OVRAL 21
(Ethinylestradiol/Norgestrel)
WYETH
Presentation
Each OVRAL 21 package
contains:
21 white, round, biconvex, 6 mm
diameter tablets each containing ethinylestradiol 50 micrograms and norgestrel
500 micrograms.
Uses
Actions
The hormonal components of OVRAL 21
inhibit ovulation by suppressing gonadotropin release. Secondary mechanisms
which may contribute to the effectiveness of OVRAL 21 as a contraceptive include
changes in the cervical mucus (which increase the difficulty of sperm
penetration) and changes in the endometrium (which reduce the likelihood of
implantation).
In addition to providing protection
against pregnancy, oral contraceptives have been reported to be associated with
the following beneficial effects: a reduction in the risk of endometrial
carcinoma; a reduction in iron-deficiency anaemia, a reduction in the risk of
ovarian cysts, a possible reduction in the incidence of ovarian carcinoma and a
reduction in the incidence of benign breast lesions. Some protection is afforded
in cystic breast disease and in the case of fibroadenomas, after long-term
use.
Pharmacokinetics
Ethinylestradiol and norgestrel are
rapidly and almost completely absorbed from the gastrointestinal tract.
Ethinylestradiol is subject to considerable first-pass metabolism with a mean
bioavailability of 40-45%. Norgestrel does not undergo first-pass metabolism and
is therefore completely bioavailable.
Norgestrel is extensively plasma
protein bound both to sex hormone binding globulin (SHBG) and albumin.
Ethinyl-estradiol, however, is bound in plasma only to albumin and enhances the
binding capacity of SHBG. Following oral administration, peak plasma levels of
each medicine occur within 1 to 4 hours.
The elimination half-life for
ethinylestradiol is approximately 25 hours. It is primarily metabolised by
aromatic hydroxylation but a wide variety of hydroxylated and methylated
metabolites are formed, and these are present both free and as conjugates with
glucuronide and sulphate. Conjugated ethinylestradiol is excreted in bile and
subject to enterohepatic recirculation. About 40% of the medicine is excreted in
the urine and 60% is eliminated in the faeces.
The elimination half-life for
norgestrel is approximately 24 hours. The medicine is primarily metabolised by
reduction of the A ring followed by glucuronidation. About 60% of norgestrel is
excreted in the urine and 40% is eliminated in the faeces.
Indications
OVRAL 21 is indicated for:
Prevention of pregnancy.
Treatment of primary dysmenorrhoea
where contraception is required as a concurrent purpose.
Dosage And Administration
For Contraceptive And
Non-Contraceptive Indications
To achieve maximum contraceptive
effectiveness, OVRAL 21 must be taken as directed and at daily intervals not
exceeding 24 hours. Patients should be instructed to take the tablets at the
same time every day, preferably after the evening meal or at bedtime.
During the first cycle of
administration, the patient is instructed to take one OVRAL 21 tablet daily for
21 consecutive days, beginning on Day 5 of her menstrual cycle. (The first day
of bleeding is Day 1). The tablets are then discontinued for the next 7 days.
Withdrawal bleeding should usually occur within 3 days after the last tablet is
taken. The next and all subsequent courses will begin on the eighth day after
discontinuance, even if withdrawal bleeding has not occurred or is still in
progress. Each 21-day course of OVRAL 21 is thus begun on the same day of the
week and follows the same schedule (21 days on, 7 days off) as the first
course.
If the patient has a history of
irregular or short (less than 24 days) menstrual cycles, the first cycle of
OVRAL 21 should begin on Day 1 so that early ovulation will be reliably
prevented. Subsequent cycles of OVRAL 21 will follow the usual schedule
described above.
OVRAL 21 is effective from the first
day of therapy if the tablets are begun as described. If the tablets are started
after Day 5 or postpartum, a mechanical, i.e. barrier method of contraception
should be used until 14 consecutive daily tablets have been taken. It must be
considered that ovulation and conception may have occurred before the tablets
were started in these situations.
The patient who is changing from
another oral contraceptive product will begin OVRAL 21 on the day she would
usually start a new package of the other product. During the first OVRAL 21
cycle, a mechanical, i.e. barrier method of contraception should be used until
14 consecutive daily tablets have been taken.
