Below are the general guidelines for dosing valacyclovir. Note that these dosages may be adjusted on a case-by-case basis for individual patients. Always follow your prescribing physician’s instructions for taking valacyclovir.
The following information comes from DailyMed, an FDA label information provider.
What if I miss a dose of valacyclovir?
According to Mayo Clinic, if you miss a dose of valacyclovir, take the missed dose as soon as possible unless you are closer in time to your next dosing time. If the latter is the case, skip the dose and wait until the next dose time is ready. Never double doses.
What if I overdose on valacyclovir?
Caution should be exercised to prevent inadvertent overdose [see USE IN SPECIFIC POPULATIONS (8.5), (8.6)]. Precipitation of acyclovir in renal tubules may occur when the solubility (2.5 mg/mL) is exceeded in the intratubular fluid. In the event of acute renal failure and anuria, the patient may benefit from hemodialysis until renal function is restored [see DOSAGE AND ADMINISTRATION (2.4)]. If you believe you or someone you know has overdosed on valacyclovir or any medication please call poison control 1- (800) 222-1222 and 911 in case of medical emergency.
Dosage and Administration
- Valacyclovir tablets may be given without regard to meals.
- Valacyclovir oral suspension (25 mg/mL or 50 mg/mL) may be prepared extemporaneously from 500 mg valacyclovir tablets for use in pediatric patients for whom a solid dosage form is not appropriate [see DOSAGE AND ADMINISTRATION (2.3)].
2.1 Adult Dosing Recommendations
Cold Sores (Herpes Labialis): The recommended dosage of valacyclovir tablets for treatment of cold sores is 2 grams twice daily for 1 day taken 12 hours apart. Therapy should be initiated at the earliest symptom of a cold sore (e.g., tingling, itching, or burning).
Genital Herpes: Initial Episode: The recommended dosage of valacyclovir tablets for treatment of initial genital herpes is 1 gram twice daily for 7-10 days. Therapy was most effective when administered within 48 hours of the onset of signs and symptoms.
Recurrent Episodes: The recommended dosage of valacyclovir tablets for treatment of recurrent genital herpes is 500 mg twice daily for 3 days. Initiate treatment at the first sign or symptom of an episode.
Suppressive Therapy: The recommended dosage of valacyclovir tablets for chronic suppressive therapy of recurrent genital herpes is 1 gram once daily in patients with normal immune function. In patients with a history of 9 or fewer recurrences per year, an alternative dose is 500 mg once daily.
In HIV-infected patients with a CD4+ cell count â¥100 cells/mm3, the recommended dosage of valacyclovir tablets for chronic suppressive therapy of recurrent genital herpes is 500 mg twice daily.
Reduction of Transmission: The recommended dosage of valacyclovir tablets for reduction of transmission of genital herpes in patients with a history of 9 or fewer recurrences per year is 500 mg once daily for the source partner.
Herpes Zoster: The recommended dosage of valacyclovir tablets for treatment of herpes zoster is 1 gram 3 times daily for 7 days. Therapy should be initiated at the earliest sign or symptom of herpes zoster and is most effective when started within 48 hours of the onset of rash.
NOTE: Depending upon the patient (immunocompromised status, etc.) the physician may alter the regimens above. There may be other indications and dosage regimens not listed above for valacyclovir.
2.2 Pediatric Dosing Recommendations
Cold Sores (Herpes Labialis): The recommended dosage of valacyclovir tablets for the treatment of cold sores in pediatric patients â¥12 years of age is 2 grams twice daily for 1 day taken 12 hours apart. Therapy should be initiated at the earliest symptom of a cold sore (e.g., tingling, itching, or burning).
Chickenpox: The recommended dosage of valacyclovir tablets for treatment of chickenpox in immunocompetent pediatric patients 2 to <18 years of age is 20 mg/kg administered 3 times daily for 5 days. The total dose should not exceed 1 gram 3 times daily. Therapy should be initiated at the earliest sign or symptom [see USE IN SPECIFIC POPULATIONS (8.4), CLINICAL PHARMACOLOGY (12.3), CLINICAL STUDIES (14.4)].
NOTE: Depending upon the patient (immunocompromised status, etc.) the physician may alter the regimens above. There may be other indications and dosage regimens not listed above for valacyclovir.
2.3 Extemporaneous Preparation of Oral Suspension
Ingredients and Preparation per USP-NF: Valacyclovir tablets 500 mg, cherry flavor, and Suspension Structured Vehicle USP-NF (SSV). Valacyclovir oral suspension (25 mg/mL or 50 mg/mL) should be prepared in lots of 100 mL.
Prepare Suspension at Time of Dispensing as Follows:
- Prepare SSV according to the USP-NF.
- Using a pestle and mortar, grind the required number of valacyclovir 500 mg tablets until a fine powder is produced (5 valacyclovir tablets for 25 mg/mL suspension; 10 valacyclovir tablets for 50 mg/mL suspension).
- Gradually add approximately 5 mL aliquots of SSV to the mortar and triturate the powder until a paste has been produced. Ensure that the powder has been adequately wetted.
- Continue to add approximately 5 mL aliquots of SSV to the mortar, mixing thoroughly between additions, until a concentrated suspension is produced, to a minimum total quantity of 20 mL SSV and a maximum total quantity of 40 mL SSV for both the 25 mg/mL and 50 mg/mL suspensions.
- Transfer the mixture to a suitable 100 mL measuring flask.
- Transfer the cherry flavor* to the mortar and dissolve in approximately 5 mL of SSV. Once dissolved, add to the measuring flask.
- Rinse the mortar at least 3 times with approximately 5 mL aliquots of SSV, transferring the rinsing to the measuring flask between additions.
- Make the suspension to volume (100 mL) with SSV and shake thoroughly to mix.
- Transfer the suspension to an amber glass medicine bottle with a child-resistant closure.
- The prepared suspension should be labeled with the following information “Shake well before using. Store suspension between 2° to 8°C (36° to 46°F) in a refrigerator. Discard after 28 days.”
*The amount of cherry flavor added is as instructed by the suppliers of the cherry flavor.
2.4 Patients With Renal Impairment
Please Note: Renal dosing may differ between adult and pediatric patients. Follow up with your prescribing physician or pharmacist regarding dosing for renal impairment.
How is Valacyclovir supplied?
Product: 63739-525
NDC: 63739-525-10 10 TABLET, FILM COATED in a BLISTER PACK / 10 in a BOX, UNIT-DOSE
Product: 63739-552
NDC: 63739-552-10 10 TABLET, FILM COATED in a BLISTER PACK / 10 in a BOX, UNIT-DOSE
Disclaimer: this article does not constitute or replace medical advice. If you have an emergency or a serious medical question, please contact a medical professional or call 911 immediately. To see our full medical disclaimer, visit our Terms of Use page.
