- Approval Id
- db79a145b23411a6
- Drug Approval Emc Name
- Postinor 1500 microgram tablet
- Drug Name
- Postinor 1500 microgram tablet
- Company Name
- Gedeon Richter (UK) Ltd
- Company Address
- 127 Shirland Road, London, W9 2EP, UK
- Company Website
- http://www.gedeonrichter.co.uk
- Company Telephone
- +44(0)207 604 8800
- Company Medical Info Direct Line
- +44 (0)207 604 8806
- Company Medical Info Email
- medinfo.uk@gedeonrichter.eu
- Company Customer Care Direct Line
- +44 (0)207 604 8800
- Atc Code
- G03AD01
- Legal Category
- Pharmacy
- Authorisation Holder
- Gedeon Richter Plc.
Gyömrői út 19-21,
H-1103 Budapest
Hungary
- Authorisation Number
- PL 04854/0105
- Authorisation Date
- 15/02/2012
- Instruction Authorisation Holder
- Gedeon Richter Plc.
Gyömrői út 19-21,
H-1103 Budapest
Hungary
- Instruction Authorisation Number
- PL 04854/0105
- Instruction Authorisation Date
- 15/02/2012
- Instruction Composition
- Each tablet contains 1500 micrograms of levonorgestrel.
Excipient \*\*with known effect\*\*: 142.5 mg lactose monohydrate.
For the full list of excipients, see section 6.1.
- Instruction Dosage Form
- Tablet.
Almost white, flat, rimmed tablet of about 8 mm diameter with an impressed mark of “G00” on one side.
- Instruction Clinical Particulars
- 4.1 Therapeutic indications
Emergency contraception within 72 hours of unprotected sexual intercourse or failure of a contraceptive method.
Postinor is indicated in adults and adolescents >16 years of age.4.2 Posology and method of administration
\*\*Posology\*\*
One tablet should be taken, as soon as possible, preferably within 12 hours, and no later than 72 hours after unprotected intercourse (see section 5.1).
Women who have used enzyme-inducing drugs during the last 4 weeks and need emergency contraception are recommended to use a non-hormonal EC, i.e. Cu-IUD or take a double dose of levonorgestrel (i.e. 2 tablets taken together) for those women unable or unwilling to use Cu-IUD (see section 4.5).
If vomiting occurs within three hours of taking the tablet, another tablet should be taken immediately.
Postinor can be used at any time during the menstrual cycle unless menstrual bleeding is overdue.
After using emergency contraception it is recommended to use a local barrier method (e.g. condom, diaphragm, spermicide, cervical cap) until the next menstrual period starts. The use of levonorgestrel does not contraindicate the continuation of regular hormonal contraception.
\*Paediatric population\*
There is no relevant use of Postinor for children of prepubertal age in the indication emergency contraception
\*\*Method of administration\*\*
For oral administration.4.3 Contraindications
Hypersensitivity to the active substance or to any of the excipients listed in section 6.1.4.4 Special warnings and precautions for use
Emergency contraception is an occasional method. It should in no instance replace a regular contraceptive method.
Emergency contraception does not prevent a pregnancy in every instance. If there is uncertainty about the timing of the unprotected intercourse or if the woman has had unprotected intercourse more than 72 hours earlier in the same menstrual cycle, conception may have occurred. Treatment with levonorgestrel following the second act of intercourse may therefore be ineffective in preventing pregnancy. If menstrual periods are delayed by more than 5 days or abnormal bleeding occurs at the expected date of menstrual periods or pregnancy is suspected for any other reason, pregnancy should be excluded. \*\*If pregnancy occurs after treatment with levonorgestrel, the possibility of an ectopic pregnancy should be considered.\*\* The absolute risk of ectopic pregnancy is likely to be low, as levonorgestrel prevents ovulation and fertilisation. Ectopic pregnancy may continue, despite the occurrence of uterine bleeding.
Therefore, levonorgestrel is not recommended for patients who are at risk of ectopic pregnancy (previous history of salpingitis or of ectopic pregnancy).
Levonorgestrel is not recommended in patients with severe hepatic dysfunction.
