Robert A. Zehnder, Linda Hart
Jul 1, 1989
Citations
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Influential Citations
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Citations
Journal
Annals of Pharmacotherapy
Abstract
Nonoxynol 9 is a nonionic surfactant used as a spermicidal agent in several over-the-counter (aTC) contraceptive products.' It has been shown to be effective in vitro against the causative agents of several sexually transmitted diseases, such as Neisseria gonorrhoeae and Treponema pallidum. 2 Additionally, contraceptive products containing nonoxynol 9 have been shown to be effective in reducing rates of gonorrhea transmission," and their use has been advocated for such.' Nonoxynol 9 has also been shown to be virucidal against herpes simplex virus (HSV) I and 2 in vitro and has been suggested as a possible treatment for herpetic infections, as well as a means of preventing viral transmission. Investigations, however, have found nonoxynol9 to be ineffective in the treatment of herpes simplex infection, and, to date, no studies have been done demonstrating that nonoxynol9 offers protection against HSV transmission. Several studies have shown nonoxynol9, or contraceptive products containing nonoxynol 9, to be virucidal against HSV in vitro. Signh et al. exposed high titer suspensions of HSV 2 to solutions containing 10070 concentrations of five different aTC contraceptive products. After incubation for 10minutes at 23"C, the residual viral infectivity was determined using assays in cultured human fibroblasts and Vero cells (African green monkey kidney cell line) as well as intracranial inoculation of mice. The infectivity of the HSB 2 suspension was determined to have decreased 1000-to 10 OOO-foid. However, because contraceptive products, and not individual components of these products, were used, it could not be determined which component was responsible for the observed virucidal effect.' Asculai et al. investigated the ability of several nonionic surfactants and aTC contraceptives to inactivate HSV I and 2 in vitro. Viral suspensions were exposed to the surfactants (at concentrations found in aTC contraceptive products) or aTC contraceptive products for one minute. Infective viral titers were determined before and after exposure. Nonoxynol 9 in a 5070 solution reduced infective HSV I titers from 1.9 x 10' plaque-forming units/mL (PFU/mL) to less than 500 PFU/mL, and HSV 2 titers were reduced from an initial 1 x 10' PFU/mL to less than 500 PFU/mL. Similarly, contraceptive products containing nonoxynol 9, regardless of concentration (Delfen cream contains 5070 nonoxynol 9, Emko foam contains 8070, and Koromex A jelly contains 0.8%) were found equally effective in reducing infective viral titers of both HSV 1 and 2 to less than 500 PFU/mL.' Using electron microscopy, the investigators also examined the morphology of HSV 2 viral particles before and after a ten-second exposure to 5% nonoxynol 9 solution. Nonoxynol 9 was found to dissolve the viral envelope and partially degrade the nucleocapsid. This dissolution of the viral envelope was proposed to be the mechanism by which nonionic surfactants inactivate the herpes simplex virus and thereby prevent infection of cultured cells.' In a double-blind controlled study involving 69 patients, Vontver et al. evaluated the effectiveness of topical nonoxynol9 in the treatment of both initial and recurrent genital herpes infections. Patients were randomly assigned to either an active drug treatment group, a placebo treatment group, or a control group. The active drug treatment group received a cream containing 5% nonoxynol9, while the placebo treatment group received an identical cream that contained no nonoxynol 9. The control group received only symptomatic therapy such as sitz baths and warm air dryers. Patients in the placebo and nonoxynol 9 treatment groups were instructed to apply the cream to the lesions five times daily until healed or for a maximum of seven days. Patients were monitored for duration of symptoms, lesions, and viral shedding." The results showed that in recurrent cases, neither nonoxynol 9 nor placebo was found to have any effect on duration of symptoms, lesions, or viral shedding. In the treatment of initial cases, results were similar in the nonoxynol 9 and placebo groups; however, the duration of symptoms, lesions, and viral shedding was actually found to be less in the control group. Regarding formation of new lesions during the course of therapy, nonoxynol 9 was found to have no inhibitory effect. In addition, no effect on recurrence of infection was seen with nonoxynol 9 use. It is concluded that nonoxynol 9 therapy had no beneficial effects in the treatment of genital herpes." Based on the demonstrated virucidal effects of nonoxynol 9 on HSV in vitro, several authors have suggested that contraceptive products containing nonoxynol 9 or other nonionic surfactants may provide an effective means of protection against transmission of herpes simplex virus. Although non ionic surfactants, including nonoxynol 9, have been shown to reduce transmission of gonorrhea, no studies have shown nonoxynol 9 to reduce transmission of HSV. Therefore, at this time, the use of contraceptive products containing nonoxynol 9 cannot be recommended specifically for preventing transmission of the herpes simplex virus. In addition, nonoxynol 9 has been shown to be ineffective in the treatment of established HSV infections and cannot be recommended for such. !::