Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent. The side effects listed below are not experienced by everyone who uses Virazole. If you are concerned about side effects, discuss the risks and benefits of Virazole with your doctor.

Although most of these side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• difficulty breathing or wheezing
• symptoms of a lung infection caused by bacteria (e.g., high Fever, chills, shaking, chest pain, or shortness of breath)

Stop taking the medication and seek immediate medical attention if any of the following occur:

• blue skin or nails
• difficult or rapid breathing
• symptoms of a serious allergic reaction (such as Hives, swelling of the face or throat, or difficulty breathing)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking Virazole.

Each 100 mL glass vial of sterile, lyophilized powder contains ribavirin 6 g. The medication is administered only by a small particle aerosol generator (SPAG-2).

Ribavirin should not be used by anyone who:

• is allergic to ribavirin or to any ingredients of the medication
• is pregnant or may become pregnant during exposure to the medication

There may be an interaction between ribavirin and any of the following:

• alfa interferons
• Azathioprine
• Influenza vaccine
• reverse transcriptase inhibitors (anti-HIV medications; e.g., abacavir, didanosine, lamivudine, zidovudine)

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with Virazole. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the Nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use Virazole.

Allergic reaction: In rare cases, Virazole may cause a Anaphylaxis (severe allergic reaction). If you notice hives, swelling of the face or throat, or difficulty breathing, stop the child from inhaling the medication and get immediate medical attention.

Pregnancy: Ribavirin may be harmful to an unborn baby. Women who are pregnant or may become pregnant should not be exposed to ribavirin. To protect an unborn baby, women who are pregnant should not provide care to patients requiring ribavirin.

Breast-feeding: It is not known if ribavirin passes into breast milk. If you are a breast-feeding mother and are exposed to Virazole, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.