Merck Sharp & Dohme


Full Prescribing Info
Each tablet contains 500 microgram lynestrenol.
Excipients/Inactive Ingredients: Potato starch, Amylopectin, Lactose monohydrate and Magnesium stearate.
Pharmacology: Pharmacodynamics: Lynestrenol (Exluton) is a progestogen-only pill, which contains the progestogen lynestrenol (ATC-class G03A C02). Like other progestogen-only pills, Lynestrenol (Exluton) is best suited for use during breast-feeding and for women who may not or do not want to use estrogens.
In the body lynestrenol is converted into the biologically active metabolite norethisterone, which binds to the progesterone receptors in the target organs (e.g. the myometrium). The contraceptive effect of Lynestrenol (Exluton) is achieved primarily by increasing the viscosity of the cervical mucus, thus reducing sperm penetration. Other effects include the decreased receptivity of the endometrium to the oocyte and the disturbed transport through the tubae. Furthermore, in about 70% of the women ovulation is inhibited, as can be concluded from both the absence of the midcycle LH-peak and the absence of an increase of luteal progesterone. No clinically relevant effects on the carbohydrate metabolism, lipid metabolism and haemostasis have been observed.
The contraceptive efficacy of Lynestrenol (Exluton) approaches that of the combined OC, provided the tablets are taken in accordance with the directions of use. In comparison with the combined pill, more irregular bleeding may occur with Lynestrenol (Exluton) whereas incidentally a period may fail to occur. Generally, after a period of adaptation, bleeding pattern with the product is acceptable.
Pharmacokinetics: Lynestrenol (LYN) is a pro-drug and is metabolised into the pharmacologically active metabolite norethisterone (NET).
Absorption: After oral dosing of Lynestrenol (Exluton), LYN is rapidly absorbed and converted into NET. Peak plasma levels are reached 2-4 hours after tablet intake. Absolute bioavailability of NET is 64%.
Distribution: NET is 96% bound to plasma proteins, predominantly to albumin (61%) and to a lesser extent to SHBG (sex hormone binding globulin) (35%).
Metabolism: Phase I metabolism of LYN includes a 3-hydroxylation and subsequently a dehydrogenation. The active metabolite NET is further reduced; degradation products are conjugated to sulphates and glucuronides.
Elimination: NET is eliminated with a mean half-life of approximately 15 hours. The plasma clearance is approximately 0.6 L per hour. Excretion of LYN and its metabolites is with urine (predominantly as glucuronides and sulphates and to a lesser extent as unchanged LYN) and faeces. The ratio of urinary:faecal excretion is 1.5:1.
Toxicology: Preclinical safety data: Reproduction studies in rabbits have shown that exposure to high doses of lynestrenol during organogenesis induces abnormalities of the central nervous system. Otherwise, toxicological studies did not reveal any effects other than those, which can be explained from the hormonal properties of lynestrenol. So far, the effects perceived in animal studies have not been confirmed in humans.
Hormonal Contraceptive.
Dosage/Direction for Use
How to take Lynestrenol (Exluton): Tablets must be taken in the order directed on the package every day at about the same time with some liquid as needed. One tablet is to be taken daily for 28 consecutive days. Each subsequent pack is started immediately after finishing the previous pack.
How to start Lynestrenol (Exluton): No preceding hormonal contraceptive use [in the past month]: Tablet-taking has to start on day 1 of the woman's natural cycle (day 1 is the first day of her menstrual bleeding). Starting on days 2-5 is allowed, but during the first cycle a barrier method is recommended in addition for the first 7 days of tablet-taking.
Changing from a combined hormonal contraceptive (combined oral contraceptive (COC), vaginal ring, or transdermal patch): The woman should start with Lynestrenol (Exluton) preferably on the day after the last active tablet (the last tablet containing the active substances), or on the day of removal of her vaginal ring, or patch. In these cases, the use of an additional contraceptive method is not necessary.
Changing from a progestogen-only-method (minipill, injection, implant) or from a progestogen-releasing intrauterine system [IUS]: The woman may switch any day from the minipill (from an implant or the IUS on the day of its removal, from an injectable when the next injection would be due); an additional contraceptive method is not necessary.
