Can I take Levothyroxine and Prednisolone together?

Why this happens

Prednisolone (a corticosteroid) can affect how your body processes thyroid hormones. It can slightly reduce the conversion of the inactive hormone (T4) into the active form (T3) and may also affect the levels of proteins in your blood that carry the thyroid hormone around. Additionally, if you are taking levothyroxine for an underactive thyroid, the underlying condition itself can change how quickly your body clears prednisolone from your system.

You should inform your doctor that you are taking both medications. They may want to perform a blood test to check your thyroid levels (TSH) shortly after you start or stop taking prednisolone. Do not change your dose of either medication without consulting your healthcare provider. If you feel unusually tired, cold, or notice a racing heart and tremors, let your doctor know.

Mental health and mood changes

Steroids like prednisolone can cause serious mental health problems including depression, suicidal thoughts, anxiety, confusion, or hallucinations. Seek medical help immediately if your mood or behaviour changes significantly.

Infection risk and chickenpox exposure

Prednisolone suppresses your immune system. You must avoid contact with anyone who has chickenpox, shingles, or measles. If you are exposed, contact your doctor immediately as you may need specialist treatment.

Adrenal suppression (Steroid Emergency Card)

If you take prednisolone for more than 3 weeks, you must not stop suddenly. This can cause a life-threatening drop in blood pressure. You should carry a Steroid Emergency Card at all times.

Heart conditions (e.g. angina, heart failure)

If you have a heart condition, your dose must be started very low and increased slowly. Contact your doctor immediately if you experience chest pain or palpitations, as levothyroxine increases the workload on your heart.

Interaction with supplements (Calcium/Iron)

Do not take calcium tablets, iron supplements, or multivitamins at the same time as levothyroxine. You must leave a gap of at least 4 hours between these supplements and your levothyroxine to ensure the medicine works.

Diabetes

Levothyroxine can raise blood sugar levels. If you have diabetes, you must monitor your blood glucose more closely when starting or changing your dose, as your diabetes medication may need to be increased.

Alcohol

It is best to avoid or strictly limit alcohol while taking levothyroxine. While there is no direct chemical reaction, alcohol can affect thyroid function and may worsen symptoms like tiredness or mood changes.

It is best to avoid or strictly limit alcohol while taking prednisolone. Both alcohol and prednisolone can irritate the stomach lining; combining them increases your risk of stomach ulcers and indigestion.

Timing of dose and food/drink

Take your levothyroxine on an empty stomach, at least 30 to 60 minutes before breakfast or any caffeine. Food, milk, and coffee prevent the medicine from being absorbed properly.

Caffeine (Coffee/Tea)

Caffeine can significantly reduce the amount of levothyroxine your body absorbs. You should wait at least 30 to 60 minutes after taking your tablet before drinking coffee or tea.

You should limit your intake of caffeine. Prednisolone can increase the effects of caffeine, which may lead to feelings of nervousness, difficulty sleeping, or a racing heart. Like prednisolone, caffeine can also increase stomach acid, raising the risk of stomach irritation.

Dairy products (Milk, Yoghurt, Cheese)

Avoid consuming dairy products at the same time as your levothyroxine. Calcium found in dairy can interfere with how your body absorbs the medicine, making it less effective. It is best to wait at least 4 hours between taking levothyroxine and consuming dairy.

Salt (Sodium)

Prednisolone causes your body to retain salt and water, which can lead to high blood pressure and swelling. You should try to limit your intake of salty foods and avoid adding extra salt to your meals.

Sugary foods and drinks

Prednisolone can increase your blood sugar levels. It is important to be mindful of your sugar intake, especially if you have diabetes or are at risk of developing it.

Soya products

Soya can interfere with the absorption of levothyroxine. If you regularly eat or drink soya products, your doctor may need to monitor your thyroid levels more closely. Avoid consuming soya at the same time as your dose.

Kelp and Seaweed

These foods are naturally high in iodine. Too much iodine can interfere with your thyroid treatment and make your condition worse.

High-fibre foods

A diet very high in fibre can reduce the absorption of levothyroxine. If you significantly change your fibre intake, inform your doctor as your dose may need adjusting.

Taking multiple medicines? Our Medicines Interaction Checker helps you check whether your prescriptions, over-the-counter medicines, and supplements are safe to take together. Simply search for your medicines to see potential interactions and what to do about them.

Disclaimer

This information is for general educational purposes only and should not be relied upon as a substitute for professional medical advice. Always consult your GP, pharmacist, or another qualified healthcare professional before making decisions about your medications. Individual circumstances may vary, and only a healthcare professional who knows your medical history can provide personalised guidance.