Valacyclovir (Oral route)
Viral DNA Polymerase Inhibitor
Guanosine Nucleoside Analog
Uses of This Medicine:
Valacyclovir is used to treat herpes virus infections, including herpes labialis (also known as cold sores), herpes zoster (also known as shingles), and herpes simplex (also known as genital herpes) in adults. It is also used to treat chickenpox and cold sores in children.
In your body, valacyclovir becomes the anti-herpes medicine, acyclovir. Although valacyclovir will not cure shingles or genital herpes, it does help relieve the pain and discomfort and helps the sores heal faster.
Valacyclovir is available only with your doctor's prescription.
Before Using This Medicine:
In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Appropriate studies have not been performed on the relationship of age to the effects of valacyclovir in children below 12 years of age with cold sores, and children below 2 years of age with chickenpox. Safety and efficacy have not been established.
Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of valacyclovir in the elderly. However, elderly patients are more likely to have age-related kidney disease, which may require an adjustment in the dose of patients receiving valacyclovir.
Studies in women suggest that this medication poses minimal risk to the infant when used during breastfeeding.
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.
Other medical problems—
The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:
Proper Use of This Medicine:
Valacyclovir works best if it is used within 48 hours after the first symptoms of shingles or genital herpes (e.g., pain, burning, or blisters) begin to appear. For recurrent outbreaks of genital herpes, valacyclovir works best if it is used within 24 hours after the symptoms begin to appear.
If you are taking valacyclovir for the treatment of chickenpox, it is best to start taking valacyclovir as soon as possible after the first sign of the chickenpox rash appears, usually within one day.
Valacyclovir may be taken with meals or on an empty stomach.
If you are using the oral suspension, use a specially marked measuring spoon or other device to measure each dose accurately. The average household teaspoon may not hold the right amount of liquid.
Drink extra fluids so you will pass more urine while you are using this medicine. This will keep your kidneys working well and help prevent kidney problems.
To help clear up your infection, keep taking valacyclovir for the full time of treatment, even if your symptoms begin to clear up after a few days. Do not miss any doses. However, do not use this medicine more often or for a longer time than your doctor ordered.
The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.
Keep out of the reach of children.
Do not keep outdated medicine or medicine no longer needed.
Ask your healthcare professional how you should dispose of any medicine you do not use.
Precautions While Using This Medicine:
If you or your child's symptoms do not improve within a few days, or if they become worse, check with your doctor.
The areas affected by genital herpes, chickenpox, or shingles should be kept as clean and dry as possible. Also, wear loose-fitting clothing to avoid irritating the sores (blisters).
It is important to remember that this medicine will not keep you from spreading herpes to others.
Herpes infection of the genitals can be caught from or spread to your partner during any sexual activity. Even though you may get herpes if your partner has no symptoms, the infection is more likely to be spread if sores are present. This is true until the sores are completely healed and the scabs have fallen off. Therefore, it is best to avoid any sexual activity if either you or your sexual partner has any symptoms of herpes. The use of a latex condom (“rubber") may help prevent the spread of herpes. However, spermicidal (sperm-killing) jelly or a diaphragm will probably not help.
Side Effects of This Medicine:
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Last Updated: 4/4/2014
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