Post-Day
Post-Day Uses, Dosage, Side Effects, Food Interaction and all others data.
Post-Day is a progestin or a synthetic form of the naturally occurring female sex hormone, progesterone. In a woman's normal menstrual cycle, an egg matures and is released from the ovaries (ovulation). The ovary then produces progesterone, preventing the release of further eggs and priming the lining of the womb for a possible pregnancy. If pregnancy occurs, progesterone levels in the body remain high, maintaining the womb lining. If pregnancy does not occur, progesterone levels in the body fall, resulting in a menstrual period. Post-Day tricks the body processes into thinking that ovulation has already occurred, by maintaining high levels of the synthetic progesterone. This prevents the release of eggs from the ovaries.
Post-Day prevents pregnancy by interfering with ovulation, fertilization, and implantation. The levonorgestrel-only containing emergency contraceptive tablet is 89% effective if it is used according to prescribing information within 72 hours after intercourse. The intrauterine and implantable devices releasing levonorgestrel are more than 99% in preventing pregnancy. Post-Day utilized as a component of hormonal therapy helps to prevent endometrial carcinoma associated with unopposed estrogen administration.
| Trade Name | Post-Day |
| Availability | Rx and/or OTC |
| Generic | Levonorgestrel |
| Levonorgestrel Other Names | 18-Methylnorethisterone, Levonorgestrel, Lèvonorgestrel, Levonorgestrelum |
| Related Drugs | Premarin, norethindrone, medroxyprogesterone, megestrol, Depo-Provera, Mirena, Nexplanon, Provera, Plan B, Plan B One-Step |
| Type | |
| Formula | C21H28O2 |
| Weight | Average: 312.4458 Monoisotopic: 312.20893014 |
| Protein binding | The protein binding of levonorgestrel ranges from 97.5-99%, and it is mainly bound to sex hormone-binding globulin (SHBG). Levonorgestrel is also bound to albumin. The prescribing information for the implanted levonorgestrel indicates that the concentration of sex hormone-binding globulin (SHBG) is reduced in the span of a few days after levonorgestrel administration, decreasing the levels of the drug. |
| Groups | Approved, Investigational |
| Therapeutic Class | Emergency Contraceptive Pill, Oral Contraceptive preparations |
| Manufacturer | |
| Available Country | Mexico |
| Last Updated: | September 19, 2023 at 7:00 am |
Uses
Post-Day is an emergency contraceptive pill for women. Post-Day 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. Post-Day 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
Post-Day is also used to associated treatment for these conditions: Endometrial Hyperplasia, Endometriosis, Hypermenorrhea, Postmenopausal Osteoporosis, Pregnant State, Moderate Menopausal Vasomotor Symptoms, Severe Vasomotor Symptoms Associated With Menopause, Emergency Contraception
How Post-Day works
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. Post-Day 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. Post-Day is reported to alter the consistency of mucus in the cervix, which interferes with sperm migration into the uterus for fertilization. Post-Day 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
Post-Day dosage
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.
Post-Day 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. Post-Day 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 Post-Day 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.
Post-Day 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 Post-Day 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 Post-Day, a pregnancy test should be performed to rule out a pregnancy.
One tablet should be taken orally with a glass of water.
Side Effects
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 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
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 Post-Day, 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 Post-Day tablet.
Interaction
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.
Food Interaction
- Take at the same time every day.
- Take with or without food. The effect of food on absorption has not been evaluated.
[Moderate] MONITOR: Grapefruit juice may increase the plasma concentrations of orally administered drugs that are substrates of the CYP450 3A4 isoenzyme.
The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruit.
Because grapefruit juice inhibits primarily intestinal rather than hepatic CYP450 3A4, the magnitude of interaction is greatest for those drugs that undergo significant presystemic metabolism by CYP450 3A4 (i.e., drugs with low oral bioavailability).
In general, the effect of grapefruit juice is concentration-, dose- and preparation-dependent, and can vary widely among brands.
Certain preparations of grapefruit juice (e.g., high dose, double strength) have sometimes demonstrated potent inhibition of CYP450 3A4, while other preparations (e.g., low dose, single strength) have typically demonstrated moderate inhibition.
