
• Thyroid: people with an underactive thyroid clear steroids more slowly, and changes in levothyroxine treatment may change the steroid dose needed.
• Vaccines and diuretics: live vaccines are avoided at immunosuppressive doses, and water pills that lower potassium add to the low potassium steroids can cause.

Who should be careful

Talk to your doctor or pharmacist before starting if you have diabetes, high blood pressure, heart failure, osteoporosis, glaucoma or cataracts, a stomach ulcer, a history of depression or psychosis, tuberculosis or hepatitis B, or if you are pregnant, since the label reports a small, inconsistent rise in cleft lip and palate with first-trimester use. Tell any doctor treating you for an infection that you take a steroid, because it can mask the signs.

How we scored it

Track record (95) and overdose marginOverdose marginHow far a normal dose is from a harmful one. A wide margin means an accidental extra dose is unlikely to cause serious harm.More in the glossary (85) are the strongest factors: acute overdose is rarely the issue. Serious side effects (45) are the weakest, reflecting infections, fractures and blood clots even after short courses and the long list of harms with long-term use. Dependence (65) reflects adrenal suppression rather than addiction.