Letrozole and norethisterone acetate versus letrozole and triptorelin in the treatment of endometriosis related pain symptoms: a randomized controlled trial.

Ferrero S, Venturini PL, Gillott DJ, Remorgida V

Reproductive biology and endocrinology : RB&E21 Jun 2011Cited by 53 (Europe PMC)

PMID21693037PMCIDPMC3141645DOI10.1186/1477-7827-9-88PepBankPUB-21693037

Summary

BackgroundWhen aromatase inhibitors are used to treat premenopausal women with endometriosis, additional drugs should be used to effectively down-regulate gonadal estrogen biosynthesis. This randomized prospective open-label study compared the efficacy in treating pain symptoms and the tolerability of letrozole combined with either norethisterone acetate or triptorelin.MethodsWomen with pain symptoms caused by rectovaginal endometriosis were treated with letrozole (2.5 mg/day) and were randomized to also receive either oral norethisterone acetate (2.5 mg/day; group N) or intramuscular injection of triptorelin (11.25 mg every 3 months; group T). The scheduled length of treatment was 6 months. A visual analogue scale and a multidimensional categorical rating scale were used to assess the severity of pain symptoms. The volume of the endometriotic nodules was estimated by ultrasonography using virtual organ computer-aided analysis. Adverse effects of treatment were recorded.ResultsA total of 35 women were randomized between the two treatment protocols. Significantly more patients in group N rated their treatment as satisfactory or very satisfactory (64.7%) as compared to group T (22.2%; p=0.028). The intensity of both non-menstrual pelvic pain and deep dyspareunia significantly decreased during treatment in both study groups, though no statistically meaningful difference between the two groups was apparent. Reduction in the volume of endometriotic nodules was significantly greater in group T than in group N. Interruption of treatment due to adverse effects significantly differed between the groups, with 8 women in group T (44.4%) and 1 woman in group N (5.9%) interrupting treatment (p=0.018). Similarly, 14 women included in group T (77.8%) and 6 women included in group N (35.3%) experienced adverse effects of treatment (p=0.018). During treatment, mineral bone density significantly decreased in group T but not in group N.ConclusionsAromatase inhibitors reduce the intensity of endometriosis-related pain symptoms. Combining letrozole with oral norethisterone acetate was associated with a lower incidence of adverse effects and a lower discontinuation rate than combining letrozole with triptorelin.

CC BYText from Europe PMC. Highlighted sentences are the source of results.

Results from this study6

No result from this study comes from a test of the peptide.

Studies that did not test the peptide alone6

In this study, Triptorelin (Trelstar, Decapeptyl) was a lab tool or a carrier, part of a mix, or the subject of a lab method. These results are not evidence about taking Triptorelin (Trelstar, Decapeptyl).

