How does valacyclovir hcl work

If it is almost time for your next dose, skip the missed dose and continue with your usual dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.

Do not dispose of medications in wastewater e. Ask your pharmacist how to dispose of medications that are no longer needed or have expired. Do not take this medication if you are allergic to valacyclovir, acyclovir, or any ingredients of the medication. Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent. The side effects listed below are not experienced by everyone who takes this medication.

If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor. Many of these side effects can be managed, and some may go away on their own over time. Contact your doctor if you experience these side effects and they are severe or bothersome.

Your pharmacist may be able to advise you on managing side effects. Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention. Stop taking the medication and seek immediate medical attention if any of the following occur:. Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication. Genital herpes: To reduce the risk of spreading the virus, wash your hands immediately after touching your skin sores.

You should avoid intimate contact when live lesions are visible on your skin. The herpes virus can still be spread even when you do not have blisters or sores. Immunosuppression weak immune system : People who have a weakened immune system should only use valacyclovir if the benefits outweigh the risks.

This drug can also make your kidney function worse. To help prevent these problems, your doctor may prescribe a lower dosage of this drug for you. For people with advanced HIV or a history of transplant: If you have advanced HIV or a history of bone marrow or kidney transplant, you may be at a higher risk of certain blood disorders.

They can result in severely low red blood cells and platelets in your body. For pregnant women: This drug is a category B pregnancy drug. That means two things:. Animal studies do not always predict the way humans would respond. Therefore, this drug should only be used in pregnancy if clearly needed.

For women who are breastfeeding: This drug may pass into breast milk and may cause side effects in a child who is breastfed. Talk to your doctor if you breastfeed your child. You may need to decide whether to stop breastfeeding or stop taking this medication.

For seniors: The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, a higher amount of a drug stays in your body for a longer time. This raises your risk of side effects. For children: This drug has not been studied for use in treatment or prevention of herpes simplex virus HSV infection in newborn babies.

The following are other age limitations for use of this drug:. All possible dosages and drug forms may not be included here. Your dosage, drug form, and how often you take the drug will depend on:.

The kidneys of older adults may not work as well as they used to. Your doctor may start you on a lowered dosage or a different treatment schedule. This can help keep levels of this drug from building up too much in your body. This drug has not been studied for the treatment of genital herpes in children younger than 18 years.

This drug has not been studied or approved for treatment of chickenpox in children younger than two years. However, because drugs affect each person differently, we cannot guarantee that this list includes all possible dosages. Always speak with your doctor or pharmacist about dosages that are right for you. Valacyclovir oral tablet is used for short-term treatment of oral herpes, genital herpes, shingles, or chickenpox. You should not stop taking this drug unless your doctor tells you to stop.

If you take too much: You could have dangerous levels of the drug in your body. Symptoms of an overdose of this drug can include more severe side effects, such as:. But if your symptoms are severe, call or go to the nearest emergency room right away. What to do if you miss a dose: Take your dose as soon as you remember.

But if you remember just a few hours before your next scheduled dose, take only one dose. 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. 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. However, spermicidal sperm-killing jelly or a diaphragm will probably not help. 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. 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. The NLM also state that dizziness is a common side effect in people using Valtrex for cold sores. Other symptoms may occur when treating either shingles or herpes with Valtrex at different or prolonged doses.

The NLM state that there are no known major drug interactions between Valtrex and other medications. There is also no known risk of taking Valtrex during pregnancy or while breastfeeding.

However, the NLM acknowledge that a very small amount will be present in breast milk. There is a risk of accidental overdose, so a person taking Valtrex should make sure they stick to the prescribed dosage. People living with kidney issues should talk to their doctor about their risk before taking the medication.

Valtrex is not the only prescription available for oral herpes. Famvir famciclovir is another antiviral medication for cold sores, shingles, and genital herpes. It has similar side effects to Valtrex, such as headaches and nausea. Like Valtrex, people take it orally. Prescription and nonprescription creams are available for a person to apply directly to their cold sores.

Prescription-strength creams include Zovirax acyclovir , while nonprescription creams include Abreva docosanol. However, creams are generally less effective than oral forms of antiviral medications, such as Valtrex.

A person with kidney issues or kidney failure should ensure their doctor is aware of their situation. People with these conditions may want to ask about possible alternatives to the medication.