• you are allergic to any ingredient in Proventil
• you are using another short-acting sympathomimetic bronchodilator (eg, metaproterenol) or epinephrine.

Contact your doctor right away if any of these apply to you.

Some medical conditions may interact with Proventil. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

• if you are pregnant, planning to become pregnant, or are breast-feeding
• if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
• if you have allergies to medicines, foods, or other substances
• if you have a history of heart problems, (eg, fast or irregular heartbeat, heart failure), blood vessel problems, high blood pressure, or low blood potassium levels
• if you have a history of seizures, diabetes, an overactive thyroid, kidney problems, or an adrenal gland tumor (pheochromocytoma)
• if you have ever had an unusual reaction to another sympathomimetic medicine (eg, pseudoephedrine)
• if you are taking a monoamine oxidase inhibitors (MAOI) (eg, phenelzine), or tricyclic antidepressant (eg, amitriptyline), or if you have taken either of these medicines within the last 14 days.

Some medicines may interact with Proventil. Tell your health care provider if you are taking any other medicines, especially any of the following:

• Diuretics (eg, furosemide, hydrochlorothiazide) because the risk of low blood potassium levels may be increased
• Catechol-O-methyltransferase (COMT) inhibitors (eg, entacapone), epinephrine, MAOIs (eg, phenelzine), short-acting sympathomimetic bronchodilators (eg, metaproterenol), stimulants (eg, amphetamine), sympathomimetics (eg, pseudoephedrine), or tricyclic antidepressants (eg, amitriptyline) because they may increase the risk of Proventil's side effects
• Beta-blockers (eg, propranolol) because they may decrease Proventil's effectiveness
• Digoxin because its effectiveness may be decreased by Proventil.

This may not be a complete list of all interactions that may occur. Ask your health care provider if Proventil may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

Important safety information:

• Proventil may cause dizziness. These effects may be worse if you take it with alcohol or certain medicines. Use Proventil with caution. Do not drive or perform other possible unsafe tasks until you know how you react to it.
• Proventil may sometimes cause severe breathing problems right after you use a dose. If this happens, seek medical care at once.
• If your usual dose does not work well, your symptoms become worse, or you need to use it more often than normal, contact your doctor at once. This may be a sign of seriously worsening asthma. Your doctor may need to change your dose or medicine.
• Proventil should work for up to 6 hours. Do NOT use more than the recommended dose or use more often than prescribed without checking with your doctor. The risk of severe heart problems and sometimes death may be increased with overuse of Proventil.
• Proventil may cause dry mouth or an unpleasant taste in your mouth. Rinsing your mouth with water after each dose may help relieve these effects.
• Tell your doctor or dentist that you take Proventil before you receive any medical or dental care, emergency care, or surgery.
• Check with your doctor before using any other inhaled medicines while you are using Proventil.
• Diabetes patients - Proventil may affect your blood sugar. Check blood sugar levels closely. Ask your doctor before you change the dose of your diabetes medicine.
• When your medicine supply begins to run low, call your doctor or pharmacy as soon as possible for a refill.
• Use Proventil with caution in the elderly; they may be more sensitive to its effects.
• Proventil should be used with extreme caution in children younger than 2 years old; safety and effectiveness in these children have not been confirmed.
• Caution is advised when using Proventil in children; they may be more sensitive to its effects.
• Pregnancy and breast-feeding: If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using Proventil while you are pregnant. It is not known if Proventil is found in breast milk. If you are or will be breast-feeding while you use Proventil, check with your doctor. Discuss any possible risks to your baby.

Check with your doctor if any of these most common side effects persist or become bothersome:

Cough; dizziness; headache; nausea; nervousness; sinus inflammation; sore or dry throat; tremor; trouble sleeping; unusual taste in mouth; vomiting.

Seek medical attention right away if any of these severe side effects occur:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); chest pain; ear pain; fast or irregular heartbeat; new or worsened trouble breathing; pounding in the chest; severe headache or dizziness; unusual hoarseness; wheezing.

This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider.