Dalfampridine

WHY is this medicine prescribed?

Dalfampridine is used to improve walking in people who have multiple sclerosis (MS; a disease in which the nerves do not function properly and may cause weakness, numbness, loss of muscle coordination, and problems with vision, speech, and bladder control). Dalfampridine may be used alone or with other medications that control the symptoms of MS. Dalfampridine is in a class of medications called potassium channel blockers. It works by strengthening the signals sent by the brain through nerves that have been damaged by MS.

Are there OTHER USES for this medicine?

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

HOW should this medicine be used?

Dalfampridine comes as an extended-release tablet to take by mouth. It is usually taken with or without food twice a day. Space your doses so that you take one dose approximately every 12 hours, and take dalfampridine at around the same times every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take dalfampridine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Swallow the tablets whole; do not split, chew, dissolve, or crush them.

Dalfampridine is not available in pharmacies. You can only get dalfampridine through the mail from a specialty pharmacy. Ask your doctor if you have any questions about receiving your medication.

Dalfampridine may help improve your walking only as long as you continue to take it. It may take 6 weeks or longer before you feel the full benefit of dalfampridine. Continue to take dalfampridine even if you feel well. Do not stop taking dalfampridine without talking to your doctor.

Your doctor or pharmacist will give you the manufacturer's patient information sheet (Medication Guide) when you begin treatment with dalfampridine and each time you refill your prescription. Read the information carefully and ask your doctor or pharmacist if you have any questions. You can also visit the Food and Drug Administration (FDA) website (http://www.fda.gov/Drugs/DrugSafety/ucm085729.htm) to obtain the Medication Guide.

What SPECIAL PRECAUTIONS should I follow?

Before taking dalfampridine,

• tell your doctor and pharmacist if you are allergic to dalfampridine, 4-aminopyridine (4-AP, fampridine) that has been prepared by your pharmacist, any other medications, or any of the ingredients in dalfampridine tablets. Ask your pharmacist or check the Medication Guide for a list of the ingredients.

• tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any other form of 4-aminopyridine (4-AP, fampridine) that has been prepared by your pharmacist. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.

• tell your doctor if you have ever had a seizure and if you have kidney disease. Your doctor will probably tell you not to take dalfampridine.

• tell your doctor if you have ever had an abnormal electroencephalogram (EEG, a test that measures electrical activity in the brain).

• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking dalfampridine, call your doctor.

What SPECIAL DIETARY instructions should I follow?

Unless your doctor tells you otherwise, continue your normal diet.

What should I do IF I FORGET to take a dose?

Skip the missed dose and continue your regular dosing schedule. Do not take more than two doses of dalfampridine in a 24-hour period and do not take a double dose to make up for a missed one.

What SIDE EFFECTS can this medicine cause?

Dalfampridine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• difficulty falling asleep or staying asleep
• dizziness
• headache
• nausea
• heartburn
• constipation
• weakness
• back pain
• difficulty with balance
• worsening of multiple sclerosis symptoms
• burning, tingling, or itching of the skin
• pain or irritation in the nose or throat

Some side effects can be serious. If you experience any of these symptoms, call your doctor or get emergency medical treatment immediately:

• seizures
• painful, difficult, or frequent urination
• fever or chills
• pain in the back, side, or stomach

Dalfampridine may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

What should I know about STORAGE and DISPOSAL of this medication?

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org

What should I do in case of OVERDOSE?

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

Symptoms of overdose may include the following:

• confusion
• seizures
• uncontrollable shaking of a part of your body
• sweating
• memory loss
• speech problems
• weakness

What OTHER INFORMATION should I know?

Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your body's response to dalfampridine.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.