Valaciclovir side effects

List of side effects
Frequent adverse events Lab abnormalities Suppression of genital herpes in HIV-infected patients Reduction of transmission Cold sores (herpes labialis) Observed during clinical practice Renal impairment
 * Herpes zoster
 * Genital herpes

Herpes zoster
Frequently reported adverse events in clinical trials of Valaciclovir in healthy patients with herpes zoster include: nausea, headache, vomitting, dizziness, and abdominal pain. Return to top

Genital herpes
Frequently reported adverse events in clinical trials of Valaciclovir in healthy patients with genital herpes include: nausea, headache, vomitting, dizziness, abdominal pain, dysmenorrhea, arthralgia, and depression. Return to top

Lab abnormalities
Laboratory abnormalities reported in clinical trials of Valaciclovir in otherwise healthy patients include: hemoglobin (<0.8 x LLN), white blood cells (<0.75 x LLN), platelet count (<100,000/mm3), AST (SGOT) (>2 x ULN), and serum creatinine (>1.5 x ULN). Return to top

Suppression of genital herpes in HIV-infected patients
In HIV-infected patients, frequently reported adverse events for Valaciclovir (500 mg twice daily; n = 194, median days on therapy = 172) and placebo (n = 99, median days on therapy = 59), respectively, included headache (13% vs. 8%), fatigue (8% vs. 5%), and rash (8% vs. 1%). Post-randomization laboratory abnormalities that were reported more frequently in valacyclovir subjects versus placebo included elevated alkaline phosphatase (4% vs. 2%), elevated ALT (14% vs. 10%), elevated AST (16% vs. 11%), decreased neutrophil counts (18% vs. 10%), and decreased platelet counts (3% vs. 0%). Return to top

Reduction of transmission
In a clinical study for the reduction of transmission of genital herpes, the adverse events reported by patients receiving Valaciclovir 500 mg once daily (n = 743) or placebo once daily (n = 741) included headache (Valaciclovir 29%, placebo 26%), nasopharyngitis (Valaciclovir 16%, placebo 15%), and upper respiratory tract infection (Valaciclovir 9%, placebo 10%). In this 8-month study, there were no clinically significant changes from baseline laboratory parameters in subjects receiving Valaciclovir compared with placebo. Return to top

Cold sores (herpes labialis)
In clinical studies for the treatment of cold sores, the adverse events reported by patients receiving Valaciclovir (n = 609) or placebo (n = 609) included headache (Valaciclovir 14%, placebo 10%) and dizziness (Valaciclovir 2%, placebo 1%). The frequencies of abnormal ALT (>2 x ULN) were 1.8% for patients receiving Valaciclovir compared with 0.8% for placebo. Other laboratory abnormalities (hemoglobin, white blood cells, alkaline phosphatase, and serum creatinine) occurred with similar frequencies in the 2 groups. Return to top

Observed during clinical practice
The following events have been identified during post-approval use of Valaciclovir in clinical practice. Because they are reported voluntarily from a population of unknown size, estimates of frequency cannot be made. These events have been chosen for inclusion due to either their seriousness, frequency of reporting, causal connection to Valaciclovir, or a combination of these factors. Return to top
 * General: facial edema, hypertension, tachycardia.
 * Allergic: acute hypersensitivity reactions including anaphylaxis, angioedema, dyspnea, pruritus, rash, and urticaria.
 * CNS symptoms: aggressive behavior; agitation; ataxia; coma; confusion; decreased consciousness; dysarthria; encephalopathy; mania; and psychosis, including auditory and visual hallucinations; seizures, tremors.
 * Eye: visual abnormalities.
 * Gastrointestinal: diarrhea.
 * Hepatobiliary tract and pancreas: liver enzyme abnormalities, hepatitis.
 * Renal: elevated creatinine, renal failure, renal pain (may be associated with renal failure).
 * Hematologic: thrombocytopenia, aplastic anemia, leukocytoclastic vasculitis, TTP/HUS.
 * Skin: erythema multiforme, rashes including photosensitivity, alopecia.

Renal impairment
Renal failureand CNS symptoms have been reported in patients with renal impairment who received Valaciclovir or acyclovir at greater than the recommended dose. Dose reduction is recommended in this patient population. Return to top