Severe malabsorption syndromes, such as Crohn's disease, might impair the efficacy of levonorgestrel.
This medicinal product contains lactose monohydrate. Patients with rare hereditary problems of galactose intolerance, total lactase deficiency or glucose-galactose malabsorption should not take this medicine.
After levonorgestrel intake, menstrual periods are usually normal and occur at the expected date. They can sometimes occur earlier or later than expected by a few days. Women should be advised to make a medical appointment to initiate or adopt a method of regular contraception. If no withdrawal bleed occurs in the next pill-free period following the use of levonorgestrel after regular hormonal contraception, pregnancy should be ruled out.
Repeated administration within a menstrual cycle is not advisable because of the possibility of disturbance of the cycle.
Limited and inconclusive data suggest that there may be reduced efficacy of Postinor with increasing body weight or body mass index (BMI) (see sections 5.1 and 5.2). In all women, emergency contraception should be taken as soon as possible after unprotected intercourse, regardless of the woman's body weight or BMI.Levonorgestrel is not as effective as a conventional regular method of contraception and is suitable only as an emergency measure. Women who present for repeated courses of emergency contraception should be advised to consider long-term methods of contraception.
Use of emergency contraception does not replace the necessary precautions against sexually transmitted diseases.4.5 Interaction with other medicinal products and other forms of interaction
The metabolism of levonorgestrel is enhanced by concomitant use of liver enzyme inducers, mainly CYP3A4 enzyme inducers. Concomitant administration of efavirenz has been found to reduce plasma levels of levonorgestrel (AUC) by around 50%.
Drugs suspected of having similar capacity to reduce plasma levels of levonorgestrel include barbiturates (including primidone), phenytoin, carbamazepine, herbal medicines containing Hypericum perforatum (St. John's Wort), rifampicin, ritonavir, rifabutin and griseofulvin.
For women who have used enzyme-inducing drugs in the past 4 weeks and need emergency contraception, the use of non-hormonal emergency contraception (i.e. a Cu-IUD) should be considered. Taking a double dose of levonorgestrel (i.e. 3000 microgram within 72 hours after the unprotected intercourse) is an option for women who are unable or unwilling to use a Cu-IUD, although this specific combination (a double dose of levonorgestrel during concomitant use of an enzyme inducer) has not been studied.
Medicines containing levonorgestrel may increase the risk of cyclosporin toxicity due to possible inhibition of cyclosporin metabolism.
Women taking such drugs should be referred to their doctor for advice.4.6 Fertility, pregnancy and lactation
\*Pregnancy\*
Levonorgestrel should not be given to pregnant women. It will not interrupt a pregnancy. In the case of continued pregnancy, limited epidemiological data indicate no adverse effects on the fetus but there are no clinical data on the potential consequences if doses greater than 1.5 mg of levonorgestrel are taken (see section 5.3.).
\*Breast-feeding\*
Levonorgestrel is secreted into breast milk. Potential exposure of an infant to levonorgestrel can be reduced if the breast-feeding woman takes the tablet immediately after feeding and avoids nursing at least 8 hours following levonorgestrel administration.
\*Fertility\*
Levonorgestrel increases the possibility of cycle disturbances which can sometimes lead to earlier or later ovulation date. These changes can result in modified fertility date, however, there are no fertility data in the long term.4.7 Effects on ability to drive and use machines
No studies on the effect on the ability to drive and use machines have been performed.4.8 Undesirable effects
The most commonly reported undesirable effect was nausea.
| | | |
| --- | --- | --- |
| \*\*System Organ Class\*\* \*\*MedDRA\*\* | \*\*Frequency of adverse reactions\*\* | |
| \*\*Very common\*\* (\*\*>1/\*\*10) | \*\*Common\*\* (\*\*>1/\*\*100 to <1/10) |
| \*\*Nervous system disorders\*\* | Headache | Dizziness |
| \*\*Gastrointestinal disorders\*\* | Nausea Abdominal pain lower | Diarrhoea Vomiting |
| \*\*Reproductive system and breast disorders\*\* | Bleeding not related to menses\\* | Delay of menses more than 7 days \\*\\* Menstruation irregular Breast tenderness |
| \*\*General disorders and administration site conditions\*\* | Fatigue | |
\\*Bleeding patterns may be temporarily disturbed, but most women will have their next menstrual period within 5-7 days of the expected time.
