Oral acyclovir for herpes zoster

Anterior Segment and External Ocular Disorders Associated with Human Immunodeficiency Virus Disease

The eye is a common site for complications of human immunodeficiency virus (HIV) infection. Although cytomegalovirus retinitis remains the most prevalent of the blinding ocular disorders that can occur in individuals with the acquired immunodeficiency syndrome (AIDS), several important HIV-associated disorders may involve the anterior segment, ocular surface, and adnexae. Some of these entities, such as Kaposi sarcoma, were well described, but uncommon, before the HIV epidemic. Others, like microsporidial keratoconjunctivitis, have presentations that differ between affected individuals with HIV disease and those from the general population who are immunocompetent. The treatment of many of these diseases is challenging because of host immunodeficiency. Survival after the diagnosis of AIDS has increased among individuals with HIV disease because of more effective antiretroviral therapies and improved prophylaxis against, and treatment of, opportunistic infections. This longer survival may lead to an increased prevalence of anterior segment and external ocular disorders. In addition, the evaluation and management of disorders such as blepharitis and dry eye, which were previously overshadowed by more severe, blinding disorders, may demand increased attention, as the general health of this population improves. Not all individuals infected with HIV receive potent antiretroviral therapy, however, because of socioeconomic or other factors, and others will be intolerant of these drugs or experience drug failure. Ophthalmologists must, therefore, still be aware of the ocular findings that develop in the setting of severe immunosuppression. This article reviews the spectrum of HIV-associated anterior segment and external ocular disorders, with recommendations for their evaluation and management.

Herpes zoster ophthalmicus

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Pharmacokinetics and safety of multiple-dose valaciclovir in geriatric volunteers with and without concomitant diuretic therapy

A randomized, double-blind study was conducted to evaluate the safety and pharmacokinetics of acyclovir following multiple-dose oral administration of valaciclovir (three times a day for 8 days) in geriatric volunteers (65 to 83 years of age). Pharmacokinetic evaluation was performed for three groups: normotensive subjects given 500-mg doses of valaciclovir (n = 11), normotensive subjects given, 1,000-mg doses of valaciclovir (n = 9), and thiazide diuretic-treated hypertensive subjects given 500-mg doses of valaciclovir (n = 9). Valaciclovir, the l-valyl ester of acylclovir, was rapidly absorbed and converted to acyclovir, with plasma valaciclovir concentrations generally undetectable or < or = 0.4 microgram/ml. The peak concentration of drug in plasma (Cmax) for acyclovir occurred at 1 to 2 h, and the half-life of acyclovir was 3 to 4 h in all three elderly groups. The Cmax and area under the concentration-time curve from 0 h to infinity (AUC0-infinity) values of acyclovir obtained on days 1 and 8 indicated no unexpected accumulation at steady state. The steady-state acyclovir Cmax (4.30 and 5.98 micrograms/ml) and daily AUC0-infinity (44 and 74 h.micrograms/ml) following dosing of valaciclovir (500 and 1,000 mg) three times a day were two to three times greater than those expected after high-dose oral acyclovir treatment (800 mg, five times daily). There were no valaciclovir-related changes or abnormalities in safety parameters and no reports of serious adverse experiences in these elderly volunteers. The plasma acyclovir concentration-time curves for the hypertensive and normotensive (500-mg valaciclovir treatment) elderly groups were almost superimposable, and acyclovir pharmacokinetic parameters for the two groups were not significantly different, indicating that concomitant thiazide diuretics do not alter acyclovir pharmacokinetics following valaciclovir dosing in the elderly. Compared with historical data for younger volunteers (creatinine clearance [CLCR] > 75 ml/min/1.73 m2), the elderly subjects (CLCR = 40 to 65 ml/min/1.73 m2) showed higher (approximately 15 to 20%) mean Cmaxs and higher (approximately 30 to 50%) mean AUC(0-infinity)s of acyclovir (P < 0.01), which were consistent with age-related decreases in CLCR. The increased acyclovir exposure from valaciclovir dosing will permit reduced dosing frequency and may result in improved efficacy in the management of herpesvirus diseases.

Ophthalmic herpes zoster

A current review of ophthalmic zoster is presented including its virology, immunology, epidemiology and pathogenesis. We give our findings in 1356 patients referred to the Zoster Clinic at Moorfields Eye Hospital, London. The treatment of the disease and its ocular complications is discussed.

