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Alpha-Norgestrel

Alpha-Norgestrel - General Information

A synthetic progestational hormone with actions similar to those of progesterone and about twice as potent as its racemic or (+-)-isomer (norgestrel). It is used for contraception, control of menstrual disorders, and treatment of endometriosis.

 

Pharmacology of Alpha-Norgestrel

Alpha-Norgestrel is used as a female contraceptive. Alpha-Norgestrel 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. Alpha-Norgestrel 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.

 

Alpha-Norgestrel for patients

PATIENT INFORMATION
WHEN TO START THE FIRST PACK OF PILLS
For the 21-day pill pack you have two choices of which day to start taking your first pack of
pills. (See DAY 1 START or SUNDAY START directions below.) Decide with your health-care
professional which is the best day for you. The 28-day pill pack accommodates a SUNDAY START only.
For either pill pack pick a time of day which will be easy to remember.
DAY 1 START
These instructions are for the 21-day pill pack only. The 28-day pill pack does not accommodate a
DAY 1 START dosage regimen.
1. Take the first "active" white pill of the first pack during the first 24 hours of your period.
2. You will not need to use a back-up nonhormonal method of birth control, since you are starting
the pill at the beginning of your period.
SUNDAY START
These instructions are for either the 21-day or the 28-day pill pack.
1. Take the first "active" white pill of the first pack on the Sunday after your period starts, even
if you are still bleeding. If your period begins on Sunday, start the pack that same day.
2. Use a nonhormonal method of birth control (such as condoms and/or spermicide) as a backup method if
you have sex anytime from the Sunday you start your first pack until the next Sunday (7 days).
WHAT TO DO DURING THE MONTH
1. TAKE ONE PILL AT THE SAME TIME EVERY DAY UNTIL THE PACK IS EMPTY.
Do not skip pills even if you are spotting or bleeding between monthly periods or feel sick to your
stomach (nausea).
Do not skip pills even if you do not have sex very often.
2. WHEN YOU FINISH A PACK OR SWITCH YOUR BRAND OF PILLS:
21 pills: Wait 7 days to start the next pack. You will probably have your period during that week. Be
sure that no more than 7 days pass between 21-day packs.
28 pills: Start the next pack on the day after your last "reminder" pill. Do not wait any days between
packs.
WHAT TO DO IF YOU MISS PILLS
The pill may not be as effective if you miss white "active" pills, and particularly if you miss the first
few or the last few white "active" pills in a pack.
If you MISS 1 white "active" pill:
1. Take it as soon as you remember. Take the next pill at your regular time. This means you may take 2 pills
in 1 day.
2. You COULD BECOME PREGNANT if you have sex in the 7 days after you miss pills. You MUST use a nonhormonal
birth-control method (such as condoms and/or spermicide) as a backup for those 7 days.
If you MISS 2 white "active" pills in a row in WEEK 1 OR WEEK 2 of your pack:
1. Take 2 pills on the day you remember and 2 pills the next day.
2. Then take 1 pill a day until you finish the pack.
3. You COULD BECOME PREGNANT if you have sex in the 7 days after you miss pills. You MUST use a nonhormonal
birth-control method (such as condoms and/or spermicide) as a backup for those 7 days.
If you MISS 2 white "active" pills in a row in THE 3rd WEEK:
The Day 1 Starter instructions are for the 21-day pill pack only. The 28-day pill pack does not accommodate a
DAY 1 START dosage regimen. The Sunday Starter instructions are for either the 21-day or 28-day pill pack.
1. If you are a Day 1 Starter:
THROW OUT the rest of the pill pack and start a new pack that same day.
If you are a Sunday Starter:
Keep taking 1 pill every day until Sunday.
On Sunday, THROW OUT the rest of the pack and start a new pack of pills that same day.
2. You may not have your period this month but this is expected. However, if you miss your period 2 months in a
row, call your health-care professional because you might be pregnant.
3. You COULD BECOME PREGNANT if you have sex in the 7 days after you miss pills. You MUST use a nonhormonal
birth-control method (such as condoms and/or spermicide) as a backup for those 7 days.
If you MISS 3 OR MORE white "active" pills in a row (during the first 3 weeks):