\\*\\*If the next menstrual period is more than 5 days overdue, pregnancy should be excluded.
\*From post-marketing surveillance additionally, the following adverse events have been reported:\*
\*Gastrointestinal disorders\*
Very rare (<1/10,000): abdominal pain
\*Skin and subcutaneous tissue disorders\*
Very rare (<1/10,000): rash, urticaria, pruritus,
\*Reproductive system and breast disorders\*
Very rare (<1/10,000): pelvic pain, dysmenorrhoea
\*General disorders and administration site conditions\*
Very rare (<1/10,000): face oedema
\*\*Reporting of suspected adverse reactions:\*\*
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the national Yellow Card Scheme, Website: www.mhra.gov.uk/yellowcard. By reporting side effects you can help provide more information on the safety of this medicine\*\*.\*\*4.9 Overdose
Serious undesirable effects have not been reported following acute ingestion of large doses of oral contraceptives. Overdose may cause nausea, and withdrawal bleeding may occur. There are no specific antidotes and treatment should be symptomatic.
- Instruction Pharmacology
- 5.1 Pharmacodynamic properties
Pharmacotherapeutic group: Sex hormones and modulators of the genital system, Emergency contraceptives, ATC code: G03AD01
\*\*Mechanism of action\*\*
The precise mode of action of levonorgestrel as an emergency contraceptive is not known.
At the recommended regimen, levonorgestrel is thought to work mainly by preventing ovulation and fertilisation if intercourse has taken place in the preovulatory phase, when the likelihood of fertilisation is the highest. Levonorgestrel is not effective once the process of implantation has begun.
\*\*Clinical efficacy and safety\*\*
The pregnancy rate was 1.1% (11/976) in an earlier clinical study (Lancet 1998; 352: 428-433) where 750 micrograms of levonorgestrel was taken as two 750 microgram doses with a 12-hour interval. Pregnancy rates appeared to increase with time of start of treatment after intercourse (0.4% [2/450] within 24 hours, 1.2% [4/338] 25-48 hours, 2.7% [5/187] if started between 49 and 72 hours).
Results from a randomised, double-blind clinical study conducted in 2001 (Lancet 2002; 360: 1803-1810) showed 1.34% (16/1 198) pregnancy rate with 1500 microgram single dose of levonorgestrel / two 750 microgram tablets of levonorgestrel taken at the same time (taken within 72 hours of unprotected sex) (compared with 1.69% [20/11 832] when two 750 microgram tablets were taken 12 hours apart). There was no difference between pregnancy rates in case of women who were treated on the third or the fourth day after the unprotected act of intercourse (p>0.2).
Meta-analysis on three WHO studies (Von Hertzen et al., 1998 and 2002; Dada et al., 2010) showed that the pregnancy rate of levonorgestrel is 1.01% (59/5 863) which means it prevents pregnancy in 99% of situations (compared to an expected pregnancy rate of about 8% in the absence of emergency contraception).
There is limited and inconclusive data on the effect of high body weight/high BMI on the contraceptive efficacy. In three WHO studies no trend for a reduced efficacy with increasing body weight/BMI was observed (Table 1), whereas in the two other studies (Creinin et al., 2006 and Glasier et al., 2010) a reduced contraceptive efficacy was observed with increasing body weight or BMI (Table 2). Both meta-analyses excluded intake later than 72 hours after unprotected intercourse (i.e. off-label use of levonorgestrel) and women who had further acts of unprotected intercourse (For pharmacokinetic studies in obese women see section 5.2).
