Benefits of Triphasic Contraceptives
The Benefits of Triphasic Contraceptives
A review of the benefits of triphasic combined oral contraceptives when compared to today’s low-dose monophasic alternatives.
Introduction:
Since their introduction in 1961, oestrogen-progestogen combined oral contraceptive (COC) pills have provided women with an effective and effortless means of contraception for 50 years [1]. Taken by 17% of all women of reproductive age, they are amongst the most widely prescribed drugs in the U.K. today[2]. Hitherto, earlier COC formulations have been associated with harmful dose-dependent side effects [3]. In time, however, a collective scientific effort has successfully improved the safety of COC’s by developing preparations that contain the minimum hormonal concentrations required to inhibit ovulation. Today COC’s contain 80-90% less oestrogen and progestogen than the earliest preparations and an in some types the newer, less androgenic, progestogens also [4]. In comparison to earlier COCs, the safety profile of current low-dose preparations is markedly superior[5].
Accompanying these therapeutic advances has been the evolution of COC administration towards multiphasic dosing regimens, in which progestogen concentrations are sequentially increased over two (biphasic) or three (triphasic) phases. In some preparations the dose of oestrogen is also increased over one of these phases [6]. Owed to such dose alterations, the phasic regimen has allowed further reductions in total monthly hormone exposure and more closely mimics the dynamic hormonal picture of the female menstrual cycle. During its conception, scientists hypothesised that such physiologically appropriate lower doses would afford triphasic COC’s fewer side-effects, whilst maintaining contraceptive efficacy and satisfactory cycle control [7-8].
Of the currently available multiphasic agents, triphasic COCs have almost replaced biphasic COC’s and contain up to 40% lower progestogen concentrations than their monophasic
A review of the benefits of triphasic combined oral contraceptives when compared to today’s low-dose monophasic alternatives.
Introduction:
Since their introduction in 1961, oestrogen-progestogen combined oral contraceptive (COC) pills have provided women with an effective and effortless means of contraception for 50 years [1]. Taken by 17% of all women of reproductive age, they are amongst the most widely prescribed drugs in the U.K. today[2]. Hitherto, earlier COC formulations have been associated with harmful dose-dependent side effects [3]. In time, however, a collective scientific effort has successfully improved the safety of COC’s by developing preparations that contain the minimum hormonal concentrations required to inhibit ovulation. Today COC’s contain 80-90% less oestrogen and progestogen than the earliest preparations and an in some types the newer, less androgenic, progestogens also [4]. In comparison to earlier COCs, the safety profile of current low-dose preparations is markedly superior[5].
Accompanying these therapeutic advances has been the evolution of COC administration towards multiphasic dosing regimens, in which progestogen concentrations are sequentially increased over two (biphasic) or three (triphasic) phases. In some preparations the dose of oestrogen is also increased over one of these phases [6]. Owed to such dose alterations, the phasic regimen has allowed further reductions in total monthly hormone exposure and more closely mimics the dynamic hormonal picture of the female menstrual cycle. During its conception, scientists hypothesised that such physiologically appropriate lower doses would afford triphasic COC’s fewer side-effects, whilst maintaining contraceptive efficacy and satisfactory cycle control [7-8].
Of the currently available multiphasic agents, triphasic COCs have almost replaced biphasic COC’s and contain up to 40% lower progestogen concentrations than their monophasic