No Interacting Influence of Lavender Oil Preparation Silexan on Oral Contraception Using an Ethinyl Estradiol/Levonorgestrel Combination

Abstract

PurposeSilexan is an oral Lavender oil preparation with proven anxiolytic efficacy. Given the high prevalence of anxiety and restlessness in younger women, oral contraceptives and Silexan will likely be co-administered.MethodsA double-blind, randomised, 2-period crossover study was performed to investigate the effects of Silexan on the pharmacokinetics and pharmacodynamics of Microgynon®, a combination oral contraceptive containing ethinyl estradiol 0.03 mg (EE) and levonorgestrel 0.15 mg (LNG) in healthy, fertile, adult females. During 2 consecutive cycles of 28 days, oral contraception was given for 21 days combined with 1 × 160 mg/day Silexan or placebo. Plasma concentration–time profiles of EE and LNG were obtained on day 18 ± 1 up to 24 h after dosing. The primary outcome measure was the area under the concentration–time curve over a dosing interval of τ = 24 h (AUCτ) for EE and LNG plasma levels. An interaction with Silexan was formally excluded if the 90 % confidence interval for the AUCτ ratio during co-administration with Silexan or placebo was included within the range of 0.80–1.25. Secondary outcomes included EE and LNG peak concentration (Cmax) and time to Cmax (tmax), follicle size, endometrial thickness, the Hoogland score, and serum levels of estradiol, progesterone, and sex hormone-binding globulin.ResultsA total of 24 women (mean age 27.3 years; mean body mass index 22.2 kg/m2) participated. The confidence intervals for the EE and LNG AUCτ and Cmax ratios fell within the pre-specified limits, indicating no interaction (point estimates [Silexan/placebo] AUCτ EE 0.97, LNG 0.94; Cmax EE 0.99, LNG 0.96). For LNG, tmax was slightly delayed. No secondary outcome indicated any impairment of contraceptive efficacy.ConclusionsCo-administration of Silexan did not affect the efficacy of a combination oral contraceptive containing EE and LNG and was well tolerated.

Silexan in anxiety disorders: Clinical data and pharmacological background

“…Doroshyenko et al (2013) and Heger-Mahn et al (2014) studied the interaction potential of Silexan in healthy volunteers. In the double-blind, randomised, placebo-controlled trials a potential influence of the herbal drug on human cytochrome P450 activity (Doroshyenko et al 2013) and on the contraceptive efficacy of a combined oral contraceptive whose active compounds are ethinylestradiol and levonorgestrel (Heger-Mahn et al 2014) were investigated.…”

“…The high prevalence of anxiety and restlessness in younger women (Bekker & van Mens-Verhulst 2007) increases the likelihood of co-administration of contraceptives and anxiolytic drugs. Thus, the interaction potential of Silexan with oral contraceptives was investigated by Heger-Mahn et al (2014) in a double-blind, randomised cross-over trial testing possible effects of Silexan on the pharmacokinetics and pharmacodynamics of a combination oral contraceptive containing ethinylestradiol (EE) 0.03 mg and levonorgestrel (LNG) 0.15 mg in healthy, fertile, adult females. During two consecutive 28-day cycles, the oral contraceptive was administered for 21 days in combination with Silexan 160 mg/day or placebo.…”

Essential oil of lavender in anxiety disorders: Ready for prime time?

“…The second was a double-blind, randomized, placebo-controlled, crossover trial conducted in 24 women taking oral contraceptives during two menstrual cycles. 41 No changes in area under the curve or maximum serum concentration (C max ) values of ethinyl estradiol or levonorgestrel were discovered, and there were no changes in secondary outcomes that may indicate impairment of oral contraceptive efficacy. However, the time to maximum concentration (T max ) for levonorgestrel was slightly delayed.…”

“…Two clinical drug interaction studies 40 , 41 have been conducted using SLO. One was conducted in 16 healthy volunteers who were administered SLO 160 mg/d for 11 days in a double-blind, randomized, placebo-controlled, crossover fashion.…”

“…Although this may not be clinically significant in the use of daily oral contraceptives, efficacy of emergency contraceptives in which efficacy is critically time dependent could be impacted. 41 Effects on glucuronosyltransferase have not been described.…”