Table 1: Meta-analysis on three WHO studies (Von Hertzen et al., 1998 and 2002; Dada et al., 2010)
| | | | | |
| --- | --- | --- | --- | --- |
| \*\*BMI (kg/m2)\*\* | \*\*Underweight\*\* \*\*0 - 18.5\*\* | \*\*Normal\*\* \*\*18.5-25\*\* | \*\*Overweight\*\* \*\*25-30\*\* | \*\*Obese\*\* \*\*≥ 30\*\* |
| \*\*N total\*\* | 600 | 3952 | 1051 | 256 |
| \*\*N pregnancies\*\* | 11 | 39 | 6 | 3 |
| \*\*Pregnancy rate\*\* | 1.83% | 0.99% | 0.57% | 1.17% |
| \*\*Confidence Interval\*\* | 0.92 – 3.26 | 0.70 – 1.35 | 0.21 – 1.24 | 0.24 – 3.39 |
Table 2: Meta-analysis on studies of Creinin et al., 2006 and Glasier et al., 2010
| | | | | |
| --- | --- | --- | --- | --- |
| \*\*BMI (kg/m2)\*\* | \*\*Underweight\*\* \*\*0 - 18.5\*\* | \*\*Normal\*\* \*\*18.5-25\*\* | \*\*Overweight\*\* \*\*25-30\*\* | \*\*Obese\*\* \*\*≥ 30\*\* |
| \*\*N total\*\* | 64 | 933 | 339 | 212 |
| \*\*N pregnancies\*\* | 1 | 9 | 8 | 11 |
| \*\*Pregnancy rate\*\* | 1.56% | 0.96% | 2.36% | 5.19% |
| \*\*Confidence Interval\*\* | 0.04 – 8.40 | 0.44 – 1.82 | 1.02 – 4.60 | 2.62 – 9.09 |
At the recommended regimen, levonorgestrel is not expected to induce significant modification of blood clotting factors, and lipid and carbohydrate metabolism.
\*\*Paediatric population\*\*
A prospective observational study showed that out of 305 treatments with levonorgestrel emergency contraceptive tablets, seven women became pregnant resulting in an overall failure rate of 2.3%. The failure rate in women under 18 years (2.6% or 4/153) was comparable to the failure rate in women 18 years and over (2.0% or 3/152).5.2 Pharmacokinetic properties
\*\*Absorption\*\*
Orally administered levonorgestrel is rapidly and almost completely absorbed.
The results of a pharmacokinetic study carried out with 16 healthy women showed that following ingestion of single dose of 1.5 mg levonorgestrel maximum drug serum levels of 18.5 ng/ml were found at 2 hours.
After reaching maximum serum levels, the concentration of levonorgestrel decreased with a mean elimination half-life of about 26 hours.
Levonorgestrel is bound to serum albumin and sex hormone binding globulin (SHBG). Only about 1.5% of the total serum levels are present as free steroid, but 65 % are specifically bound to SHBG.
The absolute bioavailability of levonorgestrel was determined to be almost 100% of the dose administered.
About 0.1% of the maternal dose can be transferred via milk to the nursed infant.
\*\*Biotransformation\*\*
The biotransformation follows the known pathways of steroid metabolism, the levonorgestrel is hydroxylated by liver enzymes mainly by CYP3A4 and its metabolites are excreted after glucuronidation by liver glucuronidase enzymes. (See section 4.5). No pharmacologically active metabolites are known.
\*\*Elimination\*\*
Levonorgestrel is not excreted in unchanged form but as metabolites. Levonorgestrel metabolites are excreted in about equal proportions with urine and faeces.
\*\*Pharmacokinetics in obese women\*\*
A pharmacokinetic study showed that levonorgestrel concentrations are decreased in obese women (BMI ≥ 30 kg/m²) (approximately 50% decrease in Cmax and AUC0-24), compared to women with normal BMI (< 25 kg/m²) (Praditpan et al., 2017). Another study also reported a decrease of levonorgestrel Cmax by approximately 50% between obese and normal BMI women, while doubling the dose (3 mg) in obese women appeared to provide plasma concentration levels similar to those observed in normal women who received 1.5 mg of levonorgestrel (Edelman et al., 2016). The clinical relevance of these data is unclear.5.3 Preclinical safety data
Animal experiments with levonorgestrel have shown virilisation of female fetuses at high doses.
Non-clinical data reveal no special hazard for humans based on conventional studies of safety pharmacology, repeat-dose toxicity, genotoxicity, carcinogenicity potential, beyond the information included in other sections of the SPC.
