Acyclovir Reduces the Duration of Fever in Patients with Infectious Mononucleosis-like Illness

Abstract

Acyclovir is known for its antiviral activity against some pathogenic viruses such as the Epstein-Barr virus (EBV) that causes infectious mononucleosis (IM) and IM-like illness. Therefore, we empirically administered acyclovir to patients with suspected EBV-IM and IM like-illness, upon their admission to our hospital. We admitted 25 patients, who were hospitalized for fever and lymphadenopathy, to the Tohoku University Hospital Infectious Disease Ward. As part of treatment, 8 of these patients were given acyclovir (750 mg/day) with their consent and were assigned to the acyclovir group; the remaining 17 patients were assigned to the control group. The mean age of acyclovir patients (all men) was 42 ± 5.2 years, and that of control patients (13 men and 4 women) was 31 ± 3.0 years. The cause of illness was confirmed as EBV-IM in 6 patients (1, acyclovir; 5, control), and remained unknown for the other 19 IM-like illness patients (7, acyclovir; 12, control). A shorter duration of hospitalization and fever was observed in the acyclovir compared to that in the control patients (hospitalization duration: 16 ± 3.7 vs. 27 ± 7.7 days, P = 0.36; fever duration: 4.5 ± 1.8 vs. 18 ± 6.5 days, P = 0.04). Additionally, serum amyloid A (SAA) levels were lower in acyclovir than that in control patients (98 ± 37 vs. 505 ± 204 μg/mL, P = 0.02). Therefore, we propose that acyclovir is a potential therapeutic agent for both EBV-IM and IM like-illnesses. Future studies should further examine its mechanism of action.

Effect of Oral Acyclovir on Hospitalized Children with Infectious Mononucleosis: A Double-blind Clinical Trial

“…In line with our study, Tynell et al reported that acyclovir significantly reduced virus influx but had no significant effect on the severity of symptoms in the intervention group (11). In another study, Usami et al reported that acyclovir can reduce the duration of the disease (17). Some other studies reported a heterogeneous pattern (19)(20)(21).…”

“…Consistent with the results of these studies, our findings indicated that acyclovir therapy had no significant effect on the clinical symptoms of patients with acute infectious mononucleosis. However, some studies reported that antiviral therapy had a significant effect on the severity of patients' clinical symptoms (10,17,18).…”