Twirla

Pregnancy Prevention

Twirla is a birth control patch used by females of reproductive potential to prevent pregnancy. It is a transdermal system, meaning the medication is absorbed through the skin and into the bloodstream. It is typically prescribed for women who prefer a weekly patch over a daily pill.

BMI Considerations

The effectiveness of Twirla is related to an individual's Body Mass Index (BMI). Healthcare providers use BMI to determine if this method of contraception is appropriate:

• BMI under 25: The patch is most effective at preventing pregnancy in women within this range.
• BMI between 25 and 30: The patch may be less effective in women with a BMI in this category compared to those with a lower BMI.
• BMI of 30 or greater: Twirla is not recommended for women who are obese (BMI of 30 or more). In this group, the patch is less effective and carries an increased risk of serious safety issues, such as blood clots.

Twirla is intended only for the prevention of pregnancy. It does not provide protection against HIV infection or other sexually transmitted diseases.

Mechanism of Action

Twirla is a transdermal system, commonly known as a patch, that delivers a continuous flow of two hormones: levonorgestrel (a progestin) and ethinyl estradiol (an estrogen). These hormones are absorbed through the skin and enter the bloodstream directly to regulate the reproductive cycle.

The medication prevents pregnancy through several different methods:

• Inhibiting Ovulation: The primary function of the hormones is to signal the brain to stop the ovaries from releasing a mature egg each month. If no egg is released, fertilization cannot occur.
• Cervical Mucus Changes: The hormones cause the mucus in the cervix to become thicker and stickier. This creates a physical barrier that makes it much harder for sperm to swim into the uterus to reach an egg.
• Uterine Lining Alterations: The patch changes the lining of the uterus, making it thinner. This change makes the environment less receptive for a fertilized egg to implant and develop.

Common Side Effects

Many individuals using Twirla experience mild side effects as their bodies adjust to the hormones. These common issues often include:

• Skin reactions at the patch site, such as redness, itching, or a rash
• Nausea or vomiting
• Headache
• Breast tenderness or pain
• Menstrual cramps or painful periods
• Weight gain
• Mood changes or depression
• Irregular bleeding or spotting between periods

Serious Side Effects

Twirla can cause serious, potentially life-threatening health problems. Seek medical attention immediately if you experience symptoms of the following:

• Blood clots: Signs may include sudden leg pain, swelling, warmth in the limb, chest pain, or shortness of breath.
• Heart attack or stroke: Symptoms include sudden numbness or weakness (especially on one side of the body), severe headache, vision changes, or crushing chest pressure.
• Liver problems: Indicators include yellowing of the skin or eyes (jaundice), dark urine, or pain in the upper right abdomen.
• Gallbladder disease: May cause severe stomach pain, fever, and nausea.
• High blood pressure: New or worsening hypertension.
• Severe allergic reactions: Symptoms include hives, swelling of the face or throat, and difficulty breathing.

Boxed Warning: Smoking and Cardiovascular Risks

Cigarette smoking increases the risk of serious cardiovascular side effects from combined hormonal contraceptives. This risk increases with age, particularly in those over 35 years old, and with the number of cigarettes smoked. For this reason, combined hormonal contraceptives are generally not recommended for individuals over 35 who smoke.

Body Mass Index (BMI) Limitations

Twirla is contraindicated in individuals with a BMI of 30 kg/m² or greater. Clinical trials showed that this medication is less effective and carries a higher risk of blood clots (venous thromboembolism) in people with higher BMIs. Effectiveness may also be reduced in individuals with a BMI between 25 and 30 kg/m².

Blood Clots and Cardiovascular Events

The use of Twirla increases the risk of serious blood clotting conditions, including:

• Deep vein thrombosis (DVT)
• Pulmonary embolism (PE)
• Stroke
• Myocardial infarction (heart attack)

The risk is highest during the first year of use or when restarting hormonal contraception after a break of four weeks or longer.

Other Contraindications

Twirla should not be used by individuals with certain medical conditions, including:

• A high risk of arterial or venous thrombotic diseases.
• Current or past breast cancer or other estrogen-sensitive cancers.
• Liver tumors (benign or malignant) or active liver disease.
• Undiagnosed abnormal uterine bleeding.
• Pregnancy.
• Use of certain Hepatitis C drug combinations.

