Ortho-Prefest - General Information

Ortho-Prefest is a form of progesterone, which is a female hormone important for the regulation of ovulation and menstruation. Ortho-Prefest is used with estradiol to treat the symptoms of menopause.


Pharmacology of Ortho-Prefest

Ortho-Prefest is used as a female contraceptive. Ortho-Prefest 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. Ortho-Prefest 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.


Ortho-Prefest for patients

Take the pill at the same time every day. Do not miss any dose.

Some risks are associated with taking oral contraceptives, for example:

  • smoke
  • high blood pressure
  • clotting disorders
  • heart attack, angina pectoris
  • stroke
  • cancer of the bresst or sex organs
  • jaundice
  • malignant or benign liver tumors

Women who experience unexplained vaginal bleeding or suspect that she is pregnant should stop taking oral contraceptives.

Oral contraceptives may cause some side effects. The most common such effects are nausea, vomiting, bleeding between menstrual periods, weight gain, breast tenderness, and difficulty wearing contact lenses. These side effects, especially nausea and vomiting, may subside within the first three months of use.

Some of the more serious side effects are:

  • Blood clots in the vessels of legs, lungs, heart or other organs
  • Stroke
  • Benign liver tumors
  • High blood pressure

Always talk to your doctor or other health care providers if you experience any unusual signs or symptoms.


Ortho-Prefest Interactions

Reduced efficacy and increased incidence of breakthrough bleeding and menstrual irregularities have been associated with concomitant use of rifampin. A similar association, though less marked, has been suggested with barbiturates, phenylbutazone, phenytoin sodium, carbamazepine, griseofulvin, topiramate, and possibly with ampicillin and tetracyclines 72. A possible interaction has been suggested with hormonal contraceptives and the herbal supplement St. John's Wort based on some reports of oral contraceptive users experiencing breakthrough bleeding shortly after starting St. John's Wort. Pregnancies have been reported by users of combined hormonal contraceptives who also used some form of St. John's Wort. Healthcare prescribers are advised to consult the package inserts of medication administered concomitantly with oral contraceptives.


Ortho-Prefest Contraindications

Oral contraceptives should not be used in women who currently have the following conditions:

  • Thrombophlebitis or thromboembolic disorders
  • A past history of deep vein thrombophlebitis or thromboembolic disorders
  • Cerebral vascular or coronary artery disease
  • Migraine with focal aura
  • Known or suspected carcinoma of the breast
  • Carcinoma of the endometrium or other known or suspected estrogendependent neoplasia
  • Undiagnosed abnormal genital bleeding
  • Cholestatic jaundice of pregnancy or jaundice with prior pill use
  • Acute or chronic hepatocellular disease with abnormal liver function
  • Hepatic adenomas or carcinomas
  • Known or suspected pregnancy
  • Hypersensitivity to any component of this product



Additional information about Ortho-Prefest

Ortho-Prefest Indication: For the prevention of pregnancy
Mechanism Of Action: Ortho-Prefest binds to androgen and progestogen receptors. Target cells include the female reproductive tract, the mammary gland, the hypothalamus, and the pituitary. Once bound to the receptor, progestins like Ortho-Prefest 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: Norgestimate
Synonyms: Dexnorgestrel Acetime; Norgestimato [Inn-Spanish]; Norgestimatum [Inn-Latin]
Drug Category: Contraceptives
Drug Type: Small Molecule; Approved

Other Brand Names containing Norgestimate: Ortho Cyclen-21; Ortho Cyclen-28; Ortho Tri-Cyclen; Ortho-Prefest;
Absorption: Not Available
Toxicity (Overdose): Not Available
Protein Binding: Not Available
Biotransformation: GI tract/Hepatic
Half Life: 12-30 hours
Dosage Forms of Ortho-Prefest: Tablet Oral
Chemical IUPAC Name: [(3E,8R,9S,10R,13S,14S,17R)-13-ethyl-17-ethynyl-3-hydroxyimino-1,2,6,7,8,9,10,11,12,14,15,16-dodecahydrocyclopenta[a]phenanthren-17-yl] acetate
Chemical Formula: C23H31NO3
Norgestimate on Wikipedia:
Organisms Affected: Humans and other mammals