DALFAMPRIDINE- dalfampridine tablet, film coated, extended release
Golden State Medical Supply, Inc.
Dalfampridine Extended-release tablets are indicated as a treatment to improve walking in adult patients with multiple sclerosis (MS). This was demonstrated by an increase in walking speed [see Clinical Studies (14)].
The maximum recommended dosage of dalfampridine extended-release tablet 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.
Dalfampridine Extended-release tablets can be taken with or without food. Administer tablets whole; do not divide, crush, chew, or dissolve dalfampridine extended-release tablets. If a dose is missed, patients should not take double or extra doses.
Estimated creatinine clearance (CrCl) should be known before initiating treatment with dalfampridine extended-release tablets, and monitored at least annually during treatment with dalfampridine extended-release tablets. CrCl can be estimated using the following equation (multiply by 0.85 for women):
|CrCl =||(140 — age) × weight ( kg)|
|SerumCr ( mg / dl)× 72|
In patients with mild renal impairment (CrCl 51 to 80 mL/min), dalfampridine extended-release tablets 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 dalfampridine extended-release tablets should be carefully considered against the risk of seizures in these patients [see Warnings and Precautions (5.2) and Clinical Pharmacology (12.4)].
Dalfampridine Extended-release tablets are contraindicated in patients with moderate or severe renal impairment (CrCl≤50 mL/min).
Dalfampridine Extended-release tablets are available in a 10 mg strength and is a white to off white, oval shaped, biconvex, film coated tablets, debossed with “FH6” on one side and plain on other side.
The use of dalfampridine extended-release tablets are contraindicated in the following conditions:
- History of seizure [see Warnings and Precautions (5.1)]
- Moderate or severe renal impairment (CrCl≤50 mL/min) [see Warnings and Precautions (5.2)]
- History of hypersensitivity to dalfampridine or 4-aminopyridine; reactions have included anaphylaxis [see Warnings and Precautions (5.4)]
Dalfampridine 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 to 14 weeks duration with dalfampridine extended-release tablets in patients with MS. In open label extension trials in MS patients, the incidence of seizures during treatment with dalfampridine extended-release tablets 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.
Dalfampridine Extended-release tablets have 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 dalfampridine extended-release tablets clinical studies. Permanently discontinue dalfampridine extended-release in patients who experience have a seizure while on treatment. Dalfampridine Extended-release tablets are contraindicated in patients with a history of seizures [see Contraindications (4)] .
Dalfampridine is eliminated through the kidneys primarily as unchanged drug [see Clinical Pharmacology (12.4)].
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, dalfampridine extended-release tablets are contraindicated in these patients [see Contraindications (4)] .
In patients with mild renal impairment (CrCl 51 to 80 mL/min), dalfampridine 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 [see Warnings and Precautions (5.1)] .
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 dalfampridine extended-release tablets in order to reduce the potential for dose-related adverse reactions.
Dalfampridine can cause anaphylaxis and severe allergic reactions. Signs and symptoms have included respiratory compromise, urticaria, and angioedema of the throat and or tongue. Dalfampridine Extended-release tablets are contraindicated in patients with a history of hypersensitivity to dalfampridine or 4-aminopyridine. Inform patients of the signs and symptoms of anaphylaxis and instruct them to discontinue dalfampridine extended-release tablets and seek immediate medical care should these signs and symptoms occur.
The following serious adverse reactions are described in more detail elsewhere in the labeling:
Because clinical studies are conducted under widely varying conditions, adverse reaction rates observed in the clinical studies of a drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in practice.
In three placebo-controlled clinical trials of up to 14 weeks duration, 4% (15/400) of patients treated with dalfampridine extended-release tablets 10 mg twice daily experienced one or more adverse reactions leading to discontinuation, compared to 2% (5/238) of placebo-treated patients. The adverse reactions leading to discontinuation of at least 2 patients treated with dalfampridine extended-release tablets and that led to discontinuation more frequently compared to placebo were headache (dalfampridine extended-release tablets 0.5%, placebo 0%), balance disorder (dalfampridine extended-release tablets 0.5%, placebo 0%), dizziness (dalfampridine extended-release tablets 0.5%, placebo 0%), and confusional state (dalfampridine extended-release tablets 0.3%, placebo 0%).
