Foscarnet-induced penile ulcer

Foscarnet-induced genital lesions: An overview with a case report

Foscarnet is an important antiviral medication used mainly in the treatment of complicated Herpes-simplex virus and cytomegalovirus (CMV) infections. Reported first in the 1990's, genital ulcers are a potential side effect in about 10% of cases. We report the case of a 29 year old man with acute myelogenous leukemia who was on ganciclovir for CMV prophylaxis. Three weeks after being switched to foscarnet because of neutropenia, he developed two, painful symmetric ulcers on the inferior aspect of glans penis. Viral and bacterial cultures were negative. Two weeks after stopping the infusion of foscarnet, the ulcers subsided without any additional treatment. It is important that physicians be aware of this potentially disfiguring side effect of foscarnet so that methods of prevention can be implemented early in the treatment of these patients.

Penile erosions associated with foscarnet therapy in a child

Foscarnet-induced genital erosions have been reported in patients treated for HIV-related herpesvirus infections in adults. We report the case of a boy with penile erosions associated with foscarnet therapy in the setting of umbilical cord blood transplantation (CBT).

Vulvar ulcers and erosions- a dermatologist's viewpoint

Vulvar ulceration can occur as the primary or secondary event in a large variety of conditions. These include infections, autoimmune and/or inflammatory diseases and dermatoses, neoplasias, and conditions with an unknown etiology. A thorough medical history and careful patient examination remain the linchpin of management. Specific microbiological, histological, immunological, and other investigations are often necessary to establish or confirm a diagnosis, but the relevant importance of these will vary in the individual patient. The specific management of each patient will also vary accordingly. Other important factors which will influence the frequency with which any physician will make one of the specific diagnoses include practice location, referral mechanisms, and population demographics. This chapter is written with the generalist dermatologist in mind. Whilst dermatoses are given prime attention, important infections and other conditions are also dealt with. The ultimate aim of the present paper is to provide the generalist dermatologist with a useful tool for the diagnosis and management of a patient that present's with a vulvar ulcer(s).

Antiviral agents

The potential severity of many viral infections and the lack of appropriate treatment for these diseases have been a source of endless frustration and helplessness for clinicians. The newly developed field of antiviral therapy is expanding at an astounding rate, with new discoveries each day. Although physicians are not yet able to cure many of the viral infections, such as HSV, HIV, and CMV, a means of controlling them is available. It is hoped that the research and investigations currently under way will lead to a future era of antiviral drugs that will be able to eradicate these diseases.

Comparative tolerability of therapies for cytomegalovirus retinitis

Cytomegalovirus (CMV) retinitis is a potentially sight-threatening complication of advanced HIV infection. The acute infection can be controlled with one of several therapies, including intravenous ganciclovir, foscarnet or cidofovir, slow release ganciclovir intraocular implants or serial intraocular injections of ganciclovir or foscarnet. The initial induction course of therapy is typically followed by lifelong maintenance therapy. In addition to the aforementioned treatments, oral ganciclovir and intravitreal fomivirsen injections are other options for maintenance therapy. The choice of agent must take into consideration factors such as comparative short and long term toxicity of the agents, route of administration and the possible need for indwelling catheters, administration time, cost and protection afforded against systemic dissemination of CMV infection. Possible drug interactions and additive toxicities of other agents needed for the management of the underlying HIV infection must also be taken into consideration. These factors can affect the tolerability of therapy as well as the quality of life of the patient. Relapse or progression of CMV retinitis may be caused by either inadequate drug concentrations at the site of the infection or by drug resistance. This may necessitate either an increase in drug dosage, a change in route of administration or a change to an alternative agent. All of these approaches can increase the risk of toxicity of the therapy. With the initiation of highly active antiretroviral therapy and partial reconstitution of the immune system, some patients have been able to successfully discontinue anti-CMV maintenance therapy, thereby decreasing long term drug toxicity. Determination of the patient predictors of success of this approach is an active area of research.