The Day 1 Starter instructions are for the 21-day pill pack only. The 28-day pill pack does not accommodate a
DAY 1 START dosage regimen. The Sunday Starter instructions are for either the 21-day or 28-day pill pack.
1. If you are a Day 1 Starter:
THROW OUT the rest of the pill pack and start a new pack that same day.
If you are a Sunday Starter:
Keep taking 1 pill every day until Sunday.
On Sunday, THROW OUT the rest of the pack and start a new pack of pills that same day.
2. You may not have your period this month but this is expected. However, if you miss your period 2 months in a
row, call your health-care professional because you might be pregnant.
3. You COULD BECOME PREGNANT if you have sex in the 7 days after you miss pills. You MUST use a nonhormonal
birth-control method (such as condoms and/or spermicide) as a backup for those 7 days.
A REMINDER FOR THOSE ON 28-DAY PACKS
If you forget any of the 7 pink "reminder" pills in Week 4:
THROW AWAY the pills you missed.
Keep taking 1 pill each day until the pack is empty.
You do not need a back-up nonhormonal birth-control method if you start your next pack on time.
FINALLY, IF YOU ARE STILL NOT SURE WHAT TO DO ABOUT THE PILLS YOU HAVE MISSED
Use a BACK-UP NONHORMONAL BIRTH-CONTROL METHOD anytime you have sex.
KEEP TAKING ONE PILL EACH DAY until you can reach your health-care professional.
PREGNANCY DUE TO PILL FAILURE
The incidence of pill failure resulting in pregnancy is approximately 1% if taken every day as directed, but the
average failure rate is approximately 5% including women who do not always take the pill exactly as directed
without missing any pills. If you do become pregnant, the risk to the fetus is minimal, but you should stop
taking your pills and discuss the pregnancy with your health-care professional.
PREGNANCY AFTER STOPPING THE PILL
There may be some delay in becoming pregnant after you stop using oral contraceptives, especially if you had
irregular menstrual cycles before you used oral contraceptives. It may be advisable to postpone conception until
you begin menstruating regularly once you have stopped taking the pill and desire pregnancy.
There does not appear to be any increase in birth defects in newborn babies when pregnancy occurs soon after
stopping the pill.
If you do not desire pregnancy, you should use another method of birth control immediately after stopping the
oral contraceptive pill.
OVERDOSE
Overdosage may cause nausea, vomiting, and fatigue/drowsiness. Withdrawal bleeding may occur in females. In
case of overdosage, contact your health-care professional or pharmacist.
OTHER INFORMATION
Your health-care professional will take a medical and family history before prescribing oral contraceptives
and will examine you. The physical examination may be delayed to another time if you request it and the health-
care professional believes that it is appropriate to postpone it. You should be reexamined at least once a year.
Be sure to inform your health-care professional if there is a family history of any of the conditions listed
previously in this leaflet. Be sure to keep all appointments with your health-care professional, because this
is a time to determine if there are early signs of side effects of oral-contraceptive use.
Do not use the drug for any condition other than the one for which it was prescribed. This drug has been
prescribed specifically for you; do not give it to others who may want birth-control pills.
HEALTH BENEFITS FROM ORAL CONTRACEPTIVES
In addition to preventing pregnancy, use of oral contraceptives may provide certain benefits. They are:
� Menstrual cycles may become more regular.
� Blood flow during menstruation may be lighter, and less iron may be lost. Therefore, anemia due to iron
deficiency is less likely to occur.
� Pain or other symptoms during menstruation may be encountered less frequently.
� Ovarian cysts may occur less frequently.
� Ectopic (tubal) pregnancy may occur less frequently.
� Noncancerous cysts or lumps in the breast may occur less frequently.
� Acute pelvic inflammatory disease may occur less frequently.
� Oral-contraceptive use may provide some protection against developing two forms of cancer: cancer of the
ovaries and cancer of the lining of the uterus.
If you want more information about birth-control pills, ask your health-care professional or pharmacist. They
have a more technical leaflet called the Professional Labeling which you may wish to read.

