Dozens of commonly prescribed and over-the-counter drugs interact with corticosteroids in ways that range from mildly inconvenient to genuinely dangerous. The interactions fall into several categories: drugs that amplify steroid side effects, drugs that change how quickly your body processes steroids, and drugs whose own risks multiply when steroids are on board. Because corticosteroids like prednisone, prednisolone, dexamethasone, and methylprednisolone are prescribed for such a wide range of conditions, the odds of landing on a problematic combination are higher than most people realize.
NSAIDs and the Risk of Stomach Bleeding
The combination of a corticosteroid with a nonsteroidal anti-inflammatory drug (NSAID) is one of the most common and most dangerous pairings. Both drug classes irritate the stomach lining on their own. Together, they dramatically raise the odds of upper gastrointestinal complications like ulcers and bleeding. A large case-control study found that taking steroids alongside moderate-to-high NSAID doses produced roughly four to thirteen times the risk of serious upper GI events compared to taking neither drug, with the risk climbing steeply at higher NSAID doses.1American Journal of Epidemiology. Steroids and Risk of Upper Gastrointestinal Complications Common NSAIDs include ibuprofen, naproxen, diclofenac, and aspirin at anti-inflammatory doses. If you need pain relief while on a steroid, acetaminophen (Tylenol) is generally a safer starting point, and your doctor may add a proton pump inhibitor to protect the stomach when anti-inflammatory therapy is unavoidable.
Fluoroquinolone Antibiotics and Tendon Rupture
Fluoroquinolone antibiotics like ciprofloxacin, levofloxacin, and moxifloxacin already carry an FDA black-box warning for tendon damage. Adding a corticosteroid makes the problem far worse. A population-based study found that people taking both a fluoroquinolone and an oral corticosteroid faced roughly a seven-fold increase in the risk of any tendon rupture and about a nineteen-fold increase in the risk of Achilles tendon rupture specifically, compared to people taking neither.2PubMed Central. Relative and Absolute Risk of Tendon Rupture with Fluoroquinolone and Concomitant Fluoroquinolone/Corticosteroid Therapy: Population-Based Nested Case–Control Study Risk also increased with cumulative exposure, meaning longer courses were worse. If you are on prednisone or another systemic steroid and develop an infection, it is worth asking your doctor whether a non-fluoroquinolone antibiotic can be used instead.
Antifungal Drugs That Raise Steroid Levels
Ketoconazole, a systemic antifungal, blocks liver enzymes responsible for breaking down prednisolone. When these two drugs are combined, steroid concentrations in the body rise and stay elevated longer, intensifying both the therapeutic and the unwanted effects of the steroid.3PubMed. Pharmacokinetics/pharmacodynamics of ketoconazole-prednisolone interaction Research in both animal models and human studies has confirmed that ketoconazole inhibits the specific enzyme pathway (6-beta-hydroxylase) that metabolizes prednisolone, increasing the body’s exposure to biologically active, unbound steroid.4PubMed. Impact of ketoconazole on the metabolism of prednisolone The practical result is that the steroid hits harder than intended, which can push side effects like blood sugar spikes, fluid retention, and immune suppression beyond what the prescribing doctor anticipated. Other azole antifungals such as itraconazole share a similar enzyme-inhibiting profile, so flagging any antifungal use to your prescriber is important if you are on corticosteroids.
Seizure Medications That Weaken Steroids
Several older anti-epileptic drugs do the opposite of ketoconazole: they speed up the liver’s breakdown of corticosteroids so much that the steroid may not work at all. Carbamazepine, phenytoin, and barbiturates are the main culprits. These drugs rev up the same liver enzyme system that metabolizes steroids, clearing them from the bloodstream faster than intended.5The Lancet Neurology. Clinically important drug interactions in epilepsy: interactions between antiepileptic drugs and other drugs – Section: Corticosteroids
In a study of ten volunteers, phenytoin increased the clearance of both total and unbound prednisolone by roughly 40 to 50 percent, and the steroid’s ability to suppress immune activity dropped by about a third.6PubMed. Phenytoin modulates the pharmacokinetics of prednisolone and the pharmacodynamics of prednisolone as assessed by the inhibition of the mixed lymphocyte reaction in humans This matters in real clinical situations. If someone with asthma, rheumatoid arthritis, or adrenal insufficiency also takes phenytoin, their steroid dose may need to be increased to get the same effect. The problem is that nobody adjusts the steroid dose automatically; the interaction often gets noticed only after the steroid seems to stop working.
Blood Thinners and Clotting Complications
Corticosteroids and warfarin have a complicated relationship. Steroids can alter the way warfarin is metabolized and also have their own effects on blood clotting, making anticoagulation harder to control. Glucocorticoids promote a hypercoagulable state on their own by boosting certain clotting factors, while anabolic steroids can disturb clotting through different pathways. A review of thrombotic complications associated with steroid use noted a clinical preference for low-molecular-weight heparin or direct oral anticoagulants over warfarin when patients need both a steroid and an anticoagulant, specifically to avoid the unpredictable warfarin-steroid interaction.7PubMed Central. Thrombotic complications of glucocorticoids and anabolic steroids If you are on warfarin and start a steroid course, expect your doctor to monitor your clotting times more frequently.