Dermatoses of the glans penis and prepuce

A wide range of infectious, neoplastic, and inflammatory dermatoses can affect the glans penis or prepuce. Some are unique to the genitalia. Other more common dermatoses may have a unique appearance when they involve genital skin and mucosa. A thorough understanding of regional anatomy and a systematic diagnostic approach are helpful in the management of a refractory penile dermatosis. We review embryology and regional anatomy, drug-induced eruptions, allergic and irritant dermatitis, infection, neoplasia, and traumatic and inflammatory dermatoses as they relate to the glans and prepuce. Our discussion focuses on the clinical features, office laboratory studies, and histopathologic findings that assist in diagnosis and treatment.

Foscarnet-Associated Penile Ulcerations

Objective:

To report a case of foscarnet-induced penile ulcerations and review literature related to this adverse effect.

Data Sources:

Case reports and review articles identified by a computerized search (MEDLINE) and manual search (Index Medicus).

Data Synthesis:

Foscarnet is a pyrophosphate analog antiviral agent that is approved by the Food and Drug Administration for treating cytomegalovirus retinitis in patients with AIDS. It also is used investigationally for other indications and human herpesvirus infections. Adverse effects include nephrotoxicity, anemia, ionized calcium abnormalities, and penile ulcerations. The majority of penile ulcers have developed within two weeks following initiation of foscarnet therapy with dosages of 180–200 mg/kg/d. Most cases required discontinuation of foscarnet to resolve the penile lesions. A postulated mechanism for this effect is inflammatory contact dermatitis from exposure to urine with elevated concentrations of foscarnet. We report a case of foscarnet-induced penile ulcerations that resolved after discontinuing this agent.

Conclusions:

Foscarnet can induce penile ulcerations. Increased awareness of this phenomenon, along with meticulous genital hygiene and urination practices, are required for its prevention.

Foscarnet. A reappraisal of its antiviral activity, pharmacokinetic properties and therapeutic use in immunocompromised patients with viral infections

The DNA polymerase of human herpes viruses, including cytomegalovirus (CMV), and the reverse transcriptase of human immunodeficiency virus (HIV) are selectively inhibited in vitro by the pyrophosphate analogue foscarnet. Inhibition is reversible on withdrawal of foscarnet and additive or synergistic effects have been demonstrated in vitro with other antiviral drugs, including ganciclovir and zidovudine. Foscarnet appears to have negligible effects on host enzymes and cells. Complete or partial clinical resolution of ocular symptoms is obtained in more than 89% of patients with acquired immunodeficiency syndrome (AIDS) and CMV retinitis during foscarnet induction therapy, but relapse occurs soon after ceasing treatment. Maintenance treatment given daily can extend the period of remission considerably. Foscarnet and ganciclovir monotherapy had similar efficacy in the treatment of CMV retinitis in patients with AIDS in several studies, and have been used concomitantly in immunocompromised patients with recalcitrant CMV infections. In 1 trial, patients receiving foscarnet survived for significantly longer than those receiving ganciclovir. Foscarnet has been used successfully in the treatment of limited numbers of immunocompromised patients with CMV-associated gastrointestinal (improvement in over 67% of patients) and other infections. Aciclovir-resistant herpes simplex infections in immunocompromised patients have also been treated successfully with foscarnet. Almost 90% of a foscarnet dose is excreted in the urine. Reversible nephrotoxicity is common during foscarnet therapy, but may be reduced by dosage adjustment and adequate hydration. Anaemia, nausea and vomiting, disturbances in electrolyte levels and genital ulceration have also been associated with administration of the drug. The different tolerability profiles of foscarnet and zidovudine facilitate the use of these agents in combination in patients with AIDS and CMV infection; whereas ganciclovir, like zidovudine, is associated with dose-limiting haematological toxicity. The apparent survival benefits seen in these patients when receiving foscarnet and zidovudine (possibly linked to synergy between zidovudine and foscarnet and/or the inherent anti-HIV activity of foscarnet), appear to offer potentially important advantages for foscarnet over ganciclovir in the treatment of selected patients with AIDS and CMV infections.