FEMALE CONTRACEPTION-PREVENTION OF PREGNANCY
Phases of Menstrual Cycle
Normally a total menstrual cycle contains 28 days including the 7 days duration of menses.This may be varied according to some physiological variables such as genetics,obesity,weight,height and the tropical environments.Some pathological conditions also may cause variations in menstrual cycle.
The menstrual cycle depends on the stimulation and secretions of the hypohalamus-anterior pituitary axis,anterior pituitary-ovary axis,followed by ovarian secretions which control the final and end female parts such as the uterus,the cervix and the vagina.These secretions and effects are generally in a pulsative manner.
A normal menstrual cycle contains three phases as follows:-
Follicular Phase in which the Graafian follicles by the action of FSH (follicular stimulating hormone) from the anterior pituitary develops and grow and begin to secrete estrogens (estradiol,estriol,and estrone).This phase is composed of approximately 9 days and a slow pulsative decrease of FSH and LH occurs due to a feed back mechanism by estrogens at hypothalamus- anterior pituitary level.
Ovulation Phase which begins on the 10 th day at which a fully developed follicle separates from the ovary and shed into the lumen of the Fallopian tube.In this stage again a pulsative increase of LH occurs and in the empty space from which the ovum detached from the ovary an yellow gland known as Corpus Luteum develops by the action of LH.The duration of this phase is only one day.
Lutinizing Phase Which starts at which the ovulation completed.Lutinizing Hormone helps to develop corpus luteum at the gap left by the detached ovum.This starts almost at the midcycle and last for the rest of the period.At the seventeenth day the peak levels of esrogen and progesterone occur.The FSH level is decreased and LH level increased.
End of the cycle If no fertilization happened the carpus luteum ceased to function,after several days steroid levels drop,and menstruation occurs.The luteal phase is thus controlled by the limited 14 days life time of corpus luteum.The entire sysem then resets and a new menstrual cycle occurs.
2.A variey of hormonal derivatives with different combinations,doses and side effects are available.
3.These drugs are mostly used by young and healthy people to prevent pregnancy.
4.In addition to their contraceptive effects these medicines also have substantial health benefits.
5.Because of use of different compounds in different combinations and strengths and in different doses no one can compare or extrapolate the side effects with that of the hormone replacement therapies.
End of the cycle If no fertilization happened the carpus luteum ceased to function,after several days steroid levels drop,and menstruation occurs.The luteal phase is thus controlled by the limited 14 days life time of corpus luteum.The entire sysem then resets and a new menstrual cycle occurs.
Hormonal Conraceptions
Prelude 1.These are the most effective drugs2.A variey of hormonal derivatives with different combinations,doses and side effects are available.
3.These drugs are mostly used by young and healthy people to prevent pregnancy.
4.In addition to their contraceptive effects these medicines also have substantial health benefits.
5.Because of use of different compounds in different combinations and strengths and in different doses no one can compare or extrapolate the side effects with that of the hormone replacement therapies.
Types
1.Combination Oral Contraceptives
These compounds mostly contains an estrogen with a progestin.These combination have the benefit of reducing the side effects of both estrogens and progestins to a minimum and giving about of 99.9% increase in benefits.
The estrogens used are commonly ethynyl estradiol and mestranol. Among this ethynylestradiol is the most frequently used.
The progestins used are mostly 19 nor progestins(nor,means methyl)
The side effects of the progestins are depending on their androgenic.estrogenic and their anti-estrogenic activities.
Desogestrel and Norgesimate are the most recently developed progestins and have less side effects than the other 19 nor compounds.
These compounds are available as three phasic preparations as :- 1)Monophasic acting on any one of the three phases of the cycle.Comes in 21 days packings.
Contains equal quatities of esrogens and progestins are presnt in each pill which is taken 1 tablet daily for 21 days with a 7 days pill free period.Excempted by some packings which contains 28 pills with the 7 day pills contains no active ingredients.