Pharmacokinetic interactions involving grapefruit juice are also subject to a high degree of interpatient variability, thus the extent to which a given patient may be affected is difficult to predict.
MANAGEMENT: Patients who regularly consume grapefruit or grapefruit juice should be monitored for adverse effects and altered plasma concentrations of drugs that undergo significant presystemic metabolism by CYP450 3A4.
Grapefruit and grapefruit juice should be avoided if an interaction is suspected.
Orange juice is not expected to interact with these drugs.
Post-Day Alcohol interaction
[Minor] The central nervous system effects and blood levels of ethanol may be increased in patients taking oral contraceptives, although data are lacking and reports are contradictory.
The mechanism may be due to enzyme inhibition.
Consider counseling women about this interaction which is unpredictable.
Post-Day Cholesterol interaction
[Moderate] Some progestogenic agents may elevate plasma LDL levels and Patients with preexisting hyperlipidemia may require closer monitoring during progestogen therapy, and adjustments made accordingly in their lipid-lowering regimen. [Moderate] Estrogens and progestogens may cause fluid retention, particularly when given in high dosages or for prolonged periods. Therapy with these agents should be administered cautiously in patients who have preexisting problems with excess fluid. In addition, patients with conditions that may be adversely affected by fluid accumulation, such as asthma, epilepsy, migraine, and cardiovascular or renal dysfunction, should be observed for exacerbation of their condition during estrogen andPost-Day Hypertension interaction
Post-Day Drug Interaction
Moderate: lamotrigine, valproic acidUnknown: aripiprazole, amphetamine / dextroamphetamine, diphenhydramine, loratadine, duloxetine, amitriptyline, lithium, pregabalin, acetaminophen, quetiapine, acetaminophen, diazepam, cyanocobalamin, pyridoxine, cholecalciferol, lisdexamfetamine, sertraline, cetirizine
Volume of Distribution
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
Orally administered levonorgestrel is absorbed in the gastrointestinal tract while levonorgestrel administered through an IUD device is absorbed in the endometrium. Post-Day 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 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
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
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
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 Post-Day is secreted into breast milk it is suggested that you breast feed immediately before taking each tablet and that you skip nursing following each Post-Day tablet administration.
Contraindication
If you have hypersensitivity to Post-Day.
Acute Overdose
No acute toxicity has been demonstrated with this medicine in case of intake of several doses
Storage Condition
Store in a cool & dry place, protected from light. Keep out of reach of children
Innovators Monograph
You find simplified version here Post-Day
Post-Day contains Levonorgestrel see full prescribing information from innovator Post-Day Monograph, Post-Day MSDS, Post-Day FDA label
FAQ
What does Post-Day do to the body?
Post-Day is in a class of medications called progestins. It works by preventing the release of an egg from the ovary or preventing fertilization of the egg by sperm (male reproductive cells). It also may work by changing the lining of the uterus (womb) to prevent development of a pregnancy.
What is the side effect of Post-Day?
Nausea/vomiting, abdominal pain, tiredness, dizziness, changes in vaginal bleeding, breast tenderness, diarrhea, or headache may occur.
How effective is Post-Day 1.5 mg?
If you take the pill within 72 hours after you've had unprotected sex, Post-Day can reduce the risk of pregnancy by up to 87% if taken as directed.
What kind of hormone is Post-Day?
Post-Day [Levonorgestrel (LNG)] is a progestin and has effects similar to those of the hormone progesterone. It works primarily by preventing ovulation and closing off the cervix to prevent the passage of sperm.
Is one Post-Day enough to stop pregnancy?
To stop unintended pregnancy, take one pill (Post-Day) as soon as possible, but no later than 72 hours after unprotected sex.
Does Post-Day affect my mood?
13.3% of the women discontinued from the clinical trial due to an adverse reaction; the most common adverse reactions (≥1% of women) leading to discontinuation were heavy/irregular bleeding (5.0%), mood swings/alteration/affect lability (1.4%), headaches/migraines (1.3%), weight increased (1.3%) and acne (1.0%).
