Infections caused by herpes simplex virus in the immunocompromised host: natural history and topical acyclovir therapy.

Sixty-three immunocompromised patients with infections caused by herpes simplex virus were evaluated in a double-blind, placebo-controlled study of topical acyclovir therapy; 33 patients received acyclovir and 30 received the placebo. The two populations of patients were balanced in terms of age, race, sex, underlying disease, preceding chemotherapy, and site, size, and duration of lesions. Acyclovir recipients experienced an acceleration in the clearance of virus (P = .0006), the resolution of pain (P = .004), and the total healing of lesions (P = .038); median temporal differences between populations averaged six days for each of these three parameters. The surface area of herpetic lesions continued to enlarge in placebo recipients after entry into the trial; in contrast, lesion surface area decreased progressively during therapy in drug recipients. The speed of healing was influenced by lesion size. Patients with lesions of greater than or equal to 50 mm2 benefited most from therapy, particularly in terms of pain resolution and time to total healing (median differences between groups, eight days). Irrespective of underlying disease, sex, preceding chemotherapy, or age, acyclovir therapy was of clinical benefit. No adverse clinical or laboratory reactions were encountered.

Treatment of varicella-zoster meningoencephalitis with acyclovir--demonstration of virus in cerebrospinal fluid by electron microscopy.

Disseminated varicella-zoster (V-Z) infection developed in three immunocompromised patients, with direct invasion of the central nervous system by virus. For two of these patients, diagnosis was confirmed by electron microscopic examination of cerebrospinal fluid (CSF) and detection of viral particles. Extensive immunologic evaluation demonstrated impairment of cellular immune function. All were treated with acyclovir at a dose of 1,500 mg/m2/day for 5-7 days. Peak and trough plasma levels of this antiviral agent were monitored during the course of therapy and were shown to be well above V-Z virustatic levels. Clinical response was noted by the third day of therapy. Vesicles and CSF were culture negative at termination of treatment. Administration of this high dose of acyclovir was not associated with hematologic, immunologic, hepatic, renal, or gastrointestinal toxicity as judged by frequent laboratory and clinical evaluation.

Acyclovir halts progression of herpes zoster in immunocompromised patients.

We conducted a placebo-controlled, double-blind study of acyclovir therapy for acute herpes zoster in immunocompromised patients. Of the 94 patients enrolled in the study, 52 had localized skin lesions at entry, and 42 had disseminated cutaneous zoster. A one-week course of intravenous acyclovir (1500 mg per square meter of body-surface area per day) halted progression of zoster in both groups, as determined by development or progression of cutaneous dissemination, development of visceral zoster, or proportion of cases deemed treatment failures. Significantly fewer patients treated with acyclovir within the first three days after the onset of exanthem had complications of zoster, as compared with patients treated with placebo (P = 0.02 by Fisher's exact test), but acyclovir also stopped progression of zoster in patients treated after three days of rash (P = 0.05 by Fisher's exact test). Acyclovir recipients with disseminated cutaneous zoster had a significantly accelerated rate of clearance of virus from vesicles, as compared with placebo recipients (P = 0.05 by the Breslow test).

Topically administered acyclovir in the treatment of recurrent herpes simplex genitalis: a controlled trial.

Eighty-eight patients with culture-proven recurrent herpes simplex genitalis were entered into a collaborative, randomized, placebo-controlled, double-blind trial to evaluate the efficacy and toxicity of a topical formulation of acyclovir. Patients entered the study within 48 hr of the onset of lesions, and the study medication was applied six times daily for five days. The duration of virus shedding from lesions present at the time of entry into the study was significantly reduced for men who received acyclovir compared with men who received placebo (P less than 0.05). There were no significant differences between the acyclovir- and placebo-treated groups of either sex in time to crusting of lesions, time required for lesions to heal, time to cessation of pain, or in frequency with which new lesions developed during the course of therapy. Mild, transient burning or pain associated with application of the study medication was a common complaint.

Acyclovir therapy of chickenpox in immunosuppressed children--a collaborative study.

