ATC kod: J05AB11
Det saknas större studier avseende könsskillnader i farmakokinetik, farmakodynamik eller säkerhet för valaciklovir. Spridda data från flera små studier indikerar inga uppenbara könsskillnader.
Kunskapsunderlaget avseende skillnader mellan kvinnor och män är begränsat och ger inte anledning att generellt differentiera i behandling mellan kvinnor och män. Eftersom valaciklovir utsöndras renalt bör risken för toxisk påverkan vid nedsatt njurfunktion beaktas.
Valaciclovir is a prodrug to aciclovir.
There are some published studies suggesting similar pharmacokinetics in late pregnancy and in the non-pregnant state, albeit no publication of such comparison within one study has been found. Recalculation of some published data, to allow comparison between studies, shows roughly similar systemic exposures (AUC and Cmax) of aciclovir following oral administration of aciclovir or valaciclovir in late pregnancy (n=15) [1] as compared to other populations [2,3]. In view of the paucity of data, differentiation of dosing regimen by sex or during pregnancy cannot be justified.
In those few placebo-controlled trials where sex was included as co-variate in exploratory analyses, no overt differences in terms of efficacy were discernible when aciclovir, or its pro-drug valaciclovir, were given orally to treat recurrent genital herpes [4,5]. Likewise, in a study with topical administration of aciclovir to immunocompromised patients (37 men, 26 women), no sex differences were discernible [6]. On the other hand, a more pronounced treatment effect was seen in men as compared to women following topical administration of aciclovir to patients with recurrent genital herpes in good health, in two placebo-controlled studies (54 men, 34 women and 63 men, 48 women, respectively) [7,8].
No studies with a clinically relevant sex analysis regarding adverse effects of aciclovir or valaciclovir have been found.It should be noted that a reduction of dose with decline in renal function is needed, as to avoid toxic side-effects from accumulation of aciclovir or its metabolites. Particularly in elderly, this might call for sex differences in dosing secondary to sex differences in decline of kidney function [9].
Regarding teratogenic aspects, please consult Janusmed Drugs and Birth Defects (in Swedish, Janusmed fosterpåverkan).
Fler kvinnor än män hämtade ut tabletter innehållande valaciklovir (ATC-kod J05AB11) på recept i Sverige år 2015, totalt 59 785 kvinnor och 27 584 män. Det motsvarar 12 respektive 6 patienter per tusen invånare. Andelen som hämtat ut läkemedel var högst i åldersgruppen 70-84 år hos män och i åldersgruppen 20-29 år hos kvinnor. I genomsnitt var tabletter innehållande valaciklovir 2,1 gånger vanligare hos kvinnor [10].
Uppdaterat: 2020-08-28
Litteratursökningsdatum: 2016-01-10
Faktagranskat av: Mia von Euler
Godkänt av: Karin Schenck-Gustafsson