Do not use Valtrex if:

• you are allergic to any ingredient in Valtrex or to acyclovir.

• Valtrex may cause dizziness. These effects may be worse if you take it with alcohol or certain medicines. Use Valtrex with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.
• Safer sex practices can lower the chances of passing genital herpes to your partner. Do not have sexual contact with your partner when you have any symptoms or outbreak of genital herpes. Use a condom made of latex or polyurethane whenever you have sexual contact.
• Use Valtrex with caution in the elderly; they may be more sensitive to its effects, especially kidney and nervous system problems.
• Valtrex should not be used in children who have not reached puberty; safety and effectiveness in children have not been confirmed.
• Pregnancy and breast-feeding: If you think you may be pregnant, contact your doctor. You will need to discuss the benefits and risks of using Valtrex while you are pregnant. Valtrex is found in breast milk. If you are or will be breast-feeding while you use Valtrex, check with your doctor. Discuss any possible risks to your baby.

Check with your doctor if any of these most common side effects persist or become bothersome:

• diarrhea; 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); aggressive behavior; bloody or dark urine; confusion; fever; hallucinations; pale skin; pinpoint bruises; seizures; shaky movements; speech problems; unsteady movement; weakness; yellowing of the skin or eyes.

If you have any questions about Valtrex, please talk with your doctor, pharmacist, or other health care provider.

Valtrex is to be used only by the patient for whom it is prescribed. Do not share it with other people.