Does Post-Day make me to gain weight?
Side effects that have been associated with the Post-Day system include weight gain, depression, acne, and loss of scalp hair (101,108–110). No one has reported alopecia, although a heavy loss of hair has been anecdotally reported.
Does Post-Day stop periods?
Post-Day may make your next monthly period later than expected by a few days. If your next period after taking Post-Day is more than 1 week late, check with your doctor right away for a pregnancy test.
How do I know if levonorgestrel is working?
Most women will have their next menstrual period at the expected time or within a week of the expected time. If your menstrual period is delayed beyond 1 week, you may be pregnant. You should get a pregnancy test and follow up with your healthcare professional.
Can Post-Day cause early period?
Post-Day is found in birth control pills, but Plan B contains a higher dose that can alter your body's natural hormone levels. The extra hormones can, in turn, affect the menstrual cycle, leading to an earlier or delayed period as well as heavier or lighter bleeding.
How long does it take for Post-Day to work?
Once absorbed into the bloodstream, which usually takes a couple of hours, Post-Day starts to affect the ovaries or uterine lining. Although it’s rare, some women may throw up within two hours of taking Post-Day.
What does Post-Day 1.5 mg do?
Post-Day tablets 1.5 mg is emergency contraception that helps prevent pregnancy after birth control failure or unprotected sex. It is a backup method of preventing pregnancy and should not be used as regular birth control.
Can Post-Day cause infertility?
The reality is using emergency contraception or the morning after pill won't affect your fertility and won't stop you from getting pregnant in the future. The reason that clinicians suggest you don't use it often is that it's not as effective as regular contraception such as the pill, implant, coil or condoms.
How does Post-Day affect my period?
Possible changes to your next period After taking Post-Day 1.5 mg tablets, most women have their next period at the usual time, although some may have their period a few days earlier or later than normal.
Is Post-Day a type of progesterone?
Post-Day is a progestogen. It is not progesterone. Neither are any of the other synthetic progesterone look-alikes.
Is one Post-Day pill enough?
A single dose of Post-Day 1.5 mg for emergency contraception as one option. As another option, they recommend two doses of Post-Day 0.75 mg may be effective when taken 12-24 hours apart.
Can a girl get pregnant even after taking Post-Day?
Yes, it's possible to get pregnant. The morning-after pill (AKA emergency contraception) can help prevent pregnancy when you take it after having unprotected sex. But, it won't prevent pregnancy for any sex you may have after taking it.
Will Post-Day make me crazy?
For some women, being on the pill can magnify these feelings, leading to anxiety disorders and depression. But if these things happen to you, it doesn't mean you're crazy; it just means you're on the wrong pill. Mood-related issues like anxiety and depression are super-common among women on the pill.
Will Post-Day make my boobs bigger?
Many birth control pills contain the same hormones, estrogen and progestin, which is a synthetic form of progesterone. Starting to take the pill can stimulate the breasts to grow. However, any increase in size is typically slight.
Does Post-Day kill sperm?
Recent studies have identified that Post-Day administered orally in emergency contraception (LNG-EC) is only efficacious when taken before ovulation. However, the drug does not consistently prevent follicular rupture or impair sperm function.
What are the chances of getting pregnant after taking Post-Day?
In comparison, it's estimated that 0.6 to 2.6% of women who take Post-Day after unprotected sex will become pregnant. The effectiveness of Post-Day may be reduced if a woman has a high body mass index (BMI).
What can I use to flush out sperm from the body?
If someone prefers to clean their vagina and vulva after sex, the safest way to do so is with unscented soap and warm water. Some people claim that urinating, showering, bathing, or using vinegar may remove semen from the vagina after sex.
How long can periods delay after taking Post-Day?
Using the Post-Day may delay your period by up to one week. If you don't get your period within three to four weeks of taking Post-Day, take a pregnancy test.
Is it normal to bleed a week after taking Post-Day?
The Food and Drug Administration (FDA) report that heavier periods are relatively common after Plan B, occurring in as many as 31% of people who have taken the drug. However, a person should not expect to experience very heavy bleeding after taking Post-Day even days or weeks later.