Neuromuscular Blocking Agents in Critical Care
This interaction is less relevant to outpatient life but is well known in intensive care units. When patients on mechanical ventilators receive both high-dose corticosteroids and neuromuscular blocking agents (drugs that temporarily paralyze muscles to facilitate ventilation), the combination can trigger a devastating weakness syndrome that lingers long after the drugs are stopped. The medical literature describes three distinct patterns: acute myopathy, prolonged neuromuscular blockade, and critical illness polyneuropathy. Patients may develop generalized weakness with elevated muscle-damage markers and abnormal findings on muscle-function testing.8Journal of Intensive Care Medicine. Generalized Paralysis in the Intensive Care Unit: Emphasis on the Complications of Neuromuscular Blocking Agents and Corticosteroids
Case reports of this interaction go back to the 1970s, and it has been described most often in asthmatics who require both steroids and paralytic agents during severe exacerbations.9Journal of Critical Care. Corticosteroids and neuromuscular blockers in development of critical illness neuromuscular abnormalities: A historical review The exact mechanism is not fully understood, but the recommendation is straightforward: these two drug classes should be combined only when absolutely necessary, and clinicians should aim to minimize the duration of overlap.10PubMed. Acute myopathy associated with combined use of corticosteroids and neuromuscular blocking agents
Oral Contraceptives and Higher Steroid Exposure
The estrogen in combined oral contraceptive pills changes how the liver handles prednisolone. Women taking oral contraceptives had more than double the total drug exposure to prednisolone compared to women not on the pill, owing to reduced clearance and higher systemic availability of the steroid.11PubMed. Pharmacokinetic interaction of contraceptive steroids with prednisone and prednisolone This does not mean oral contraceptives are dangerous to take with steroids, but it does mean the effective dose of the steroid is higher than the number on the pill bottle. For short courses, this usually does not matter much. For people on long-term prednisone who also take oral contraceptives, the extra steroid exposure could contribute to cumulative side effects over time. Mentioning contraceptive use to whoever is managing your steroid therapy can help with dose calibration.
Antacids and Reduced Steroid Absorption
Aluminum- and magnesium-containing antacids can interfere with prednisone absorption if taken at the same time. In healthy volunteers, taking prednisone with certain antacid formulations reduced the bioavailability of the steroid to roughly 57 to 74 percent of the expected level. In patients with chronic active liver disease, the effect was similar, with bioavailability dropping to about 65 to 87 percent depending on the antacid and the patient’s response status.12Gastroenterology. Decreased bioavailability of prednisone due to antacids in patients with chronic active liver disease and in healthy volunteers A reduction of a quarter to nearly half of your steroid dose getting absorbed is enough to undermine treatment. The fix is simple: separate the doses by at least two hours. Take the steroid first, wait, then take the antacid, or vice versa.
SSRIs and Added Gastrointestinal Bleeding Risk
Selective serotonin reuptake inhibitors (SSRIs) like fluoxetine, sertraline, and paroxetine affect serotonin levels in the gut as well as the brain, and this can impair the ability of platelets to form clots in the GI tract. When SSRIs are combined with drugs already known to damage the stomach lining, including both NSAIDs and corticosteroids, the risk of GI bleeding appears to rise further.13Gastroenterology. What Drugs Should Not Be Taken With Steroids? This three-way interaction (SSRI plus NSAID plus steroid) is the worst scenario, but even the SSRI-steroid pair warrants awareness. People on long-term prednisone who also take an SSRI should watch for signs of GI trouble: dark stools, stomach pain, or unexplained fatigue that could signal slow blood loss.
Licorice and Herbal Products
Real licorice root (not the artificially flavored candy most people encounter in the United States) contains glycyrrhizin, a compound that mimics the hormone aldosterone. Glycyrrhizin’s active metabolite blocks an enzyme that normally inactivates cortisol in the kidneys and also binds directly to mineralocorticoid receptors.14PubMed Central. Licorice: From Pseudohyperaldosteronism to Therapeutic Uses The result is fluid retention, potassium loss, and elevated blood pressure. If you are already taking a corticosteroid that has its own mineralocorticoid activity (hydrocortisone and prednisone both do to varying degrees), licorice root can amplify those effects to a clinically meaningful degree. Licorice shows up in herbal teas, traditional remedies, and some European confectionery. People on steroids should check supplement and tea labels for licorice root or glycyrrhiza.
More broadly, herbal supplements are a poorly regulated category, and several common ones affect liver enzymes in ways that could alter steroid metabolism. St. John’s wort, for instance, is a potent enzyme inducer that can lower steroid levels in the same way seizure medications do. If you take any herbal supplement regularly, tell your prescriber before starting a corticosteroid course.
