Valganciclovir

Valganciclovir is an antiviral drug used for the treatment of cytomegalovirus (CMV) infection that affects the eyes in people with AIDS. The condition is also known as CMV retinitis. This medicine also used to prevent cytomegalovirus infection in people who had an organ transplant from a CMV positive donor.

CMV retinitis is a serious viral eye infection of the retina. It is most often found in people with weakened immune systems. The retina is the light-sensing nerve layer that lines the back of the eye. This condition is caused by the cytomegalovirus which is one of the herpes viruses that infects most adults. The vast majority of people who have cytomegalovirus have no symptoms of infection. They will never have any problems because of the virus. But in people with weakened immune systems, the virus can reactivate and spread to the retina. This can lead to vision-threatening eye problems. 

The symptoms of CMV retinitis can begin with a slow onset of floaters with blurred vision over a few days. This can lead to a loss of peripheral vision. Sometimes, the symptoms begin with a blind spot in the center of vision. Wherein, it may lead to a loss of central vision. The symptoms usually happen first in one eye but often progress to the other eye. People with CMV retinitis often develop a detached retina.

AIDS is the late stage of HIV infection. This happens when the immune system of the body is badly damaged because of the virus. A person with HIV is considered to have progressed to AIDS when;

  • They develop one or more opportunistic infections regardless of their CD4 count
  • The number of their CD4 cells falls below 200 cells per cubic millimeter of blood 

Without HIV medicine, people with AIDS typically survive for about 3 years. If someone has a dangerous opportunistic illness, life expectancy without treatment falls to about 1 year. HIV medicine can still help people at this stage of HIV infection and it can even be lifesaving. 

How does Valganciclovir work for CMV infection?

Valganciclovir works by blocking the action of an enzyme called DNA polymerase that is found in the CMV virus. This enzyme is required by the virus for it to copy genetic material. The virus must multiply and survive. This medicine is also incorporated into the DNA of the virus. By blocking the action of DNA polymerase and disrupting viral DNA, Valganciclovir prevents CMV from multiplying. This controls the infection and helps the immune system to deal with it. 

CMV is a member of the herpes group of viruses. In healthy people, this common virus normally produces symptoms milder than the common cold. However, in people whose immune systems are compromised such as people with AIDS, or people who have had an organ transplant, it can cause serious infection. It is because the immune system cannot fight it. This is referred to as an opportunistic infection. In immunocompromised people, infection with CMV can lead to complications such as a condition called CMV retinitis. In CMV retinitis the virus causes severe inflammatory changes in the retina of the eye, which can lead to blindness.

How to use Valganciclovir?

Take this medication with food usually1-2 times a day. Each dose should be taken by mouth as a whole with a full glass of water. Wash your hands well before and after taking the medicine. Avoid contact with broken or crushed tablets on your skin, mucous membrane, and eyes. Also, avoid breathing in the dust from the tablets. If contact occurs, wash the area thoroughly with soap and water. If the medication gets in your eyes, rinse them thoroughly with plain water. 

The dosage is based on your medical condition and response to the treatment. In children, the dosage is also based on their body size. The doctor should keep track of your child’s height and weight. It is to make sure that the dose is right for them. This medication works best when the amount of drug in your body is kept at a constant level. You should take this at the same time and in the same way each day. Continue taking Valganciclovir exactly as prescribed by your doctor. Do not change your dose or stop taking it even for a short time unless directed by your doctor. Changing or skipping your dose without approval from your doctor may increase the risk of side effects or make the infection worse. 

What are the side effects of Valganciclovir?

Common side effects:

  • Upset stomach
  • Diarrhea
  • Loss of balance or coordination
  • Dizziness
  • Unsteadiness
  • Drowsiness
  • Shaking
  • Constipation
  • Diarrhea
  • Cold symptoms such as sneezing, stuffy nose, cough, or sore throat 

Tell your doctor if you have these serious side effects:

  • Changes in the amount of urine
  • Seizures 
  • Mental/mood changes 

If these side effects persist or get worse, call for medical helps right away. 

Precautions 

  • This medicine may reduce your ability to drive or operate machinery safely. Do not drive or operate machinery until you know how this medicine affects you.
  • This medicine can sometimes cause a decrease in the normal amounts of blood cells in the blood. You will need to have regular blood tests to check your blood cells during your treatment.
  • Valganciclovir has the potential to cause cancers and to reduce fertility in men and women. It will only be used when the benefits of using it outweigh any possible risks. You should discuss this with your doctor.
  • Valganciclovir can cause birth defects if it is taken during pregnancy or if men taking it father a child. Women taking this medicine must use effective contraception to avoid getting pregnant during treatment. Men taking this medicine should use barrier contraceptives to prevent fathering a child both during and for at least three months following treatment. 
  • Valganciclovir is used in a lower dose or with extra monitoring in people with kidney or liver problems, low levels of white blood cells, history of blood disorders, or those who are receiving radiotherapy treatment. 
  • This is not recommended for use in people who are allergic to this drug and those with hemodialysis for kidney failure.