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Treating shingles (herpes zoster), cold sores (fever blisters or herpes labialis), and treating, suppressing, or reducing transmission of genital herpes in patients with healthy immune systems. It is also used to treat chickenpox in children and teenagers. It is also used to suppress genital herpes in patients with HIV infection.
Valacyclovir is an antiviral. It works by stopping viral replication. However, valacyclovir does not eliminate the virus; it is not a cure. When used as a suppressive therapy in patients with healthy immune systems with genital herpes using safer sex practices, the risk of spreading the infections to others is reduced.
Contact your doctor or health care provider right away if any of these apply to you.
Some medical conditions may interact with valacyclovir. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:
Some MEDICINES MAY INTERACT with valacyclovir. Tell your health care provider if you are taking any other medicines, especially any of the following:
This may not be a complete list of all interactions that may occur. Ask your health care provider if valacyclovir may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.
Use valacyclovir as directed by your doctor. Check the label on the medicine for exact dosing instructions.
Ask your health care provider any questions you may have about how to use valacyclovir.
All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:
Seek medical attention right away if any of these SEVERE side effects occur:
Dizziness; headache; nausea; stomach pain; vomiting.
Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); agitation; aggressive behavior; bloody or dark urine; change in the amount of urine produced; confusion; depression; fatigue; fever; hallucinations; joint pain; lower back pain; painful menstrual periods; pale skin; pinpoint bruises; seizures; severe abdominal pain; severe or persistent headache; shaky movements; speech problems; swelling of the face, hands, feet, or entire body; unsteady movement; unusual bruising or bleeding; weakness; yellowing of the skin or eyes.
This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider. Call your doctor for medical advice about side effects. To report side effects to the appropriate agency, please read the Guide to Reporting Problems to FDA.
Contact 1-800-222-1222 (the American Association of Poison Control Centers), your local poison control center (http://www.aapcc.org ), or emergency room immediately.Proper storage of valacyclovir:
Store valacyclovir at room temperature, between 59 and 77 degrees F (15 and 25 degrees C). Store away from heat, moisture, and light. Do not store in the bathroom. Keep valacyclovir out of the reach of children and away from pets.
This information should not be used to decide whether or not to take valacyclovir or any other medicine. Only your health care provider has the knowledge and training to decide which medicines are right for you. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about valacyclovir. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to valacyclovir. This information is not specific medical advice and does not replace information you receive from your health care provider. You must talk with your healthcare provider for complete information about the risks and benefits of using valacyclovir.
Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only your health care provider has the knowledge and training to decide which medicines are right for you. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this medicine. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not specific medical advice and does not replace information you receive from your health care provider. You must talk with your healthcare provider for complete information about the risks and benefits of using this medicine.
It is possible that some side effects of valacyclovir may not have been reported. These can be reported to the FDA here. Always consult a healthcare professional for medical advice.
Applies to valacyclovir: oral tablet
As well as its needed effects, valacyclovir may cause unwanted side effects that require medical attention.
If any of the following side effects occur while taking valacyclovir, check with your doctor immediately:More common
Some valacyclovir side effects may not need any medical attention. As your body gets used to the medicine these side effects may disappear. Your health care professional may be able to help you prevent or reduce these side effects, but do check with them if any of the following side effects continue, or if you are concerned about them:More common
Applies to valacyclovir: oral tablet
Gastrointestinal side effects have included nausea (up to 15%), abdominal pain (up to 11%), and vomiting (up to 6%). Constipation, anorexia, diarrhea, elevated amylase, and elevated serum lipase have been reported. Diarrhea has been reported during postmarketing experience. In clinical trials of otherwise healthy individuals, frequencies were higher for patients over 50 years of age than for younger patients.[Ref]
Nervous system side effects have included headache (up to 38%) and dizziness (up to 4%). Central nervous system effects including agitation, seizures, and encephalopathy have been reported. Choreiform movements, myoclonus, vasculitic mononeuritis multiplex, somnolence, and Cotard's syndrome have been reported. Agitation, ataxia, coma, decreased consciousness, dysarthria, encephalopathy, seizures, and tremors have been reported during postmarketing experience. Neurotoxicity has been most commonly reported in patients with renal failure, the elderly, and in patients following bone marrow transplant, and is associated with high serum concentrations of acyclovir.[Ref]
Acyclovir neurotoxicity is almost exclusively seen in patients with renal failure. These patients may have longstanding chronic renal failure, or acute failure which may be attributed to acyclovir. One group of six bone marrow transplant patients exhibited abnormal EEGs with diffuse slowing. Although more commonly seen with intravenous administration of higher doses, neurotoxicity has also been reported in patients receiving oral doses of acyclovir. Following discontinuation of therapy, mental status recovered within about a week. Several patients with chronic renal failure exhibiting neurotoxicity improved dramatically following hemodialysis.
