Valganciclovir

BRAND NAMES

Valcyte: It includes the active component, valganciclovir. It is available in tablet and oral solution form and is used to treat and prevent illness caused by the CMV virus in persons who have undergone organ transplantation.
MECHANISM OF ACTION

Valganciclovir is a prodrug that is quickly transformed to ganciclovir following oral administration. It is a guanosine analogue that is activated by viral thymidine kinase to monophosphate. The triphosphate analogue of ganciclovir inhibits viral DNA polymerase activity by blocking DNA chain elongation. It results in chain termination or the formation of shot, non-infectious viral DNA fragments.

PHARAMCOKINETICS

ABSORPTION

Valganciclovir is efficiently absorbed from the gastrointestinal system, with valganociclovir tablets having an absolute bioavailability of roughly 60%.

DISTRIBUTION

The mean volume of distribution of valganciclovir is 0.703±0.134L/kg.

METABOSLIM

It is rapidly metabolized in the intestinal wall and liver to ganciclovir. No other metabolites have been detected.

EXCRETION

Valganciclovir is eliminated primarily by renal excretion as ganciclovir via glomerular filtration and active tubular secretion.

PHARMACODYNAMICS

Valganciclovir is an antiviral drug that treats cytomegalovirus infections. It functions as a prodrug for ganciclovir since it is the l-valyl ester of the drug. After oral dosing, intestinal and hepatic esterases quickly convert it to ganciclovir. Following this, it is integrated into DNA and cannot be read correctly by DNA polymerase. This stops the elongation of viral DNA.

DOSAGE AND ADMINISTARTION

Valganciclovir is available in both tablet and oral solution forms. It is often consumed with meals once or twice each day. 
It is available in tablet form (450mg) and powder for oral solution (50mg/ml).

DRUG INTERACTIONS

Drug interaction of valganciclovir may interact with

Antibiotics – imipenem

Gout medicine – probenecid

Antifungal – amphotericinB

Anti-protozoals – pentamidine

Anti-cancer – vinblastine

Immune-suppressants – tacrolimus

HIV-AIDS – tenofovir and zidovudine

Hepatitis B infection medicine - -adefovir

CONTRAINDICATIONS

It is contraindicated with history of significant hypersensitivity reaction.

SIDE EFFECTS

Side effects of valganciclovir may includes

• Nausea
• Vomiting
• Eye pain
• Diarrhea
• Headache
• Pain in the abdomen
• Weight loss
• Mouth ulcers
• Anxiety
• Depression

Serious side effects of valganciclovir may includes

• Vision problems
• Decreased urination
• Blood in urine
• Vision problems
• Rash
• Hives
• Swelling of the legs
• Seizures
• Yellowing of the skin
• Numbness in the hands or feet

OVERDOSE

Symptoms of overdose may includes

• Vomiting
• Stomach upset
• Diarrhea
• Seizures
• Bloody urine
• Shaking hands
• Stomach pain
• Pale skin
• Dizziness
• Sore throat
• Excessive tiredness
• Weakness
• Fast Heart beat

TOXICITY

Valganciclovir overdose is also likely to cause greater renal damage.