 

Alpha-Norgestrel Interactions

Changes in contraceptive effectiveness associated with coadministration of other products: Contraceptive effectiveness may be reduced when hormonal contraceptives are coadministered with antibiotics, anticonvulsants, and other drugs that increase the metabolism of contraceptive steroids. This could result in unintended pregnancy or breakthrough bleeding. Examples include rifampin, rifabutin, barbiturates, primidone, phenylbutazone, phenytoin, dexamethasone, carbamazepine, felbamate, oxcarbazepine, topiramate, griseofulvin, and modafinil.

Several cases of contraceptive failure and breakthrough bleeding have been reported in the literature with concomitant administration of antibiotics such as ampicillin and other penicillins, and tetracyclines, possibly due to a decrease of enterohepatic recirculation of estrogens.

However, clinical pharmacology studies investigating drug interactions between combined oral contraceptives and these antibiotics have reported inconsistent results. Enterohepatic recirculation of estrogens may also be decreased by substances that reduce gut transit time.

Several of the anti-HIV protease inhibitors have been studied with coadministration of oral combination hormonal contraceptives; significant changes (increase and decrease) in the plasma levels of the estrogen and progestin have been noted in some cases. The safety and efficacy of oral contraceptive products may be affected with coadministration of anti-HIV protease inhibitors. Health-care professionals should refer to the label of the individual anti-HIV protease inhibitors for further drug-drug interaction information.

Herbal products containing St. John’s Wort (Hypericum perforatum) may induce hepatic enzymes (cytochrome P 450) and p-glycoprotein transporter and may reduce the effectiveness of contraceptive steroids. This may also result in breakthrough bleeding.

During concomitant use of ethinyl estradiol containing products and substances that may lead to decreased plasma steroid hormone concentrations, it is recommended that a nonhormonal backup method of birth control be used in addition to the regular intake of Lo/Ovral. If the use of a substance which leads to decreased ethinyl estradiol plasma concentrations is required for a prolonged period of time, combination oral contraceptives should not be considered the primary contraceptive.

After discontinuation of substances that may lead to decreased ethinyl estradiol plasma concentrations, use of a nonhormonal back-up method of birth control is recommended for 7 days. Longer use of a back-up method is advisable after discontinuation of substances that have led to induction of hepatic microsomal enzymes, resulting in decreased ethinyl estradiol concentrations. It may take several weeks until enzyme induction has completely subsided, depending on dosage, duration of use, and rate of elimination of the inducing substance.

Increase in plasma levels associated with coadministered drugs: Coadministration of atorvastatin and certain oral contraceptives containing ethinyl estradiol increase AUC values for ethinyl estradiol by approximately 20%. The mechanism of this interaction is unknown. Ascorbic acid and acetaminophen increase the bioavailability of ethinyl estradiol since these drugs act as competitive inhibitors for sulfation of ethinyl estradiol in the gastrointestinal wall, a known pathway of elimination for ethinyl estradiol. CYP 3A4 inhibitors such as indinavir, itraconazole, ketoconazole, fluconazole, and troleandomycin may increase plasma hormone levels. Troleandomycin may also increase the risk of intrahepatic cholestasis during coadministration with combination oral contraceptives.

Changes in plasma levels of coadministered drugs: Combination hormonal contraceptives containing some synthetic estrogens (eg, ethinyl estradiol) may inhibit the metabolism of other compounds. Increased plasma concentrations of cyclosporin, prednisolone and other corticosteroids, and theophylline have been reported with concomitant administration of oral contraceptives. Decreased plasma concentrations of acetaminophen and increased clearance of temazepam, salicylic acid, morphine, and clofibric acid, due to induction of conjugation (particularly glucuronidation), have been noted when these drugs were administered with oral contraceptives.

The prescribing information of concomitant medications should be consulted to identify potential interactions.

Interactions With Laboratory Tests

Certain endocrine- and liver-function tests and blood components may be affected by oral contraceptives:

a. Increased prothrombin and factors VII, VIII, IX, and X; decreased antithrombin 3; increased norepinephrine-induced platelet aggregability.

b. Increased thyroid-binding globulin (TBG) leading to increased circulating total thyroid

hormone, as measured by protein-bound iodine (PBI), T4 by column or by radioimmunoassay. Free T3 resin uptake is decreased, reflecting the elevated TBG; free T4 concentration is unaltered.

