Medically reviewed by Jessica Swirble, PharmD
Last updated on 3/28/2024

Drug Information | Side Effects | Use & Dosage | Request a Prescription

The use of valacyclovir has been shown to cause side effects in some patients.

Common mild side effects include:

• Nausea
  
• Vomiting
  
• Headache
  
• Dizziness
  
• Constipation
  
• Upset stomach/ stomach pain
  
• Diarrhea
  
• Joint pain
  
• Fatigue
  
• Cold symptoms
  
  

More severe side effects are rare but may include:

• Allergic reactions (rash, itching, difficulty breathing, swelling of the face, lips, or throat)
  
• Neurological symptoms (confusion, hallucinations, tremors)
  
• Unusual bleeding or bruising
  
• Signs of liver problems (yellowing of the skin or eyes, dark urine, abdominal pain)
  
  

If you experience any severe or persistent side effects while taking valacyclovir, seek medical attention promptly.

Before starting treatment with valacyclovir, tell your healthcare provider about any existing medical conditions, allergies, or other medications you are taking. This includes prescription drugs, over-the-counter medications, and dietary supplements, as they may interact with this drug.

Tell your provider if you are taking these medications or supplements:

• Cimetidine
  
• Probenecid
  
• Methotrexate
  
• Cancer medications
  
  

You should also mention medical conditions such as:

• Kidney disease
  
• Liver disease
  
• HIV or AIDS
  
  

Tell your provider if you have had a bone marrow transplant.

If you are pregnant, planning to become pregnant, or breastfeeding, consult your healthcare provider before using valacyclovir to assess potential risks and benefits.

You can follow your regular diet while taking valacyclovir. Talk to your healthcare provider about the use of this drug with food, beverages, alcohol, and tobacco.

Drink plenty of water while taking valacyclovir to stay hydrated and support kidney function.

Avoid alcohol while using valacyclovir, as it may increase the risk of side effects or interfere with the medication's effectiveness.

Practice safe sex to reduce the risk of transmitting herpes to others, even while taking valacyclovir.

Your healthcare provider will provide specific instructions regarding the use of valacyclovir with food, beverages, and other medications. It's essential to follow their guidance to ensure the effectiveness of the treatment and minimize the risk of side effects.

If you suspect an overdose of valacyclovir or experience severe symptoms, seek immediate medical attention or contact a poison control center.

Severe symptoms may include:

• Dizziness
  
• Confusion
  
• Seizures
  
  

If an individual has collapsed, is having trouble breathing, or is unresponsive, call 9-1-1 immediately.