acyclovir and Delirium

Neurotoxicity associated with acyclovir use is infrequently encountered. However, the half-life of acyclovir is greatly prolonged in patients with end-stage renal disease, predisposing these patients to neurological side effects that are generally reversible but occasionally severe. In general, renal dialysis effectively decreases the serum level of acyclovir, which correlates with toxicity. We report an unusual case of delirium and coma in a patient undergoing hemodialysis who was receiving what appeared to be an appropriately adjusted dose of acyclovir.

Topics: Acyclovir; Aged; Coma; Delirium; Herpes Simplex; Humans; Kidney Failure, Chronic; Male; Penile Diseases; Renal Dialysis; Ulcer

Topics: Acyclovir; Antineoplastic Agents, Alkylating; Antiviral Agents; Brain Stem Neoplasms; Cognitive Dysfunction; Cranial Irradiation; Dacarbazine; Delirium; Dexamethasone; Diagnosis, Differential; Encephalitis, Herpes Simplex; Female; Glioma; Herpesvirus 1, Human; Humans; Leukocytosis; Magnetic Resonance Imaging; Seizures; Temozolomide; Young Adult

A 70-year-old man developed herpes zoster over the right L5-S2 region for 3 days and was admitted for acyclovir therapy. He had a medical history of rectal cancer status post-colostomy and end-stage renal disease undergoing thrice weekly hemodialysis. Without a prior loading dose, acyclovir 500 mg (7.7 mg/kg) daily was given intravenously in two divided doses. On the third dosage, the patient became confused and agitated and developed insomnia. Within the following 24 h, delirium, visual and auditory hallucinations, disorientation to place and time, as well as impaired recent memory occurred. At the same time, a transient low grade fever (38 degrees C) was noted but resolved spontaneously after ice pillow (Fig. 1). The etiology was vigorously explored. He had no history of any neurological or psychiatric disorders. Drug history was reviewed, but no other medications besides acyclovir were currently being used. Physical examination revealed neither meningeal signs nor focal neurological deficits. Serum blood urea nitrogen, glucose, and electrolytes were within normal limits except for an elevated creatinine level at 6.2 and 5.7 mg/dl (before and after neuropsychotic symptoms, respectively). Complete blood count with differentiation was also unremarkable. Cerebrospinal fluid examination was not possible as the patient's family refused the lumbar puncture. Moreover, an electroencephalograph study and head computed tomography scan disclosed no abnormalities. Acyclovir-induced neurotoxicity was suspected. Therefore, acyclovir was discontinued. Subsequently, serum acyclovir and CMMG were checked by enzyme-linked immunosorbent assay. Serum acyclovir level was 1.6 mg/l (normal therapeutic level, 0.12-10.8 mg/l) and CMMG level was 5 mg/l. Emergent hemodialysis (4-h/session) was given; the neuropsychotic symptoms, including agitation, delirium, and visual and auditory hallucinations, greatly abated after the second session. The patient fully recovered after three consecutive days of hemodialysis; the serum was rechecked and revealed that the acyclovir level was below 0.5 mg/l and the CMMG level was undetectable. At the same time, his herpetic skin lesions resolved well.

Topics: Acyclovir; Aged; Antiviral Agents; Delirium; Guanine; Hallucinations; Herpes Zoster; Humans; Kidney Failure, Chronic; Male; Renal Dialysis

In differential diagnosis of a delir also adverse effects of medicaments have to be taken into account beside other causes. We report a case of an agitated delir with nocturnal disturbance of consciousness, confusion, restlessness and sleeplessness. This delir existed exclusively during the therapy of a cutaneous herpes zoster with zovirax-pills which can only be explained by a causal connection--after exclusion of other causes. As a so far undescribed predisposition for neurotoxicity of oral therapy with acyclovir signs of vascular encephalopathy were found in the patient's cranial magnetic resonance imaging. The central nervous side effects of acyclovir were summarized shortly.

Topics: Acyclovir; Aged; Antiviral Agents; Brain; Delirium; Dementia, Vascular; Diagnosis, Differential; Herpes Zoster; Humans; Magnetic Resonance Imaging; Male; Psychoses, Substance-Induced