Norgestrel
| Evidence Level: L4 | Predicted Indications: 10 |
Table of Contents
Norgestrel: From Contraception to Amenorrhea
One-Sentence Summary
Norgestrel is a synthetic progestin (a racemate of levonorgestrel) that is marketed in Singapore as an oral tablet, but no approved indication text is available in the data compiled for this report. The TxGNN model predicts it may be effective for amenorrhea, but there are 0 clinical trials and only 20 publications that are mostly general contraception reviews, so the supporting evidence is weak.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Not stated in the Singapore licence data (the product is a progestin used for contraception) |
| Predicted New Indication | Amenorrhea |
| TxGNN Prediction Score | 98.81% |
| Evidence Level | L4 |
| Singapore Market Status | ✓ Marketed |
| Number of Registrations | 1 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Detailed mechanism of action data is not available for this drug. Based on known information, norgestrel is a synthetic progestin (the racemate of levonorgestrel). Its established use is hormonal contraception, and mechanistically it may be applicable to amenorrhea.
Progestins are used clinically to induce withdrawal bleeding and to manage hypothalamic or hormonal amenorrhea. Combined norgestrel/ethinyl estradiol can also provide estrogen-progestin replacement. This gives the TxGNN prediction a plausible biological basis.
However, the link is indirect. The retrieved literature is largely general contraception reviews, and no trial tests norgestrel for treating amenorrhea. The prediction should therefore be treated as a research question rather than as confirmed efficacy.
Clinical Trial Evidence
Currently no related clinical trials registered.
Literature Evidence
No randomised controlled trials were found. The table lists the most relevant publications, with reviews and clinical studies prioritised.
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 11751066 | 2002 | Clinical study (indirect) | Eur J Endocrinol | Oral estrogen and bone mineral density in adolescents with anorexia nervosa. Only indirectly relevant |
| 8403908 | 1993 | Multicentre comparative trial | Contraception | Two low-dose combined oral contraceptives (norgestrel-based vs norethindrone acetate-based) compared in 892 postpartum women |
| 5639191 | 1968 | Clinical study | Obstet Gynecol | Norgestrel plus ethinyl estradiol as a low-dose oral agent for fertility control |
| 2752751 | 1989 | Non-comparative study | Contraception | Norgestrel 0.075 mg mini-pill in 200 breast-feeding women, assessing acceptability and contraceptive efficacy |
| 756597 | 1977 | Not classified | Riv Ital Ginecol | Post-pill amenorrhea and prolactin (Italian-language article) |
| 2660092 | 1989 | Review | Pediatr Clin North Am | Principles of hormonal contraception in sexually active adolescents |
| 7838435 | 1994 | Review | Nurse Pract | Brief review of combined oral contraceptive pills |
| 12306285 | 1971 | Review | Drug Ther | Effectiveness, side effects and metabolic changes of oral contraceptives |
| 6508652 | 1984 | Review | Aust Fam Physician | General review of oral contraceptives |
| 8305302 | 1994 | Case report | Br J Dermatol | Progesterone-induced cyclical urticaria not controlled by conjugated oestrogens plus norgestrel; controlled by buserelin |
Singapore Market Information
| Authorization Number | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| SIN04778P | PROGYLUTON TABLET (Bayer Weimar GmbH und Co. KG) | Tablet, sugar coated (oral) | Not stated in the licence data |
Safety Considerations
Drug Interactions: The interaction screen returned 100 records. The 20 shown in the data compiled for this report are all rated Moderate, and mostly involve glucose-lowering drugs:
- Antidiabetic agents: acarbose, alogliptin, metformin, canagliflozin, empagliflozin, ertugliflozin, chlorpropamide, glimepiride, nateglinide, albiglutide, liraglutide, and several insulin products
- Other drugs: aprepitant and clarithromycin
Hormonal contraceptives can alter glucose tolerance, so blood glucose monitoring is advisable when norgestrel is combined with antidiabetic therapy.
Package insert warnings and contraindications were not available. Please refer to the package insert for these.
Conclusion and Next Steps
Decision: Hold
Rationale: The TxGNN score is high (98.81%), and progestins have a plausible role in some forms of amenorrhea. However, there are no clinical trials, and the literature consists mainly of general contraception reviews and indirect studies. The evidence remains at the L4 level, and package insert safety information is missing.
To proceed, the following is needed:
- The Singapore package insert (warnings, contraindications and approved indication) from the HSA website
- Detailed mechanism of action data from DrugBank
- A focused literature search on progestin treatment of primary and secondary amenorrhea, including guidelines and comparative studies
- Clarification of which amenorrhea types (for example hypothalamic or post-pill) are the target population
- A safety review for this population, especially estrogen status, thromboembolic risk and pregnancy exclusion
Other predicted indications (all rated Hold): Breast fibrocystic disease, benign mammary dysplasia, apocrine adenosis of breast, blunt duct adenosis of breast, lactation disease, breast adenosis, fat necrosis of breast, breast abscess and scalp dermatosis. These have no trials. The retrieved literature for lactation disease and breast adenosis is indirect or unrelated, so they are not recommended for further evaluation at this stage.
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.