01HumanNot a test of Triptorelin (Trelstar, Decapeptyl) aloneRandomized controlled trialEfficacy outcome
In women with rectovaginal endometriosis, letrozole plus triptorelin and letrozole plus norethisterone acetate reduced pelvic pain without a significant between-group difference.
In plain wordsIn women, pelvic pain decreased without significant differences between letrozole plus triptorelin and letrozole plus norethisterone acetate.
Peptide
Triptorelin (Trelstar, Decapeptyl)
Outcome
No significant changeNon-menstrual pelvic pain
Study
n = 35
Comparator
Letrozole plus norethisterone acetate
Outcome group
Pain · Reproductive and sexual health
Source sentences
Summary
The intensity of both non-menstrual pelvic pain and deep dyspareunia significantly decreased during treatment in both study groups, though no statistically meaningful difference between the two groups was apparent.
2 context sentences(design, population, supporting numbers)
Summary · context
Women with pain symptoms caused by rectovaginal endometriosis were treated with letrozole (2.5 mg/day) and were randomized to also receive either oral norethisterone acetate (2.5 mg/day; group N) or intramuscular injection of triptorelin (11.25 mg every 3 months; group T).
Summary · context
The scheduled length of treatment was 6 months.
In this study, Triptorelin (Trelstar, Decapeptyl) was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Triptorelin (Trelstar, Decapeptyl).
Show in the study text Report a problemFND-2169303701
02HumanNot a test of Triptorelin (Trelstar, Decapeptyl) aloneRandomized controlled trialEfficacy outcome
In women with rectovaginal endometriosis, deep dyspareunia decreased with letrozole plus triptorelin without a significant difference from letrozole plus norethisterone acetate.
In plain wordsIn women, painful intercourse decreased without significant differences between letrozole plus triptorelin and letrozole plus norethisterone acetate.
Peptide
Triptorelin (Trelstar, Decapeptyl)
Outcome
No significant changeDeep dyspareunia
Study
n = 35
Comparator
Letrozole plus norethisterone acetate
Outcome group
Pain · Reproductive and sexual health
Source sentences
Summary
The intensity of both non-menstrual pelvic pain and deep dyspareunia significantly decreased during treatment in both study groups, though no statistically meaningful difference between the two groups was apparent.
2 context sentences(design, population, supporting numbers)
Summary · context
Women with pain symptoms caused by rectovaginal endometriosis were treated with letrozole (2.5 mg/day) and were randomized to also receive either oral norethisterone acetate (2.5 mg/day; group N) or intramuscular injection of triptorelin (11.25 mg every 3 months; group T).
Summary · context
The scheduled length of treatment was 6 months.
In this study, Triptorelin (Trelstar, Decapeptyl) was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Triptorelin (Trelstar, Decapeptyl).
Show in the study text Report a problemFND-2169303702
03HumanNot a test of Triptorelin (Trelstar, Decapeptyl) aloneRandomized controlled trialEfficacy outcome
In women with rectovaginal endometriosis, letrozole plus triptorelin reduced nodule volume more than letrozole plus norethisterone acetate.
In plain wordsIn women with endometriosis, letrozole plus triptorelin reduced nodule volume more than letrozole plus norethisterone acetate.
Peptide
Triptorelin (Trelstar, Decapeptyl)
Outcome
DecreaseEndometriotic nodule volume reduction
Study
n = 35
Comparator
Letrozole plus norethisterone acetate
Outcome group
Sex hormones and fertility · Reproductive and sexual health
Source sentences
Summary
Reduction in the volume of endometriotic nodules was significantly greater in group T than in group N.
2 context sentences(design, population, supporting numbers)
Summary · context
Women with pain symptoms caused by rectovaginal endometriosis were treated with letrozole (2.5 mg/day) and were randomized to also receive either oral norethisterone acetate (2.5 mg/day; group N) or intramuscular injection of triptorelin (11.25 mg every 3 months; group T).
Summary · context
The scheduled length of treatment was 6 months.
In this study, Triptorelin (Trelstar, Decapeptyl) was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Triptorelin (Trelstar, Decapeptyl).
Show in the study text Report a problemFND-2169303703
04HumanNot a test of Triptorelin (Trelstar, Decapeptyl) aloneRandomized controlled trialSafety outcome
In women with endometriosis, adverse-effect discontinuation was higher with letrozole plus triptorelin than with letrozole plus norethisterone acetate.
In plain wordsIn women with endometriosis, more stopped letrozole plus triptorelin for adverse effects than letrozole plus norethisterone acetate.