If transient spotting or breakthrough
bleeding occurs, the patient is instructed to continue the regimen since such
bleeding is usually without significance. If the bleeding is persistent or
prolonged, the patient is advised to consult her physician.
In the nonlactating mother, OVRAL 21
may be begun immediately after delivery or at the first postpartum examination,
whether or not menstruation has resumed.
Missed Tablet
The patient should be instructed that
if one active tablet is missed and there is a delay of more than 12 hours after
the normal time of taking it, it should be taken as soon as possible, with the
next tablet being taken at the usual time, even if it means taking two tablets
on the same day. If two consecutive active tablets are missed, they should both
be taken as soon as remembered. The next tablet should be taken at its usual
time.
Each time the patient misses one or
two consecutive active tablets, an additional method of contraception such as a
condom or no intercourse should be used for the next fourteen days, irrespective
of bleeding. If three consecutive tablets are missed, OVRAL 21 should be
discontinued and the remainder of the package discarded. A new package should be
started immediately after the last tablet was taken. An additional method of
contraception such as condom or no intercourse should be used until fourteen
consecutive daily tablets have been taken.
If withdrawal bleeding does not occur
and OVRAL 21 has been taken according to directions, it is unlikely that the
patient has conceived. She should be instructed to begin a second course of
OVRAL 21 on the usual day. If bleeding does not occur at the end of this second
cycle, OVRAL 21 should not be taken until diagnostic procedures to exclude the
possibility of pregnancy have been performed.
If the patient has not adhered to the
prescribed regimen (missed one or more tablets or started taking them on a day
later than recommended), the probability of pregnancy should be considered at
the time of the first missed period before OVRAL is resumed.
Contraindications
OVRAL 21 should not be used in women
with any of the following conditions:
Thrombophlebitis, thromboembolic
disorders or cerebrovascular accident.
A history of deep-vein
thrombophlebitis or thromboembolic disorders.
Cerebral-vascular or coronary-artery
disease.
Known or suspected carcinoma of the
breast.
Known or suspected estrogen-dependent
neoplasia.
Undiagnosed abnormal genital
bleeding.
Known or suspected pregnancy.
Benign or malignant liver tumour
which developed during the use of estrogen-containing products.
Liver disease or a past history of
cholestatic jaundice, pruritus of pregnancy or herpes gestationis.
Disturbance of lipometabolism.
Hemiplegic migraine.
Warnings And Precautions
Concurrent use of antibiotics or
anticonvulsants may reduce the effective concentrations of the steroids and
hence impair the contraceptive effect (see INTERACTIONS ).
Diarrhoea or vomiting can jeopardise
the contraceptive effect by affecting absorption.
A thorough history and physical
examination should be performed before prescribing oral contraceptives with
special attention given to blood pressure, breasts, abdomen, and pelvic organs.
As a general rule, oral contraceptives should not be prescribed for longer than
one year without another physical examination being performed.
Under the influence of
estrogen-containing oral contraceptives, pre-existing uterine leiomyomata may
increase in size.
Oral contraceptives may cause
depression. Patients with a history of depression should be carefully observed
and the medicine discontinued if depression recurs to a serious
degree.
These agents may cause some degree of
fluid retention. Women with cardiac or renal dysfunction, convulsive disorders,
migraine, or asthma require careful observation since these conditions may be
exacerbated by the fluid retention which may occur in users of oral
contraceptives.
Cholestatic jaundice has been
reported in users of oral contraceptives. If this occurs, the medicine should be
discontinued. Patients with a history of jaundice during pregnancy should be
carefully observed whilst taking oral contraceptives.
Steroid hormones may be poorly
metabolised in patients with impaired liver function and should be administered
with caution to such patients.
Users of oral contraceptives may have
disturbances in normal tryptophan metabolism which may result in a relative
pyridoxine deficiency. The clinical significance of this is yet to be
determined.
Serum folate levels may be depressed
by oral contraceptive use. Women who become pregnant shortly after discontinuing
these medicines may have a greater chance of developing folate deficiency and
its complications.
Laboratory Tests - Papanicolaou
smears should be performed before prescribing these medicines and periodically
during their administration. Baseline and periodic blood glucose determinations
should be performed in patients predisposed to diabetes mellitus.
