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

The following side effects have been reported by at least 1% of people taking . 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.

• anxiety
• back pain
• Constipation
• Diarrhea
• dizziness
• drowsiness
• dry, red itchy skin
• fatigue
• Fever
• headache
• heartburn
• joint pain
• nausea or vomiting
• trembling
• trouble sleeping
• 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 check with your doctor or seek medical attention

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

• confusion
• high blood pressure
• numbness, tingling, or burning sensations
• signs of an infection (e.g., cough, chills, mouth sores, redness on any area of your body, nasal congestion, sore throat, runny nose, night sweats, pain or burning when urinating)
• signs of graft rejection (transplanted organ not functioning properly; e.g., feeling ill or uncomfortable, fever)
• signs of kidney problems (e.g., swelling of the legs, decreased urine amount, lower back pain)
• symptoms of Anemia (e.g., feeling tired, shortness of breath, paleness, rapid heartbeat)
• symptoms of Depression (e.g., lack of motivation or energy, feelings of worthlessness or guilt, difficulty concentrating)
• unusual bleeding and bruising
• unusual tiredness or weakness
• white patches on the mouth, tongue, or throat

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

• seizures
• signs of a serious allergic reaction (e.g., swelling of the face or throat, Hives, 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 .

Each pink, oval, biconvex, film-coated tablet, engraved "H" on one side and "96" on the other contains 450 mg of valganciclovir. Nonmedicinal ingredients: crospovidone, povidone and magnesium stearate. Opadry pink YS-1-14519A film-coating: hypromellose, titanium dioxide, polysorbate 80, polyethylene glycol, and iron oxide red.

Do not take valganciclovir if you:

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

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

• didanosine
• imipenem - cilastatin
• Mycophenolate Mofetil
• tenofovir
• 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 . Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications that 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 .

Blood disorders: Valganciclovir can cause a reduction in certain blood cells, which can lead to serious problems. People with certain severe blood disorders (e.g., anemia, neutropenia, thrombocytopenia) may not be able to use . Your doctor will monitor you closely while you are taking for any signs of blood cell problems.

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

Drowsiness/reduced alertness: Valganciclovir may reduce alertness. Avoid activities such as driving or operating machinery until you know whether the medication affects you in this way.

Kidney Disease: People with reduced kidney function may need a lower dose of . Valganciclovir may also cause kidney problems. Your doctor will monitor you while you are on .

Fertility and pregnancy: Valganciclovir may decrease fertility in both men and women, and these effects may last for some time after the medication has been stopped. should not be used during pregnancy because it can harm the developing child. Men and women who are taking valganciclovir should ensure their partners are aware of the risks and practice effective birth control, which includes barrier protection (e.g., condoms) and one additional form of contraception (e.g., birth control pills, intrauterine device). Effective birth control should be practiced for at least 90 days after stopping the medication.

Breast-feeding: It is not known if valganciclovir passes into breast milk. It is recommended that women taking should not breast-feed.

Children: The safety and effectiveness of using have not been established for children.

Seniors: Seniors may require lower doses of due to age-related decreases in kidney function.

Valganciclovir belongs to a group of medications known as antivirals. It is used to treat a viral eye infection called cytomegalovirus (CMV) retinitis for people with acquired immunodeficiency syndrome (AIDS). It can also be used to prevent CMV disease in people who have received an organ transplant and are at risk of the condition. It works by slowing the growth of the CMV virus that causes the infection. Valganciclovir does not cure CMV disease, but it does prevent the virus from spreading as quickly as it would without treatment.

may be available under multiple brand names and/or in several different forms. Any specific brand name of may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of may not be used for all of the conditions discussed here.

Your doctor may have suggested for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking , speak to your doctor. Do not stop taking without consulting your doctor.

Do not give to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take if their doctor has not prescribed it.