C. Other binding proteins may be elevated in serum ie, corticosteroid binding globulin (CBG), sex hormone-binding globulins (SHBG) leading to increased levels of total circulating corticosteroids and sex steroids respectively. Free or biologically active hormone concentrations are unchanged.

d. Triglycerides may be increased and levels of various other lipids and lipoproteins may be affected.

e. Glucose tolerance may be decreased.

f. Serum folate levels may be depressed by oral-contraceptive therapy. This may be of clinical significance if a woman becomes pregnant shortly after discontinuing oral contraceptives.

 

Alpha-Norgestrel Contraindications

Combination oral contraceptives should not be used in women with any of the following conditions:

Thrombophlebitis or thromboembolic disorders

A past history of deep-vein thrombophlebitis or thromboembolic disorders

Cerebral-vascular or coronary-artery disease (current or history)

Thrombogenic valvulopathies

Thrombogenic rhythm disorders

Major surgery with prolonged immobilization

Diabetes with vascular involvement

Headaches with focal neurological symptoms

Uncontrolled hypertension

Known or suspected carcinoma of the breast or personal history of breast cancer

Carcinoma of the endometrium or other known or suspected estrogen-dependent neoplasia

Undiagnosed abnormal genital bleeding

Cholestatic jaundice of pregnancy or jaundice with prior pill use

Hepatic adenomas or carcinomas, or active liver disease, as long as liver function has not returned to normal

Known or suspected pregnancy

Hypersensitivity to any of the components of Lo/Ovral

 

Additional information about Alpha-Norgestrel

Alpha-Norgestrel Indication: Used as an oral contraceptive to prevent pregnancy
Mechanism Of Action: Alpha-Norgestrel binds to the progesterone and estrogen receptors. Target cells include the female reproductive tract, the mammary gland, the hypothalamus, and the pituitary. Once bound to the receptor, progestins like Alpha-Norgestrel will slow the frequency of release of gonadotropin releasing hormone (GnRH) from the hypothalamus and blunt the pre-ovulatory LH (luteinizing hormone) surge.
Drug Interactions: Not Available
Food Interactions: Avoid alcohol.
Take with food.
Avoid excessive quantities of coffee or tea (Caffeine).
Increase dietary intake of magnesium, folate, vitamin B6, B12, and/or consider taking a multivitamin.
Take at the same time everyday.
Generic Name: Norgestrel
Synonyms: Not Available
Drug Category: Contraceptives
Drug Type: Small Molecule; Approved
Other Brand Names containing Norgestrel: Alesse; Alpha-Norgestrel; Component of Lo/Ovral; Component of Ovral; DL-Norgestrel; LD Norgestrel; Ld Norgestrel [French]; Lo/Ovral; Logynon; Methylnorethindrone; Microgynon; Microlut; Monovar; NOG; Neogest; Norgeston; Norgestrel [Progestins]; Norgestrel [Usan-Ban-Inn-Jan]; Norgestrelum [Inn-Latin]; Ovral; Ovran; Postinor; Stediril; Tetragynon; Trinordiol;
Absorption: 65%
Toxicity (Overdose): Nausea, vomiting, and drowsiness/fatigue; Withdrawal bleeding; LD50=mg/kg (orally in rat)
Protein Binding: Norgestrel-binding protein in the plasma appeared to be a protein different from human serum albumin, corticosteroid-binding globulin and sex-steroid-binding protein. High binding (>95%).
Biotransformation: Hepatic
Half Life: 5-14 hours
Dosage Forms of Alpha-Norgestrel: Insert, extended release Intrauterine
Tablet Oral
Chemical IUPAC Name: (8R,9S,10R,13S,14S,17R)-13-ethyl-17-ethynyl-17-hydroxy-1,2,6,7,8,9,10,11,12,14,15,16-dodecahydrocyclopenta[a]phenanthren-3-one
Chemical Formula: C21H28O2
Norgestrel on Wikipedia: http://en.wikipedia.org/wiki/Norgestrel
Organisms Affected: Humans and other mammals