Although there have been no similar reports in clinical trials of valacyclovir completed to date, the assumption may be made that neurotoxicity can also occur with valacyclovir based on the fact that plasma acyclovir concentrations from oral valacyclovir administration tend to be much higher than those obtained with oral acyclovir.[Ref]
Psychiatric side effects have included depression (up to 7%) and disorientation. Central nervous system effects including hallucinations, confusion, and delirium have been reported. Aggressive behavior, confusion, mania, and psychosis (including auditory and visual hallucinations) have been reported during postmarketing experience.
Transient renal dysfunction has been reported with both oral and intravenous administration of acyclovir. Crystallization of the drug in the renal tubules is thought to be the mechanism for the development of renal dysfunction based on findings of crystalluria in several case reports and at least one prospective study. Inadequate hydration of the patient and rapid administration of the drug may contribute to the development of crystalluria. Acute tubular necrosis and interstitial nephritis have also been reported in association with acyclovir therapy. Although there have been no similar reports in clinical trials of valacyclovir completed to date, the assumption may be made that renal toxicity can also occur with valacyclovir based on the fact that plasma acyclovir concentrations from oral valacyclovir administration tend to be much higher than those obtained with oral acyclovir.[Ref]
Renal side effects have included acute renal failure, elevated serum creatinine (up to 0.7%), renal toxicity, and renal failure (presenting as an increase in serum creatinine and blood urea nitrogen). Renal failure and renal pain (may be associated with renal failure) have been reported during postmarketing experience. Renal effects are transient and resolve over several days following discontinuation of therapy. Renal damage is most likely due to crystallization of acyclovir in the renal tubules. Patients with preexisting renal insufficiency are at greater risk for developing neurotoxicity and further deterioration in renal function.[Ref]
Hematologic side effects have included thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS), and decreased neutrophil counts (18%), platelet counts (up to 3%), hemoglobin (up to 0.8%), and white blood cells (up to 1.3%). Thrombocytopenia, aplastic anemia, leukocytoclastic vasculitis, and TTP/HUS have been reported during postmarketing experience.[Ref]
TTP/HUS, including some fatalities, has been reported during clinical trials in patients with advanced HIV disease and in allogeneic bone marrow transplant and renal transplant recipients, who were receiving 8 g valacyclovir per day.[Ref]
Hepatic side effects have included elevated AST (up to 16%), ALT (up to 14%), and bilirubin. Liver enzyme abnormalities and hepatitis have been reported during postmarketing experience.[Ref]
Hypersensitivity side effects have included acute hypersensitivity reactions (including anaphylaxis, angioedema, dyspnea, pruritus, rash, and urticaria) during postmarketing experience. Stevens-Johnson syndrome has been reported.[Ref]
Dermatologic side effects have included rash (8%). Erythema multiforme, rashes including photosensitivity, and alopecia have been reported during postmarketing experience.[Ref]
Cardiovascular side effects have included hypertension and tachycardia during postmarketing experience.[Ref]
Ocular side effects have included visual abnormalities during postmarketing experience.[Ref]
Respiratory side effects have included nasopharyngitis (16%) and upper respiratory tract infection (9%).[Ref]
Musculoskeletal side effects have included arthralgia (up to 6%).[Ref]
Genitourinary side effects have included dysmenorrhea (up to 8%).[Ref]
Other side effects have included fatigue (8%). Facial edema has been reported during postmarketing experience.[Ref]
Metabolic side effects have included elevated alkaline phosphatase (4%) and hypoglycemia. At least one case of hypercalcemia has been reported.[Ref]
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