Tegsedi works by decreasing a protein called transthyretin (TTR, made primarily in the liver). Hereditary transthyretin-mediated amyloidosis (hATTR) is a rare condition in which abnormal deposits of TTR protein build up in many parts of the body, interfering with normal function.

Tegsedi injection is used to treat polyneuropathy (damage of multiple nerves throughout the body) in adults with hATTR. Tegsedi can help reduce symptoms such as pain, numbness, tingling, abnormal heartbeats, diarrhea, constipation, weakness, and problems with movement in your arms or legs.

Tegsedi is available only from a certified pharmacy under a special program.

Tegsedi can make it easier for you to bleed, even from a minor injury. Seek medical attention if you have bleeding that will not stop. Bleeding may also happen inside your body, such as in your stomach or intestines, or in your brain.

Bleeding may also happen inside your body. Call your doctor at once if you have signs such as severe headache, neck stiffness, bleeding in the whites of your eyes, black or bloody stools, pink or brown urine, or coughing up blood or vomit that looks like coffee grounds.

Before taking this medicine

You should not use Tegsedi if you are allergic to inotersen, or if you have:

• low levels of platelets in your blood (your doctor will test you for this); or

• kidney problems caused by using Tegsedi in the past.

To make sure Tegsedi is safe for you, tell your doctor if you have:

• a liver transplant;

• a bleeding or blood clotting disorder; or

• kidney disease.

Tell your doctor if you are pregnant or breastfeeding.

If you are pregnant, your name may be listed on a pregnancy registry to track the effects of Tegsedi on the baby.

Take Tegsedi exactly as prescribed by your doctor. Follow all directions on your prescription label and read all medication guides or instruction sheets.

Tegsedi is injected under the skin once weekly. Your care provider will show you where on your body to inject this medicine. Use a different place each time you give an injection. Do not inject into the same place two times in a row.

Read and carefully follow any Instructions for Use provided with your medicine. Ask your doctor or pharmacist if you don't understand all instructions.

Prepare an injection only when you are ready to give it. Do not use Tegsedi injection if it has changed color or has particles in it. Call your pharmacist for new medicine.

Use Tegsedi on the same day each week.

Your doctor may recommend that you take a vitamin A supplement. Take only the amount of vitamin A your doctor has prescribed. An overdose of vitamin A can cause vision problems or other serious side effects.

It is especially important to avoid taking too much vitamin A if you are pregnant.

Call your doctor at once if you have vision problems (especially at night) while you are taking vitamin A.

Tegsedi can make it easier for you to bleed, even from a minor injury. Seek medical attention if you have bleeding that will not stop. Bleeding may also happen inside your body, such as in your stomach or intestines, or in your brain.

You will need frequent medical tests. Your weekly injections may be delayed based on the results. You may also need medical tests for a short time after you stop using this medicine.

Store Tegsedi n the refrigerator. Protect from light and do not freeze. Keep each prefilled syringe in the carton until it is time for your injection.

Take a syringe out of the refrigerator and let it reach room temperature for 30 minutes before injecting your dose. Do not warm the syringe with hot water, sunlight, or a microwave.

Each prefilled syringe is for one use only. Throw it away after one use, even if there is still medicine left inside.

Use a needle and syringe only once and then place them in a puncture-proof "sharps" container. Follow state or local laws about how to dispose of this container. Keep it out of the reach of children and pets.

Usual Adult Dose of Tegsedi for Amyloidogenic Transthyretin Amyloidosis:

284 mg subcutaneously once a week

Comments: If a dose is missed and it is not within 2 days of next scheduled dose, the dose should be administered as soon as possible; if the missed dose is within 2 days of next scheduled dose, skip the missed dose and take the next scheduled dose on the scheduled day.

Use: For the treatment of polyneuropathy of hereditary transthyretin-mediated amyloidosis in adults.

You should not use Tegsedi if you are allergic to inotersen, or if you have:

• low levels of platelets in your blood (your doctor will test you for this); or

• kidney problems caused by using Tegsedi in the past.

To make sure Tegsedi is safe for you, tell your doctor if you have:

• a liver transplant;

• a bleeding or blood clotting disorder; or

• kidney disease.

Tell your doctor if you are pregnant or breastfeeding.

If you are pregnant, your name may be listed on a pregnancy registry to track the effects of Tegsedi on the baby.

Use the medicine as soon as you can, but skip the missed dose if your next dose is due in less than 2 days. Do not use two injections at one time.

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

Avoid injecting Tegsedi into skin that is red, bruised, injured, or irritated. Do not inject into skin areas with scars or tattoos.

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

Call your doctor at once if you have:

• sudden numbness or weakness (especially on one side of the body), slurred speech, drooping eyelids, problems with vision or balance;

• puffy eyes, swelling in your hands or feet, shortness of breath;

• vomiting, weight loss;

• back pain, muscle weakness;

• easy bruising, unusual bleeding (from your nose, gums, or a cut), purple or red spots under your skin;

• heavy menstrual bleeding;

• signs of bleeding inside your body severe headache, neck stiffness, bleeding in the whites of your eyes, black or bloody stools, pink or brown urine, or coughing up blood or vomit that looks like coffee grounds;

• liver problems - loss of appetite, stomach pain (upper right side), dark urine, jaundice (yellowing of the skin or eyes); or

• a reaction within 2 hours after an injection - headache, chest pain, flu-like symptoms, warmth or chills, redness on the palms of your hands, muscle or joint pain, uncontrolled muscle movements.

Common Tegsedi side effects may include:

• bleeding or bruising;

• nausea;

• fever;

• tiredness;

• headache; or

• pain or redness where an injection was given.

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.

Tegsedi can harm your kidneys, especially if you also use certain medicines for infections, cancer, osteoporosis, organ transplant rejection, bowel disorders, high blood pressure, or pain or arthritis (including Advil, Motrin, and Aleve).

Tell your doctor about all your other medicines, especially:

• a blood thinner - warfarin, Coumadin, Jantoven; or

• medicine used to prevent blood clots - such as adenosine, clopidogrel, prasugrel, ticagrelor, ticlopidine, and others.

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