- Instruction Pharmaceutical Particulars
- 6.1 List of excipients
Potato starch,
Maize starch,
Silica, colloidal anhydrous,
Magnesium stearate,
Talc,
Lactose monohydrate.6.2 Incompatibilities
Not applicable.6.3 Shelf life
5 years6.4 Special precautions for storage
Store in the original package in order to protect from light.6.5 Nature and contents of container
One tablet in PVC//aluminium blister and cardboard cartons.6.6 Special precautions for disposal and other handling
No special requirements.
- Instruction Content
- ## Composition
Each tablet contains 1500 micrograms of levonorgestrel.
Excipient \*\*with known effect\*\*: 142.5 mg lactose monohydrate.
For the full list of excipients, see section 6.1.
## Pharmaceutical Form
Tablet.
Almost white, flat, rimmed tablet of about 8 mm diameter with an impressed mark of “G00” on one side.
## Clinical Particulars
4.1 Therapeutic indications
Emergency contraception within 72 hours of unprotected sexual intercourse or failure of a contraceptive method.
Postinor is indicated in adults and adolescents >16 years of age.4.2 Posology and method of administration
\*\*Posology\*\*
One tablet should be taken, as soon as possible, preferably within 12 hours, and no later than 72 hours after unprotected intercourse (see section 5.1).
Women who have used enzyme-inducing drugs during the last 4 weeks and need emergency contraception are recommended to use a non-hormonal EC, i.e. Cu-IUD or take a double dose of levonorgestrel (i.e. 2 tablets taken together) for those women unable or unwilling to use Cu-IUD (see section 4.5).
If vomiting occurs within three hours of taking the tablet, another tablet should be taken immediately.
Postinor can be used at any time during the menstrual cycle unless menstrual bleeding is overdue.
After using emergency contraception it is recommended to use a local barrier method (e.g. condom, diaphragm, spermicide, cervical cap) until the next menstrual period starts. The use of levonorgestrel does not contraindicate the continuation of regular hormonal contraception.
\*Paediatric population\*
There is no relevant use of Postinor for children of prepubertal age in the indication emergency contraception
\*\*Method of administration\*\*
For oral administration.4.3 Contraindications
Hypersensitivity to the active substance or to any of the excipients listed in section 6.1.4.4 Special warnings and precautions for use
Emergency contraception is an occasional method. It should in no instance replace a regular contraceptive method.
Emergency contraception does not prevent a pregnancy in every instance. If there is uncertainty about the timing of the unprotected intercourse or if the woman has had unprotected intercourse more than 72 hours earlier in the same menstrual cycle, conception may have occurred. Treatment with levonorgestrel following the second act of intercourse may therefore be ineffective in preventing pregnancy. If menstrual periods are delayed by more than 5 days or abnormal bleeding occurs at the expected date of menstrual periods or pregnancy is suspected for any other reason, pregnancy should be excluded. \*\*If pregnancy occurs after treatment with levonorgestrel, the possibility of an ectopic pregnancy should be considered.\*\* The absolute risk of ectopic pregnancy is likely to be low, as levonorgestrel prevents ovulation and fertilisation. Ectopic pregnancy may continue, despite the occurrence of uterine bleeding.
Therefore, levonorgestrel is not recommended for patients who are at risk of ectopic pregnancy (previous history of salpingitis or of ectopic pregnancy).
Levonorgestrel is not recommended in patients with severe hepatic dysfunction.
Severe malabsorption syndromes, such as Crohn's disease, might impair the efficacy of levonorgestrel.
This medicinal product contains lactose monohydrate. Patients with rare hereditary problems of galactose intolerance, total lactase deficiency or glucose-galactose malabsorption should not take this medicine.
After levonorgestrel intake, menstrual periods are usually normal and occur at the expected date. They can sometimes occur earlier or later than expected by a few days. Women should be advised to make a medical appointment to initiate or adopt a method of regular contraception. If no withdrawal bleed occurs in the next pill-free period following the use of levonorgestrel after regular hormonal contraception, pregnancy should be ruled out.