Systemic antiviral drugs used in ophthalmology

Over the past two decades, the recognition of viral enzymes and proteins that can serve as molecular targets of drugs has revolutionized the treatment of viral infections. Beginning with acyclovir, a number of systemically administered agents which are both relatively safe and effective for the treatment of herpetic infections and human immunodeficiency virus (HIV) infections have become widely available. Because of increased numbers of herpes virus infections, as well as the rising epidemic of HIV infections, the ophthalmologist is, more likely than ever before to be involved in the treatment of severe and frequent ocular infections caused by herpes viruses. In addition, the acute retinal necrosis (ARN) syndrome has been demonstrated to be caused by herpes viruses and a once rare retinal infection caused by cytomegalovirus is common in patients with the acquired immunodeficiency syndrome (AIDS). In this article, four systemic antiviral drugs (Vidarabine, Acyclovir, Ganciclovir, and Foscarnet) that have demonstrated usefulness in the treatment of ophthalmic disease are reviewed in detail with regard to their mechanisms, applications, effectiveness, and side effects.

Oral acyclovir for herpes zoster ophthalmicus

BACKGROUND

Reports on the natural history of herpes zoster ophthalmicus stress its high morbidity related to vicious scars on eyelids, ocular complications, and post-herpetic neuralgia. Early treatment with oral acyclovir is effective, but the optimal duration of treatment has not been defined.

METHODS

The authors performed a bicentric, prospective, randomized, double-masked study of 86 patients with acute herpes zoster ophthalmicus, within 72 hours of skin eruption, who received oral acyclovir (800 mg 5 times daily), either for 7 days (plus 7 days oral placebo) or for 14 days. All patients concomitantly received ophthalmic 3% acyclovir ointment; follow-up was at least 6 months.

RESULTS

Statistical analyses of subjective symptoms, skin lesions, and ocular complications showed no significant differences between the groups, suggesting that a 7-day course of treatment was sufficient. Drug tolerance was good. Pooled data from both groups corroborated earlier reports that prompt treatment with oral acyclovir reduces the severity of the skin eruption, the incidence and severity of late ocular manifestations, and the intensity of postherpetic neuralgia. At 6 months, late ocular inflammatory complications were seen in 29.1% of our 86 patients, versus 50% to 71% of untreated patients described by others. Only 13% of our patients experienced post-herpetic neuralgia, which in no case required the use of analgesics.

CONCLUSION

The authors believe it is not useful to prolong treatment with 800 mg of oral acyclovir 5 times daily for more than 7 days in herpes zoster ophthalmicus. This study confirms the efficacy of oral acyclovir not only against skin lesions and ocular complications, but also against postherpetic neuralgia in herpes zoster ophthalmicus.

Double-masked trial of topical acyclovir and steroids in the treatment of herpes zoster ocular inflammation

Ninety seven new patients with ophthalmic zoster were randomly allocated to three topical treatment groups: acyclovir (ACV) ointment and placebo drops (AP), placebo ointment with steroid drops (PS), and acyclovir ointment with steroid drops (AS). The dosage administered was determined by the score of the ocular inflammation. Follow-up was for at least one year. The results showed that topical ACV alone is insufficient for severe ocular inflammation but is not inclined to lead to recurrences in milder cases. Topical steroid alone is effective but tends to necessitate prolonged treatment. Combined steroid and ACV is questionably better than steroid alone and causes marginally fewer rebound inflammations.

Severe herpes zoster infection in the United Kingdom: experience in a regional infectious disease unit

Seventy-three cases of severe herpes zoster infection admitted to a regional infectious disease unit over a 3-year period were reviewed. Complications were common. Elderly patients were in the majority (55%), were hospitalized for longer and accounted for 78% of all complications. Acyclovir therapy was used in 44 cases with a reduction in both the duration of hospital stay and complication rate.

Human infection with herpes zoster: etiology, pathophysiology, diagnosis, clinical course, and treatment

Herpes zoster is a cutaneous vesicular eruption resulting from recrudescence of the chickenpox virus. It is mainly a disease of adults, with a predisposition for the elderly or immunocompromised. Although usually localized, the disease can disseminate to visceral organs. Diagnosis is often made based on the characteristic pattern of the lesion and clinical features. Tzanck smear, viral isolation, seroconversion, antibody titers, and monoclonal antibodies may further aid or confirm the diagnosis. Clinical features of herpes zoster may follow a progression through 3 stages, prodromal, acute, and chronic. The prodromal and acute phases seldom require more than symptomatic management. The chronic pain syndrome, postherpetic neuralgia (PHN), demands a more aggressive approach. Pharmacologic intervention, neuroaugmentation, and/or surgery may prevent or alleviate PHN, but universal response to any of these therapeutic approaches is unlikely. Tricyclic antidepressants remain the first choice in treating this pain syndrome. A trial of antiviral therapy may be warranted in patients with disseminated disease or in immunocompromised patients with localized disease. Of the antiviral agents, acyclovir is considered the drug of choice by most clinicians.

