Before using budesonide, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients (such as lactose, milk proteins found in some brands), which can cause allergic reactions or other problems.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: eye disease (such as cataracts, glaucoma), high blood pressure, liver disease, thyroid problems, diabetis, stomach/intestinal problems, bone loss (osteoporosis), current/past infections (such as tuberculosis, positive tuberculosis test, herpes, fungal), bleeding problems, mental/mood conditions (such as psychosis, anxiety, depression).

Before having surgery or emergency treatment, or if you get a serious illness/injury, tell your doctor or dentist that you are using this medication or have used a corticosteroid taken by mouth within the past 12 months. Tell your doctor immediately if you develop unusual/extreme tiredness or weight loss.

Tell your doctor if you are pregnant before using this medication. Infants born to mothers who have used corticosteroids for a long time may have hormone problems.

Some products that may interact with this drug include: aldesleukin, other drugs that weaken the immune system (such as azathioprine, cyclosporine, cancer, chemotherapy), mifepristone. Other medications can affect the removal of budesonide from your body, which may affect how budesonide works. Examples include azole antifungals (such as ketokonazole), boceprevir, macrolide antibiotics (such as erythromycin, rifamycins (such as rifabutin), St. John's wort, drugs used to treat seizures (such as carbamazepine, phenytoin), among others.

Dry/irritated throat, hoarseness, voice changes, bad taste in the mouth, runny nose, or nosebleeds may occur. If any of these effects persist or worsen, notify your doctor or pharmacist promptly.

Many people using this medication do not have serious side effects. Infrequently, this medication may cause severe sudden worsening of breathing problems/asthma immediately after use. If you have sudden worsening of breathing, use your quick-relief inhaler and seek immediate medical attention.Because this drug works by weakening the immune system, it may lower your ability to fight infections. This may make you more likely to get a serious (rarely fatal) infection or make any infection you have worse. Tell your doctor immediately if you have any signs of infection (such as ear pain, sore throat, fever, chills).

Use of this medication for prolonged or repeated periods may result in yeast infection. Contact your doctor if you notice white patches in your mouth or on your tongue.

Tell your doctor immediately if any of these rare but serious side effects occur: unusual tiredness, vision problems, easy bruising/bleeding, puffy face, unusual hair growth, mental/mood changes (such as depression, mood swings, agitation), muscle weakness/pain, thinning skin, slow wound healing, increased thirst/urination.A very serious allergic reaction to this drug is rare.

Seek immediate medical attention if you notice any symptoms of a serious allergic reaction: rash/itching, swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.