Other Immunosuppressants and Infection Risk
Corticosteroids suppress the immune system, and stacking them with other immunosuppressant drugs compounds that effect. This is sometimes done deliberately, as in organ transplant medicine or severe autoimmune disease, where the combination of a steroid with a biologic or non-biologic disease-modifying drug is standard practice. But it comes at a cost. The infection risk with corticosteroids alone is dose-dependent, and adding a second immunosuppressant pushes that risk higher.15PubMed Central. Infection Risk and Safety of Corticosteroid Use Clinicians managing these combinations typically monitor for infections more aggressively, adjust vaccine schedules (live vaccines are generally contraindicated), and try to use the lowest effective steroid dose. If you are on methotrexate, a TNF inhibitor, or another immunosuppressant and your doctor adds prednisone, it is reasonable to ask about infection-prevention strategies.
Blood Pressure Medications
Steroids raise blood pressure through sodium and water retention, and they can blunt the effect of antihypertensive drugs. NSAIDs do the same thing through different mechanisms, and both drug classes have been identified as among the most important prescription drugs that interfere with blood pressure control.16PubMed Central. Drug interactions and drugs that affect blood pressure If you take medication for high blood pressure and start a steroid, your blood pressure readings may creep up even if nothing else has changed. Your doctor may need to temporarily increase your antihypertensive dose or add another agent for the duration of the steroid course. Home blood pressure monitoring during a steroid course is a practical step that can catch the problem early.
Diabetes Medications and Blood Sugar
Corticosteroids reliably raise blood glucose, sometimes dramatically. They do this by promoting glucose production in the liver and reducing insulin sensitivity in muscle and fat tissue. For people with diabetes who are already on insulin or oral hypoglycemic agents, a steroid course can send blood sugars into a range that their usual medication cannot handle. The interaction is not technically a drug-drug interaction in the pharmacokinetic sense; the steroid does not change how metformin or insulin is absorbed or metabolized. It simply overwhelms the glucose-lowering capacity of the existing regimen. Clinicians typically manage this by increasing insulin doses or adding a short-acting insulin while the steroid is on board, then tapering back down once the steroid stops. If you have diabetes and are prescribed steroids, checking your blood sugar more frequently during the course is essential.
Steroid Eye Drops and Glaucoma Medications
Steroid interactions are not limited to pills. Steroid eye drops are widely prescribed after eye surgery, for allergic eye conditions, and for certain inflammatory diseases of the eye. Chronic use of topical steroids can raise intraocular pressure, and if that pressure goes unmonitored, it can progress to steroid-induced glaucoma and permanent optic nerve damage.17PubMed Central. Steroid-induced Glaucoma: An Avoidable Irreversible Blindness This is particularly relevant for people already taking glaucoma medications to control their eye pressure, because the steroid can counteract the pressure-lowering drugs. Over-the-counter steroid eye drops available in some countries make this problem worse, since people may use them without any monitoring. If you use steroid eye drops for more than a couple of weeks, regular pressure checks with an eye doctor are important regardless of whether you have a history of glaucoma.
Anabolic Steroids and Liver-Stressing Drugs
Anabolic steroids are a different class from corticosteroids, but many people conflate the two, and the drug interaction landscape differs. Anabolic steroids place significant metabolic stress on the liver. Research in animal models has shown that anabolic steroids combined with a high-fat diet worsened markers of liver damage, reduced protective HDL cholesterol, increased liver and blood triglyceride levels, ramped up oxidative stress, and aggravated non-alcoholic fatty liver disease.18PubMed. Food-drug interaction: Anabolic steroids aggravate hepatic lipotoxicity and nonalcoholic fatty liver disease induced by trans fatty acids Anyone using anabolic steroids (whether prescribed for a medical condition or used illicitly for performance enhancement) should be especially cautious about adding other liver-taxing substances. That includes acetaminophen at high doses, certain cholesterol-lowering drugs, alcohol, and oral antifungals like ketoconazole. The compounded liver burden can push what would be individually tolerable drugs into a range that causes real harm.
Practical Steps for Safer Steroid Use
Drug interactions with steroids are common enough that a few habits can meaningfully reduce your risk. Keep a written list of everything you take, including over-the-counter painkillers, supplements, and herbal products, and show it to every prescriber. When starting a new steroid course, ask specifically whether any of your current medications need dose adjustments. Separate antacids from steroid doses by at least two hours. Monitor blood pressure and blood sugar more frequently during steroid courses, especially if you already take medications for either condition. And if you develop new symptoms while on a steroid, like unusual bruising, stomach pain, tendon pain, or muscle weakness, report them promptly rather than assuming they are normal side effects of the steroid itself. The steroid may be fine on its own; the combination with something else in your medicine cabinet may be the real problem.