Cardiovascular
Disorder
Cigarette smoking increases the risk
of serious cardiovascular side effects from the use of oral contraceptives. The
risk increases with age and with heavy smoking (15 or more cigarettes per day)
and is quite marked in women over 35 years of age. Women who use oral
contraceptives should be strongly advised not to smoke.
Thromboembolic
Disorders
An increased risk of thromboembolic
and thrombotic disease associated with the use of oral contraceptives is well
established. This risk is increased with age. The physician should be alert to
the earliest manifestations of those disorders (e.g. thrombophlebitis, pulmonary
embolism, cerebrovascular insufficiency, cerebral haemorrhage, cerebral
thrombosis, coronary occlusion, retinal thrombosis, mesenteric thrombosis).
Should any of these occur or be suspected, the medicine should be discontinued
immediately.
A four- to six-fold increased risk of
thromboembolic complications following surgery has been reported in users of
oral contraceptives. Oral contraceptives should be discontinued at least 4 weeks
before surgery associated with an increased risk of thromboembolism or prolonged
immobilisation.
Myocardial Infarction And Coronary
Artery Disease
An increased risk of myocardial
infarction associated with the use of oral contraceptives has been reported.
Studies found that the greater the number of underlying risk factors for
coronary-artery disease (age, cigarette smoking, hypertension,
hyper-cholesterolaemia, obesity, diabetes, history of pre-eclamptic toxaemia)
the higher the risk of developing myocardial infarction, regardless of whether
or not the patient used an oral contraceptive. Oral contraceptives, however,
were found to be a clear additional risk factor.
Ocular Lesions
Discontinue oral contraceptives and
institute appropriate diagnostic and therapeutic measures if there is
unexplained, gradual or sudden, partial or complete loss of vision, proptosis or
diplopia; papilloedema; or any evidence of retinal vascular lesions or optic
neuritis.
Carcinoma
Long-term continuous administration
of either natural or synthetic estrogen in certain animal species increases the
frequency of carcinoma of the breast, cervix, vagina, and liver. At present,
there is no confirmed evidence from human studies which would indicate that an
increased risk of cancer is associated with oral contraceptives. Close clinical
surveillance is nevertheless essential in all women taking these medicines. In
all cases of undiagnosed, persistent, or recurrent abnormal vaginal bleeding,
appropriate diagnostic measures should be taken to eliminate the possibility of
malignancy. Women with a strong family history of breast cancer or who have
breast nodules, fibrocystic disease, or abnormal mammograms should be monitored
with particular care.
Hepatic Tumours
Benign hepatic adenomas have been
found to be associated with the use of oral contraceptives. Although benign,
hepatic adenomas may rupture and cause death through intra-abdominal
haemorrhage. This has been reported in short- and long-term users of oral
contraceptives. Such lesions may present as an abdominal mass or with the signs
and symptoms of an acute abdomen and should be considered if the patient has
abdominal pain and tenderness or evidence of intra-abdominal bleeding. A few
cases of hepatocellular carcinoma have been reported in women taking oral
contraceptives. This condition is exceedingly rare; the relationship between
oral contraceptives and this disease has not been conclusively
determined.
Elevated Blood
Pressure
An increase in blood pressure has
been reported in patients receiving oral contraceptives. In some women,
hypertension may occur within a few months of beginning use. In the first year
of use, the prevalence of women with hypertension is low but the incidence
increases with increasing exposure. Age is also strongly correlated with the
development of hypertension in oral contraceptive users. Women who previously
have had hypertension during pregnancy may be more likely to develop an
elevation of blood pressure when given oral contraceptives. If blood pressure
rises markedly, the medicine should be discontinued. Hypertension that develops
as a result of taking oral contraceptives usually returns to normal after
discontinuing the medicine.
Gallbladder Disease
Studies report an increased risk of
surgically confirmed gallbladder disease in users of estrogens and oral
contraceptives.
Headache
The onset or exacerbation of migraine
or development of headache of a new pattern which is recurrent, persistent, or
severe requires discontinuation of the medicine and evaluation of the
cause.
Carbohydrate And Lipid Metabolic
Effects
A decrease in glucose tolerance has
been observed in a significant percentage of patients on oral contraceptives.
For this reason, prediabetic and diabetic patients should be carefully observed
whilst receiving the medicine. An increase in triglycerides and total
phospholipids has been observed in patients receiving oral
contraceptives.
