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 takes Ganciclovir. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking Ganciclovir. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• abdominal or stomach pain
• Diarrhea
• Fever
• headache
• nausea
• pain and swelling at injection site
• weight loss

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

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

• signs of Anemia (low red blood cells; e.g., pale skin, unusual tiredness or weakness)
• signs of bleeding (e.g., unusual bleeding or bruising, bleeding gums, unexplained nosebleeds)
• signs of decreased kidney function (e.g., decreased urine production, loss of appetite, nausea)
• signs of infection (e.g., fever, chills, or sore throat)
• vision changes

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

• signs of a serious allergic reaction, e.g.:
• abdominal cramps
• difficulty breathing
• nausea and vomiting
• swelling of the face and throat
• signs of a severe skin reaction, e.g.:
• a rash combined with fever or discomfort
• a rash covering a large area of the body
• a rash that spreads quickly
• blistering
• peeling

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 Ganciclovir.

Each 10 mL clear, glass vial of sterile powder contains ganciclovir sodium equivalent to 500 mg of ganciclovir. Nonmedicinal ingredient: sodium 46 mg (2 mEq).

Do not use Ganciclovir if you:

• are allergic to ganciclovir or any ingredients of Ganciclovir
• are allergic to valganciclovir, acyclovir, or Valacyclovir

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

• abacavir
• adefovir
• didanosine
• emtricitabine
• entecavir
• imipenem
• lamivudine
• mycophenolate
• probenecid
• tenofovir
• Trimethoprim

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 Ganciclovir. 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 Ganciclovir.

Bleeding: Ganciclovir can cause a decrease in the number of platelets that are produced in the body. Platelets are responsible for forming clots. If you experience unusual bruising or bleeding, bleeding gums, unusual nosebleeds, stools that look like coffee grounds or blood in urine, contact your doctor as soon as possible.

Blood disorders: If you have any blood disorders (e.g., anemia, thrombocytopenia), discuss with your doctor how Ganciclovir may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Ganciclovir, and whether any special monitoring is needed.

Cancer: Although it has not been clearly demonstrated in humans, there is the possibility that ganciclovir might cause certain types of cancer. If you have concerns, discuss this with your doctor.

Drowsiness/reduced alertness: Ganciclovir may reduce alertness by causing drowsiness, dizziness, or confusion. Some people have had seizures while using Ganciclovir. Avoid hazardous activities such as driving or operating machinery until you know whether the medication affects your ability to perform such tasks.

Fertility: Ganciclovir may decrease fertility in both males and females, and these effects may persist after the medication has been stopped and may be permanent.

Kidney function: The kidneys remove ganciclovir from the body. People who have decreased kidney function may experience higher than expected levels of ganciclovir in the blood and therefore an increased level of side effects.

If you have reduced kidney function or Kidney Disease, discuss with your doctor how Ganciclovir may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Ganciclovir, and whether any special monitoring is needed.

Red blood cells: Ganciclovir may cause low levels of red blood cells. If you experience symptoms of reduced red blood cell count (anemia) such as shortness of breath, feeling unusually tired, pale skin, decreased blood pressure or pounding heartbeat, contact your doctor as soon as possible.

Reduced white blood cells: Ganciclovir can cause low levels of white blood cells. This usually happens within 1 to 2 weeks of starting treatment. Your doctor should order regular blood tests to monitor for changes in the numbers of blood cells during treatment. If you experience symptoms of an infection (e.g., fever, sore throat) contact your doctor immediately.

Pregnancy: Ganciclovir should not be used during pregnancy because it can be harmful to the developing child. Women who are taking Ganciclovir should use an effective method of birth control (e.g., birth control pill, condoms) while they are taking Ganciclovir. Men who are taking Ganciclovir should use a barrier method of birth control (e.g., a condom) while they are using Ganciclovir, and for at least 90 days after stopping the medication.

Breast-feeding: It is not known if ganciclovir passes into breast milk. Due to the severity of side effects with ganciclovir and the risk of harm to the baby, women should not breast feed while they are using this medication.
Children: The safety and effectiveness of using this medication have not been established for children less than 12 years of age.

Seniors: The safety of using ganciclovir has not been established for seniors. Seniors are generally at an increased risk of side effects. Your doctor should closely monitor the effects of Ganciclovir when it is being given to a senior.