Combee R

Uses

Treatment of moderate to severe vasomotor symptoms associated with the menopause.

Treatment of moderate to severe symptoms of vulvar and vaginal atrophy associated with the menopause. When prescribing solely for the treatment of symptoms of vulvar and vaginal atrophy, topical vaginal products should be considered.

Treatment of hypoestrogenism due to hypogonadism, castration or primary ovarian failure.

Treatment of breast cancer (for palliation only) in appropriately selected women and men with metastatic disease.

Treatment of advanced androgen-dependent carcinoma of the prostate (for palliation only).

Prevention of osteoporosis. When prescribing solely for the prevention of postmenopausal osteoporosis, therapy should only be considered for women at significant risk of osteoporosis and for whom non-estrogen medications are not considered to be appropriate.

Levonorgestrel is an emergency contraceptive pill for women. Levonorgestrel should be used within 72 hours of unprotected intercourse. It should not be taken as regular birth control pill. This medicine is also known as morning after pill. Levonorgestrel belongs to a group of medicines called progestogen.

This contraception is used as soon as possible, preferably within 12 hours and no later than 72 hours (3 days) after the unprotected sexual intercourse, particularly. If you have had a sexual intercourse whereas either yourself or your partner did not use a contraceptive method

• If you have forgotten to take consecutive 3 regular contraceptive pills
• If your partner’s condom has broken, slipped or been improperly removed or if he has forgotten to use it
• If you fear that your intrauterine device has been expelled
• If your vaginal diaphragm or your contraceptive cap has moved or if have removed it too easily
• If you are afraid that the method of coitus interruptus has failed or if you have had sexual intercourse during the period when you are supposed to be fertile while using the rhythm method
• In the event of rape

Combee R is also used to associated treatment for these conditions: Atrophic Vaginitis, Breast Cancer, Breast engorgement caused by Postpartum state, Hypogonadism female, Kraurosis Vulvae, Metastatic Breast Cancer, Osteoporosis, Postmenopausal Osteoporosis, Premature Ovarian Failure (POF), Prostate Cancer, Urogenital atrophy, Vasomotor Symptoms Associated With Menopause, Vulvovaginal Atrophy, Advanced androgen dependent Prostate cancer, Female castration, Hypoestrogenism, Contraception, Hormone Replacement Therapy, PalliationEndometrial Hyperplasia, Endometriosis, Hypermenorrhea, Postmenopausal Osteoporosis, Pregnant State, Moderate Menopausal Vasomotor Symptoms, Severe Vasomotor Symptoms Associated With Menopause, Emergency Contraception

How Combee R works

Estrogen is found in the the breast, uterine, ovarian, skin, prostate, bone, fat, and brain tissues. The main source of estrogen in adult women during the reproductive period of life is the ovarian follicle, which secretes 70 to 500 mcg of estradiol each day. After menopause, however, the majority of endogenous estrogen is produced by transformation of androstenedione (which is secreted by the adrenal cortex) to estrone in the peripheral tissues. Both estrone and its sulphate conjugated form, estrone sulphate, represent the most abundant estrogens found in postmenopausal women.

Estradiol, however, is considerably more potent than estrone and estriol at the estrogen receptor (ER). As a result, the higher estrone concentration in postmenopausal population, can cause various undesirable effects. These effects may include hot flashes, chills, vaginal dryness, mood swings, irregular menstruation, and chills, in addition to sleep problems.

Estradiol workings by binding to subtypes of the estrogen receptor: estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ). It also exerts potent agonism of G Protein-coupled estrogen receptor (GPER), which is recognized an important regulator of this drug's rapid effects. Once the estrogen receptor has bound to its ligand, it enters the nucleus of the target cell, regulating gene transcription and formation of of messenger RNA. This mRNA makes contact with ribosomes producing specific proteins that express the effect of estradiol upon the target cell. Agonism of estrogen receptors increases pro-estrogenic effects, leading to the relief of vasomotor and urogenital symptoms of a postmenopausal or low estradiol state.

Mechanism of action on ovulation

Oral contraceptives containing levonorgestrel suppress gonadotropins, inhibiting ovulation. Specifically, levonorgestrel binds to progesterone and androgen receptors and slows the release of gonadotropin-releasing hormone (GnRH) from the hypothalamus. This process results in the suppression of the normal physiological luteinizing hormone (LH) surge that precedes ovulation. It inhibits the rupture of follicles and viable egg release from the ovaries. Levonorgestrel has been proven to be more effective when administered before ovulation.