Examples of Monophasics
1.Ethynylestradiol /Norethindrone combinations contains ethynylestradiol ranges from 0.020 to 0.050mg; norethindrone acetate as progestin in various amounts ranges from 0.4 to 1.5 mg according to the brands
2.Ethynylestradiol /Levonorgestrel combination contains levonorgestrel 0.15 mg
3.Ethynylestradiol / Norgestrel contains norgestrel 0.3 and 0.5 in different brands
4.EthynylestrEthynylestradiolne diacetate combination contains the ethynodione diacetate 1 mg
5.Mestranol /Norethindrone combinations contains norethindrone 1 mg.
6.Ethynylestradiol / Desogesrel combinations contains desogesrel 0.15 mg.
7.Ethynylestradiol / Norgestimate combinations contains norgestimate 0.25 and 0.5 mg
2.Biphasics are acting on any two of the menstrua phases.They provide two different pills contains variying amount of active ingredients to be taken at different times during he 21 day cycle.This reduces the total amount steroids administered and thereby reduces their side effects.The amount variations of the steroids closely approximate the variations of steroids secreted in phases.For example generally the ratio of estrogen to progeserone higher in luteal phase and hence the amount of progestins can be reduced conveniently.These methods are developed in late 1980.
Examples of Biphasics
1.Ethynylestradiol / Norethindrone combinations contains 0.035 mg/5 mg in 10 tablets and 0.035 mg/1mg in 11 tablets in the brand NELOVA 10/11 and 0.035mg/0.5mg in 7tablets and 0.35mg/1mg in 14 tablets.in the brand JENSET-28
Triphasic these preparetions are acting on all three phases similar to biphasic their formula provides the amount of steroids according to the occuring during the phases.
Examples of the Triphasics
1.Ethynylestradiol/Norethindrone combination contains in all preparations the ratio of ethynylestradiol is 0.035mg to the ratio of the norethindrone ranges from 0.5,0.75 and 1 mg in 7,7,7 tablets in one pack respectively according to the three phases to be taken as in ORTHONOVUM 7,7,7
2.Ethynylestradiol/Norgestimate combination contains the amount of esradiol is 0.035mg to the ratio to norgestimate 0.18,0.215,0.25mg in 7,7,7 tablets per pack as in ORTHO-TRYCYCLIN
Remember that any pills which contains >50 microgram of estrogen is known as high dosed and if it contains <50 microgram is considered as low dosed.The lower limit is =20mic.gm.
Remember that any pills which contains >50 microgram of estrogen is known as high dosed and if it contains <50 microgram is considered as low dosed.The lower limit is =20mic.gm.
2.Progestin Only Conraceptives
These combination has been deviced for particularly to whom estrogens are contra indicated like heart patients with high blood pressure and thrombo embolic diseases and breast cancer etc.
Eventhough they are less efficacious they are widely used.
These agents block ovulations but less consistantly than combination tablets,suggesting that the they have some other additional mechanisms.
Preparation include the minipill or the oral preparations of low dose progestins.These has to be taken daily without interrution;subdermal implants of 216 norgestrel as in NORPLANT is available for slow release and for a prolonged duration (for 5 years)
An Intra Uterine Device (Progestasert) that releases low amount of progestin locally is available to be used on yearly basis.
Examples of Progesin Only Contraceptives
Norethindrone as 0.35 mg is available for oral use as in MICRONOR AND NOR-QD
Norgesrel as 0.075 available as in OVERETTE
Postcoital Contraceptives
These are available for preventing pregnancy decided on an emergency situation within 72 hours afer an unprotected coitus or intercourse.
1.Ethynylesradiol 100 micro gram combined with 1 mg Norgesrel to be taken twice 12 hour apart but initiated within 72 hours afer intercourse.
2.Ethynylestradiol alone in a dose of 2.5mg twice daily for 5 days initiated within 72 hours of the intercourse.
3.Conjugated estrogens 30 mg daily for 5 days.started within 72 hrs ater coitus.