Use During Or Immediately Preceding
Pregnancy
Pregnancy Category B3. Foetal
abnormalities, including heart defects and limb defects, have been reported in
offspring of women who have taken oral contraceptives in early pregnancy.
Pregnancy should be ruled out before an oral contraceptive regimen is begun and
should be considered in women who have missed two consecutive menstrual periods.
The possibility of pregnancy should be considered at the first missed period if
the patient has not adhered to the prescribed regimen. Further oral
contraceptive use should be withheld until pregnancy has been ruled
out.
Oral contraceptives have not been
shown to have any deleterious effects on the foetus or to increase the incidence
of miscarriage in women who discontinue their use prior to conception. However,
in women who discontinue oral contraceptives with the intent of becoming
pregnant, a nonhormonal method of contraception is recommended for three months
before attempting to conceive.
Female sex hormones have been used
during pregnancy in an attempt to treat threatened or habitual abortion. There
is considerable evidence that estrogens are ineffective for these indications,
and there is no evidence from well-controlled studies that progestogens are
effective for these uses.
The administration of
progestogen-only or estrogen-progestogen combinations to induce withdrawal
bleeding should not be used as a test for pregnancy.
Use During Lactation
Estrogen-containing oral
contraceptives given in the postpartum period may interfere with lactation.
There may be a decrease in the quantity and quality of the breast milk.
Furthermore, a small fraction of the hormonal components of such oral
contraceptives has been identified in the milk of mothers receiving them. The
effects, if any, on the breast-fed infant have not been determined. If feasible,
the use of estrogen-containing oral contraceptives should be deferred until the
infant has been weaned.
Bleeding
Irregularities
Breakthrough bleeding, spotting and
amenorrhoea are frequent reasons for patients discontinuing oral contraceptives.
Organic disease should be excluded when breakthrough bleeding appears for the
first time in women who have been previously well controlled and in all cases of
irregular vaginal bleeding. In undiagnosed persistent or recurrent abnormal
bleeding from the vagina, appropriate diagnostic measures are indicated to rule
out pregnancy or malignancy. If pathology has been excluded, continuation of
OVRAL 21 or a change to another formulation may solve the problem. Changing to a
regimen with a higher estrogen content, whilst potentially useful in minimising
menstrual irregularity, should be done only if necessary, since this may
increase the risk of thromboembolic disease.
Women with a history of
oligomenorrhoea or secondary amenorrhoea or young women without regular cycles
may have a tendency to remain anovulatory or to become amenorrhoeic after
discontinuation of oral contraceptives. Women with these pre-existing problems
should be advised of this possibility and encouraged to use other methods of
contraception. Post-use anovulation, possibly prolonged, may also occur in women
without previous irregularities.
Ectopic Pregnancy
Ectopic as well as intrauterine
pregnancy may occur in contraceptive failures.
Adverse Effects
The most serious adverse reactions
associated with the use of oral contraceptives are indicated under WARNINGS AND
PRECAUTIONS. The following have also been reported and are believed to be
medicine-related:
Nausea and/or vomiting are usually
the most common adverse reactions.
The following reactions, as a general
rule, are seen much less frequently or only occasionally:
Gastrointestinal disturbances such as
bloating and abdominal cramps
Change in menstrual flow
Dysmenorrhoea
Chloasma or melasma which may be
persistent
Breast changes including tenderness,
enlargement, and secretion
Increase or decrease in
weight
Cervical erosion and changes in
cervical secretion
Rash (allergic)
Vaginal candidiasis
Change in corneal curvature
(steepening)
Intolerance to contact
lenses
Breakthrough bleeding
Amenorrhoea during and after
treatment
Anovulation post treatment
Cholestatic jaundice
Pruritus
Photosensitivity
Migraine
Drowsiness
The following adverse reactions have
also been reported in users of oral contraceptives.
Premenstrual-like syndrome
Hirsutism
Cataracts
Loss of scalp hair
Changes in libido
Erythema multiforme
Chorea
Erythema nodosum
Changes in appetite
Haemorrhagic eruption
Cystitis-like syndrome
Vaginitis
Headache
Porphyria
Nervousness
Haemolytic uraemic
syndrome
Dizziness
Effects On Laboratory
Tests
Estrogen-containing preparations
affect the following blood components and endocrine- and liver-function
tests:
Increased prothrombin and Factors II,
V, VII, VIII, IX, X and XII; decreased antithrombin 3; increased
noradrenaline-induced platelet aggregability.