Mechanism of action in cervical mucus changes

Similar to other levonorgestrel-containing contraceptives, the intrauterine (IUD) forms of levonorgestrel likely prevent pregnancy by increasing the thickness of cervical mucus, interfering with the movement and survival of sperm, and inducing changes in the endometrium, where a fertilized ovum is usually implanted. Levonorgestrel is reported to alter the consistency of mucus in the cervix, which interferes with sperm migration into the uterus for fertilization. Levonorgestrel is not effective after implantation has occurred. Interestingly, recent evidence has refuted the commonly believed notion that levonorgestrel changes the consistency of cervical mucus when it is taken over a short-term period, as in emergency contraception. Over a long-term period, however, levonorgestrel has been proven to thicken cervical mucus. The exact mechanism of action of levonorgestrel is not completely understood and remains a topic of controversy and ongoing investigation.

Effects on implantation*

The effects of levonorgestrel on endometrial receptivity are unclear, and the relevance of this mechanism to the therapeutic efficacy of levonorgestrel is contentious. Prescribing information for levonorgestrel IUDs state that they exert local morphological changes to the endometrium (e.g. stromal pseudodecidualization, glandular atrophy) that may play a role in their contraceptive activity.

Mechanism of action in hormone therapy

When combined with estrogens for the treatment of menopausal symptoms and prevention of osteoporosis, levonorgestrel serves to lower the carcinogenic risk of unopposed estrogen therapy via the inhibition of endometrial proliferation. Unregulated endometrial proliferation sometimes leads to endometrial cancer after estrogen use.

Dosage

Combee R dosage

Oral:

• Prostate cancer: 10 mg 3 times/day for at least 3 month.
• Menopausal vasomotor symptoms: 1-2 mg/day on a cyclical or continuous regimen
• Prevention of postmenopausal osteoporosis: 0.5 mg/day in cyclical regimen.
• Hypogonadism: 1-2 mg/day in a cyclic regimen.

Vaginal:

• Vulvular and vag atrophy: Insert 2-4 g/day for 2 wk. Maintenance: 1 g 1-3 times/wk.
• Postmenopausal vag atrophy; Urogenital symptoms: Insert a ring and keep in place for 90 days.
• Atrophic vaginitis: Insert 1 tab once daily for 2 wk. Maintenance: 1 tab twice wkly. Attempt to discontinue or taper medication at 3-6 monthly intervals.

levonorgestrel 0.75 mg Tablets should be taken at the same time, orally, as soon as possible but within 72 hours after unprotected intercourse. The total dosage for one complete regimen of levonorgestrel consists in a single dose of 1.50 mg levonorgestrel.

Levonorgestrel 1.5 mg Tablets should be taken as soon as possible, preferably within 12 hours, and no later than 72 hours (3 days) after having unprotected sex. Levonorgestrel 1.5 mg tablets can be taken at any time in the menstrual cycle assuming the person is not already pregnant. The tablet should not be chewed but should be swallowed whole with water. If a regular method of contraception, such as the contraceptive pill, is already being used, this can be continued at the regular times. If unprotected intercourse takes place again after the use of Levonorgestrel 1.5 mg tablets (also if this is during the same menstrual cycle), the tablet will not exert its contraceptive effect and there is again the risk of pregnancy.

Levonorgestrel can be taken at any moment during the menstrual cycle. After using an emergency contraception, it is recommended to use a local contraceptive mean (condom, spermicide, cervical cap) until the next menstrual period resume.

The use of Levonorgestrel does not contraindicate the continuation of regular hormonal contraception. If you have used this medicine while you were using an oral contraception (contraceptive pill), you should carry on taking the usual tablets until the end of the treatment. In case no menstrual period occurs in the next pill free period following the use of Levonorgestrel, a pregnancy test should be performed to rule out a pregnancy.

One tablet should be taken orally with a glass of water.

Side Effects

GI disturbances, genitourinary changes, haematologic disorders, CV and CNS effects, endocrine and metabolic disorders, cholestatic jaundice, local skin reactions, chorea, contact lens intolerance, steeping of corneal curvature, pulmonary thromboembolism, carbohydrate intolerance.

Undesirable effects which have been observed are:

• Nausea and vomiting
• Dizziness, fatigue, headache
• Abdominal pain
• A feeling of breast tenderness
• Bleeding can occur after taking this medicine

Inform doctor of any unwanted effect which is not mentioned here

Toxicity

The NOAEL (no-observed-adverse-effect-level) oral toxicity of estradiol after 90 day in rats was 0.003 mg/kg/day for blood, female reproductive, and male reproductive, endocrine, and liver toxicity. Oral TDLO of ethinyl estradiol is 21 mg/kg/21D intermittent, woman) with an oral LD50 of 960 mg/kg in the rat.