Following first-trimester abortion: The woman may start immediately; an additional contraceptive method is not necessary.
Following delivery or second-trimester abortion: For breastfeeding women see Use in Pregnancy & Lactation.
The woman should be advised to start at day 21 to 28 after delivery or second-trimester abortion. When starting later, she should be advised to additionally use a barrier method for the first 7 days of tablet-taking. However, if intercourse has already occurred, pregnancy should be excluded before the actual start of Lynestrenol (Exluton) use or the woman has to wait for her first menstrual period.
Management of missed tablets: Contraceptive protection may be reduced if more than 27 hours have elapsed between two tablets. If the user is less than 3 hours late in taking any tablet, the missed tablet should be taken as soon as it is remembered and the next tablet should be taken at the usual time. If she is more than 3 hours late, she should follow the same advice but also additionally use a barrier method for the next 7 days of tablet-taking. If tablets were missed in the very first week of use and intercourse took place in the week before the tablets were missed, the possibility of a pregnancy should be considered.
Advice in case of gastro-intestinal disturbances: In case of severe gastro-intestinal disturbance, absorption may not be complete and additional contraceptive measures should be taken. If vomiting occurs within 3-4 hours after tablet-taking, absorption may not be complete. In such an event, the advice concerning missed tablets, as given in Management of missed tablets previously, is applicable.
There have been no reports of serious deleterious effects from overdose. Since the toxicity of lynestrenol is very low, with Lynestrenol (Exluton) toxic serious symptoms are not expected to occur when several tablets are taken simultaneously. Symptoms that may occur in this case are: nausea, vomiting and, in young girls, slight vaginal bleeding. There are no antidotes and further treatment should be symptomatic.
Progestogen-only contraceptives should not be used in the presence of any of the conditions listed as follows. Should any of the conditions appear for the first time during the use of Lynestrenol (Exluton), the product should be stopped immediately.
Known or suspected pregnancy; Active venous thromboembolic disorder; Presence or history of severe hepatic disease as long as liver function values have not returned to normal; Known or suspected sex-steroid sensitive malignancies; Undiagnosed vaginal bleeding; Hypersensitivity to the active substance or to any of the excipients.
If any of the conditions/risk factors mentioned as follows is present, the benefits of progestogen use should be weighed against the possible risks for each individual woman and discussed with the woman before the woman decides to start with Lynestrenol (Exluton). In the event of aggravation, exacerbation or first appearance of any of these conditions, the woman should contact the physician. The physician should then decide on whether the use of Lynestrenol (Exluton) should be discontinued as follows.
The risk for breast cancer increases in general with increasing age. During the use of oral contraceptives (OCs) the risk of having breast cancer diagnosed is slightly increased. This increased risk disappears gradually within 10 years after discontinuation of OC use and is not related to the duration of use, but to the age of the woman when using the OC.
The expected number of cases diagnosed per 10,000 women who use combined OCs (up to 10 years after stopping) relative to never users over the same period have been calculated for the respective age groups and are presented in the table as follows. (See Table 1.)

Click on icon to see table/diagram/image

The risk in POP users is possibly of similar magnitude as that associated with combined OCs. However, for POPs the evidence is less conclusive. Compared to the risk of getting breast cancer ever in life, the increased risk associated with OCs is low. The cases of breast cancer diagnosed in OC users tend to be less advanced than in those who have not used OCs. The increased risk in OC users may be due to an earlier diagnosis, biological effects of the pill or a combination of both.
Since a biological effect of progestogens on liver cancer cannot be excluded an individual benefit/risk assessment should be made in women with liver cancer.
When acute or chronic disturbances of liver function occur, the woman should be referred to a specialist for examination and advice.
If a sustained hypertension develops during the use of Lynestrenol (Exluton), or if a significant increase in blood pressure Lynestrenol (Exluton) not adequately respond to antihypertensive therapy, the discontinuation of Lynestrenol (Exluton) should be considered.
