Letrozole in Tubal Ectopic Pregnancy

Study Overview
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Brief Summary
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This is a multi-centred randomized controlled trial on the addition of letrozole in the medical management of tubal ectopic pregnancies. Tubal ectopic pregnancies are abnormal pregnancies in the Fallopian tube, rather than in the womb. They occurred in around 1-2% of all pregnancies. Methotrexate (MTX) given by the intramuscular route i.e. systemic, a commonly used drug for cancer , was a widely used alternative for management for unruptured tubal ectopic pregnancies and was recommended as first line treatment for selected women. Letrozole, aromatase inhibitor, can suppose oestradiol level. Combination of letrozole with misprostol has shown to improve the complete abortion rate in miscarriage. As a result, addition of letrozole may cause a higher success rate in the medical treatment of ectopic pregnancy. As the evidence of combination of MTX and letrozole in tubal ectopic pregnancies is not available, the objective of the present study is to evaluate the efficacy of combination of MTX and letrozole compared to MTX alone in women with tubal ectopic pregnancies.

Detailed Description
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Tubal ectopic pregnancies occur in around 1-2% of all pregnancies. Traditionally, surgery with salpingectomy was the mainstay of treatment; however, it comes with anaesthetic and operatives risks in addition to an increased cost for operative procedures. In recent years, systemic methotrexate (MTX), a dihydrofolate reductase inhibitor, has been a widely used alternative for management for unruptured tubal ectopic pregnancies. The success rate of systemic MTX at a doses of 50mg/m2 body surface area is around 70% which ranges from 65 to 95%, depending greatly on the level of human chorionic gonadotrophin (hCG), the size of adnexal mass and presence of fetal heart pulsation. Use of systemic MTX as the first-line management has been proposed for women with unruptured ectopic pregnancy where the adnexal mass is smaller than 35mm, serum hCG level is less than 5000 IU/l and fetal heartbeat is absent. Letrozole is a third generation non-steroidal reversible aromatase inhibitor. It can suppress oestradiol level up to 95% to 99% after administration according to pharmacodynamics and pharmacokinetics studies. Oestrogen is important in the support of early pregnancy, other than progesterone with well-known pivotal effect on the maintenance of early pregnancy. Animal studies showed the combination of mifepristone and letrozole worked synergistically and induced almost 100% termination of pregnancies in rats. Letrozole induced 50% miscarriage rate in pregnant baboons. Letrozole combined with vaginal misoprostol regimen was associated with a higher complete abortion rate than misoprostol alone in pregnancies up to 63 days. The use of letrozole in ectopic pregnancy has never been explored. It is hypothesized that letrozole can suppress serum oestradiol level, which in turn, may cause failure of pregnancy in ectopic pregnancy. The aim of this study is to investigate the clinical effectiveness of letrozole in addition to MTX in the medical treatment of ectopic pregnancy.

Official Title
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Randomized Controlled Trial on Use of Letrozole in the Medical Management of Tubal Ectopic Pregnancies

Conditions
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Tubal Pregnancy

Intervention / Treatment
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* Other: Placebos
* Drug: Letrozole tablets


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Presence of heterogenous adnexal mass on USG suggestive of tubal ectopic pregnancy with hCG level >=1500 IU/L and <= 5000 IU/L Absence of fetal heart pulsation Mean diameter of adnexal mass <= 3.5cm Haemodynamically stable No significant abdominal pain Exclusion Criteria: Presence of significant amount of free fluid in pelvis Allergic to MTX Deranged liver function test (AST/ ALT or GGT >= 2 upper limit of normal) Deranged renal function test (eGFR <= 45ml/min) Heterotopic pregnancies

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Participants will be randomized into either receive letrozole or placebo capsules.
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Letrozole<br>Participants will be given letrozole 10mg daily for one week after standard medical management for tubal ectopic pregnancy by methotrexate injection. Subsequently they will receive the standard management for medical management of tubal ectopic prengnacies. | Drug: Letrozole tablets<br>* Letrozole 10mg daily for one week.<br>* Other names: Letrozole;|
| Placebo Comparator: Placebo<br>Participants will be given identical looking placebo for one week and receive the same standard management for medical management of tubal ectopic pregnancies. | Other: Placebos<br>* Placebo 4 tablets a day for one week.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Treatment success | Proportion of women with treatment success defined as normalization of serum hCG level <10IU/L without additional medical or surgical intervention | 2 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| hCG normalization duration | Duration of time until hCG normalization measured in days | 2 months | 
| Number of participants experienced side effects | Side effects after letrozole | 2 months | 
| Duration of hospitalization | Duration of hospitalization | 2 months | 
| Participant satisfaction: proportion of women who would recommend this treatment to a friend | Treatment satisfaction measured as proportion of women who would recommend this treatment to a friend | 2 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Tubal ectopic pregnancy, Methotrexate, Letrozole