Repeated administration within a menstrual cycle is not advisable because of the possibility of disturbance of the cycle.
Limited and inconclusive data suggest that there may be reduced efficacy of Postinor with increasing body weight or body mass index (BMI) (see sections 5.1 and 5.2). In all women, emergency contraception should be taken as soon as possible after unprotected intercourse, regardless of the woman's body weight or BMI.Levonorgestrel is not as effective as a conventional regular method of contraception and is suitable only as an emergency measure. Women who present for repeated courses of emergency contraception should be advised to consider long-term methods of contraception.
Use of emergency contraception does not replace the necessary precautions against sexually transmitted diseases.4.5 Interaction with other medicinal products and other forms of interaction
The metabolism of levonorgestrel is enhanced by concomitant use of liver enzyme inducers, mainly CYP3A4 enzyme inducers. Concomitant administration of efavirenz has been found to reduce plasma levels of levonorgestrel (AUC) by around 50%.
Drugs suspected of having similar capacity to reduce plasma levels of levonorgestrel include barbiturates (including primidone), phenytoin, carbamazepine, herbal medicines containing Hypericum perforatum (St. John's Wort), rifampicin, ritonavir, rifabutin and griseofulvin.
For women who have used enzyme-inducing drugs in the past 4 weeks and need emergency contraception, the use of non-hormonal emergency contraception (i.e. a Cu-IUD) should be considered. Taking a double dose of levonorgestrel (i.e. 3000 microgram within 72 hours after the unprotected intercourse) is an option for women who are unable or unwilling to use a Cu-IUD, although this specific combination (a double dose of levonorgestrel during concomitant use of an enzyme inducer) has not been studied.
Medicines containing levonorgestrel may increase the risk of cyclosporin toxicity due to possible inhibition of cyclosporin metabolism.
Women taking such drugs should be referred to their doctor for advice.4.6 Fertility, pregnancy and lactation
\*Pregnancy\*
Levonorgestrel should not be given to pregnant women. It will not interrupt a pregnancy. In the case of continued pregnancy, limited epidemiological data indicate no adverse effects on the fetus but there are no clinical data on the potential consequences if doses greater than 1.5 mg of levonorgestrel are taken (see section 5.3.).
\*Breast-feeding\*
Levonorgestrel is secreted into breast milk. Potential exposure of an infant to levonorgestrel can be reduced if the breast-feeding woman takes the tablet immediately after feeding and avoids nursing at least 8 hours following levonorgestrel administration.
\*Fertility\*
Levonorgestrel increases the possibility of cycle disturbances which can sometimes lead to earlier or later ovulation date. These changes can result in modified fertility date, however, there are no fertility data in the long term.4.7 Effects on ability to drive and use machines
No studies on the effect on the ability to drive and use machines have been performed.4.8 Undesirable effects
The most commonly reported undesirable effect was nausea.
| | | |
| --- | --- | --- |
| \*\*System Organ Class\*\* \*\*MedDRA\*\* | \*\*Frequency of adverse reactions\*\* | |
| \*\*Very common\*\* (\*\*>1/\*\*10) | \*\*Common\*\* (\*\*>1/\*\*100 to <1/10) |
| \*\*Nervous system disorders\*\* | Headache | Dizziness |
| \*\*Gastrointestinal disorders\*\* | Nausea Abdominal pain lower | Diarrhoea Vomiting |
| \*\*Reproductive system and breast disorders\*\* | Bleeding not related to menses\\* | Delay of menses more than 7 days \\*\\* Menstruation irregular Breast tenderness |
| \*\*General disorders and administration site conditions\*\* | Fatigue | |
\\*Bleeding patterns may be temporarily disturbed, but most women will have their next menstrual period within 5-7 days of the expected time.
\\*\\*If the next menstrual period is more than 5 days overdue, pregnancy should be excluded.
