valaciclovir hydrochloride at a glance
Medicine class
Systemic antiviral; an aciclovir prodrug.
Main roles
Shingles, genital and other herpes simplex infections, recurrent eye herpes and specialist CMV prevention after solid-organ transplantation.
Taking the tablets
Swallow whole with water. Food does not reduce aciclovir bioavailability from valaciclovir.
Kidney safety
Kidney function affects clearance; adequate fluid intake is particularly important for people at risk of dehydration.
What is valaciclovir hydrochloride used for?
The selected product is licensed for:
Treating shingles, including ophthalmic shingles, in adults with normal immunity and selected adults with mild or moderate immunosuppression.
Treating and suppressing herpes simplex infections of the skin and mucous membranes, including first and recurrent genital herpes, in the licensed age and immune-status groups.
Treating cold sores in adults and adolescents.
Treating and suppressing recurrent ocular herpes simplex infections.
Preventing cytomegalovirus infection and disease after solid-organ transplantation in adults and adolescents.
How does valaciclovir hydrochloride work?
Valaciclovir is absorbed and rapidly converted to aciclovir. In herpes-infected cells, aciclovir is activated to a form that inhibits viral DNA polymerase and terminates viral DNA chains, restricting further viral replication.
valaciclovir hydrochloride preparations and strengths
Tablet
Route: Oral
Strengths: 250 mg, 500 mg, 1000 mg
How to take valaciclovir hydrochloride
Follow the dispensing-label and prescriber instructions. The appropriate regimen depends on the infection, immune status and kidney function.
Take by mouth and swallow tablets whole with water.
Food does not materially reduce absorption of the active aciclovir exposure.
Take consistently as directed.
Drink fluids regularly, particularly if older, at risk of dehydration or affected by kidney problems.
Do not alter or stop prescribed treatment without discussing it with the prescriber.
valaciclovir hydrochloride side effects
Common or expected effects
- Headache
- Nausea
- Dizziness
- Vomiting or diarrhoea
- Rash, itching or sensitivity to sunlight
Get urgent medical advice
- Severe allergic reaction, including facial or throat swelling, breathing difficulty or collapse
- Severe skin reactions causing widespread rash, blistering, peeling, fever or mucosal ulcers
- Kidney injury, which may cause kidney-area pain, blood in the urine or little or no urine
- Neurological toxicity such as severe confusion, hallucinations, marked drowsiness, seizures or reduced consciousness
valaciclovir hydrochloride in pregnancy
Experience with valaciclovir in pregnancy is limited, although registry and post-marketing information has not indicated malformation or fetal/newborn toxicity. Because valaciclovir becomes aciclovir, the prescriber should weigh the benefits of treating the infection against any potential risk. Tell the prescriber or midwife if pregnant, planning pregnancy or pregnancy occurs during treatment.
valaciclovir hydrochloride while breastfeeding
Valaciclovir can be used during breastfeeding when clinically appropriate. It is converted to aciclovir; only small amounts reach milk and significant infant absorption is unlikely. Specialist guidance recommends precautionary monitoring for drowsiness, irritability, rash, vomiting or diarrhoea, primarily for healthy, full-term infants.
valaciclovir hydrochloride interactions
Check all prescribed, non-prescription and herbal products because kidney clearance is central to valaciclovir safety.
Nephrotoxic medicines, including aminoglycosides, platinum compounds, methotrexate, pentamidine, foscarnet, ciclosporin and tacrolimus
Combined use may increase the risk of kidney injury and warrants caution and renal-function monitoring, especially when kidney function is already impaired.
Iodinated contrast media
Concurrent exposure may add to kidney risk, so renal function and hydration require appropriate consideration.
Cimetidine or probenecid
These reduce renal clearance of aciclovir and increase systemic exposure, which may be important when exposure is already high or kidney function is reduced.
Common questions about valaciclovir hydrochloride
Answers are fully visible for fast scanning and source review.
Can valaciclovir hydrochloride cure herpes?
No. It restricts viral replication and can shorten or suppress outbreaks, but herpes viruses remain in the body and may reactivate.
Can valaciclovir hydrochloride stop genital herpes spreading to a partner?
It can reduce viral shedding and transmission risk but does not remove it. Avoid sex during symptoms and continue safer-sex measures.
Can valaciclovir hydrochloride be taken with food?
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.