Loestrin Fe 1 / 20 (norethisterone and ethinyl estradiol) is an oral hormonal contraceptive which is used for the prevention of pregnancy.
Indications for use
- Oral contraception.
Mechanism of action
The drug inhibits the gonadotropic function of the pituitary gland, the development of the follicle and interferes with the process of ovulation. The contraceptive effect is enhanced by increasing the viscosity of cervical mucus and reducing the susceptibility of the endometrium to the blastocyte.
Dosage and mode of application
Each Loestrin Fe 1 / 20 pack contains 28 tablets:
- 21 active tablets (20 mcg ethinyl estradiol / 1 mg norethisterone);
- 7 inert tablets.
The first tablet is taken on the first menstrual period, for 28 days in a row. The interval between two doses should not exceed 26 hours. After abortion or childbirth, you must wait for the first menstruation before taking birth control pills.
- Symptoms: nausea, vomiting, vaginal bleeding;
- Treatment: there is no specific antidote. Stop taking pills and begin symptomatic therapy.
In some cases, Loestrin Fe 1 / 20 tablets can cause the following side effects:
- tenderness of the mammary glands.
With long-term use: chloasma, discomfort when wearing contact lenses, increased risk of developing thromboembolic diseases.
Do not use Loestrin Fe 1 / 20 in the following cases:
- hypersensitivity to norethisterone and ethinyl estradiol;
- pregnancy, lactation;
- hormone-dependent tumors of the mammary glands and uterus;
- severe disorders of liver function and tumors;
- thromboembolic diseases (including in the anamnesis);
- thrombosis of arteries and veins;
- diabetes mellitus with vascular complications;
- vaginal bleeding of unclear etiology.
Use the drug with caution in patients with diabetes mellitus, arterial hypertension, varicose veins, phlebitis, otosclerosis, multiple sclerosis, epilepsy, liver disease, endometriosis, Sydenham disease. The drug should be discontinued at the onset of pregnancy, migraine headaches, acute visual impairment, hearing, acute thrombosis, congestion of bile or jaundice, increased blood pressure, prolonged bed rest.
The contraceptive may interact with barbiturates, some antiepileptic drugs (carbamazepine, phenytoin) – these drugs may enhance the metabolism of norethisterone and ethinyl estradiol.
The effectiveness of birth control pills can be reduced by certain antibiotics (ampicillin, rifampicin) and with regular excessive use of ethanol. When taking combination oral contraceptives, it may be necessary to correct the dosage regimen for hypoglycemic drugs.
Pregnancy and breastfeeding
Treatment should be discontinued immediately at the onset of pregnancy, as well as 3 months before the planned pregnancy. The drug is not used during lactation.
What if I miss a pill?
If a delay in taking pills is over 36 hours, the contraceptive effect is not reliable.
- If you miss 1 pill on Week 1 or 2, you need to take 2 pills the next day and then return to your usual dosing schedule;
- If you miss 2 pills in a row during the Week 1 or 2, you need to take 2 pills in the next 2 days and then return to your usual dosing schedule. In addition, you need to use a backup contraceptive method until the end of the current period;
- If you miss a pill during the Week 3, use an additional contraceptive method until the end of the current period and skip 7 inert tablets.
Moderate spotting during the course does not require discontinuation of birth control pills; in case of severe bleeding, stop taking the tablets and consult a doctor.
Diarrhea / vomiting can reduce the contraceptive effect of the drug. In this cases, you should continue taking pills and use additional non-hormonal methods of contraception).
Before taking the drug and every 6 months, it’s recommended to undergo a general medical and gynecological examinations (including gynecological monitoring, examination of the mammary glands, liver function, control of blood pressure and cholesterol concentration in the blood, urinalysis, cytological smear analysis).
The contraceptive may change the results of skin allergy tests, reducing the concentration of LH and FSH.
Use of Loestrin Fe 1 / 20 after delivery is recommended after the first normal menstrual cycle.
The drug may reduce milk production in a lactation period. Norethisterone and ethinyl estradiol in small quantities are excreted in breast milk.
Smoking women who take oral hormonal contraceptives have an increased risk of vascular diseases with serious consequences. The risk increases with age and depending on the number of cigarettes smoked per day. (especially over the age of 35).