There is limited information in the literature regarding estrogen overdose. Estradiol overdose likely leads to the occurrence of estrogen-associated adverse effects, including nausea, vomiting, abdominal pain, breast tenderness, venous thrombosis, and vaginal bleeding. It is generally recommend to discontinue estradiol treatment and offer supportive care in the case of an overdose.

The oral LD50 in rats is greater than 5000 mg/kg.

An overdose of this drug, like other contraceptives, may cause nausea and withdrawal bleeding. Provide symptomatic treatment in the case of a levonorgestrel overdose and contact the local poison control center. There is no specific antidote for a levonorgestrel overdose.

Precaution

Conditions exacerbated by fluid retention; hypercalcaemia, cerebrovascular diorders, coronary artery disease, gall bladder diseases; lipid effects; familial defects of lipoprotein metabolism. May increase BP, risk of venous thromboembolism, breast cancer, benign hepatic adenoma, endometrial cancer and size of preexisting uterine leiomyomata. Dosage should be reduced in hepatic impairment. Lactation. Child.

Emergency contraception must be used exceptionally, since

• It does not allow to prevent a pregnancy in every instance
• The associated hormonal overdosing is not advisable in case of regular intake
• It cannot replace a regular contraception

After taking Levonorgestrel, menstrual period usually occurs at the expected date nevertheless, it can occur earlier or later by a few days. After taking this tablet, it is therefore mandatory to check the absence of pregnancy by performing a pregnancy test in case of abnormal bleeding at the date of expected period or in case of menstrual delay of more than 5 days. The use of emergency contraception does not replace the necessary precautions against sexually transmitted diseases and the measures to be taken in case of risk of transmission. If vomiting would occur within 2 hours after taking this medicine it is recommended to take immediately another Levonorgestrel tablet.

Interaction

CYP1A2 and CYP3A4 inducers e.g. aminoglutethimide, carbamazepine, phenobarbital, and rifampin may decrease the effects of estradiol. May enhance the effects of hydrocortisone and prednisolone when used together.

Simultaneous administration of certain anticonvulsant agents (phenobarbiton, phenytoin, primidone, carbamazepin), also other medications such as rafimpicin and griseofulvin can reduce or suppress the effectiveness of this emergency contraception.

Volume of Distribution

Estrogens administered exogenously distribute in a similar fashion to endogenous estrogens. They can be found throughout the body, especially in the sex hormone target organs, such as the breast, ovaries and uterus.

One pharmacokinetic study determined a mean steady-state volume of distribution of 1.5 mg of levonorgestrel to be 162.2 L in those with normal BMI and in the range of 404.7 L to 466.4 L in obese patients with a body mass index of at least 30. Mean volume of distribution in 16 patients receiving 0.75 mg of levonorgestrel in another pharmacokinetic study was 260 L. The Plan B one-step FDA label reports an apparent volume of distribution of 1.8 L/kg.

Elimination Route

The absorption of several formulations of estradiol is described below:

Oral tablets and injections

First-pass metabolism in the gastrointestinal tract rapidly breaks down estradiol tablets before entering the systemic circulation. The bioavailability of oral estrogens is said to be 2-10% due to significant first-pass effects. The esterification of estradiol improves the administration (such as with estradiol valerate) or to sustain release from intramuscular depot injections (including estradiol cypionate) via higher lipophilicity. After absorption, the esters are cleaved, which leads to the release of endogenous estradiol, or 17β-estradiol.

Transdermal preparations

The transdermal preparations slowly release estradiol through intact skin, which sustains circulating levels of estradiol during a 1 week period of time. Notably, the bioavailability of estradiol after transdermal administration is about 20 times higher than after oral administration. Transdermal estradiol avoids first pass metabolism effects that reduce bioavailability. Administration via the buttock leads to a Cmax of about 174 pg/mL compared to 147 pg/mL via the abdomen.

Spray preparations

After daily administration, the spray formulations of estradiol reach steady state within 7-8 days. After 3 sprays daily, Cmax is about 54 pg/mL with a Tmax of 20 hours. AUC is about 471 pg•hr/mL.

