What Are the Most Common Valacyclovir Side Effects?

Valacyclovir side effects are typically mild and may include dizziness, headache, or gastrointestinal disturbances. Depression, insomnia, or loss of appetite may also occur when taking this medication. More serious potential valacyclovir side effects include confusion, decreased urination, or seizures. A severe and potentially fatal allergic reaction known as anaphylaxis may cause symptoms such as difficulty breathing, facial swelling, or chest pain. Any specific questions or concerns about possible valacyclovir side effects in an individual situation should be discussed with a doctor or other medical professional.

The headaches and dizziness associated with the use of this medication are usually mild and may fade as the body adjusts to the drug. A sudden or severe headache should be reported to a doctor immediately to make sure an aneurysm or stroke is not the cause of the pain. Digestive issues such as nausea, vomiting, or diarrhea are relatively common valacyclovir side effects, although these symptoms do not typically cause the need to discontinue use of the medication. If severe abdominal pain occurs or if the patient experiences black or bloody vomit or diarrhea, emergency medical assistance is recommended.

Muscle and joint pain may occur when taking this medication and can range from mild to severe in nature. Over-the-counter or prescription pain medications may help to reduce these symptoms. Some patients experience enough pain that they must discontinue the use of this drug, although dosage adjustments may help avoid this. It is important that this medication is discontinued only under the direct supervision of a doctor in order to avoid the risks of developing complications.

Hallucinations, confusion, or the development of seizures are possible valacyclovir side effects that should be discussed with the supervising physician right away. Frequent urination, visual disturbances, or a rash consisting of multiple blisters may be a sign of significant complications that require immediate treatment. Blood test results may appear abnormal during treatment with this medication, but they generally return to normal when the drug is discontinued.

An allergic reaction to valacyclovir is not a common occurrence, although it can prove to be fatal if not treated immediately. Increased heart rate, difficulty breathing, and facial swelling are typical symptoms of anaphylaxis and should be considered a medical emergency. Hospitalization is often required, and the patient may require the use of life support measures such as oxygen therapy or a ventilator. An injectible medication known as epinephrine may be prescribed in case the patient has a repeat occurrence of anaphylaxis.