Table 1 lists adverse reactions that occurred in ≥2% of patients treated with dalfampridine extended-release tablets 10 mg twice daily, and more frequently than in placebo-treated patients, in controlled clinical trials.
|Adverse Reaction||Placebo (N=238)||Dalfampridine Extended-release Tablets 10 mg twice daily (N=400)|
|Urinary tract infection||8%||12%|
|Multiple sclerosis relapse||3%||4%|
Other Adverse Reactions
Dalfampridine Extended-release tablets have been evaluated in a total of 1,952 subjects, including 917 MS patients. A total of 741 patients have been treated with dalfampridine extended-release tablets for over six months, 501 for over one year and 352 for over two years. The experience in open-label clinical trials is consistent with the safety profile observed in the placebo-controlled clinical trials. As in controlled clinical trials, a dose-dependent increase in the incidence of seizures has been observed in open-label clinical trials with dalfampridine extended-release tablets in patients with MS as follows: dalfampridine extended-release tablets 10 mg twice daily 0.41 per 100 person-years (95% confidence interval 0.13 to 0.96); dalfampridine 15 mg twice daily 1.7 per 100 person-years (95% confidence interval 0.21 to 6.28).
The following adverse event has been identified during post-marketing experience with dalfampridine. Because adverse events are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure: vomiting.
Concurrent treatment with OCT2 inhibitors, such as cimetidine, may cause increased exposure to dalfampridine [see Clinical Pharmacology (12.3)] . 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 dalfampridine extended-release tablets should be considered against the risk of seizures in these patients.
No interaction was identified between dalfampridine and baclofen [see Clinical Pharmacology (12.3)] .
Pregnancy Category C
There are no adequate and well-controlled studies of dalfampridine extended-release tablets in pregnant women. Administration of dalfampridine to animals during pregnancy and lactation resulted in decreased offspring viability and growth at doses similar to the maximum recommended human dose (MRHD) of 20 mg/day. Dalfampridine Extended-release tablets should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
In developmental toxicity studies in rats and rabbits, dalfampridine was administered orally at doses up to 10 and 5 mg/kg/day, respectively, during the period of organogenesis. These doses are approximately 5 times the MRHD on a body surface area (mg/m 2) basis. No evidence of developmental toxicity was found in either species at the highest doses tested, which were maternally toxic. Oral administration of dalfampridine (at doses of 1, 3, and 9 to 6 mg/kg/day; high dose reduced during the second week of dosing) to rats throughout the pregnancy and lactation periods resulted in decreased offspring survival and growth. The no-effect dose for pre- and postnatal developmental toxicity in rats (1 mg/kg) is approximately 0.5 times the MRHD on a mg/m 2 basis.
The effect of dalfampridine extended-release tablets on labor and delivery in humans is unknown.
It is not known whether dalfampridine is excreted in human milk. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions in nursing infants from dalfampridine, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.
Safety and effectiveness of dalfampridine extended-release tablets in patients younger than 18 years of age have not been established.
Clinical studies of dalfampridine extended-release tablets did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently than younger subjects. A population PK analysis showed that dalfampridine clearance modestly decreased with increasing age, but not sufficiently to necessitate a modification of dose with age. Other reported clinical experience has identified no differences in responses between the elderly and younger patients.
Dalfampridine is known to be substantially excreted by the kidneys and the risk of adverse reactions, including seizures, is greater with increasing exposure of dalfampridine. Because elderly patients are more likely to have decreased renal function, it is particularly important to know the estimated creatinine clearance (CrCl) in these patients [see Warnings and Precautions (5.2)].
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