Síndrome de Ramsay Hunt tipo II en mujer mayor de 90 años / Ramsay Hunt Syndrome type II in women older than 90 years of age

El Síndrome de Ramsay Hunt o Herpes Zóster Ótico, se define por la asociación de parálisis facial periférica con la presencia de erupción eritemato-vesicular en el oído externo, por el virus de la Varicela-Herpes Zóster. Objetivo: Establecer la evolución de la reactivación del virus de la varicela en personas mayores de 90 años. Presentación del Caso clínico: paciente femenina de 91 años, con antecedente de artritis reumatoide e hipertensión arterial no controlada; inicia con erupción maculo papular en hemicara izquierda que evoluciona a vesículas, acompañada de fiebre y mal estado general; concomitante presenta otalgia. Es ingresada por el servicio de Medicina Interna al Hospital Escuela Universitario donde se instaura tratamiento: Aciclovir 500mg intravenoso cada 8 horas, Pregabalina 1 cápsula vía oral cada 12 horas y Prednisona 50mg vía oral cada día, con buena respuesta terapéutica; se da de alta con mejoría de sus síntomas y resolución de lesiones faciales. Conclusión: Para la aparición del síndrome de Ramsay Hunt II en esta paciente, el principal factor de riesgo fue la edad; su evolución fue favorable y sin secuelas al instaurarse el tratamiento en forma oportuna...(AU)

In vitro evaluation of cutaneous penetration of acyclovir from semisolid commercial formulations and relation with its effective antiviral concentration

ABSTRACT The evaluation of drug permeation/penetration of semisolid formulations into animal skin can be useful to supplement the pharmaceutical equivalence. This paper describes the in vitro assessment of acyclovir (ACV) into porcine skin from commercial formulations with etermination of drug concentration in different layers of cutaneous tissue to correlate with effective antiviral concentration in order to improve the equivalence decision. Studies were conducted using Franz cells and porcine skin. Selected pharmaceutical creams containing ACV had identical (reference and generic) and different (similar) excipients. A software program was employed for the simulation of antiviral effectiveness in the skin. Regarding ACV skin penetration, the first batch of the generic product showed a significant difference from reference and similar products, while in the second batch all products demonstrated equivalent drug penetration in the skin. Simulation studies suggest that formulations analysed exhibit a pharmacological effect even when in contact with Herpes simplex strains of high IC50 (inhibitory concentration required to reduce viral replication by 50%). According to results, it can be assumed that the in vitro cutaneous permeation/penetration study does not supply sensitivity information regarding small alterations of ACV semisolid formulations due to the variability inherent to the method, although it can be relevant to pharmaceutical equivalence studies in the development of semisolid products.

Vitreous pharmacokinetics and electroretinographic findings after intravitreal injection of acyclovir in rabbits

OBJECTIVES: Acute retinal necrosis is a rapidly progressive and devastating viral retinitis caused by the herpesvirus family. Systemic acyclovir is the treatment of choice; however, the progression of retinal lesions ceases approximately 2 days after treatment initiation. An intravitreal injection of acyclovir may be used an adjuvant therapy during the first 2 days of treatment when systemically administered acyclovir has not reached therapeutic levels in the retina. The aims of this study were to determine the pharmacokinetic profile of acyclovir in the rabbit vitreous after intravitreal injection and the functional effects of acyclovir in the rabbit retina. METHODS: Acyclovir (Acyclovir; Bedford Laboratories, Bedford, OH, USA) 1 mg in 0.1 mL was injected into the right eye vitreous of 32 New Zealand white rabbits, and 0.1 mL sterile saline solution was injected into the left eye as a control. The animals were sacrificed after 2, 9, 14, or 28 days. The eyes were enucleated, and the vitreous was removed. The half-life of acyclovir was determined using high-performance liquid chromatography. Electroretinograms were recorded on days 2, 9, 14, and 28 in the eight animals that were sacrificed 28 days after injection according to a modified protocol of the International Society for Clinical Electrophysiology of Vision. RESULTS: Acyclovir rapidly decayed in the vitreous within the first two days after treatment and remained at low levels from day 9 onward. The eyes that were injected with acyclovir did not present any electroretinographic changes compared with the control eyes. CONCLUSIONS: The vitreous half-life of acyclovir is short, and the electrophysiological findings suggest that the intravitreal delivery of 1 mg acyclovir is safe and well tolerated by the rabbit retina.

An HPLC-UV method for the measurement of permeability of marker drugs in the Caco-2 cell assay

The Caco-2 cell line has been used as a model to predict the in vitro permeability of the human intestinal barrier. The predictive potential of the assay relies on an appropriate in-house validation of the method. The objective of the present study was to develop a single HPLC-UV method for the identification and quantitation of marker drugs and to determine the suitability of the Caco-2 cell permeability assay. A simple chromatographic method was developed for the simultaneous determination of both passively (propranolol, carbamazepine, acyclovir, and hydrochlorothiazide) and actively transported drugs (vinblastine and verapamil). Separation was achieved on a C18 column with step-gradient elution (acetonitrile and aqueous solution of ammonium acetate, pH 3.0) at a flow rate of 1.0 mL/min and UV detection at 275 nm during the total run time of 35 min. The method was validated and found to be specific, linear, precise, and accurate. This chromatographic system can be readily used on a routine basis and its utilization can be extended to other permeability models. The results obtained in the Caco-2 bi-directional transport experiments confirmed the validity of the assay, given that high and low permeability profiles were identified, and P-glycoprotein functionality was established.

Antivirales de uso clínico actual / Antiviral drugs for clinical use

Numerosos fármacos antivirales han sido aprobados para ser empleados en adultos y niños, incluidos recién nacidos e individuos con defectos de la inmunidad, para el tratamiento de infecciones virales respiratorias, de la piel y las mucosas; el sistema nervioso central. Uno de los principales blancos de estos medicamentos es la ADN polimerasa, que incorpora nucleótidos trifosfatos en el extremo 3'OH de las cadenas de ADN y ha sido exitosamente inhibida por análogos de nucleósidos como adenina arabinósido y aciclovir. El descubrimiento de los retrovirus ha enfocado la atención hacia transcriptasa reversa, que copia el ARN viral en ADN proviral biténico, éste se integra al ADN huésped y luego es transcrito por la ARN polimerasa celular a nuevas répticas de ARN viral. Los esfuerzos para bloquear la transcriptasa reversa han resultado en drogas como la zidovudina (azidotimidina) usada para tratar el síndrome de inmunodeficiencia adquirida (SIDA) y sus análogos dideoxicitidina, dideoxiadenosina y dideoxilinosina