The use of acyclovir in children

Acute kidney injury due to acyclovir

Acyclovir is an antiviral agent widely used in herpetic infections in children. Although acyclovir is generally well tolerated, severe nephrotoxicity has been reported in some cases. In this report, we present a 16-year-old girl who developed acute renal failure due to acyclovir treatment and who needed repetitive hemodialysis. Renal biopsy was performed in order to confirm the diagnosis. A diagnosis of drug-related acute tubulointerstitial nephritis with focal tubular necrosis was made.

The effect of acyclovir on the tubular secretion of creatinine in vitro

Background

While generally well tolerated, severe nephrotoxicity has been observed in some children receiving acyclovir. A pronounced elevation in plasma creatinine in the absence of other clinical manifestations of overt nephrotoxicity has been frequently documented. Several drugs have been shown to increase plasma creatinine by inhibiting its renal tubular secretion rather than by decreasing glomerular filtration rate (GFR). Creatinine and acyclovir may be transported by similar tubular transport mechanisms, thus, it is plausible that in some cases, the observed increase in plasma creatinine may be partially due to inhibition of tubular secretion of creatinine, and not solely due to decreased GFR. Our objective was to determine whether acyclovir inhibits the tubular secretion of creatinine.

Methods

Porcine (LLC-PK1) and human (HK-2) renal proximal tubular cell monolayers cultured on microporous membrane filters were exposed to [2-¹⁴C] creatinine (5 μM) in the absence or presence of quinidine (1E+03 μM), cimetidine (1E+03 μM) or acyclovir (22 - 89 μM) in incubation medium.

Results

Results illustrated that in evident contrast to quinidine, acyclovir did not inhibit creatinine transport in LLC-PK1 and HK-2 cell monolayers.

Conclusions

The results suggest that acyclovir does not affect the renal tubular handling of creatinine, and hence, the pronounced, transient increase in plasma creatinine is due to decreased GFR, and not to a spurious increase in plasma creatinine.

Determinants of aciclovir-induced nephrotoxicity in children

BACKGROUND

Aciclovir is the drug of choice for severe systemic herpes virus infections. Nephrotoxicity is one of the clinically significant adverse effects of this drug, but studies examining nephrotoxicity in children are scarce.

OBJECTIVE

To identify risk factors for aciclovir-associated nephrotoxicity in the pediatric population.

PATIENTS AND METHODS

A retrospective review was conducted on all children (mean age 81 months; n = 126 [74 boys]) who were treated with aciclovir in a tertiary center between July 2005 and January 2006 and who met our inclusion criteria. Glomerular filtration rate (GFR) was calculated on the first day of treatment and at the peak measured creatinine level while on therapy, using Schwartz's method.

RESULTS

Aciclovir therapy was associated with a significant increase in serum creatinine levels and a parallel decrease in GFR (n = 93; both p <or= 0.0001). Children with immunosuppression who received a variety of other nephrotoxic drugs exhibited more severe nephrotoxicity than those not receiving nephrotoxic drugs. In multiple regression analysis, the use of nephrotoxic drugs (p = 0.02) and impaired GFR at baseline (p = 0.04) were predictive for nephrotoxicity.

CONCLUSIONS

Within the recommended age-dependent dosage schedule of aciclovir there was no effect of dose per kg, age, or sex on nephrotoxicity. The predictors of aciclovir nephrotoxicity were the concomitant use of nephrotoxic drugs and impaired GFR at baseline.

Herpes zoster in childhood: case report and review of the literature

Herpes zoster in childhood is uncommon even in the setting of known risk factors such as primary varicella zoster infection before 12 months of age and immunocompromised states. We report a 7-year-old, otherwise healthy girl with shingles, and review the risk factors, prognosis, and treatment of pediatric zoster.

Acyclovir-induced renal failure: course and risk factors

Of 19 children treated with high-dose intravenous acyclovir, 7, all of whom had encephalitis, also had a restricted fluid intake. Of these, 3 experienced non-oliguric renal insufficiency (plasma creatinine up to 176, 250 and 351 mumol/l, respectively) which resolved within 1 week of discontinuing acyclovir. Renal function was stable in the remaining 4 patients in this group and in the 12 children treated with acyclovir but without fluid restriction. We suggest the decreased renal function resulted from intratubular acyclovir crystalluria.

Clinical laboratory applications of monoclonal antibodies

Monoclonal antibody (MAb) technology is well recognized as a significant development for producing specific serologic reagents to a wide variety of antigens in unlimited amounts. These reagents have provided the means for developing a number of highly specific and reproducible immunological assays for rapid and accurate diagnosis of an extensive list of diseases, including infectious diseases. The impact that MAbs have had in characterizing infectious disease pathogens, as well as their current and future applications for use in clinical microbiology laboratories, is reviewed. In addition, the advantages (and disadvantages) of the use of MAbs in a number of immunoassays, such as particle agglutination, radioimmunoassays, enzyme-linked immunosorbent assays, immunofluorescent-antibody assays, and immunohistology, are explored, including the use of these reagents in novel test system assays. Also, nucleic acid probe technology is compared with the use of MAbs from the perspective of their respective applications in the diagnosis of infectious disease agents. There is no question that hybridoma technology has the potential to alter significantly the methods currently used in most clinical microbiology laboratories.

Antiviral treatment of herpes simplex infection in neonates and pregnant women

Herpes simplex infections in neonates include (1) infections beginning in skin or mucous membranes, (2) infections of the central nervous system, and (3) disseminated herpes of the newborn. Early recognition of infections beginning in skin or mucous membranes is essential because 75% will disseminate internally if untreated. Skin lesions provide important diagnostic clues in herpes of the nervous system and disseminated herpes, but they often appear late and in only about 60% of infected neonates. Acyclovir and vidarabine are effective therapies but they must be administered early to prevent serious damage or death. Herpetic skin lesions in neonates may be confused with pyodermas. Direct immunofluorescence and cultures are reliable diagnostic tests. Congenital herpes may cause widespread skin involvement and multiple eye and nervous system diseases. The mother is the source of neonatal herpes in about two thirds of cases. Asymptomatic genital shedding of virus late in pregnancy does not accurately predict whether maternal cultures will be positive at the time of delivery. The risk of the infant acquiring neonatal herpes from a mother with recurrent herpes at birth is about 5%, but the risk is much higher if the mother has true primary genital infection.

Nausea and vomiting possibly associated with intravenous acyclovir

Nausea and vomiting have not been clearly associated with parenteral acyclovir. We report a pediatric patient who developed nausea and vomiting apparently associated with intravenous acyclovir therapy. The child received acyclovir (1500 mg/m2/d) for treatment of recurrent varicella zoster with possible dissemination. Nausea and vomiting could be attributed only to acyclovir therapy. Discontinuing the drug resulted in a resolution of the adverse symptoms. Adverse effects of parenteral acyclovir can mimic the early manifestations of Reye's syndrome, which is an important consideration in children with viral infections. It is necessary to distinguish the cause of nausea and vomiting for proper management of patients.

Is eczema herpeticum associated with the use of hot tubs?

Cutaneous bacterial infections, most commonly caused by Pseudomonas aeruginosa, have been clearly linked to use of hot tubs. A 10-year-old female with atopic eczema developed eczema herpeticum after hot tub use with a friend who had "fever blisters"; herpes simplex virus was recovered from cutaneous vesicles. Since herpesvirus has been shown to survive in the hot tub environment, herpes simplex should be considered as another potential cause of disease in the spa setting.