Drug Overview:
Valganciclovir hydrochloride is a drug that acts against cytomegalovirus diseases, especially in adult patients with acquired immunodeficiency syndrome (AIDS) or patients who are at risk of having cytomegalovirus infection after an organ transplant. Valganciclovir medication is commercially available as tablets and solutions. Oral tablets are available at the dose of 450 mg and solutions at 50 mg/ml dosage.
How Does the Drug Valganciclovir Work?
Valganciclovir is a prodrug of Ganciclovir which is a mixture of two diastereomers. Esterase enzymes present in the liver and intestine convert these diastereomers into Ganciclovir. In cytomegalovirus infection, the phosphorylation of Ganciclovir to the monophosphate by protein kinase occurs, and it is further phosphorylated to form triphosphate by the enzyme cellular kinase. The Ganciclovir triphosphate inhibits the synthesis of viral DNA (deoxyribonucleic acid) by getting incorporated into the DNA strand itself, replacing other bases. Thus the Ganciclovir incorporated DNA strand becomes unstable and is not read by the DNA polymerase enzyme resulting in the termination of viral DNA elongation.
Uses:
Valganciclovir is used to treat cytomegalovirus (CMV) and retinitis (eye infection that can cause blindness) in people who have acquired immunodeficiency syndrome (AIDS). Valganciclovir is also used to prevent cytomegalovirus disease in people who have received a heart, kidney, or kidney-pancreas transplant and those with a chance of getting CMV disease.
Doses: Valganciclovir is available in the form of oral tablets (450 mg) and liquid solutions (50 mg/ml). It should be taken once or twice daily with food in the frequency and dose schedule prescribed by the doctor based on the underlying symptoms.
Warnings:
-
Risk of Blood problems: There is a risk of a decrease in WBC (white blood cells), RBC (red blood cell), and platelet count while taking Valganciclovir. Caution should be taken while administering the drug in patients who are on blood thinners or have bleeding disorders.
-
Risk of Renal Impairment: Valganciclovir can cause renal impairment, so the drug should be administered cautiously in patients undergoing hemodialysis (removing waste products from the blood by a machine).
-
Fetal Toxicity: The drug Valganciclovir has been reported to have teratogenic potential, and it can harm the fetus. Ganciclovir may cause fetal toxicity when administered to pregnant women based on findings in animal studies.
-
Risk of Carcinogenicity: Valganciclovir has a risk of causing cancer, according to animal studies. The risk of cancer in humans on Valganciclovir is not yet reported.
-
Risk of Infertility: Valganciclovir has been reported to decrease fertility in both men and women.
For Patients:
What Do You Need to Know About Cytomegalovirus Diseases?
Cytomegalovirus is a DNA (deoxyribonucleic acid) virus that can affect people of any age group (mostly adults), with a wide variety of infections affecting the eyes, lungs, liver, stomach, esophagus, kidney, and intestine. Cytomegalovirus mostly affects people who are immunocompromised, like patients with AIDS (acquired immunodeficiency syndrome) or recipients of organ transplants. It can be life-threatening and can cause end-organ dysfunction in patients with compromised immune systems.
Learn More About Valganciclovir:
When and Why to Take Valganciclovir Medication?
In Adults, Valganciclovir Tablets Are Used:
1. To treat cytomegalovirus retinitis AIDS patients. When the CMV virus infects the eyes, it is called CMV retinitis. If CMV retinitis is not treated, it can cause blindness.
2. To prevent CMV disease in people who have received a kidney, heart, or kidney-pancreas transplant and those with a high risk of getting CMV disease. Valganciclovir does not cure CMV retinitis. You may still get retinitis, or the existing retinitis can worsen during or after treatment with Valganciclovir. It is important to stay under a healthcare provider’s care and get the eyes checked at least every four to six weeks during treatment with Valganciclovir.
In Children, Valganciclovir Tablets or Oral Solution Are Used:
1. To prevent CMV disease in children aged four months to 16 years who have received a kidney transplant and have a high risk of getting CMV disease.
2. To prevent CMV disease in children aged one month to 16 years who have received a heart transplant and have a high risk of getting CMV disease.
It stands unknown yet whether Valganciclovir is safe and effective in children and infants to prevent CMV disease during a liver or kidney transplant.
Dosage For patients with AIDS: In AIDS patients who are detected with cytomegalovirus retinitis or colitis, Valganciclovir in the dose of 900 mg (two Valganciclovir tablets, 450 mg each), to be taken twice a day for 21 days is usually prescribed by the physician. Valganciclovir treats infections by inhibiting the spread and growth of the cytomegalovirus by terminating the viral DNA (deoxyribonucleic acid) synthesis.
Valganciclovir in the dose of 900 mg (two Valganciclovir tablets 450 mg) once daily is also a preferred drug in patients who have undergone organ transplant surgeries to prevent the risk of cytomegalovirus infections.