Vaginal ring and cream preparations

Estradiol is efficiently absorbed through the mucous membranes of the vagina. The vaginal administration of estrogens evades first-pass metabolism. Tmax after vaginal ring delivery ranges from 0.5 to 1 hour. Cmax is about 63 pg/mL. The vaginal cream preparation has a Cmax of estradiol (a component of Premarin vaginal estrogen conjugate cream) was a Cmax of 12.8 ± 16.6 pg/mL, Tmax of 8.5 ± 6.2 hours, with an AUC of 231 ± 285 pg•hr/mL.

Orally administered levonorgestrel is absorbed in the gastrointestinal tract while levonorgestrel administered through an IUD device is absorbed in the endometrium. Levonorgestrel is absorbed immediately in the interstitial fluids when it is inserted as a subdermal implant. After insertion of the subdermal implant, the Cmax of levonorgestrel is attained within 2-3 days.The Cmax following one dose of 0.75 mg of oral levonorgestrel is reached within the hour after administration, according to one reference. In a pharmacokinetic study of 1.5 mg of levonorgestrel in women with a normal BMI and those considered to be obese (BMI>30), mean Cmax was found to be 16.2 ng/mL and 10.5 ng/mL respectively. Tmax was found to be 2 hours for those with normal BMI and 2.5 hours for patients with increased BMI. The bioavailability of levonorgestrel approaches 100%.

Mean AUC has been shown to be higher in patients with a normal BMI, measuring at 360.1 h × ng/mL versus a range of 197.28 to 208.1 h × ng/mL in an obese group of patients. Obesity may contribute to decreased efficacy of levonorgestrel in contraception.

Half Life

The terminal half-lives for various estrogen products post oral or intravenous administration has been reported to range from 1-12 hours. One pharmacokinetic study of oral estradiol valerate administration in postmenopausal women revealed a terminal elimination half-life of 16.9 ± 6.0 h. A pharmacokinetic study of intravenous estradiol administration in postmenopausal women showed an elimination half-life of 27.45 ± 5.65 minutes. The half-life of estradiol appears to vary by route of administration.

The elimination half-life of a 0.75 mg dose of 1.5 mg of levonorgestrel ranges between 20-60 hours post-administration. A pharmacokinetic study of women with a normal BMI and BMI over revealed an elimination half-life of 29.7 h and 41.0-46.4 hours, respectively. Another pharmacokinetic study revealed a mean elimination half-life of 24.4 hours after a 0.75 mg dose of levonorgestrel was administered to 16 patients.

Clearance

In one pharmacokinetic study, the clearance of orally administered micronized estradiol in postmenopausal women was 29.9±15.5 mL/min/kg. Another study revealed a clearance of intravenously administered estradiol was 1.3 mL/min/kg.

Clearance was found to 4.8 L/h in healthy female volunteers with a normal BMI, and 7.70-8.51 L/h in obese patients after a single 1.5 mg dose. After a 0.75 mg dose of levonorgestrel in 16 patients in another pharmacokinetic study, mean clearance was calculated at 7.06 L/h. Following levonorgestrel implant removal, the serum concentration falls below 100 pg/mL within the first 96 hours and further falls below the sensitivity of detection within the range of 5 days to 2 weeks.

Elimination Route

Estradiol is excreted in the urine with both glucuronide and sulfate conjugates.

Approximately 45% of an oral levonorgestrel dose and its conjugated or sulfate metabolites are found to be excreted in the urine. Approximately 32% of an orally ingested dose is found excreted in feces, primarily in the form of glucuronide conjugates of levonorgestrel.

Pregnancy & Breastfeeding use

Pregnancy Category X. Studies in animals or human beings have demonstrated foetal abnormalities or there is evidence of foetal risk based on human experience or both, and the risk of the use of the drug in pregnant women clearly outweighs any possible benefit. The drug is contraindicated in women who are or may become pregnant.

The medicine is not indicated in case of pre-existing pregnancy and cannot interrupt it in case of failure of this contraceptive mean with persisting pregnancy. Epidemiological studies indicates no adverse effects of progestogen on malformation of a fetus. Lactation is possible. However, since Levonorgestrel is secreted into breast milk it is suggested that you breast feed immediately before taking each tablet and that you skip nursing following each Levonorgestrel tablet administration.

Contraindication

Hypersensitivity; undiagnosed vag bleeding; thrombophloebitis or thromboembolic disorders; breast carcinoma except in selected patients being treated for metastatic disease; oestrogen-dependent tumor; porphyria; pregnancy.

If you have hypersensitivity to Levonorgestrel.

Acute Overdose

No acute toxicity has been demonstrated with this medicine in case of intake of several doses

Storage Condition

Store at room temperature.

Store in a cool & dry place, protected from light. Keep out of reach of children

Innovators Monograph

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