4.Estrone with a dose of 5 mg three times daily for 5 days initiated within 72 hrs afer the coitus
5.Diethylstilbestrol 25 mg twice daily for 5 days but this regimen is largely reduced because of its side effects.
Among all the above the laest regimen successfully employed is the estradiol- norgestrel combination which is low dosed and more effective and safe provided that the regimen should be initiated within 72 hrs ater the intercourse.
The mechanism is unclear but beleived to be the delay in tubal transportation or development of endometrium hostile to implantation.
These high doses of estrogens frequently causes side effects such as
1.Head aches
2.Dizziness
3.Nausea
4.Vomiting
Because of the frequency and severity the above side effects Post Coital Contraceptives are in appropriate in many situations
Mechanisms of Actions
1.Combination Oral Contraceptives
These are mainly act by preventing ovulation by suppressing FSH and LH.
2.Progestin Only Preparations
Block ovulation similar to combination pills but less efficacious.These are largely acting on hypothalamus-anterior pituitary axis and suppressing Gonadotropin Releasing Hormone pulses.Also thickening of cervix to prevent the entry of sperm,and endometrial alteration to hostile the implantation of the ovum into the uterus are also the action of these preparations to avoid pregnancy.3
In general the women if she take the pill without forgot daily the she had the contraceptive protection well .
In general the women if she take the pill without forgot daily the she had the contraceptive protection well .
Toxicities of Oral Hormonal Contraceptives
1.Formations of Blood Clots
2.Increased risks of Breast Cancer but this is questionable as convincing reports are suggesting that these compounds are reducing the incidences of endometrial and breast cancers especially by combination oral preparations.
3.Breast tenderness.
4.Headache
5.Gallstones
6.Acne
7.Weight gain.
8.Irregular,unpredictable breakthrough bleeding which leads to amenorrhea after 1 year use.(Typical to progestin alone contraceptives)
9.Visual problems
10.Non cancerous liver tumor
9.Visual problems
10.Non cancerous liver tumor
Contraindications
1.Pregnancy
2.History of Thrombo embolism
3.Coronary Artery Disease like Angina,and MI
4.Central vascular disease
5.Congenital Hyperlipidemia
6.Breast or endometrial cancer
Drug Interactions
1.Contraceptive pills and smoking are disasterous as nicotine intracts with the hormones so seriouly.
2.Anti convulsants such as phenytoin (Dilantin),barbiturates and rifampin are all make the pill less potent
3.Antibiotics such as Penicillins,tetracyclins,doxycyclins,and antifungal griseofulvin also will eliminate the contraceptive hormones very fast from our body and the pills ineffective.
The oralcontraceptives does not give any protections against sexually transmitted infections.
6.Breast or endometrial cancer
Drug Interactions
1.Contraceptive pills and smoking are disasterous as nicotine intracts with the hormones so seriouly.
2.Anti convulsants such as phenytoin (Dilantin),barbiturates and rifampin are all make the pill less potent
3.Antibiotics such as Penicillins,tetracyclins,doxycyclins,and antifungal griseofulvin also will eliminate the contraceptive hormones very fast from our body and the pills ineffective.
The oralcontraceptives does not give any protections against sexually transmitted infections.
LONG ACTING CONTRACEPTIVE HORMONES
These methods are giving a convenience and no need to rely on daily doses of the pill without forgot
Medroxyprogesterone acetate is available in ijection form by the trade name Depo-Provera and can give a 4 years contraceptive protection for a woman.The injection site should not be rubbed and massaged to keep the absorption to delay inorder to prolong the effect.
Breast cancer is more common in youngers below 27 years and less common in women above 35 years.
Contraception can easily be reversed after withdrawal of the drug in lean body than a fatty woman
Breast cancer is more common in youngers below 27 years and less common in women above 35 years.
Contraception can easily be reversed after withdrawal of the drug in lean body than a fatty woman