How Effective Is Valganciclovir Against Cytomegalovirus Infections?
- According to the research, Valganciclovir helps in inhibiting the growth of cytomegalovirus in AIDS patients with cytomegalic retinitis or colitis.
- Valganciclovir also showed proven results in preventing the risk of cytomegalovirus infection in patients who are immunocompromised, like organ transplant recipients.
Things to Inform Your Doctor Before They Prescribe You Valganciclovir:
-
Inform your doctor if you are allergic to any medications.
-
Inform your doctor if you are under any other medications or supplements like blood thinners or anticoagulants.
-
Inform your doctor if you have systemic disorders like diabetes, liver disease, blood disorders, and kidney disease.
-
Inform your doctor if you are undergoing hemodialysis or radiation treatment.
-
Women who are pregnant, planning to become pregnant, and breastfeeding mothers should inform their doctor about the condition.
-
Inform your doctor if you have undergone any recent surgeries like an organ transplant.
Starting Valganciclovir Medications:
How to Take Valganciclovir?
- Valganciclovir is to be taken in the exact dose and frequency as prescribed by the doctor. Valganciclovir is available in oral tablet form at a dose of 450 mg. For active cytomegalovirus retinitis infections, it is advised to take 900 mg (two Valganciclovir tablets 450 mg) twice a day for 21 days as an induction dose. In the case of inactive cytomegalovirus retinitis, the doctor prescribes the maintenance dose of 900 mg (two Valganciclovir tablets 450 mg) once daily.
- To prevent CMV (cytomegalovirus) infection in patients with kidney, liver, or other solid organ transplants, the dose of 900 mg (two Valganciclovir tablets 450 mg) once daily is started by the doctor within ten days of the organ transplant surgery for 100 days post-surgery.
- It is advised not to split, chew, or crush the tablet.
- Valganciclovir tablets should be taken with food.
Things to Do After You Start Taking Valganciclovir
-
Inform your doctor in case you have any side effects from the medications, like weight loss, mouth ulcers, blood in urine, or joint pain.
-
Inform your doctor in case of improvement of symptoms during the follow-up visits.
-
Keep track of the improvement in health conditions.
Look Out for the Side Effects:
Common side effects of Valganciclovir are:
-
Nausea and vomiting.
-
Pain and tenderness in the abdomen.
-
Headaches.
-
Weight loss.
-
Eye pain.
-
Joint pain.
-
Anxiety.
-
Mouth ulcers.
Some serious side effects are:
-
Blood in the urine.
-
Decreased urination.
-
Blurred vision.
-
Itching.
-
Rashes.
-
Loss of appetite.
-
Yellowing of skin or eyes.
-
Numbness and tingling sensation in hands and feet.
-
Swelling of the upper and lower extremities.
In case of any side effects noticed with Valganciclovir medications, inform your doctor immediately.
Dietary Alterations: Patients are advised to stay hydrated by consuming plenty of fluids while on Valganciclovir medication.
What Should Be Done if You Forgot a Dose?
Try to take the missed dose as soon as you remember. If it is time for another dose, skip the missed dose, and take your regular dose. Avoid overdosing to compensate for the missed dose. Take your regular doses from the next day.
What Should Be Done in Case of Valganciclovir Overdose?
In case of Valganciclovir overdose, call the poison control helpline number immediately.
How to Store Valganciclovir?
-
The drug Valganciclovir tablets are stored at room temperature of 20 to 25-degree celsius.
-
The oral drug Valganciclovir is stored in the refrigerator at two to eight degrees Celsius. It should no longer be preserved for more than 49 days.
Avoid Self-Prescription:
Valganciclovir is always used under a doctor's supervision and prescription. After completing a clinical examination and recording the drug and systemic history of the patient, the doctor prescribes the medicine in the required dose and frequency based on the diagnosis.
Staying On Valganciclovir
-
It is important to take the drug in exact doses and frequency as prescribed by the doctor.
-
In case any dose is missed, inform your doctor immediately.
-
Any side effects noticed after taking Valganciclovir should be informed to the doctor.
-
Keep track of the improvement of your health condition and inform your doctor during the follow-up visits.
-
In case of worsening of the health condition, inform your doctor immediately.
For Doctors:
Indications:
-
The drug Valganciclovir is indicated in patients with cytomegalovirus infections like cytomegalic retinitis or colitis (mostly seen in patients with AIDS).
-
The drug Valganciclovir is also indicated in patients who have undergone organ transplant surgery to prevent the risk of cytomegalovirus infections, as the immunity of such patients is highly compromised.
Pharmacology:
Mechanism of Action:
The drug Valganciclovir is a prodrug of Ganciclovir and acts by inhibiting and restricting the synthesis of viral DNA (deoxyribonucleic acid) by getting incorporated into the DNA strand itself, replacing other adenosine bases. Thus the Ganciclovir triphosphate (phosphorylated form) incorporated DNA strand becomes unstable and is not read by the DNA polymerase enzyme resulting in the termination of viral DNA elongation.
