This document provides information about oral contraceptives. It discusses the types of oral contraceptives including combination pills (monophasic, biphasic, triphasic), progestin pills, and morning after pills. Combination pills contain both estrogen and progesterone while progestin pills only contain progesterone. The document explains the mode of action of oral contraceptives by suppressing LH and FSH to inhibit ovulation. Potential side effects are also outlined such as nausea, headaches, and weight gain. In summary, this document reviews the different types of oral contraceptive pills, their mode of action in preventing pregnancy, and possible adverse effects.

1. 4th UNIT
ORAL CONTRACEPTIVES
Prepared by
G. Nikitha, M.Pharmacy
Assistant Professor
Department of Pharmaceutical Chemistry
Sree Dattha Institute Of Pharmacy
Hyderabad
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Subject: Medicinal Chemistry-II
Year: B.Pharmacy 3rd Year
Semister: 1st Semister

2. Contents
 Introduction
 Types of oral contraceptives
 Mode of action
 Adverse effects and Uses
 Reference
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3. Introduction
The advent of oral contraceptive pills has revolutionized the
method of contraception. They are also known as birth control pills.
They are composed of estrogen and progesterone or only
progesterone. Apart from being available over the counter other
advantage offered by them includes.
 Reliability
 Rapid reversal of fertility
 Reduced changes of developing premenstrual tension,
dysmenorrhoea, rheumatoid arthritis, haemolytic anaemia
 Reduced risk of pelvic inflammatory disease which is high with
IUCDs.
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4. Types of oral contraceptives
1. Combination Pills
 These are the most common and safest method of contraception and
are 99-99.5% effective. They contained balanced formulation of
both oestrogen and progestins.
 The first pill is taken on 5th day of menstrual cycle and continued
till 21 days next 7 days are pill free period i.e no pills are taken on
those days. The next course starts on the 5th day of menses.
 Combination ills suppress the production of luteinizing hormone
(LH) and follicle stimulating hormone (FSH) by negative feedback
mechanism (feedback inhibition process).
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5.  In the absence of LH and FSH ovulation is inhibited which is
similar to natural process occurring during pregnancy by the release
of oestrogen and progesterone from the ovaries and placenta. This
effect occurs mainly due to oestrogen.
 Progesterone ensures the withdrawal of bleeding after stopping the
medication. It also makes the cervical mucus thick by increasing the
viscosity and hence makes the sperm penetration difficult through
the cervix.
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6. Combination pills are as follows:
a. Monophasic Combination Pills:
The name Monophasic is given to these combination pills as there is
no phasic increase or decrease in oestrogen and progestin content
during the time period of dosage i.e 21days.
b. Biphasic Combination Pills:
These pills on administration mimic the hormonal changes
occurring during the menstrual cycle. They contain fixed dose of
estrogen for about 21 days and the dose of progesterone is increased
for two successive periods.
 I period from day 1 to 10- Ethinyl oetradiol (35mg) and
norethindrone (0.5mg)
 II period from day 11 to 21- Ethinyl oetradiol (35mg) and
norethindrone (1.0mg)
 The remaining 7 days are pill free days.
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7. c. Triphasic Combination Pills:
 These pills on administration mimic the hormonal changes
occurring during the menstrual cycle. They have higher dose of
oestrogen at mid cycle while progesterone doses are increase for
increased three successive phases.
 I period from day 1 to 06- Ethinyl oetradiol (30μg) and Norgetrel
(0.05mg)
 II period from day 7 to 11 - Ethinyl oetradiol (40μg) and Norgetrel
(0.075mg)
 III period from day 12 to 21- Ethinyl oetradiol (30μg) and Norgetrel
(0.125mg)
 The remaining 7 days are pill free days.
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8. 2. Progestin Pills/ Minipill:
 These pills are given to those individuals in whom oestrogen are
contraindicated. They contain small doses of progesterone and are
administrated throughout the menstrual cycle. The success rate of
minipills is less when compared to that of combination therapy. As
progesterone levels in blood stream increases, side effects like
headache, acne, breast tenderness, bleeding disorders and water
retention are seen,
 Progestin increases the viscosity of cervical mucus and makes the
sperm penetration difficult. They also prepare the endometrium
prematurely for secretory phase.
Examples:
 Norethindrone-0.35mg, Norgetrel-75μg.
 This pill is taken daily without interruption.
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9. Mode of action:
 The mode of action is primarily on cervical mucus which is made
inhospitable to sperm, the progetogen probably also hinders
implantation through its effects on the endometrium and the motility
and secretion of the fallopian tube.
Trade name Progestin (dose) Oestrogen (dose)
Combined Pills
Mala-D[21 tabs and ferrous
sulphate]
60mg tabs
Norgetrel (0.3mg) Ethinyloestradiol (30μg)
Ovral-G Norgetrel (0.5mg) Ethinyl oestradiol (50μg)
Bandhan, Ovral Levonorgestrel (0.15mg) Ethinyl oestradiol (30μg)
NOVELON Desogestrel (0.15mg) Ethinyl oestradiol (30μg)
FEMLION Desogestrel (0.15mg) Ethinyl oestradiol (20μg)
Levonorgestrel 0.5mg and Ethinyl oestradiol 0.1mg taken as early as
possible but within 73 hours of unprotected intercourse and repeated after
12hour.
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10. Side Effects:
 Nausea, vomiting
 Breast fullness
 Mastalgia
 Head ache
 Dizziness, Depression
 Pelvic Pain
 Weight gain
 Irritation, Skin changes
 Owing to fluid retension
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11. 3. Morning after pills/ Post-coital:
These pills are generally taken after unprotected sexual intercourse
and contain high dose of oestrogen and progestins.
Example: Centchroman is a non-steroidal contraceptive agent which
acts on oestrogen antagonist. In India the drug is available over the
counter under the brand name of Saheli. This drug is devoid of any
adverse effects characteristic to other oral contraceptives. On
cessation of centroman therapy, fertility reverses within 6 months
and the women can conceive.
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12. Adverse Effects:
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Oestrogenic Effects Progestogenic Effects
Mild Effects
Nausea, migraine, breast tenderness,
mild oedema, Withdrawal Bleeding
fails to occur.
Increase in appetite, increase in weight,
acne, Hirusutism, rise in body
temperature, decrease in libido
Moderate Effects
Vertigo, precipitation of diabetes, leg
and Uterine cramps
Breakthrough bleeding, urethral dilation,
amenorrhea (absence of menses)
Serious Effects
Thromboembolism, cholestatic
jaundice, hepatic Oedema,
cholelithiasis
Myocardial infarction, cerebrothromboisis

13. Reference books
 Text book of Medicinal chemistry volume-1-3rd edition by
V.Alagarasamy.
 Text book of Medicinal chemistry volume-2-3rd edition by
V.Alagarasamy.
 Medicinal chemistry by Rama Rao Nadendla.
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14. Thank YOU
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