\*From post-marketing surveillance additionally, the following adverse events have been reported:\*
\*Gastrointestinal disorders\*
Very rare (<1/10,000): abdominal pain
\*Skin and subcutaneous tissue disorders\*
Very rare (<1/10,000): rash, urticaria, pruritus,
\*Reproductive system and breast disorders\*
Very rare (<1/10,000): pelvic pain, dysmenorrhoea
\*General disorders and administration site conditions\*
Very rare (<1/10,000): face oedema
\*\*Reporting of suspected adverse reactions:\*\*
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the national Yellow Card Scheme, Website: www.mhra.gov.uk/yellowcard. By reporting side effects you can help provide more information on the safety of this medicine\*\*.\*\*4.9 Overdose
Serious undesirable effects have not been reported following acute ingestion of large doses of oral contraceptives. Overdose may cause nausea, and withdrawal bleeding may occur. There are no specific antidotes and treatment should be symptomatic.
## Pharmacological Properties
5.1 Pharmacodynamic properties
Pharmacotherapeutic group: Sex hormones and modulators of the genital system, Emergency contraceptives, ATC code: G03AD01
\*\*Mechanism of action\*\*
The precise mode of action of levonorgestrel as an emergency contraceptive is not known.
At the recommended regimen, levonorgestrel is thought to work mainly by preventing ovulation and fertilisation if intercourse has taken place in the preovulatory phase, when the likelihood of fertilisation is the highest. Levonorgestrel is not effective once the process of implantation has begun.
\*\*Clinical efficacy and safety\*\*
The pregnancy rate was 1.1% (11/976) in an earlier clinical study (Lancet 1998; 352: 428-433) where 750 micrograms of levonorgestrel was taken as two 750 microgram doses with a 12-hour interval. Pregnancy rates appeared to increase with time of start of treatment after intercourse (0.4% [2/450] within 24 hours, 1.2% [4/338] 25-48 hours, 2.7% [5/187] if started between 49 and 72 hours).
Results from a randomised, double-blind clinical study conducted in 2001 (Lancet 2002; 360: 1803-1810) showed 1.34% (16/1 198) pregnancy rate with 1500 microgram single dose of levonorgestrel / two 750 microgram tablets of levonorgestrel taken at the same time (taken within 72 hours of unprotected sex) (compared with 1.69% [20/11 832] when two 750 microgram tablets were taken 12 hours apart). There was no difference between pregnancy rates in case of women who were treated on the third or the fourth day after the unprotected act of intercourse (p>0.2).
Meta-analysis on three WHO studies (Von Hertzen et al., 1998 and 2002; Dada et al., 2010) showed that the pregnancy rate of levonorgestrel is 1.01% (59/5 863) which means it prevents pregnancy in 99% of situations (compared to an expected pregnancy rate of about 8% in the absence of emergency contraception).
There is limited and inconclusive data on the effect of high body weight/high BMI on the contraceptive efficacy. In three WHO studies no trend for a reduced efficacy with increasing body weight/BMI was observed (Table 1), whereas in the two other studies (Creinin et al., 2006 and Glasier et al., 2010) a reduced contraceptive efficacy was observed with increasing body weight or BMI (Table 2). Both meta-analyses excluded intake later than 72 hours after unprotected intercourse (i.e. off-label use of levonorgestrel) and women who had further acts of unprotected intercourse (For pharmacokinetic studies in obese women see section 5.2).
