Valaciclovir is the non-proprietary name for an antiviral medication predominantly used to treat herpes outbreaks. The medication helps prevent outbreaks and reduces the severity of outbreaks that do happen.

Though somewhat less common, the medication has other applications as well. Valaciclovir may be used to help treat:

• Herpes simplex virus type I
• Herpes simplex virus type II
• Varicella zoster virus (shingles)
• Epstein-Barr virus
• Cytomegalovirus (after an organ transplant)

The medication works by attacking an enzyme needed by the viruses to replicate and spread. Unable to thrive, the virus is more easily defeated by the immune system. This provides several benefits to patients, depending on the condition being treated:

• Prevents an outbreak from starting
• Reduces the severity of symptoms
• Reduces the duration of an outbreak
• Reduces the frequency of outbreaks

Treatment with Valaciclovir may not prevent all outbreaks all of the time, but will significantly reduce the frequency with which they happen. Outbreaks that do occur will be shorter and symptoms will not be as apparent or troublesome.

While Valaciclovir is effective at treating symptoms of viral outbreaks, it is not a cure. It may inhibit spread of viruses to others, but does not eliminate the possibility. Herpes in particular is highly contagious and practicing safe sex is highly advisable even if Valaciclovir is being taken.

As an antiviral medication, Valaciclovir will have little effect on bacterial or fungal infections and should not be used to treat them.

Dosage & Administration

Valaciclovir comes in tablets, which should be swallowed whole. Taking with food is optional, but food may help ease gastrointestinal side effects. Plenty of fluids should be consumed for the duration of treatment.

Treatment depends largely on what is being treated.

To treat herpes:

• Treatment should begin at the earliest symptoms an outbreak is starting.
• Take 1000 mg of Valaciclovir per day.
• Treatment typically continues for 5 days.

To reduce or prevent recurrent herpes outbreaks:

• Take 500 mg per day.
• Treatment should continues for 6 to 12 months, at which point treatment should be reevaluated.

To treat shingles:

• Treatment should begin within 72 hours of the first symptoms.
• Take 1000 mg three times per day (total daily dose of 3000 mg).
• Treatment typically continues for 7 days.

To treat Epstein-Barr virus:

• Dosage strength varies by individual; usually between 500 mg to 1500 mg a day, but in some cases as high as 3000 mg.
• It may take several months of treatment before improvements are noticeable.
• Duration of treatment should be determined by a doctor.

To prevent cytomegalovirus:

• Treatment should begin immediately after an organ transplant
• Take 2000 mg four times per day (total daily dose of 8000 mg).
• Treatment typically continues for three months (90 days), but may be longer according to doctor instructions.

Taking smaller-dose Valaciclovir tablets together constitutes one large dose; for example, two 500 mg tablets taken together is the same as taking one 1000 mg tablet.

Valaciclovir is rarely given to children except in cases of organ transplants.

It's important to complete treatment even if symptoms improve or disappear. Discontinuing treatment too soon contributes to virus resistance.

Potential Complications

Side effects from Valaciclovir are fairly rare when the medication is used properly. Most are mild and do not warrant medical attention unless they are severe or persistent:

• Headache
• Nausea
• Fatigue
• Vertigo
• Vomiting
• Diarrhea

Other precautions to ensure treatment goes well:

• Patients with liver or kidney disease should discuss risks with a doctor before use.
• Valaciclovir should not be used in children except to prevent cytomegalovirus after an organ transplant.
• Women who are pregnant or nursing should not take Valaciclovir without explicit doctor instruction.
• A few patients become extremely sensitive to sunlight and tanning beds during treatment, and may need to avoid exposure.
• A rash or swelling of lips, eyes, tongue or throat indicate an allergic reaction and call for immediate medical attention.

Some other drugs are known to interact with Valaciclovir, making treatment less effective. A pharmacist or doctor can point out potentially conflicting medications.