Epidemiological investigations have associated the use of combined OCs with an increased incidence of venous thromboembolism (VTE, deep venous thrombosis and pulmonary embolism). Although the clinical relevance of this finding for lynestrenol used as a contraceptive in the absence of an estrogenic component is unknown, Lynestrenol (Exluton) should be discontinued in the event of a thrombosis.
Discontinuation of Lynestrenol (Exluton) should also be considered in case of long-term immobilisation due to surgery or illness. Women with a history of thrombo-embolic disorders should be made aware of the possibility of a recurrence.
The protection with progestogen-only pills against ectopic pregnancies is not as good as with combined oral contraceptives, which has been associated with the frequent occurrence of ovulations during the use of progestogen-only pills. Additional risk factors for ectopic pregnancy include a history of ectopic pregnancy and tubal damage from infection or surgery. Should pregnancy occur in spite of the use of Lynestrenol (Exluton), the physician should exclude extra-uterine pregnancy. In addition, in case of amenorrhea or abdominal pain the possibility of an ectopic pregnancy should be included in the differential diagnosis.
Chloasma may occasionally occur, especially in women with a history of chloasma gravidarum. Women with a tendency to chloasma should avoid exposure to the sun or ultraviolet radiation whilst taking Lynestrenol (Exluton).
Although progestogens may have an effect on peripheral insulin resistance and glucose tolerance, there is no evidence for a need to alter the therapeutic regimen in diabetics using progestogen-only pills. However, diabetic patients should be carefully observed while taking progestogen-only pills.
The following conditions have been reported both during pregnancy and during sex steroid use, but an association with the use of progestogens has not been established: jaundice and/or pruritus related to cholestasis; gallstone formation; porphyria; systemic lupus erythematosus; haemolytic uraemic syndrome; Sydenham's chorea; herpes gestationis; otosclerosis- related hearing loss, (hereditary) angioedema.
Lynestrenol (Exluton) contains less than 50 mg lactose and therefore should not be administered to patients w/ rare hereditary problems of galactose intolerance, the Lapp lactase deficiency, or glucose-galactose malabsorption.
Special Precautions
Medical examination/consultation: Before prescription, a thorough case history should be taken and a thorough gynaecological examination is recommended to exclude pregnancy. Bleeding disturbances, such as oligomenorrhoea and amenorrhoea should be investigated before prescription. The interval between check-ups depends on the circumstances in each individual case. If the prescribed product may conceivably influence latent or manifest disease (see Warnings), the control examinations should be timed accordingly. Despite the fact that Lynestrenol (Exluton) is taken regularly, bleeding disturbances may occur (see Changes in vaginal bleeding pattern as follows). If bleeding is very frequent and irregular, another contraceptive method should be considered. If the symptoms persist, an organic cause should be ruled out. Management of amenorrhoea during treatment depends on whether or not the tablets have been taken in accordance with the instructions and may include a pregnancy test. The treatment should be stopped if a pregnancy occurs.
Women should be advised that Lynestrenol (Exluton) does not protect against HIV (AIDS) and other sexually transmitted diseases.
Reduced efficacy: The efficacy of progestogen-only pills may be reduced in the event of missed tablets (see Management of missed tablets under Dosage & Administration), gastro-intestinal disturbances (see Advice in case of gastro-intestinal disturbances under Dosage & Administration) or concomitant medication (see Interactions).
Changes in vaginal bleeding pattern: During the use of a progestogen-only contraceptive, vaginal bleeding may become more frequent or of longer duration in some women, whereas in others bleeding may become incidental or be totally absent. These changes are often a reason for the woman to reject the method or to be non-compliant. Acceptance of bleeding pattern can be improved by offering women who have chosen to use Lynestrenol (Exluton) careful counselling on this point.
Evaluation of vaginal bleeding should be done on an ad hoc basis and may include examination to exclude malignancy or pregnancy (see Medical examination/consultation previously).
Follicular development: With all low-dose hormonal contraceptives, follicular development occurs and occasionally the follicle may continue to grow beyond the size it would attain in a normal cycle. Generally, these enlarged follicles disappear spontaneously. Often, they are asymptomatic; in some cases they are associated with mild abdominal pain. They rarely require surgical intervention.