Additional Precautions

• Liver Disease: Discontinuation is necessary if jaundice or acute liver impairment occurs.
• High Blood Pressure: Blood pressure should be monitored regularly, as hormonal contraceptives can cause elevations.
• Gallbladder Disease: There is an increased risk of gallbladder disease in users of combined hormonal contraceptives.
• Migraines: Use should be discontinued if there is a new onset of severe headaches or an increase in the frequency or severity of migraines.
• Metabolic Effects: Individuals with prediabetes or diabetes should be monitored closely for changes in glucose tolerance.

Pregnancy

Twirla is a hormonal patch used to prevent pregnancy and should not be used by individuals who are already pregnant. If pregnancy occurs while using the patch, it should be removed and discontinued immediately. Current evidence suggests that the accidental use of hormonal contraceptives during early pregnancy does not significantly increase the risk of birth defects.

Breastfeeding

The use of hormonal contraceptives containing estrogen, such as Twirla, can decrease the quantity and quality of breast milk. Small amounts of the active hormones may also pass into breast milk and could potentially affect a nursing infant. Healthcare providers generally recommend using other forms of birth control until a nursing infant is completely weaned. It is important to discuss the risks and benefits of various contraceptive methods with a clinician while breastfeeding.

Dosage Form

Twirla is available as a transdermal system, which is a patch applied to the skin. The patch is round, beige, and consists of three layers designed to deliver medication through the skin and into the bloodstream.

Strengths

This medication is provided in a single strength. It contains a combination of two active ingredients:

• Levonorgestrel (a progestin)
• Ethinyl estradiol (an estrogen)

The system is designed to release a specific daily dose of these hormones continuously over a period of seven days. Each patch is worn for one week before being replaced.

FDA Approval Status

The U.S. Food and Drug Administration (FDA) approved Twirla in February 2020. It is a combined hormonal contraceptive patch containing the active ingredients levonorgestrel and ethinyl estradiol.

Approved Indications

Twirla is indicated for use by women of reproductive potential to prevent pregnancy. Its use is specifically restricted based on the user's body mass index (BMI) due to safety and efficacy concerns identified during clinical trials.

Boxed Warnings

The FDA has required a Boxed Warning for Twirla regarding the following risks:

• Cigarette Smoking and Cardiovascular Events: Cigarette smoking increases the risk of serious cardiovascular events from combined hormonal contraceptive use. This risk increases with age, particularly in women over 35 years of age, and with the number of cigarettes smoked. For this reason, Twirla is contraindicated in women over 35 who smoke.
• Body Mass Index (BMI) and Thromboembolism: Twirla is contraindicated in women with a BMI of 30 kg/m² or greater. Clinical data showed that women in this BMI category have an increased risk of venous thromboembolism (blood clots) and that the patch is less effective in preventing pregnancy compared to women with a lower BMI.

Limitations of Use

Twirla may have reduced effectiveness in women with a BMI of 25 kg/m² or greater but less than 30 kg/m². Healthcare providers are advised to consider this limitation when prescribing the patch to individuals in this weight range.

How Twirla Prevents Pregnancy

Twirla works as a combined hormonal contraceptive. It uses two hormones, levonorgestrel and ethinyl estradiol, to prevent pregnancy in three primary ways:

• Stopping ovulation: It prevents the ovaries from releasing an egg each month.
• Thickening cervical mucus: This makes it harder for sperm to reach an egg.
• Changing the uterine lining: It thins the lining of the uterus, making it less likely for a fertilized egg to attach.

Effectiveness and Weight Considerations

While Twirla is an effective method of birth control, its reliability can be affected by body weight. Clinical studies have shown that the patch may be less effective in women with a body mass index (BMI) of 25 or more. Twirla should not be used by women with a BMI of 30 or more, as the risk of pregnancy is higher and there is an increased risk of serious side effects like blood clots.

Usage for Contraception

To maintain its effectiveness as birth control, the patch must be replaced on the same day each week for three consecutive weeks. This is followed by a seven-day patch-free interval during which a withdrawal bleed (similar to a period) usually occurs. It is important to apply the patch to clean, dry skin on the abdomen, buttock, or upper torso (excluding the breasts).