Note: This document contains side effect information about valacyclovir. Some dosage forms listed on this page may not apply to the brand name Valtrex.
Applies to valacyclovir: oral tablets.
Side effects include:
Headache, nausea, vomiting.
For Healthcare Professionals
Applies to valacyclovir: compounding powder, oral tablet.
General
The most common side effects reported were headache, nausea, and abdominal pain.[Ref]
Nervous system
Cytomegalovirus (CMV) prophylaxis after renal or heart transplants:
-Very common (10% or more): Headache (up to 57%), somnolence (up to 21%)
-Common (1% to 10%): Dizziness, tremor
Other indications:
-Very common (10% or more): Headache (up to 38%)
-Common (1% to 10%): Dizziness, migraine
-Uncommon (0.1% to 1%): Somnolence
-Frequency not reported: Central nervous system (CNS) effects (including seizures, encephalopathy)
-Postmarketing reports: Seizures/convulsions, tremors, ataxia, coma, decreased consciousness, dizziness, dysarthria, encephalopathy[Ref]
CNS side effects (including seizures, encephalopathy) have been reported in patients with or without reduced renal function and in patients with preexisting renal disease receiving doses higher than recommended for their level of renal function. Reversible neurological reactions (including dizziness, rarely decreased consciousness, and very rarely tremor, ataxia, dysarthria, convulsions, encephalopathy, coma) have been reported; such events were generally seen in patients with renal dysfunction or other predisposing factors. Neurological reactions occurred more often in organ transplant recipients receiving high doses (8 g/day) for CMV prophylaxis, compared with lower doses. Elderly patients were more likely to have CNS side effects.[Ref]
Respiratory
CMV prophylaxis after renal or heart transplants:
-Very common (10% or more): Increased cough (up to 57%), dyspnea (up to 36%)
Other indications:
-Very common (10% or more): Rhinitis (up to 26%), influenza syndrome (up to 20%), nasopharyngitis (up to 16%), pharyngitis (up to 12%)
-Common (1% to 10%): Upper respiratory tract infection, sinusitis, bronchitis, increased coughing
-Frequency not reported: Rhinorrhea
-Postmarketing reports: Dyspnea[Ref]
Musculoskeletal
CMV prophylaxis after renal or heart transplants:
-Very common (10% or more): Myalgia (up to 57%), back pain (up to 29%)
-Common (1% to 10%): Arthralgia
Other indications:
-Very common (10% or more): Back pain (up to 12%)
-Common (1% to 10%): Arthralgia, myalgia[Ref]
Other
CMV prophylaxis after renal or heart transplants:
-Very common (10% or more): Peripheral edema (up to 50%), asthenia (up to 43%), pain (up to 43%), general edema (up to 21%), chest pain (up to 21%)
-Common (1% to 10%): Fever, edema
Other indications:
-Very common (10% or more): Infection (up to 18%), pain (up to 11%), fever (up to 11%)
-Common (1% to 10%): Fatigue, asthenia, chills, elevated alkaline phosphatase, accidental injury, unevaluable reaction
-Frequency not reported: Abnormal alkaline phosphatase
-Postmarketing reports: Facial edema[Ref]
Cardiovascular
CMV prophylaxis after renal or heart transplants:
-Very common (10% or more): Pericardial effusion (up to 43%), hypertension (up to 21%)
Other indications:
-Postmarketing reports: Hypertension, tachycardia[Ref]
Gastrointestinal
CMV prophylaxis after renal or heart transplants:
-Very common (10% or more): Nausea (up to 21%), constipation (up to 21%)
-Common (1% to 10%): Diarrhea, abdominal pain, vomiting
Other indications:
-Very common (10% or more): Diarrhea (up to 19%), nausea (up to 16.5%), abdominal pain (up to 12%)
-Common (1% to 10%): Vomiting, constipation, dyspepsia, dry mouth, flatulence, tooth disorder, rectal disorder
-Postmarketing reports: Diarrhea, abdominal discomfort, vomiting[Ref]
Psychiatric
CMV prophylaxis after renal or heart transplants:
-Very common (10% or more): Depression (up to 21%), insomnia (up to 21%), sleep disorder (21%)
-Common (1% to 10%): Hallucination, confusion
Other indications:
-Common (1% to 10%): Depression, insomnia, nervousness
-Frequency not reported: CNS effects (including agitation, hallucinations, confusion, delirium)
-Postmarketing reports: Aggressive behavior, agitation, confusion, mania, psychosis, auditory and visual hallucinations, psychotic symptoms[Ref]
CNS side effects (including agitation, hallucinations, confusion, delirium) have been reported in patients with or without reduced renal function and in patients with preexisting renal disease receiving doses higher than recommended for their level of renal function. Reversible neurological reactions (including confusion, hallucinations) have been reported; such events were generally seen in patients with renal dysfunction or other predisposing factors. Neurological reactions occurred more often in organ transplant recipients receiving high doses (8 g/day) for CMV prophylaxis, compared with lower doses. Elderly patients were more likely to have CNS side effects.[Ref]
Hematologic
Decreased WBCs (less than 0.75 times the lower limit of normal [0.75 x LLN]), platelet count (less than 100,000/mm3) and hemoglobin (less than 0.8 x LLN) have been reported in up to 1.3%, up to 1.1%, and up to 0.8% of patients, respectively.
