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Combined Hormonal Contraceptives (21-day regimen)

Drug Class: Commonly Known As: Category:
Oral Contraceptives Mercilon, Microgynon, Yasmin, Liza, Belara Adult

Combined Hormonal Contraceptives (21-day regimen) - What is it for

Combined hormonal contraceptives contain two types of female hormones, estrogen and progestogen. This medication can help prevent ovulation and regulates other naturally occurring hormones in the body. When taken correctly, this prevents pregnancy and promotes regular menstrual bleeding.

There are typically two types of regimens depending on the medication you are prescribed.

This leaflet describes the combined hormonal contraceptives with a 21-day regimen, which includes:

  • Chlormadinone acetate 2mg, Ethinylestradiol 30mcg (e.g. Belara®)
  • Desogestrel 150mcg, Ethinylestradiol 20mcg (e.g. Mercilon®)
  • Levonorgestrel 150mcg, Ethinylestradiol 30mcg (e.g. Microgynon® 30)
  • Drospirenone 3mg, Ethinylestradiol 30mcg (e.g. Yasmin®, Liza®)

Combined Hormonal Contraceptives (21-day regimen) - Side Effects, Precautions, and Contraindications

What side effects can Combined Hormonal Contraceptives (21-day regimen) cause?

​Common side effects include:

  • Spotting or bleeding may occur between your periods during the first few months of taking oral contraceptives. However, if this continues after the third month, check with your doctor.
  • Nausea, vomiting, bloating and stomach cramps
    • Take the medication after food to reduce these side effects 
  • Breast tenderness 
  • Headache or migraine
    • You may take painkillers such as Paracetamol to manage headaches
  • Unable to tolerate contact lenses
  • Weight changes, mood swings
    • Take medication at the same time every day to avoid huge changes in the hormone levels in your body
  • Pigmentation of the skin
    • Apply sunblock when you are outdoors and avoid long hours of sun exposure

Inform your doctor if the side effects above become severe and bother you.

Using a combined hormonal medication increases a woman’s risk of developing blood clots compared to a woman not taking any combined hormonal contraception. The risk of developing blood clot in a vein is highest during the first year a woman uses the medication. Other risk factors of developing blood clots include smoking and obesity. However, the formation of blood clot is rare and the doctor would have considered the risks against the benefits before making the recommendation.

The symptoms of blood clot may include one or more of the following:

  • Any unusual sudden cough, breathlessness or difficulty in breathing
  • Severe pain in the chest which may reach the left arm
  • Severe pain in legs or swelling in either of your legs
  • Weakness or numbness in any part of your body
  • Change in your speech, including slurring of words
  • Change in your senses of hearing, smell or taste
  • Vision changes such as loss of vision or blurred vision

Other rare but serious effects that you may or may not experience:

  • Unusual, severe or long lasting headache or worsening of migraine
  • Dizziness or fainting
  • Severe pain in your abdomen
  • Dark urine or light coloured stools
  • Nausea and vomiting
  • Loss of appetite
  • Yellowing of eyes or skin

The symptoms of a drug allergy include one or more of the following:

  • Swollen face/eyes/lips/tongue
  • Difficulty in breathing
  • Itchy skin rashes over your whole body

If you experience any of these symptoms, you should stop your medication and see your healthcare professional immediately.

Before taking Combined Hormonal Contraceptives (21-day regimen), what precautions must I follow?

​Inform your healthcare professional if:

  • You are allergic to this medication or any of the other ingredients of this medication
  • You are pregnant, planning to become pregnant, or breastfeeding
  • You are taking any other medications, including supplements, traditional medications and herbal remedies
  • You have a history of or current medical conditions such as liver problems, stroke, clotting disorders, heart diseases, migraine headaches, epilepsy (fits), diabetes or cancer
  • You are a smoker

What food or medicine must I avoid when I take Combined Hormonal Contraceptives (21-day regimen)?

​Some medications including antibiotics and antifungals may affect how the medication works or be affected by the medication.  Please inform your other healthcare professionals about this medication which you are taking if you are seeing them for other medical conditions. 