Pharmacodynamics:
The drug Valganciclovir, a prodrug of Ganciclovir, has antiviral or virustatic potential against the cytomegalovirus (DNA virus). It acts by inhibiting the synthesis of viral DNA (deoxyribonucleic acid), thus improving the condition of patients with cytomegalovirus infections.
Chemical Taxonomy:
Ingredients:
Active Ingredient: The only active ingredient is Valganciclovir hydrochloride for both tablets and liquid form.
Inactive Ingredients:
For Valganciclovir Tablets
-
Microcrystalline cellulose.
-
Povidone K-30.
-
Crospovidone.
-
Stearic acid.
For Valganciclovir liquid solution (50 mg/ml)
-
Sodium benzoate.
-
Fumaric acid.
-
Povidone K-30.
-
Mannitol.
-
Saccharin sodium.
Absorption:
-
The drug Valganciclovir is well absorbed by GIT (gastrointestinal tract).
-
The bioavailability of the oral tablet is around 60 percent following administration with food.
Distribution:
-
The steady-state volume of distribution of Valganciclovir is approximately 0.703 to 0.134 L/Kg.
-
Because of the quick conversion of a prodrug Valganciclovir to Ganciclovir, the plasma protein binding capacity of Valganciclovir is not known.
Metabolism:
The drug Valganciclovir is metabolized by rapid hydrolysis in the intestinal and liver to convert into Ganciclovir.
Elimination:
The drug Valganciclovir is eliminated in the form of Ganciclovir by the kidneys through glomerular filtration or renal tubular secretion.
Toxicity:
The overdose of the drug Valganciclovir has shown toxic effects on the kidneys, according to the studies.
Warning and Precautions:
-
The drug Valganciclovir should be cautiously given to patients with bleeding disorders as it has shown a reduction in red and white blood cell counts. It has also shown a tremendous decrease in platelet count in a few patients.
-
The drug has shown toxic effects on the kidney as well as the liver, so it should be avoided in patients undergoing hemodialysis and should be used cautiously in patients with liver and kidney disorders.
-
The drug Valganciclovir is toxic to the fetus and is also excreted in breast milk, so it should be avoided in pregnant women and breastfeeding mothers.
Doses and Forms:
-
The drug Valganciclovir is available in oral tablet form at a dose of 450 mg.
-
Valganciclovir is available in the form of an oral liquid solution at a dose of 50 mg/ml.
Administration of the Drug:
-
The drug Valganciclovir is prescribed in doses of 900 mg (two 450 mg tablets) twice daily for 21 days in AIDS patients with cytomegalo retinitis or colitis as an induction dose, followed by a maintenance dose of 900 mg (two 450 mg tablets) once daily.
-
For prevention of cytomegalovirus infections in immunocompromised patients (patients with recent organ transplants), it is prescribed in the dose of 900 mg (two 450 mg tablets) once daily within 10 days of transplant and is continued till 100 days post-transplant surgery.
-
Oral solutions of Valganciclovir can be given in oral liquid solution form in doses of 50 mg/ml in children with a risk of developing cytomegalovirus infections.
Contraindications:
The drug Valganciclovir is contraindicated in patients who have had a demonstrated clinically significant hypersensitivity reaction (e.g., anaphylaxis) to Valganciclovir, Ganciclovir, or any component of the formulation.
Drug Interactions:
-
The drug Valganciclovir increases the risk of cytopenia (decrease in blood cell level) when given in combination with Abacavir.
-
The excretion rate of Valganciclovir is decreased if it is given in combination with Aceclofenac, Acetaminophen, Acyclovir, Acetylsalicylic acid, and Acemetacin resulting in increased serum levels of the drug.
-
The excretion rate of Valganciclovir is increased if it is given in combination with Acetazolamide.
Other Specifications:
Valganciclovir in Pregnant and Lactating Women:
The drug Valganciclovir should be avoided in women who are pregnant and breastfeeding mothers as the drug has harmful effects on the fetus and is also excreted through the breast milk. Inform your doctor if you are pregnant, planning for pregnancy, or are a breastfeeding mother. It is advised not to become pregnant while on Valganciclovir medication.
Valganciclovir in a Patient With Renal Impairment:
Valganciclovir has shown toxic effects on the kidneys, according to research, so it should be given cautiously with dose adjustments based on renal clearance as it can lead to kidney dysfunction in the patients.
Valganciclovir in a Patient With Hematological Disorders:
The drug Valganciclovir has shown a decrease in the red blood cell, white blood cells, and platelet count resulting in myelosuppression (decrease in bone marrow activity), so it should be used very cautiously in patients with blood disorders, patients with low hemoglobin counts, and are on radiotherapy.
