AMPYRA (dalfampridine) is a potassium channel blocker, available in a 10 mg tablet strength. Each tablet contains 10 mg dalfampridine, formulated as an extended-release tablet for twice-daily oral administration. Dalfampridine is also known by its chemical name, 4-aminopyridine, with the following structure: AMPYRA (dalfampridine) extended-release tablets are available in a 10 mg strength and are white to off-white, biconvex, oval shaped, film-coated, non-scored tablets with flat edge, debossed with "A10" on one side, containing 10 mg of dalfampridine. Inactive ingredients consist of colloidal silicon dioxide, hydroxypropyl methylcellulose, magnesium stearate, microcrystalline cellulose, polyethylene glycol, and titanium dioxide. Dalfampridine is a fine white powder with a molecular weight of 94.1, CAS 504-24-5, and a molecular formula of C 5 H 6 N 2 . At ambient conditions, dalfampridine is soluble in water, methanol, acetone, tetrahydrofuran, isopropanol, acetonitrile, N,N-dimethylformamide, dimethylsulfoxide, and ethanol. Chemical Structure

AMPYRA is indicated as a treatment to improve walking in adult patients with multiple sclerosis (MS). This was demonstrated by an increase in walking speed . AMPYRA ® (dalfampridine) is a potassium channel blocker indicated to improve walking in adult patients with multiple sclerosis (MS). This was demonstrated by an increase in walking speed ( 1 , 14 ).

AMPYRA is available in a 10 mg strength and is a film-coated, white to off-white, biconvex, oval shaped, non-scored tablet with flat edge, debossed with "A10" on one side. 10 mg tablets

The maximum recommended dosage is 10 mg twice daily (approximately 12 hours apart). There is no evidence of additional benefit with doses greater than 10 mg twice daily. Adverse reactions, including seizures, were more frequent at higher doses. Take with or without food. Administer tablets whole; do not divide, crush, chew, or dissolve Patients should not take double or extra doses if they miss a dose. Estimated creatinine clearance (CrCl) should be known before initiating treatment with AMPYRA. In patients with mild renal impairment (CrCl 51–80 mL/min), AMPYRA may reach plasma levels associated with a greater risk of seizures, and the potential benefits of AMPYRA should be carefully considered against the risk of seizures in these patients ( 2.3 , 5.2 , 8.6 ) 2.1 Dosage Information The maximum recommended dosage of AMPYRA is one 10 mg tablet twice daily and should not be exceeded. Take doses approximately 12 hours apart. There is no evidence of additional benefit at doses greater than 10 mg twice daily. Adverse reactions, including seizures, and discontinuations because of adverse reactions were more frequent at higher doses

Administration Instructions AMPYRA can be taken with or without food. Administer tablets whole; do not divide, crush, chew, or dissolve AMPYRA tablets. If a dose is missed, patients should not take double or extra doses

Renal Monitoring Prior to and During Treatment Estimated creatinine clearance (CrCl) should be known before initiating treatment with AMPYRA, and monitored at least annually during treatment with AMPYRA. CrCl can be estimated using the following equation (multiply by 0.85 for women): crcl-eqn-102716.jpg 2.4 Dosage in Patients with Renal Impairment In patients with mild renal impairment (CrCl 51–80 mL/min), AMPYRA plasma levels may approach those seen at a dose of 15 mg twice daily, a dose that is 1.5 times the maximum recommended dose and may be associated with an increased risk of seizures. As mild renal impairment is common after age 50, estimating CrCl is particularly important in these patients. The potential benefits of AMPYRA should be carefully considered against the risk of seizures in these patients [ see Warnings and Precautions and Clinical Pharmacology ]. AMPYRA is contraindicated in patients with moderate or severe renal impairment (CrCl≤50 mL/min).

AMPYRA can cause seizures; the risk of seizures increases with increasing AMPYRA doses; discontinue AMPYRA and do not restart if a seizure occurs Avoid concomitant use with other forms of 4-aminopyridine (4-AP, fampridine), since the active ingredient is the same AMPYRA can cause anaphylaxis. Discontinue and do not restart AMPYRA if this occurs 5.1 Seizures AMPYRA can cause seizures. Increased incidence of seizures has been observed at 20 mg twice daily (2 times the maximum recommended dosage) in controlled clinical studies of 9–14 weeks duration with dalfampridine in patients with MS. In open-label extension trials in MS patients, the incidence of seizures during treatment with dalfampridine 15 mg twice daily (1.7/100PY) was over 4 times higher than the incidence during treatment with 10 mg twice daily (0.4/100PY). In the post-marketing period seizures have been reported. The majority of seizures occurred at the recommended dose and in patients without a history of seizures, and generally within days to weeks of starting therapy. AMPYRA has not been evaluated in patients with a history of seizures or with evidence of epileptiform activity on an EEG, as these patients were excluded from clinical trials. The risk of seizures in patients with epileptiform activity on an EEG is unknown, and could be substantially higher than that observed in AMPYRA clinical studies. Permanently discontinue AMPYRA in patients who have a seizure while on treatment. AMPYRA is contraindicated in patients with a history of seizures

Renal Impairment AMPYRA is eliminated through the kidneys primarily as unchanged drug . Because patients with moderate to severe renal impairment (CrCl ≤50mL/min) would require a dose lower than 10 mg twice daily and no strength smaller than 10 mg is available, AMPYRA is contraindicated in these patients . In patients with mild renal impairment (CrCl 51–80 mL/min), AMPYRA plasma levels may approach those seen at a dose of 15 mg twice daily, a dose that may be associated with an increased risk of seizures

Concurrent Treatment with Other Forms of 4-Aminopyridine Avoid concomitant use with other forms of 4-aminopyridine (4-AP, fampridine) since the active ingredient is the same. Instruct patients to discontinue use of any product containing 4-aminopyridine prior to initiating treatment with AMPYRA in order to reduce the potential for dose-related adverse reactions

Anaphylaxis AMPYRA can cause anaphylaxis and severe allergic reactions. Signs and symptoms have included respiratory compromise, urticaria, and angioedema of the throat and or tongue. AMPYRA is contraindicated in patients with a history of hypersensitivity to AMPYRA or 4-aminopyridine. Inform patients of the signs and symptoms of anaphylaxis and instruct them to discontinue AMPYRA and seek immediate medical care should these signs and symptoms occur.

OCT2 Inhibitors: Concomitant use may cause an increased exposure and potential risk of seizures 7.1 OCT2 Inhibitors Concurrent treatment with OCT2 inhibitors, such as cimetidine, may cause increased exposure to dalfampridine [ see Clinical Pharmacology ]. Elevated levels of dalfampridine increase the risk of seizures [ see Warnings and Precautions (5.1 , 5.2) ]. The potential benefits of taking OCT2 inhibitors concurrently with AMPYRA should be considered against the risk of seizures in these patients

Baclofen No interaction was identified between dalfampridine and baclofen .