Effect of cimetidine on herpes zoster infection

Cimetidine was administered to two patients for herpes zoster infection. An acute pain-relieving effect was observed. The patients were followed for 11 and 14 months without developing postherpetic neuralgia. Possible mechanisms for prevention of postherpetic neuralgia by cimetidine are discussed.

Herpes zoster and its neurological complications

Ninety-three Chinese patients with cutaneous herpes zoster were seen during a 4-year period. Thoracic zoster occurred most commonly, followed by ophthalmic, cervical and lumbosacral zoster. Neurological complications were present in eleven patients (11.8%), the commonest being Ramsay-Hunt syndrome and segmental limb paresis. The clinical picture, pathogenesis, treatment and outcome of segmental limb paresis, myelitis and delayed contralateral hemiparesis following zoster ophthalmicus are discussed. Nine immunocompromised patients received intravenous adenine arabinoside (vidarabine) or acycloguanosine (acyclovir), and no cutaneous or visceral spread occurred in these patients.

Demonstration of herpes group virus in acute retinal necrosis syndrome

Tissue for pathologic examination was obtained from three cases of acute retinal necrosis syndrome. Virus particles belonging to the herpesvirus family were demonstrated in retinal biopsies from two patients, one of whom was immunosuppressed. Despite removal of large biopsy specimens, the retina has remained attached for 20 months postoperatively in one case and for three months in the other. In a third patient with acquired immune deficiency syndrome, the clinical course and postmortem immunopathology were suggestive of a herpes simplex virus infection, initially affecting the retina and subsequently the optic nerves, chiasm, tracts, and central nervous system. These cases illustrate that the virus associated with the acute retinal necrosis syndrome is easily demonstrable using vitrectomy and endoretinal biopsy in the acute phase of the disease, but may be difficult to demonstrate in chronically detached atrophic retinas.

Problems of intensive therapy in childhood cancer

Tremendous progress has been made in the treatment of childhood cancers. Certain hematologic malignancies have an impressive cure rate with the current intensive antineoplastic treatment regimens. There is optimism that the treatment of children who have advanced stage solid tumors with intensive, multimodality therapy may improve their chances for long-term survival. These treatment programs, though potentially curative, are highly toxic, with severe myelosuppression and damage to other organ systems. An awareness of these potential toxicities, an understanding of how to prevent or minimize certain problems, and the ability to treat those complications which do arise are all essential to the successful management of childhood cancer.

Oral acyclovir in the treatment of acute herpes zoster ophthalmicus

Seventy-one nonimmunocompromised patients with herpes zoster ophthalmicus, presenting within seven days of onset of characteristic skin eruption, were enrolled in a prospective, longitudinal, randomized, double-masked, placebo-controlled trial with oral acyclovir. In a previous interim report we noted more prompt resolution of dermatomal signs and symptoms with acyclovir treatment. There was also a reduction of viral shedding in acyclovir-treated patients coupled with a trend to greater rate of microdissemination of the virus in placebo-treated patients (Cobo LM, et al. Ophthalmology 1985; 92:1574-83). While further substantiating these findings, we report that a ten-day course of treatment with oral acyclovir (600 mg, five times a day) is well-tolerated and significantly reduces the incidence and severity of the most common complications of herpes zoster ophthalmicus: dendritiform keratopathy, stromal keratitis, and uveitis. While this acyclovir treatment regimen reduces the zoster-related pain during the acute phase of the disease, especially in patients treated within 72 hours of onset of skin lesions, it has no evident effect on either incidence, severity, or duration of post-herpetic neuralgia in the patients studied.

Treatment of peripheral neuropathies

There are three general approaches to treatment of peripheral neuropathy. First, an attempt should be made to reverse the pathophysiological process if its nature can be elucidated. Second, nerve metabolism can be stimulated and regeneration encouraged. Third, even if the neuropathy itself cannot be improved, symptomatic therapy can be employed. This review outlines the options available for each approach.