A randomized double-blind, placebo-controlled, multicenter investigation assessed the usefulness of acyclovir in the treatment of immunosuppressed children with chickenpox. Twelve patients received placebo and eight received acyclovir. If the event of clinical deterioration, patients could be removed from the study to receive acyclovir. Eighteen patients had skin lesions within 96 hours of admission to the study. Nineteen patients had malignancies. The two groups of patients were similar in age, in concomitant or preceding immunosuppressive therapy, in status of malignancy, and in presenting granulocyte and lymphocyte counts. Zoster immune globulin or plasma had been given to 50% of the placebo group but to only 25% of the acyclovir group. One patient in each group had pneumonitis at entry. Of the patients without pneumonitis at entry, five of the 11 placebo patients compared with none of the seven acyclovir patients developed pneumonitis during treatment (P = 0.054). No evidence of toxicity related to acyclovir was observed.

Pharmacokinetics of orally administered acyclovir in patients with herpes progenitalis.

The pharmacokinetics of acyclovir administrated orally in a dose of 200 mg every four hours, five times a day to adults with herpes progenitalis was determined. Peak plasma acyclovir levels are found 1.5 to 1.75 hours after oral administration; peak levels range from 1.4 to 4.0 microM with a mean of 2.5 microM. Acyclovir levels in saliva are well correlated with simultaneous plasma levels, saliva levels being approximately 13 percent of plasma levels. Simultaneous plasma and vaginal secretion acyclovir levels are poorly correlated; peak levels in vaginal secretions range from 0.5 to 3.6 microM.

Double-blind controlled trial of topical acyclovir in genital herpes simplex virus infections.

Sixty-nine patients with first episodes and 111 with recurrent episodes of genital herpes simplex virus (HSV) infection were enrolled in a double-blind trial comparing a 5 percent topical acyclovir ointment versus placebo, polyethylene glycol (PEG). Among acyclovir recipients with first episodes of genital herpes, the mean duration of viral shedding from genital lesions, 2.0 days, mean duration of local pain or itching, 3.6 days, and mean time to healing of lesions, 11.2 days, were less than in placebo recipients 4.6, 6.7, and 15.8 days, respectively (p less than 0.05 for each comparison). Among patients with recurrent genital herpes, the mean duration of viral shedding from genital lesions was 0.8 days in acyclovir recipients compared with 1.7 days in placebo recipients (p less than 0.001). Among men with recurrent genital herpes, the mean time to crusting and healing of lesions was 3.5 and 7.5 days in acyclovir recipients compared with 5.0 and 9.7 days in placebo recipients, p = 0.03 and 0.07, respectively. No significant differences in the duration of symptoms or healing times were noted between acyclovir- and placebo-treated women with recurrent genital herpes. Acyclovir therapy was not associated with a decrease in frequency of clinical recurrences or an increase in the time of the next recurrence in patients with either first or recurrent genital herpes. Topical acyclovir appears effective in shortening some of the clinical manifestations of genital HSV infections.

Acyclovir tolerance in humans.

Acyclovir tolerance has been explored in a broad range of human populations and dosage regimens with intravenous, topical, and oral formulations. Phase I pharmacokinetic/tolerance studies assured safety in special populations at unique risk of complicated herpes infections who were simultaneously at increased risk of toxicity to anti-DNA chemotherapeutic agents. Further safety evaluations accompanied placebo-controlled Phase II studies in infected patients who represent future users of acyclovir. These studies confirm acyclovir as the safest antiherpes agent to be explored in clinical studies to date.

Neonatal acyclovir pharmacokinetics in patients with herpes virus infections.

A preliminary analysis is presented of the pharmacokinetics of acyclovir in neonatal patients with herpes simplex virus infections. Mean peak acyclovir levels (microM +/- SD) at 5, 10, and 15 mg/kg per dose were 30.0 +/- 9.9, 61.2 +/- 18.3, and 86.1 +/- 23.5, with corresponding mean trough levels (microM +/- SD) of 5.3 +/- 3.4, 10.1 +/- 8.4, and 13.8 +/- 11.1, respectively. The mean half-life (t 1/2 beta) of acyclovir was 3.78 +/- 1.21 hours. The mean percent urinary recovery of acyclovir (+/- SD) at each dosage level was similar, with an overall mean recovery of 65 percent. The mean acyclovir concentration in urine did not exceed the solubility of acyclovir in bladder urine (1,300 micrograms/ml). Generally, neonatal acyclovir pharmacokinetics was consistent with previous reports from studies of adults.

Treatment of herpes virus infections in immunocompromised patients with acyclovir by continuous intravenous infusion.

