Valganciclovir

Oral
Cytomegaloviral retinitis in AIDS patients

Oral
Prophylaxis of cytomegalovirus infection in organ transplantation

Haemodialysis patients: Not recommended.

CrCl (mL/min)	Dosage
<10	Not recommended.
10-24	Induction treatment: 450 mg every 2 days. Maintenance treatment: 450 mg twice weekly.
25-39	Induction treatment: 450 mg once daily. Maintenance treatment: 450 mg every 2 days.
40-59	Induction treatment: 450 mg bid. Maintenance treatment: 450 mg once daily.
≥60	Induction treatment: 900 mg bid. Maintenance treatment: 900 mg once daily.

Should be taken with food. Take during or immediately after meals.

Oral solution: Reconstitute with 91 mL of purified water; add approx half the volume of water in the bottle, recap then shake the bottle for about 1 minute, add the remainder of the water to the bottle and shake the bottle well for another minute thereafter.

Hypersensitivity to valganciclovir or ganciclovir. Haemodialysis patients (CrCl <10 mL/min). Lactation.

Patient with known hypersensitivity to aciclovir, penciclovir or their prodrugs (e.g. valaciclovir, famciclovir); pre-existing haematological cytopenia or history of drug-related haematological cytopenia. Not indicated for patients if their absolute neutrophil count is <500 cells/mm³, platelet count is <25,000 cells/mm³, or haemoglobin is <8 g/dL. Not intended for use in liver transplant recipients (recommendation may vary among countries, refer to country-specific guidelines). Renal impairment. Elderly. Pregnancy.

Significant: Hypersensitivity reactions; haematologic toxicity (e.g. severe leucopenia, neutropenia, anaemia, pancytopenia, bone marrow failure, aplastic anaemia); acute renal failure, temporary or permanent spermatogenesis inhibition, fertility suppression, birth defects, cancer.
Ear and labyrinth disorders: Ear pain.
Eye disorders: Eye pain, visual impairment, vitreous floaters, retinal detachment (HIV patients treated for cytomegaloviral retinitis), conjunctivitis, macular oedema.
Gastrointestinal disorders: Nausea, abdominal pain, dyspepsia, flatulence, mouth ulceration, dysgeusia, dysphagia, upper abdominal pain, constipation, vomiting, diarrhoea, abdominal distention, pancreatitis.
General disorders and administration site conditions: Pain, fatigue, chills, pyrexia, malaise, asthenia.
Hepatobiliary disorders: Hepatic function abnormal.
Infections and infestations: Candida infections (including oral candidiasis), sepsis, influenza.
Investigations: Increased serum phosphatase, AST, ALT, serum creatinine; decreased creatinine renal clearance.
Metabolism and nutrition disorders: Decreased appetite, decreased weight.
Musculoskeletal and connective tissue disorders: Back pain, muscle spasm, arthralgia, myalgia.
Nervous system disorders: Headache, dizziness, insomnia, neuropathy peripheral, paraesthesia, hypoaesthesia, seizure.
Psychiatric disorders: Confusional state, anxiety, depression.
Renal and urinary disorders: UTI, renal impairment.
Respiratory, thoracic and mediastinal disorders: Cough, dyspnoea, URTI.
Skin and subcutaneous tissue disorders: Rash, pruritus, dermatitis, cellulitis, night sweats, alopecia.
Vascular disorders: Hypotension.
Potentially Fatal: Bleeding associated with thrombocytopenia.

This drug may cause dizziness, sedation, confusion, and seizure; if affected, do not drive or operate machinery. Women of childbearing potential must use effective contraceptive methods during and at least 30 days after treatment. Men with female partners of childbearing potential should use barrier methods of contraception during and for 90 days after treatment.

Confirm pregnancy status prior to treatment. Monitor CBC and platelet count (baseline and periodically during treatment; more frequently during treatment in infants, patients with renal impairment, history of drug-induced leucopenia, neutrophil counts <1,000 cells/mm³ at treatment initiation); serum creatinine (baseline and periodically during treatment).

Symptoms: Abdominal pain, diarrhoea, vomiting, generalised tremor, seizure, myelosuppression (e.g. leucopenia, neutropenia, granulocytopenia, pancytopenia, bone marrow failure), hepatitis, liver function disorder, elevated creatinine, worsening of haematuria in patient with pre-existing renal impairment, acute kidney injury. Management: Symptomatic and supportive treatment. Adequate hydration and haemodialysis may be useful in reducing serum concentrations of valganciclovir. May consider the use of haematopoietic growth factors.

Increased risk of haematological adverse effects with zidovudine. Increased serum concentration of didanosine. Increased plasma concentration with probenecid. Increased risk of seizures with imipenem-cilastatin. Enhanced toxic effects with myelosuppressive drugs or agents affecting renal function (e.g. nucleosides [e.g. didanosine, stavudine, zidovudine], nucleotide analogues [e.g. adefovir, tenofovir], immunosuppressants [e.g. ciclosporin, mycophenolate mofetil, tacrolimus], antineoplastic agents [e.g. doxorubicin, hydroxyurea, vinblastine, vincristine], and anti-infective agents [e.g. amphotericin B, dapsone, flucytosine, pentamidine, trimethoprim/sulfonamides]).

High-fat meals increase the plasma concentration of valganciclovir.

Description:
Mechanism of Action: Valganciclovir, an antiviral drug, is a prodrug of ganciclovir. Ganciclovir competitively inhibits the binding of deoxyguanosine-triphosphate to DNA polymerase, thereby preventing viral DNA synthesis.
Pharmacokinetics:
Absorption: Well absorbed from the gastrointestinal tract. Food (high-fat meal) increases absorption. Bioavailability: Approx 60%. Time to peak plasma concentration: 1-3 hours (ganciclovir).
Distribution: Widely distributed to all tissue including CSF and ocular tissue. Plasma protein binding: 1-2% (ganciclovir).
Metabolism: Rapidly and extensively metabolised in the intestinal wall and liver via hydrolysis by intestinal mucosal cells and hepatocytes into ganciclovir.
Excretion: Via urine (80-90%, mainly as ganciclovir). Elimination half-life: 4.08 hours (ganciclovir).

Source: National Center for Biotechnology Information. PubChem Compound Summary for CID 135413535, Valganciclovir. https://pubchem.ncbi.nlm.nih.gov/compound/Valganciclovir. Accessed Nov. 23, 2023.

Store between 15-30°C. Reconstituted oral solution: Store between 2-8°C for ≤49 days. Do not freeze. Follow applicable procedures for receiving, handling, administration, and disposal.

Thuốc kháng virus

J05AB14 - valganciclovir ; Belongs to the class of nucleosides and nucleotides excluding reverse transcriptase inhibitors. Used in the systemic treatment of viral infections.

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