TTP/HUS (in some cases resulting in death) has occurred in patients with advanced HIV-1 disease (including those receiving this drug for prolonged periods), in allogeneic bone marrow transplant recipients, and in renal transplant recipients during clinical trials of this drug at doses of 8 g/day.
Leukopenia was primarily reported in immunocompromised patients.
Renal insufficiency, microangiopathic hemolytic anemia, and thrombocytopenia (sometimes in combination) have been reported in severely immunocompromised patients (especially those with advanced HIV disease) receiving high doses (8 g/day) of this drug for prolonged periods in clinical trials. Such findings have been seen in patients not treated with this drug who had the same underlying/concurrent conditions.[Ref]
CMV prophylaxis after renal or heart transplants:
-Very common (10% or more): Anemia (up to 12%)
-Common (1% to 10%): Leukopenia, thrombocytopenia
Other indications:
-Very common (10% or more): Decreased neutrophil counts (up to 18%)
-Common (1% to 10%): Decreased WBCs, decreased platelet counts
-Uncommon (0.1% to 1%): Decreased hemoglobin
-Frequency not reported: Abnormal hemoglobin, abnormal WBCs
-Postmarketing reports: Thrombocytopenia, aplastic anemia, leukocytoclastic vasculitis, thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS), leukopenia, thrombotic microangiopathy, microangiopathic hemolytic anemia[Ref]
Hepatic
CMV prophylaxis after renal or heart transplants:
-Common (1% to 10%): Increased ALT, increased AST
Other indications:
-Very common (10% or more): Elevated AST (up to 16%), elevated ALT (up to 14%)
-Common (1% to 10%): Abnormal ALT, elevated AST
-Postmarketing reports: Hepatitis, liver enzyme abnormalities, reversible increases in liver function tests[Ref]
Increased AST (greater than 2 times the upper limit of normal [2 x ULN]) has been reported in up to 4.1% of patients. Abnormal ALT (greater than 2 x ULN) has been reported in 1.8% of patients.[Ref]
Dermatologic
CMV prophylaxis after renal or heart transplants:
-Common (1% to 10%): Pruritus
Other indications:
-Common (1% to 10%): Rash, acne, pruritus
-Frequency not reported: Herpes simplex
-Postmarketing reports: Erythema multiforme, rashes (including photosensitivity), alopecia, pruritus, urticaria, angioedema, drug reaction with eosinophilia and systemic symptoms (DRESS)[Ref]
Hypersensitivity
Other indications:
-Common (1% to 10%): Allergic reaction
-Postmarketing reports: Acute hypersensitivity reactions (including anaphylaxis, angioedema, dyspnea, pruritus, rash, urticaria), anaphylaxis[Ref]
Metabolic
Other indications:
-Common (1% to 10%): Anorexia
-Frequency not reported: Dehydration
Genitourinary
Other indications:
-Common (1% to 10%): Dysmenorrhea, urinary tract infection
-Postmarketing reports: Hematuria[Ref]
Renal
Other indications:
-Uncommon (0.1% to 1%): Increased serum creatinine
-Frequency not reported: Abnormal serum creatinine
-Postmarketing reports: Renal failure/renal insufficiency, renal pain, renal impairment, acute renal failure, intratubular precipitation of acyclovir (aciclovir) crystals in the kidney[Ref]
Increased serum creatinine (greater than 1.5 x ULN) has been reported in up to 0.7% of patients.
Renal pain may have been associated with renal failure.
Renal insufficiency, microangiopathic hemolytic anemia, and thrombocytopenia (sometimes in combination) have been reported in severely immunocompromised patients (especially those with advanced HIV disease) receiving high doses (8 g/day) of this drug for prolonged periods in clinical trials. Such findings have been seen in patients not treated with this drug who had the same underlying/concurrent conditions.[Ref]
Ocular
Other indications:
-Postmarketing reports: Visual abnormalities[Ref]
