Valacyclovir is used to treat herpes zoster (shingles) in immunocompetent patients; treatment of first-episode genital herpes; episodic treatment of recurrent genital herpes; suppression of recurrent genital herpes and reduction of heterosexual transmission of genital herpes in immunocompetent patients; suppression of genital herpes in HIV-infected individuals; treatment of herpes labialis (cold sores). Valacyclovir is an antiviral drug. It slows the growth and prevents the spread of herpes virus. It lessens the symptoms of these infections; however, it is not a cure for herpes virus infections.
Valacyclovir should be taken exactly as directed by your doctor. It should be taken with a full glass of water, with or without food. Even if you feel better, take all valacyclovir that has been prescribed for you. Your symptoms may start to improve before the infection is completely treated. Take valacyclovir regularly to the most benefit. Store at room temperature and away from moisture and heat.
Valacyclovir should be started as soon as possible after the first appearance of symptoms; however, do not take valacylcovir without first talking to your doctor. Tell your doctor if you have kidney disease or immune system problems. You may need a dosage adjustment or special monitoring during treatments. It is not expected to be harmful to an unborn baby; however, it is not known whether valacyclovir passes into breast milk and how it may affect a nursing baby. Talk to your doctor if you are breast feeding a baby.
Symptoms of overdose may include: seizures, hallucinations, and kidney damage.
If you experience an allergic reaction (difficulty breathing, closing of the throat, swelling of the lips, tongue, or face; or hives), stop taking valacyclovir and seek emergency medical attention. Less serious side effects are: nausea, vomiting, diarrhea, constipation, or abdominal pain; headache; dizziness; or tremors.
You may need a dosage adjustment or special monitoring during treatment if you are taking probencid or cimetidine. Other drugs that can affect valacyclovir are over-the-counter medicines, vitamins, minerals, and herbal products.
Herpes infections are contagious, and you can infect other people even during treatment. Wash your hands frequently to prevent transmission. Valacylcovir does not prevent the spread of genital herpes. Avoidance of sexual intercourse and use of latex condoms may prevent spreading the virus to others. Lesions caused by herpes viruses should be kept as clean and dry as possible. Wearing loose clothing may help to prevent irritation.
Valacyclovir hydrochloride is a white to off-whitepowder with the molecular formula C13H20N6O4·HCl and a molecular weight of 360.80. The maximum solubility in water at 25°C is 174 mg/mL. The pka’s for valacyclovir hydrochloride are 1.90, 7.47, and 9.43. Valacylcovir Caplets are for oral administration. Each caplet contains valacyclovir hydrochloride equivalent to 500 mg or 1 gram valacyclovir and the inactive ingredients carnauba wax, colloidal silicon dioxide, crospovidone, FD&C Blue No. 2 Lake, hypromellose, magnesium stearate, microcrystalline cellulose, polyethylene glycol, polysorbate 80, povidone, and titanium dioxide. The blue, film-coated caplets are printed with edible white ink.
Valacylcovir has the following structural formula: