Twirla patches contain a combination of two female hormones, ethinyl estradiol and levonorgestrel.

Twirla is a prescription medicine used as birth control to prevent pregnancy.

Twirla is for use by women with a BMI less than 30 kg/m2 who can become pregnant. Twirla patches have been shown to have reduced effectiveness in women with a BMI in the range 25 to 30 kg/m2.

You should not use Twirla if you have: uncontrolled high blood pressure, heart disease, coronary artery disease, health problems caused by diabetes (such as damage to your kidneys, eyes, nerves, or blood vessels), undiagnosed vaginal bleeding, liver disease or liver cancer, severe migraine headaches, if you also take certain hepatitis C medication, if you will have major surgery, if you smoke and are over 35, or if you have ever had a heart attack, a stroke, a blood clot, jaundice caused by pregnancy or this medicine, or cancer of the breast, uterus/cervix, or vagina.

Using Twirla can increase your risk of blood clots, stroke, or heart attack (especially if you smoke). You should not use this medicine if you smoke and are over 35 years old.

Use Twirla exactly as prescribed by your doctor. Follow all directions on your prescription label and read all medication guides or instruction sheets. Do not wear more than one skin patch at a time. Never cut a skin patch.

Apply a new Twirla skin patch every 7 days for 3 weeks in a row (21 days). Change your patch on the same day of the week, and wear each patch for 7 full days. On Day 22, remove the patch and wait 7 days before applying a new patch. Your patch-free week should not be longer than 7 days.

Apply the Twirla patch to clean, dry skin that is not broken or irritated and won't be rubbed by tight clothing (such as a waistband).

You may need to use back-up birth control (such as a condom/diaphragm with spermicide) when you first start using this medicine, or if a patch has become loose or has been off for longer than 1 day. Read and carefully follow all instructions about what to do if a patch gets loose or falls off, or if you forget to change your patch on time.

If you need major surgery or will be on long-term bed rest, do not use wear a skin patch for at least 4 weeks ahead of time and 2 weeks afterward.

You may have breakthrough bleeding, especially during the first 3 months. Tell your doctor if this bleeding is very heavy, or if you miss 2 or more regular periods.

Store Twirla patches at room temperature away from moisture and heat. Do not freeze or refrigerate. Keep each patch in its foil pouch until you are ready to apply it.

After removing a skin patch fold it in half, sticky side in, and throw it away in a place where children and pets cannot get to it. Do not flush a used patch down the toilet.

Twirla patches are used in a 28-day (four-week) cycle. A new patch is applied and worn for seven days for three consecutive weeks (Weeks 1, 2, and 3). No Twirla patch is worn during Week 4 (the patch-free week), when withdrawal bleeding is expected.

On the day after Week 4 ends, a new 28-day cycle is started by applying a new Twirla patch. Under no circumstances should there be more than a 7-day patch-free interval between each 28 day dosing cycle.

Using Twirla can increase your risk of blood clots, stroke, or heart attack. You are even more at risk if you have high blood pressure, diabetes, high cholesterol, or if you are overweight

Smoking can greatly increase your risk of blood clots, stroke, or heart attack. Your risk increases the older you are and the more you smoke. You should not use Twirla patches if you smoke and are over 35 years old.

Your risk of serious blood clot may be higher with the use of birth control skin patches than with the use of birth control pills.

You should not use Twirla if you have:

• untreated or uncontrolled high blood pressure;

• heart disease (chest pain, coronary artery disease, history of heart attack, stroke, or blood clot);

• an increased risk of having blood clots due to a heart problem or a hereditary blood disorder;

• diabetes (and you are over 35, have high blood pressure, have had diabetes longer than 20 years, or if diabetes has caused damage to your kidneys, eyes, nerves, or blood vessels);

• a history of hormone-related cancer, or cancer of the breast, uterus/cervix, or vagina;

• unusual vaginal bleeding that has not been checked by a doctor;

• liver disease or liver cancer;

• severe migraine headaches (with aura, numbness, weakness, or vision changes), especially if you are older than 35; or

• if you take any hepatitis C medication containing ombitasvir/paritaprevir/ritonavir (Viekira).

To make sure Twirla patches are safe for you, tell your doctor if you have ever had

• heart disease, high blood pressure, or if you are prone to having blood clots;

• high cholesterol that is not controlled;

• depression;

• migraine headache;

• diabetes, gallbladder disease;

• jaundice caused by pregnancy or hormonal birth control;

• hereditary angioedema;

• irregular menstrual cycles; or

• dark patches of skin on your face (chloasma).

Do not use this medicine if you are pregnant. You may need to have a negative pregnancy test before using Twirla. Tell your doctor if you think you may be pregnant.

Ethinyl estradiol and levonorgestrel can slow breast milk production. You should not breastfeed while using this medicine.

During your patch-free week, do not go without wearing a patch for longer than 7 days. Missing a dose increases your risk of becoming pregnant and you may need to use back-up birth control. Call your doctor if you miss a period for 2 months in a row.

If you forget to apply a Twirla patch at the start of a new cycle:

• Apply a patch as soon as you remember and start a new cycle on that day (3 weeks wearing a weekly patch, 1 week off). Use back-up birth control such as a condom/diaphragm with spermicide during the first week of your new cycle.

If you forget to change your patch during the 3-week wearing time:

• If it has been 24-48 hours since your scheduled patch change, apply a new patch and change it on your regular change day.

• If it has been more than 48 hours since your scheduled patch change, apply a new patch and start a new cycle on that day (3 weeks wearing a weekly patch, 1 week off). Use back-up birth control during the first week.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Do not smoke while using Twirla patches, especially if you are older than 35 years of age.

Grapefruit may interact with ethinyl estradiol and levonorgestrel and lead to unwanted side effects. Avoid the use of grapefruit products.

This medicine may cause darkening of your facial skin (chloasma), especially if you've ever had chloasma during a pregnancy. Avoid sunlight or tanning beds. Use sunscreen (SPF 30 or higher) when you are outdoors.

Avoid applying makeup, lotions, powders, or oils to the skin where you apply a skin patch.

Get emergency medical help if you have signs of an allergic reaction to Twirla: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Stop using this medicine and call your doctor at once if you have:

• signs of a stroke - sudden numbness or weakness (especially on one side of the body), severe headache, problems with vision or speech;

• signs of a blood clot - sudden vision loss, stabbing chest pain, feeling short of breath, coughing up blood, swelling or pain in an arm or leg;

• heart attack symptoms - chest pain or pressure, pain spreading to your jaw or shoulder, nausea, sweating;

• severe headache, pounding in your neck or ears;

• jaundice (yellowing of the skin or eyes);

• swelling in your hands, ankles, or feet;

• a change in the pattern or severity of migraine headaches; or

• symptoms of depression - sleep problems, weakness, tired feeling, mood changes.

Common Twirla side effects may include:

• menstrual cramps;

• nausea;

• weight gain;

• headache; or

• skin reactions where a patch was worn - bumps, redness, skin color changes, itching, rash, dryness, pain, swelling, bleeding.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Many drugs can interact with ethinyl estradiol and levonorgestrel, and some drugs can make hormonal birth control less effective, which may result in pregnancy. Tell your doctor about all your other medicines, especially:

• acetaminophen, aprepitant, ascorbic acid (vitamin C), bosentan, levothyroxine, St. John's wort;

• antibiotic or antifungal medicine - fluconazole, griseofulvin, itraconazole, ketoconazole, rifabutin, rifampin, voriconazole;

• antiviral medicine to treat HIV or hepatitis C - atazanavir, boceprevir, darunavir, efavirenz, etravirine, fosamprenavir, indinavir, lopinavir, nelfinavir, nevirapine, ritonavir, telaprevir, tipranavir;

• cholesterol medicine - atorvastatin, rosuvastatin; or

• seizure medicine - carbamazepine, felbamate, lamotrigine, oxcarbazepine, phenobarbital, phenytoin, rufinamide, topiramate.

This list is not complete and many Other drugs may interact with ethinyl estradiol and levonorgestrel. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.