Effects on ability to drive and use machines: On the basis of the pharmacodynamic profile, Lynestrenol (Exluton) is expected to have no or negligible influence on the ability to drive and use machines.
Use In Pregnancy & Lactation
Lynestrenol (Exluton) should not be used during pregnancy. If a pregnancy occurs, Lynestrenol (Exluton) treatment should be stopped immediately. Animal studies have shown that very high doses of progestogenic substances may cause masculinization of female foetuses.
Extensive epidemiological studies have revealed neither an increased risk of birth defects in children born to women who used OCs prior to pregnancy, nor a teratogenic effect when OCs were taken inadvertently during early pregnancy. Although this probably also applies to all OCs, it is not clear whether this is also the case for Lynestrenol (Exluton).
Similar to other progestogen-only contraceptives, Lynestrenol (Exluton) does not influence the production or the quality of breast milk, but a small amount of progestogen is excreted in the breast milk. The amount of lynestrenol and metabolites excreted in the milk is about 0.14% of the daily administered dose, but no adverse effects on infant growth and development have been reported.
Adverse Reactions
In women using (combined) oral contraceptives a number of (serious) undesirable effects have been reported. These include venous thromboembolic disorders, arterial thromboembolic disorders, hormone- dependent tumours (e.g. breast cancer), and chloasma, some of which are discussed in more detail in Precautions.
Other side effects that have been reported in users of hormonal contraceptives, but for which the association has been neither confirmed nor refuted are: See Table 2.

Click on icon to see table/diagram/image
Drug Interactions
Interactions between oral contraceptives and other medicinal products may lead to breakthrough bleeding and/or contraceptive failure. No specific interaction studies have been performed with Lynestrenol (Exluton). The following interactions have been reported in the literature (mainly with combined contraceptives but occasionally also with progestogen-only contraceptives).
Hepatic metabolism: Interactions can occur with medicinal products that induce microsomal enzymes, which can result in increased clearance of sex hormones (such as hydantoins, (e.g., phenytoin), barbiturates (e.g., phenobarbital), primidone, carbamazepine, rifampicin; and possibly also oxcarbazepine, topiramate, felbamate, ritonavir, nelfinavir, griseofulvin and products containing St. John's wort (Hypericum perforatum)).
Women on treatment with any of these drugs should temporarily use a barrier method in addition to Lynestrenol (Exluton) or choose another method of contraception. The barrier method should be used during the time of concomitant drug administration and for 28 days after their discontinuation.
During treatment with medical charcoal, the absorption of the steroid in the tablet may be reduced and thereby the contraceptive efficacy. In such an event, the advice concerning missed tablets, as given in Management of missed tablets under Dosage & Administration is applicable.
Hormonal contraceptives may interfere with the metabolism of other drugs. Accordingly, plasma and tissue concentrations may be affected (e.g., cyclosporin).
Note: The prescribing information of concomitant medications should be consulted to identify potential interactions.
Laboratory tests: Data obtained with combined OCs have shown that contraceptive steroids may influence the results of certain laboratory tests, including biochemical parameters of liver, thyroid, adrenal and renal function, serum levels of (carrier) proteins, e.g., corticosteroid binding globulin and lipid/lipoprotein fractions, parameters of carbohydrate metabolism and parameters of coagulation and fibrinolysis. The changes generally remain within the normal range. To what extent this also applies to progestogen-only contraceptives is not known.
Caution For Usage
Incompatibilities: Not applicable.
Store at temperatures not exceeding 30°C. Do not freeze.
Do not freeze.
Shelf life: 5 years.
MIMS Class
ATC Classification
G03AC02 - lynestrenol ; Belongs to the class of progestogens. Used as systemic contraceptives.
Tab 500 mcg (white, round and flat bevelled-edge, coded TT above 2 on one side and ORGANON on the reverse) x 28's.
Register or sign in to continue
Asia's one-stop resource for medical news, clinical reference and education
Sign up for free
Already a member? Sign in