Combined Hormonal Contraceptives (21-day regimen) - Dosage and How to Use

How should Combined Hormonal Contraceptives (21-day regimen) be used?

  • ​Do not stop taking your medication without checking with your healthcare professional.
  • If you are switching from other forms of contraception, please seek advice from your healthcare professional.
  • You should take this medication after food.
  • You may start taking this medication on the first or second day of your menses (if this is your first time taking hormonal contraceptives or restarting this medication after a break).
  • If you are also using it for contraceptive purposes, a barrier method of contraception (e.g. condoms), is recommended for the first 7 days of taking this medication for the first time.
  • You should take one tablet daily for 21 days in a row, preferably at the same time every day.  After completion of the pack, there will be 7 days where you do not need to take any tablets (7-day tablet-free interval), during which you will experience withdrawal bleeding (menses) within two to three days after the last tablet.
  • Start taking your next pack of medication after the 7-day tablet-free days, even if you are still having menstrual bleeding.

What should I do if I miss a dose?

If you forget to take a dose, you must follow the steps below to ensure that the contraceptive effect is not reduced.

Within 12 hours:
Take the missed tablet as soon as you remember. Take the next tablet at your usual time.

More than 12 hours:
If the missed tablet is within

  • Week 1 of the pack:
    • Take the missed tablet as soon as you remember, even if it means taking 2 tablets at the same time.
    • Continue to take your tablets at your usual time on the next day.
    • Use a barrier method such as a condom for the next 7 days.

If sexual intercourse happened in the previous 7 days, you may be pregnant. See your doctor for advice as soon as possible.

  • Week 2 of the pack:
    • Take the missed tablet as soon as you remember, even if it means taking 2 tablets at the same time.
    • Continue to take your tablets at your usual time on the next day.
    • If you have taken your tablets correctly in the 7 days before the first missed tablet, there is no need to use extra contraceptive precautions. However if this is not the case, or you have missed more than 1 tablet, use a barrier method such as a condom for the next 7 days.
  • Week 3 of the pack:  Depending on whether you have taken your tablets correctly in the 7 days before the first missed tablet, you would have to follow the following options: 
​No missed tablets in the last 7 days

​Take the missed tablet as soon as you remember, even if it means taking 2 tablets at the same time.

Continue to take your tablets at your usual time and start the next pack right away without the 7-day tablet free period i.e. no gap should be left between packs. Your menses may not come until the second pack is finished, but there is no need to worry. However, if your menses do not occur after the next pack is finished, you should take a pregnancy test to make sure you are not pregnant.
OR
Stop taking medication from the current pack for 7 days (7-day tablet free period). A withdrawal bleed (menses) usually occurs and then start a new pack after 7 days.

​Missed tablets in the last 7 days

​Take the missed tablet as soon as you remember, even if it means taking 2 tablets at the same time.

Continue to take your tablets at your usual time and start the next pack right away without the 7-day tablet free period i.e. no gap should be left between packs. Your menses may not come until the next pack is finished, but there is no need to worry. However, if your menses do not occur after the next pack is finished, you should take a pregnancy test to make sure you are not pregnant.
AND
Use a barrier method such as a condom for the next 7 days

**If you miss your period (especially with missed tablets), check with your doctor to find out if you are pregnant before continuing to take the next cycle of contraceptives.

If you vomit or suffer from diarrhea within 3 to 4 hours of taking this medication, the tablet may not be absorbed. This is considered a missed dose. You should then follow the instructions above.

What should I do if I overdose?

Combined Hormonal Contraceptives (21-day regimen) - Handling and Storage

How should I handle Combined Hormonal Contraceptives (21-day regimen) safely?

How should I store Combined Hormonal Contraceptives (21-day regimen)?

Keep away from children;#Keep in a cool, dry place, away from direct sunlight;#

How should I dispose of Combined Hormonal Contraceptives (21-day regimen) safely?

​Pack this medication into a black trash bag and seal it tightly before throwing into the rubbish chute or bin.

Combined Hormonal Contraceptives (21-day regimen) - Additional Information

  • Updated on Sunday, January 31, 2021
  • Article contributed by PSS National Medication Information Workgroup PSS National Medication Information Workgroup

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