Valganciclovir is an oral antiviral drug that is closely related to ganciclovir. It is used to treat cytomegalovirus (CMV) infections in patients with HIV or AIDS and to prevent CMV infections in immunosuppressed patients, such as those on immunosuppressive drugs post-transplant. The drug is available by prescription only and should be used under strict medical supervision.
The drug is known by differing trade names, depending on the country and manufacturer. It is available in most countries as an oral preparation, either as tablets or powder, which is reconstituted before use into an oral solution. The tablet strength is normally 450mg, and the oral solution, once reconstituted, is 50mg/ml.
The dose and duration of therapy will be determined by the prescribing doctor. It may be taken for a prolonged period of time, and prescribing instructions should be followed precisely. Valganciclovir should be taken with food. Dosage adjustments may be made in patients who have renal dysfunction.
Cytomegalovirus is caused by a herpes virus, which in a healthy, immunocompetant person usually causes no problems. In immunocompromised people, such as those with HIV or those on immunosuppressive drugs after organ transplantation, the disease may cause cytomegalovirus retinitis. This is a serious condition that if left untreated may result in blindness.
Valganciclovir works by crippling the CMV. It blocks DNA polymerase, an enzyme that is necessary for viral replication in the body, without which the condition cannot progress. Essentially, the drug prevents long-term damage associated with CMV retinitis, which may include blindness. Early recognition of CMV and treatment is vital.
Transplant patients are routinely prescribed immunosuppressive drugs to prevent rejection of the donor organ. This, however, may also lower the transplant patient’s resistance to other infections due to the immune system being suppressed. Valganciclovir is used in these patients to prevent CMV infections.
As with any medication, valganciclovir may interact with other drugs and be contraindicated in some patients with concomitant diseases. These should be discussed with the prescribing doctor before commencement of therapy. Pregnancy, desired pregnancy or lactation should also be discussed prior to treatment.
Valganciclovir may cause adverse effects. They may include headache, trouble sleeping and some blood disorders, including anemia. The prescribing doctor will monitor any patient taking valganciclovir for potential adverse effects. A baseline full blood count and routine monitoring of the blood throughout the course of treatment may be recommended. Should any untoward effects be experienced, the patient should seek medical attention immediately.