Sixteen immunocompromised patients with herpes virus infections were treated for three to five days with continuously administered intravenous acyclovir. Patients received initial acyclovir infusions over 5 minutes in dosages ranging from 1.5 to 5.0 mg/kg followed by continuously infused acyclovir at 7.2, 14.4, 21.6, 28.8, 36.0, or 43.2 mg/kg per day. The mean serum plateau levels of acyclovir determined by radioimmunoassay ranged from 4.1 microM for the 7.2 mg/kg per day dosage to 36.6 microM for the 43.2 mg/kg per day dose. A mean of 75 percent of acyclovir administered was recovered in the urine of patients treated. Eleven of 13 patients with varicella-zoster virus (VZV) infections had no new vesicle formation after three days of acyclovir treatment and all patients ceased to have new vesicles after five days of therapy. For the nine patients from whom complete viral cultures were available, six ceased to shed virus at three days, and viral shedding ceased by five days in all patients treated with acyclovir. No clinical or laboratory adverse reactions were associated with acyclovir therapy. These data suggest that acyclovir given by continuous intravenous infusion may be useful in the treatment of herpes virus infections in immunocompromised patients.

Acyclovir kinetics in end-stage renal disease.

Acyclovir (ACV) is almost entirely eliminated by the kidneys and has a terminal plasma half-life (t1/2) of 2 to 3 hr in subjects with normal renal function. To determine the drug's kinetics and tolerance in patients with severe renal failure, six anuric subjects on long-term hemodialysis were studied. Each received a 1-hr infusion of 2.5 mg/kg IV ACV. The kinetics are well described by a two-compartment open model. ACV terminal plasma t 1/2 and the total body clearance were 19.5 +/- 5.9 hr (mean +/- SD) and 28.6 +/- 9.5 ml/min/1.73 m2. Peak (end of infusion) and 8- and 24-hr plasma ACV concentrations were 37.5 +/- 23.3, 10.3 +/- 2.9, and 6.4 +/- 2.4 microM. Approximately 48 hr after the start of the infusion the subjects were hemodialyzed for 6 hr. The pre- and posthemodialysis ACV plasma levels were 2.74 +/- 1.38 and 1.11 +/- 0.60 microM. The terminal ACV t1/2 during hemodialysis was 5.7 +/- 0.85 hr. During hemodialysis paired arterial and venous samples showed that ACV was readily dialyzed, with a mean coefficient of extraction of 0.45 +/- 0.12. The dialysis clearance of acyclovir was 81.8 +/- 12.6 ml/min. None of the patients had any ACV-related adverse effects. Since ACV elimination is markedly reduced in end-stage renal failure and because ACV is readily hemodialyzible, dosage modification are needed to avoid cumulation and to replace dialyzed drug.

Intravenous acyclovir to treat mucocutaneous herpes simplex virus infection after marrow transplantation: a double-blind trial.

Acyclovir, a new antiviral agent, was compared to a placebo in a randomized double-blind trial of treatment for culture-proven herpes simplex virus infection after marrow transplantation. Patients received either intravenous acyclovir at 750 mg/m2 body surface area per day or a placebo for 7 days. Thirteen of 17 patients given acyclovir had a beneficial response as compared with two of 17 given the placebo (p less than 0.01). The duration of positive cultures was shorter among acyclovir recipients (3 versus 17 days, p less than 0.00005). Also shorter were the median days to resolution of pain (10 versus 16 days, p = 0.03), to crusting of lesions (7 versus 14 days, p = 0.01), and to total healing (14 versus 28 days, p = 0.03). No acyclovir toxicity was observed. Recurrent infection was common. Acyclovir provided significant antiviral and clinical efficacy without toxicity in highly immunosuppressed patients but had no effect on virus latency.

Acyclovir for chronic mucocutaneous herpes simplex virus infection in immunosuppressed patients.

Over 25 episodes of severe chronic and recurrent mucocutaneous herpes simplex virus infections in five immunodeficient patients were successfully treated with intravenous or oral acyclovir treatment. Acyclovir was shown to inhibit viral shedding rapidly, to be well tolerated, and to permit the complete healing of lesions. As expected, a course of acyclovir did not prevent later recurrences of the herpes virus infections. However, symptomatic recurrences were successfully suppressed during long (up to 65-day) courses of oral acyclovir.