Peptide
Triptorelin (Trelstar, Decapeptyl)
Outcome
IncreaseDiscontinuation due to adverse effects
Study
n = 35
Comparator
Letrozole plus norethisterone acetate
Outcome group
Adverse events · Whole body
Measurements
Discontinuation
44.4%
letrozole plus triptorelin
Discontinuation
5.9%
letrozole plus norethisterone acetate
Discontinuation
8 women
letrozole plus triptorelin
Discontinuation
1 women
letrozole plus norethisterone acetate
Source sentences
Summary
Interruption of treatment due to adverse effects significantly differed between the groups, with 8 women in group T (44.4%) and 1 woman in group N (5.9%) interrupting treatment (p=0.018).
2 context sentences(design, population, supporting numbers)
Summary · context
Women with pain symptoms caused by rectovaginal endometriosis were treated with letrozole (2.5 mg/day) and were randomized to also receive either oral norethisterone acetate (2.5 mg/day; group N) or intramuscular injection of triptorelin (11.25 mg every 3 months; group T).
Summary · context
The scheduled length of treatment was 6 months.
In this study, Triptorelin (Trelstar, Decapeptyl) was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Triptorelin (Trelstar, Decapeptyl).
Show in the study text Report a problemFND-2169303704
05HumanNot a test of Triptorelin (Trelstar, Decapeptyl) aloneRandomized controlled trialSafety outcome
In women with endometriosis, adverse effects were more frequent with letrozole plus triptorelin than with letrozole plus norethisterone acetate.
In plain wordsIn women with endometriosis, adverse effects were more frequent with letrozole plus triptorelin than letrozole plus norethisterone acetate.
Peptide
Triptorelin (Trelstar, Decapeptyl)
Outcome
IncreaseAny adverse effects
Study
n = 35
Comparator
Letrozole plus norethisterone acetate
Outcome group
Adverse events · Whole body
Measurements
Adverse effects
77.8%
letrozole plus triptorelin
Adverse effects
35.3%
letrozole plus norethisterone acetate
Adverse effects
14 women
letrozole plus triptorelin
Adverse effects
6 women
letrozole plus norethisterone acetate
Source sentences
Summary
Similarly, 14 women included in group T (77.8%) and 6 women included in group N (35.3%) experienced adverse effects of treatment (p=0.018).
2 context sentences(design, population, supporting numbers)
Summary · context
Women with pain symptoms caused by rectovaginal endometriosis were treated with letrozole (2.5 mg/day) and were randomized to also receive either oral norethisterone acetate (2.5 mg/day; group N) or intramuscular injection of triptorelin (11.25 mg every 3 months; group T).
Summary · context
The scheduled length of treatment was 6 months.
In this study, Triptorelin (Trelstar, Decapeptyl) was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Triptorelin (Trelstar, Decapeptyl).
Show in the study text Report a problemFND-2169303705
06HumanNot a test of Triptorelin (Trelstar, Decapeptyl) aloneRandomized controlled trialSafety outcome
In women with endometriosis, bone mineral density decreased significantly with letrozole plus triptorelin but not with letrozole plus norethisterone acetate.
In plain wordsIn women with endometriosis, bone density decreased with letrozole plus triptorelin but not with letrozole plus norethisterone acetate.
Peptide
Triptorelin (Trelstar, Decapeptyl)
Outcome
DecreaseBone mineral density
Study
n = 35
Comparator
Letrozole plus norethisterone acetate
Outcome group
Bone and joint · Musculoskeletal
Source sentences
Summary
During treatment, mineral bone density significantly decreased in group T but not in group N.
2 context sentences(design, population, supporting numbers)
Summary · context
Women with pain symptoms caused by rectovaginal endometriosis were treated with letrozole (2.5 mg/day) and were randomized to also receive either oral norethisterone acetate (2.5 mg/day; group N) or intramuscular injection of triptorelin (11.25 mg every 3 months; group T).
Summary · context
The scheduled length of treatment was 6 months.
In this study, Triptorelin (Trelstar, Decapeptyl) was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Triptorelin (Trelstar, Decapeptyl).
Show in the study text Report a problemFND-2169303706

AI wrote and checked these results. AI can make mistakes, so check important results against the source.

Version history

PepBank keeps every version of the data on this study. Status changes from Retraction Watch, Europe PMC and Crossref are listed with their source.

Version 2Current
22 Oct 2026, 02:26 UTC
Study results updated
Version 1
21 Oct 2026, 18:59 UTC
First added · source update from Europe PMC

Subjects

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