Drugs Used in the Treatment of Obstetric and Gynecological Disorders

Drugs for Menstrual Disorders

The main disorders associated with menstruation that may require treatment include:

• Amenorrhoea
• Dysmenorrhoea
• Menorrhagia
• Premenstrual syndrome
• Menopause

Amenorrhoea

Amenorrhoea is the absence of menstruation. A break in menstruation of 6 months or more is considered pathological in an adult woman who is not pregnant, lactating, or has reached menopause.

Amenorrhoea may be classified as:

• Primary Amenorrhoea: Occurs when a female fails to have her first menstrual cycle by age 16 in the presence of normal secondary sexual characteristics.
• Secondary Amenorrhoea: The absence of menses for 6 months or more in a woman whose normal menstruation has been established.

Management

• Identification and correction of any underlying disorder

Dysmenorrhoea

Dysmenorrhoea is painful menstruation that prevents normal activity and requires medication.

Dysmenorrhoea may be classified as:

• Primary Dysmenorrhoea: Usually begins with the first menstrual period and is characterized by cramping lower abdominal pain, nausea, vomiting, headache, and faintness. The cause is thought to be due to excessive prostaglandin production that causes the uterus to contract painfully.
• Secondary Dysmenorrhoea: Usually affects older women who complain of congested ache with lower abdominal cramps which usually starts a few days before menstruation. It is associated with various disorders such as endometriosis, pelvic inflammatory disease, fibroids, or the presence of an IUD.

Drugs used in the treatment of primary dysmenorrhoea inhibit either ovulation or prostaglandin production.

Examples:

• NSAIDs such as mefenamic acid, ibuprofen, indomethacin, naproxen, piroxicam, and diclofenac
• Oral contraceptives
• Progestogens (norethisterone)
• Antispasmodics (hyoscine and drotaverin)

Menorrhagia

Menorrhagia is excessive menstrual bleeding. It may be associated with pelvic disorders such as fibroids, use of copper intrauterine devices, complications of pregnancy, malignant tumors, or dysfunctional bleeding. Menorrhagia may lead to iron deficiency anemia as well as impairing the quality of life of the patient.

Drugs used in the treatment of menorrhagia include:

• Combined oral contraceptives
• Mefenamic acid
• Norethisterone
• Medroxyprogesterone
• Tranexamic acid

Pre-menstrual Syndrome

Pre-menstrual syndrome is a cyclic recurrence of psychological and physical symptoms that affect women in the days before menstruation. Symptoms include increased irritability, depression, anxiety, bloating, headache, and breast tenderness.

Drugs used in the treatment of pre-menstrual syndrome include:

• Calcium supplements
• Pyridoxine (vitamin B6)
• Bromocriptine
• Spironolactone
• Mefenamic acid
• Fluoxetine
• Paroxetine
• Atenolol

Note:

• Bromocriptine, mefenamic acid, and spironolactone suppress physical symptoms.
• Fluoxetine, paroxetine, and atenolol mostly suppress psychological symptoms.

Menopause

Menopause is the occurrence of no menstrual periods for one year after the age of 40 or permanent cessation of ovulation after loss of ovarian activity.

Signs and Symptoms:

• Atrophic vaginitis
• Dyspareunia
• Complete cessation of menses
• Heavier bleeding
• Osteoporosis
• Anxiety
• Depression
• Insomnia
• Inability to concentrate
• Irritability
• Decreased libido
• Urinary incontinence
• Hot flashes
• Night sweats
• Headache
• Tiredness

Treatment involves the use of hormone replacement therapy and vaginal lubricants.

Norethisterone

Available Preparations:

• Tablets: 5 mg

Available Brands: Regulate-N®, Primolut-N®

Indications:

• Dysfunctional uterine bleeding
• Pre-menstrual syndrome
• Delay of menstruation
• Endometriosis
• Dysmenorrhoea
• Contraception

Contraindications:

• Pregnancy
• Severe liver impairment
• Previous or existing liver tumors
• Severe arterial disease
• Undiagnosed vaginal bleeding
• Porphyria
• Hypersensitivity to norethisterone

Dosage:

• Dysfunctional Bleeding:

1. To stop bleeding: 5 mg 3 times daily for 10 days
2. To prevent bleeding: 5 mg twice daily from day 19-26 of the cycle

• Dysmenorrhoea: 5 mg 3 times daily from day 5-24 for 3-4 cycles
• Endometriosis: 10-15 mg daily for 4-6 months or longer starting on day 5 of cycle (if spotting occurs, increase dose to 20-25 mg daily, reduce once bleeding has stopped)
• Delay of Menstruation: 5 mg 3 times daily starting 3 days before anticipated onset of menstruation (menstruation occurs 2-3 days after stopping)
• Pre-menstrual Syndrome: 5 mg 2-3 times daily from day 19-26 for seven cycles

Side Effects:

• Nausea
• Dizziness
• Headache
• Menstrual disturbance
• Weight gain
• Depression
• Insomnia

Dydrogesterone

Available Preparations:

• Tablets: 10 mg

Available Brands: Duphaston®

Indications:

• Endometriosis
• Dysfunctional uterine bleeding
• Pre-menstrual syndrome
• Habitual and threatened abortion
• Hormone replacement therapy
• Infertility
• Dysmenorrhoea
• Amenorrhoea
• Irregular cycles

Contraindications:

• Severe liver impairment
• Previous or existing liver tumors
• Severe arterial disease
• Undiagnosed vaginal bleeding
• Porphyria
• Known hypersensitivity to dydrogesterone

Dosage:

• Endometriosis: 10 mg 2-3 times daily from day 5-25 of cycle or continuously
• Dysfunctional Bleeding:

1. To stop bleeding: 10 mg twice daily (together with an estrogen) for 5-7 days
2. To prevent bleeding: 10 mg twice daily (together with an estrogen) from day 11-25 of cycle

• Dysmenorrhoea: 10 mg twice daily from day 5-25 of cycle
• Amenorrhoea: 10 mg twice daily from day 11-25 of cycle with estrogen therapy from day 1-25 of cycle
• Pre-menstrual Syndrome: 10 mg twice daily from day 12-26 of cycle
• Irregular Cycles: 10 mg twice daily from day 11-25 of cycle
• Habitual Abortion: 10 mg twice daily from day 11-25 of cycle until conception, then continuously until week 20 of pregnancy

Side Effects:

• Nausea
• Dizziness
• Headache
• Menstrual disturbance
• Weight gain
• Depression
• Insomnia