Valacyclovir

Valacyclovir tablets are a deoxynucleoside analogue DNA polymerase inhibitor indicated for: Adult Patients ( 1.1 ) Cold Sores (Herpes Labialis) Genital Herpes Treatment in immunocompetent patients (initial or recurrent episode) Suppression in immunocompetent or HIV-1–infected patients Reduction of transmission Herpes Zoster Pediatric Patients ( 1.2 ) Cold Sores (Herpes Labialis) Chickenpox Limitations of Use ( 1.3 ) The efficacy and safety of valacyclovir tablets have not been established in immunocompromised patients other than for the suppression of genital herpes in HIV-1–infected patients. …

• 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 ]
• Adult Dosage Cold Sores 2 grams every 12 hours for 1 day Genital Herpes Initial episode 1 gram twice daily for 10 days Recurrent episodes 500 mg twice daily for 3 days Suppressive therapy Immunocompetent patients 1 gram once daily Alternate dose in patients with less than or equal to 9 recurrences/year 500 mg once daily HIV-1–infected patients 500 mg twice daily Reduction of transmission 500 mg once daily Herpes Zoster 1 gram 3 times daily for 7 days Pediatric Dosage Cold Sores (aged greater than or equal to 12 years) 2 grams every 12 hours for 1 day Chickenpox (aged 2 to less than 18 years) 20 mg/kg 3 times daily for 5 days; not to exceed 1 gram 3 times daily Valacyclovir oral suspension (25 mg/mL or 50 mg/mL) can be prepared from the 500 mg valacyclovir tablets
• 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 10 days. …

Valacyclovir Tablets, USP are available containing 556.2 mg or 1.112 grams of valacyclovir hydrochloride, USP (hydrous), which are equivalent to 500 mg or 1 gram of valacyclovir, on the anhydrous basis, respectively. The 500 mg tablets are white, film-coated, oval, unscored tablets with M122 imprinted with black ink on one side of the tablet and plain on the other side of the tablet. …

• Valacyclovir is indicated for treatment of cold sores
• In pediatric patients aged greater than or equal to 12 years and for treatment of chickenpox
• In pediatric patients aged 2 to less than 18 years [see Indications and Usage , Dosage and Administration ]
• The use of valacyclovir tablets for treatment of cold sores is based on 2 double-blind, placebo-controlled clinical trials in healthy
• Adults and adolescents (aged greater than or equal to 12 years) with a history of recurrent cold sores [see Clinical Studies ] . …

Of the total number of subjects in clinical trials of valacyclovir tablets, 906 were 65 and over, and 352 were 75 and over. In a clinical trial of herpes zoster, the duration of pain after healing (post-herpetic neuralgia) was longer in subjects 65 and older compared with younger adults. Elderly patients are more likely to have reduced renal function and require dose reduction. …

• Advise the patient to read the FDA-approved patient labeling (Patient Information)
• Severe Cutaneous Adverse Reactions Inform patients that severe skin reactions including acute generalized exanthematous pustulosis (AGEP), drug reaction with eosinophilia and systemic symptoms (DRESS), toxic epidermal necrolysis (TEN), Stevens-Johnson syndrome (SJS), and erythema multiforme (EM) have been reported with valacyclovir
• Advise patients to immediately contact their healthcare provider if they develop a rash. …

• Valacyclovir tablets are contraindicated in patients who have had a demonstrated clinically significant hypersensitivity reaction [e.g., anaphylaxis, severe cutaneous adverse reactions (SCARs)] to valacyclovir, acyclovir, or any component of the formulation [see Warnings and Precautions , Adverse Reactions ]
• Hypersensitivity to valacyclovir (e.g., anaphylaxis), acyclovir, or any component of the formulation

No clinically significant drug-drug or drug-food interactions with valacyclovir tablets are known [see Clinical Pharmacology (12.3) ].

Thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS): Has occurred in patients with advanced HIV-1 disease and in allogenic bone marrow transplant and renal transplant patients receiving 8 grams per day of valacyclovir tablets in clinical trials. Discontinue treatment if clinical symptoms and laboratory findings consistent with TTP/HUS occur. ( 5.1 ) Acute renal failure: May occur in elderly patients (with or without reduced renal function), patients with underlying renal disease who receive higher-than-recommended doses of valacyclovir tablets for their level of renal function, patients who receive concomitant nephrotoxic drugs, or inadequately hydrated patients. …

The following serious adverse reactions are discussed in greater detail in other sections of the labeling: Thrombotic Thrombocytopenic Purpura/Hemolytic Uremic Syndrome [see Warnings and Precautions (5.1) ]. Acute Renal Failure [see Warnings and Precautions (5.2) ] . Central Nervous System Effects [see Warnings and Precautions (5.3) ] . Severe Cutaneous Adverse Reactions [see Warnings and Precautions (5.4) ] . The most common adverse reactions reported in at least 1 indication by greater than 10% of adult subjects treated with valacyclovir tablets and observed more frequently with valacyclovir tablets compared with placebo are headache, nausea, and abdominal pain. …

8.1 Pregnancy Risk Summary Clinical data over several decades with valacyclovir and its metabolite, acyclovir, in pregnant women, have not identified a drug associated risk of major birth defects. There are insufficient data on the use of valacyclovir regarding miscarriage or adverse maternal or fetal outcomes (see Data ) . There are risks to the fetus associated with untreated herpes simplex during pregnancy (see Clinical Considerations ). …

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) ] .

Take it when you remember, unless it is nearly time for the next dose. Then skip the missed one. Never take two doses at once to make up for it. Check your leaflet, as some medicines are different.