Genital herpes simplex virus infection: clinical course and attempted therapy.

The epidemiology, clinical course, diagnosis, and attempted treatments of herpes genitalis are reviewed. Herpes genitalis is an increasingly common sexually transmitted disease for which there is no effective treatment. It can occur in either sex and is mot commonly first found in patients 14 to 29 years old. Initial exposure to the virus may result in prolonged local symptoms (pain, itching, discharge) and signs (ulcerative lesions) as well as fever, malaise, myalgias, and fatigue. After the initial exposure, the virus may be found in a latent stage in the dorsal nerve root ganglia in the sacral area, and recurrences of disease may ensue. The frequency and clinical course of recurrent genital herpes can be of varying duration and severity. Although antiviral substances, immune potentiators, topical surfactants, and photodynamic inactivation have been used to treat genital herpes infections, there is no proven effective therapy.

Single-dose pharmacokinetics of acyclovir.

The pharmacokinetics of intravenously administered acyclovir were studied in 10 patients with advanced malignancies. After doses of 0.5 and 1.0 mg/kg, the slow disposition half-life values (t1/2beta) ranged from 2.2 to 3.1 h for the 1-h infusions and from 1.8 to 3.7 h for the 6-h infusions. Plasma levels, measured by radioimmunoassay, reached a maximum at the end of the 1-h infusions and approached steady state at 3 to 4 h into the 6-h infusions. Mean peak plasma concentrations obtained at 0.5 and 1.0 mg/kg administered over 1 h were 3.03 and 5.99 microM, respectively. Mean peak levels for the 6-h infusions were 1.07 microM at 0.5 mg/kg and 2.58 microM at 1.0 mg/kg. The mean urinary elimination of acyclovir was 44.7% of the administered doses. No clinical or laboratory abnormalities were noted in the 10 patients studied.

Comparative in vitro imunotoxicology of acyclovir and other antiviral agents.

In vitro lymphocyte blastogenic responses to the commonly employed mitogens phytohemagglutinin, pokeweed, and concanavalin A were evaluated when acyclovir, adenine arabinoside, cytosine arabinoside, and idoxuridine were added to the culture materials. Similarly, specific antigen-induced blastogenic responses, including herpes group antigens, and cytotoxicity and leukocyte inhibitory factor assays with herpes group viruses were determined in the presence and absence of antiviral agents. No depression of these cellular immmune responses by acyclovir or adenine arabinoside ws demonstrated. This was in contrast to the effects of cytosine arabinoside and idoxuridine, which severely inhibited blastogenic and cytotoxic responses but not leukocyte inhibitory factor production. Even at concentrations up to 20 microgram/ml, the antiviral agent acyclovir did not depress selected cellular immune responses that are important for successful elimination of invading herpes group viruses.

Acyclovir kinetics after intravenous infusion.

The disposition and safety of the antiviral drug acyclovir were studied in 14 subjects with advanced malignancies. Acyclovir was administered by a 1-hr intravenous infusion at doses of 0.5, 1.0, 2.5, and 5.0 mg/kg. At the end of infusion, mean peak plasma levels (+/- SEM), determined by radioimmunoassay, were 6.4 +/- 0.7, 12.1 +/- 2.3, 14.9 +/- 2.7, and 33.7 +/- 7.1 microM. The plasma concentration-time profiles could be described by a biexponential equation. The half-life of acyclovir in the slow disposition phase ranged from 2.2 to 5 hr and the drug was detected in the plasma for at least 18 hr after infusion. The total body clearance ranged from 117 to 396 ml/min/1.73 m2. A proportionality between area under the curve and dose suggests that acyclovir exhibits dose-independent kinetics in the dose range studied. There was wide variation in cumulative urinary excretion of unchanged drug, ranging from 30 to 69% of the dose. From renal clearances of acyclovir, which were higher than creatinine clearances, it appears that both glomerular filtration and tubular secretion contribute to its renal excretion. Analysis of the urine by reverse-phase high-performance liquid chromatography revealed the presence of the metabolite 9-carboxymethoxymethylguanine. There was no indication of toxicity either clinically or from laboratory findings in any of the study subjects. This study demonstrates that in addition to selectivity and low toxicity, the kinetic profile and metabolic disposition of acyclovir make it an attractive candidate for therapy in a variety of herpes infections.