Table 1: Meta-analysis on three WHO studies (Von Hertzen et al., 1998 and 2002; Dada et al., 2010)
| | | | | |
| --- | --- | --- | --- | --- |
| \*\*BMI (kg/m2)\*\* | \*\*Underweight\*\* \*\*0 - 18.5\*\* | \*\*Normal\*\* \*\*18.5-25\*\* | \*\*Overweight\*\* \*\*25-30\*\* | \*\*Obese\*\* \*\*≥ 30\*\* |
| \*\*N total\*\* | 600 | 3952 | 1051 | 256 |
| \*\*N pregnancies\*\* | 11 | 39 | 6 | 3 |
| \*\*Pregnancy rate\*\* | 1.83% | 0.99% | 0.57% | 1.17% |
| \*\*Confidence Interval\*\* | 0.92 – 3.26 | 0.70 – 1.35 | 0.21 – 1.24 | 0.24 – 3.39 |
Table 2: Meta-analysis on studies of Creinin et al., 2006 and Glasier et al., 2010
| | | | | |
| --- | --- | --- | --- | --- |
| \*\*BMI (kg/m2)\*\* | \*\*Underweight\*\* \*\*0 - 18.5\*\* | \*\*Normal\*\* \*\*18.5-25\*\* | \*\*Overweight\*\* \*\*25-30\*\* | \*\*Obese\*\* \*\*≥ 30\*\* |
| \*\*N total\*\* | 64 | 933 | 339 | 212 |
| \*\*N pregnancies\*\* | 1 | 9 | 8 | 11 |
| \*\*Pregnancy rate\*\* | 1.56% | 0.96% | 2.36% | 5.19% |
| \*\*Confidence Interval\*\* | 0.04 – 8.40 | 0.44 – 1.82 | 1.02 – 4.60 | 2.62 – 9.09 |
At the recommended regimen, levonorgestrel is not expected to induce significant modification of blood clotting factors, and lipid and carbohydrate metabolism.
\*\*Paediatric population\*\*
A prospective observational study showed that out of 305 treatments with levonorgestrel emergency contraceptive tablets, seven women became pregnant resulting in an overall failure rate of 2.3%. The failure rate in women under 18 years (2.6% or 4/153) was comparable to the failure rate in women 18 years and over (2.0% or 3/152).5.2 Pharmacokinetic properties
\*\*Absorption\*\*
Orally administered levonorgestrel is rapidly and almost completely absorbed.
The results of a pharmacokinetic study carried out with 16 healthy women showed that following ingestion of single dose of 1.5 mg levonorgestrel maximum drug serum levels of 18.5 ng/ml were found at 2 hours.
After reaching maximum serum levels, the concentration of levonorgestrel decreased with a mean elimination half-life of about 26 hours.
Levonorgestrel is bound to serum albumin and sex hormone binding globulin (SHBG). Only about 1.5% of the total serum levels are present as free steroid, but 65 % are specifically bound to SHBG.
The absolute bioavailability of levonorgestrel was determined to be almost 100% of the dose administered.
About 0.1% of the maternal dose can be transferred via milk to the nursed infant.
\*\*Biotransformation\*\*
The biotransformation follows the known pathways of steroid metabolism, the levonorgestrel is hydroxylated by liver enzymes mainly by CYP3A4 and its metabolites are excreted after glucuronidation by liver glucuronidase enzymes. (See section 4.5). No pharmacologically active metabolites are known.
\*\*Elimination\*\*
Levonorgestrel is not excreted in unchanged form but as metabolites. Levonorgestrel metabolites are excreted in about equal proportions with urine and faeces.
\*\*Pharmacokinetics in obese women\*\*
A pharmacokinetic study showed that levonorgestrel concentrations are decreased in obese women (BMI ≥ 30 kg/m²) (approximately 50% decrease in Cmax and AUC0-24), compared to women with normal BMI (< 25 kg/m²) (Praditpan et al., 2017). Another study also reported a decrease of levonorgestrel Cmax by approximately 50% between obese and normal BMI women, while doubling the dose (3 mg) in obese women appeared to provide plasma concentration levels similar to those observed in normal women who received 1.5 mg of levonorgestrel (Edelman et al., 2016). The clinical relevance of these data is unclear.5.3 Preclinical safety data
Animal experiments with levonorgestrel have shown virilisation of female fetuses at high doses.
Non-clinical data reveal no special hazard for humans based on conventional studies of safety pharmacology, repeat-dose toxicity, genotoxicity, carcinogenicity potential, beyond the information included in other sections of the SPC.
## Pharmaceutical Particulars
6.1 List of excipients
Potato starch,
Maize starch,
Silica, colloidal anhydrous,
Magnesium stearate,
Talc,
Lactose monohydrate.6.2 Incompatibilities
Not applicable.6.3 Shelf life
5 years6.4 Special precautions for storage
Store in the original package in order to protect from light.6.5 Nature and contents of container
One tablet in PVC//aluminium blister and cardboard cartons.6.6 Special precautions for disposal and other handling
No special requirements.