Increased thyroid-binding globulin
(TBG) leading to increased circulating total-thyroid hormone, as measured by
protein-bound iodine (PBI), T4 by column, or T4 by radioimmunoassay. Free T3
resin uptake is decreased, reflecting the elevated TBG; free T4 concentration is
unaltered.
Decreased pregnanediol excretion.
Reduced response to metyrapone test.
Increased sulphobromophthalein
retention.
The results of these tests should not
be regarded as reliable until oral contraceptive use has been discontinued for
1-2 months. Abnormal tests should then be repeated.
Oral contraceptives may produce false
positive results when neutrophil alkaline phosphatase activity is evaluated for
the early diagnosis of pregnancy.
The glucose tolerance test is usually
impaired. Fasting blood glucose levels may also be raised.
Lipid metabolism may be affected with
changed serum levels of HDL cholesterol, triglycerides and phospholipids being
observed.
Serum albumin levels are usually
decreased (along with the associated calcium levels).
Analytical interference is observed
with the Zimmerman test for urinary 17-keto and 17-ketogenic
steroids.
Abnormal results in the following
tests may indicate impairment of organ function: Liver-increase in serum
transaminases, alkaline phosphatase, gamma glutamyl transpeptidase, bilirubin
and binding proteins.
Interactions
Reduced contraceptive efficacy and
increased incidence of breakthrough bleeding have been associated with the
concomitant use of oral contraceptives and rifampicin. A similar association has
been reported with the use of ampicillin, penicillin V, tetracycline, neomycin,
chloramphenicol, sulphonamides, nitrofurantoin, barbiturates, phenylbutazones,
meprobamate, phenacetin- and pyrazolone-containing analgesics, chlorpromazine,
dihydroergotamine and chlordiazepoxide.
Breakthrough bleeding has been
reported in patients taking oral contraceptives and St. John's wort (hypericum
perforatum). St. John's wort may induce hepatic microsomal enzymes which
theoretically may result in reduced efficacy of oral contraceptives. If oral
contraceptives and St. John's wort are used concomitantly, a non-hormonal
back-up method of birth control is recommended.
Oral contraceptives have been
reported to antagonise the effectiveness of antihypertensive agents,
anticonvulsants, oral anticoagulants, and hypoglycaemic agents. Patients should
be carefully monitored for a decreased response to these medicines.
Oral contraceptives may alter the
effectiveness of other medicines such as theophylline, phenothiazines,
corticosteroids, beta-adrenergic antagonists, tricyclic antidepressants,
caffeine and cyclosporin, by either potentiating/enhancing their pharmacological
effect or by decreasing their clearance.
Oral contraceptives may interfere
with the oxidative metabolism of diazepam and chlordiazepoxide, resulting in
plasma accumulation of the parent compound. Patients receiving these
benzodiazepines on a long-term basis should be monitored for increased sedative
effects.
The effects of other benzodiazepines
on oral contraceptive metabolism have not been determined.
Overdosage
Serious ill effects have not been
reported following acute ingestion of large doses of oral contraceptives by
young children. Overdosage may cause nausea; withdrawal bleeding may occur in
females.
Pharmaceutical
Precautions
Store below 25°C.
Medicine
Classification
Prescription Medicine.
Package Quantities
Three month pack containing 3
blisters.
Further Information
Ethinylestradiol is a white to creamy
white, odourless, crystalline powder. It is insoluble in water and soluble in
alcohol, chloroform, ether, vegetable oils, and aqueous solutions of alkali
hydroxides. Chemically, ethinylestradiol is
19-nor-17a-pregna-1,3,5(10)-trien-20-yne-3,17-diol and has the following
structure:
Norgestrel is a white, or nearly
white, practically odourless, crystalline powder that is insoluble in water,
sparingly soluble in alcohol and soluble in chloroform and acetone. Chemically,
norgestrel is ( + )-13-ethyl-17-hydroxy-18,19-dinor-17a-pregn-4-en-20-yn-3-one
and has the following structure: