Dalfampridine - Empowering Multiple Sclerosis With Enhanced Mobility

Overview

Dalfampridine is typically prescribed alone or in combination with other drugs to help reduce or alleviate the symptoms of multiple sclerosis (MS). It is prescribed to improve motor function and walking in people with MS. This medication is the first drug approved for use, specifically in improving mobility in MS patients.

Multiple sclerosis is a degenerative condition (due to degenerating cell changes influencing the tissues and organs) in which the myelin sheath (insulating cover) of the nerve cells in the brain is damaged. Such damage to the nerve fiber disrupts the ability of certain parts of the central nervous system (CNS) to transmit signals (messengers), leading to a range of signs and symptoms with physical, psychiatric, and mental health problems.

The Food and Drug Administration (FDA) of the United States approved Dalfampridine on January 22, 2010.

Drug group

Potassium channel blockers are a group of drugs used to treat arrhythmias, an abnormal heartbeat. These drugs are also used to improve movement or mobility in patients with multiple sclerosis. These drugs act by inhibiting the action of potassium efflux through cell membranes. Hence, these agents interfere with the conduction or electrical activity through potassium channels.

Available doses and dosage forms:

• Dalfampridine is a potassium channel blocker available as a 10-milligram tablet.

• Dalfampridine is an extended-release tablet that is white to off-white in color and oval biconvex in shape.

For Patients

How Does Dalfampridine Work?

The primary treatment for multiple sclerosis typically involves the use of immunosuppressants. These, along with physiotherapy, help control symptoms and slow disease progression while providing relief to patients with multiple sclerosis. Some also receive chemotherapy, steroids, or anti-inflammatory drugs. Physical exercise and counseling are essential tools to treat symptoms of multiple sclerosis.

Dalfampridine is a neurofunctional modifier used to enhance walking in individuals with multiple sclerosis. When the nerves do not function normally, patients may experience loss of muscle coordination, numbness, weakness, impaired vision, speech discrepancy, and problems with bladder control. Dalfampridine is either used alone or in conjunction with other medications that help relieve the symptoms of multiple sclerosis. It belongs to the group of pharmaceutical drugs called the potassium channel blockers. This medication works by reinforcing the signals sent by the brain through the nervous system that have been deactivated or damaged by multiple sclerosis.

What Is the Dosage of Dalfampridine?

Dalfampridine comes in extended-release tablet form. The maximum adult dosage for multiple sclerosis is 10 milligrams orally every 12 hours. The adults and geriatrics are usually advised to take a 10-milligram Dalfampridine tablet twice a day, 12 hours apart. This can be taken with or without the meal.

What Are the Things to Inform the Doctor Before Taking the Drug?

Inform the doctor if :

• You are hypersensitive to Dalfampridine, 4-aminopyridine, or other ingredients in the medication.

• You have moderate to severe kidney disease.

• You currently or previously had seizure attacks.

• You take other medications, including over-the-counter medications, prescription drugs, nutritional supplements, vitamins, and herbal products.

• You are taking other forms of 4-aminopyridine. The doctor might change the medication's dosage or closely monitor the person for side effects.

• Have you ever had an irregular or abnormal electroencephalogram (EEG), a test that measures the brain's electrical activity?

• You are pregnant or have any plans to conceive. Call and tell the doctor if one gets pregnant while taking this medication.

• Be sure to inform the doctor if you are breastfeeding.

How Is Dalfampridine Administered?

• Follow the doctor’s directions and prescription label guidelines for taking Dalfampridine correctly.

• One must use the medication exactly as directed.

• Take the medications 12 hours apart.

• One should not take more than two Dalfampridine tablets in a day or within a 24-hour period.

• Dalfampridine can be taken with or without a meal.

• Swallow the Dalfampridine tablet as a whole. Do not chew, crush, or break the tablet.

• Breaking the Dalfampridine tablet can cause the release of too much of the drug at one time, increasing the risk of seizure.

• Do not take the tablet that has been broken or crushed.

What Are the Uses of Dalfampridine?

Dalfampridine is used mainly for multiple sclerosis (MS) treatment. These are its primary applications:

• Improved walking capability: Dalfampridine has marketing authorization for use in improving walking abilities in patients with multiple sclerosis. It also contributes to increasing general mobility and walking rate.

• Conduction of nerves: It works by blocking potassium channels and can assist axons in overcoming the problem of impulse transmission resulting from nerve demyelination, allowing them to interact with other nerves.

• Managing symptoms: In addition to walking, Dalfampridine is used by many people with Multiple Sclerosis, and may lead to an improvement in other symptoms, such as weakness and fatigue.

Warnings and Precautions:

• Your doctor should follow up and evaluate you at regular intervals to ensure this medication works effectively. Blood and urine may be necessary to search for any signs of harm.

• If you have a seizure while taking this medication, you should then talk to your doctor.

• Dalfampridine should not be taken together with other aminopyridine drugs, such as compounded 4-AP or Fampridine. Corticosteroids and salicylic acid may interact, increasing the likelihood of more severe side effects.

• Severe allergic reactions, such as anaphylactic reactions, which are dangerous if not well managed, should be expected when using this medication. These side effects may include dizziness, lightheadedness, or a persistently spinning sensation in the room or within your body.

• As with any medication, do not operate any automobiles or machines or do other tasks that need alertness until you know how this drug affects you.

• Avoid using other substances without consulting your doctor. This includes, but is not limited to, over-the-counter (OTC) drugs, prescription drugs, vitamins, and herbal supplements.

What Are the Side Effects of Dalfampridine?

Dalfampridine can induce allergic reactions in people hypersensitive to the drug. If you experience any of the following side effects, seek emergency medical care promptly.

• Hives.

• Rashes.

• Difficulty breathing.

• Swelling of the face.

• Swelling of the lips, throat, or tongue.

Moreover, one should stop taking the medication and seek professional help straight away if experiencing any seizures.

Common side effects:

The following side effects are common in people taking Dalfampridine. These can resolve on their own with time. However, one should reach out to a doctor and seek medical care if any of the symptoms persist or are distressing daily life.

• Weakness.

• Multiple sclerosis relapse.

• Dizziness.

• Balance problems.

• Sleep problems, including insomnia.

• Headache.

• Back pain.

• Stuffy nose.

• Sinus pain.

• Sinus throat.

• Nausea.

• Constipation.

• Stomach upset.

• Numbness or tingling sensation.

• Painful urination.

Serious side effects:

Dalfampridine can cause serious side effects in some instances. Call the healthcare provider and inform them if you are experiencing any of the following issues.

• Pain or burning sensation while urinating.

• Relapse or worsening of multiple sclerosis symptoms.

Dietary considerations:

People taking Dalfampridine can follow the classic diet guidelines unless their doctor makes any changes or restrictions. Discuss with your healthcare providers the restrictions, beverages, food, and activities to avoid while taking Dalfampridine medication.

Missed dose:

Take the missed dose as soon as you remember. You can skip the missed dose and proceed with the next one at the regularly scheduled time, if it is almost time for the next dose. Never use two doses of Dalfampridine at one time for compensation.

Overdose:

Seek poison helpline services or emergency medical attention promptly if one has taken an overdose of Dalfampridine. Overdose can cause undesirable reactions, including confusion and seizures.

Storage:

Keep the Dalfampridine medication in the container it came in. Store the medicines at a room temperature of about 25 degrees Celsius. It is crucial to store them away from excess moisture and heat to prevent contamination. Any medication should be kept out of the sight and reach of children.

For Doctors

Indication:

Dalfampridine is a neurofunctional modifier indicated to improve walking speed in individuals with multiple sclerosis (MS).

Dose:

Dalfampridine is an extended-release tablet available in a 10-milligram strength.

Multiple sclerosis:

• Dalfampridine helps improve walking in individuals with multiple sclerosis by increasing walking speed.

• The recommended dosage of Dalfampridine is 10 milligrams orally twice daily, 12 hours apart. This can be taken with or without food.

Dosing considerations: renal impairment

• In moderate to severe renal impairment cases with creatinine clearance of less than 50 milliliters per minute, Dalfampridine is contraindicated since it increases the risk of seizure attacks.

• The risk of seizure is unknown and undetermined in mild degrees of renal impairment. However, plasma levels can be the same as the levels of 15 milligrams twice daily, a dosage that is potentially associated with seizure risk.

Hepatic impairment

• The usage and safety of Dalfampridine in people with hepatic impairment have not been studied.

• However, it is not predicted to change the dosing recommendation.

What Are the Pharmacological Aspects of Dalfampridine?

Pharmacodynamics

Dalfampridine belongs to the broad-spectrum lipophilic potassium channel blockers. This drug class binds more favorably to the open state of the potassium channel than the closed state in the central nervous system (CNS). The significant and potential target of Dalfampridine is the potassium channels susceptible in multiple sclerosis patients. Moreover, Dalfampridine does not prolong the QTc interval.

Mechanism of action

In multiple sclerosis, the axons (nerve fibers) are progressively demyelinated, exposing the potassium channels in the CNS. This results in the leakage and release of potassium ions, causing depolarization of the cells and a decline in neuronal excitability. The impact of multiple sclerosis is the impairment of neuromuscular transmission, making it more difficult to trigger the action potential.

Dalfampridine's mechanism of action inhibits the voltage-gated potassium channels exposed in the central nervous system. This helps maintain the transmembrane potential while prolonging the duration of the action potential. Therefore, the drug Dalfampridine ensures that the potential is high enough to precipitate conduction in those demyelinated nerve fibers exposed in multiple sclerosis patients. Dalfampridine also expedites synaptic and neuromuscular transmission by removing conduction blocks from demyelinated axons.

Pharmacokinetics

Absorption:

• Dalfampridine undergoes rapid and complete absorption from the gastrointestinal tract following oral administration.

• The time to maximum plasma concentration (Tmax) is one hour for the immediate-release form and 3.5 hours for the extended-release form.

• The Cmax of 10 mg extended-release Dalfampridine is 17.3 to 21.6 ng/mL.

• The relative bioavailability of 10 milligrams of extended-release Dalfampridine tablets compared to the aqueous solution is 96 percent.

Distribution:

• The volume of distribution of 10 milligrams of extended-release Dalfampridine is 2.6 liters per kilogram.

• The protein binding capacity of 10 milligrams of extended-release Dalfampridine is one to three percent.

Metabolism:

• Dalfampridine does not undergo extensive hepatic metabolism.

• Hence, the drugs that influence the cytochrome P450 enzyme when co-administered with Dalfampridine are not anticipated to interact with each other.

• The metabolites are 3-hydroxy-4-aminopyridine sulfate and 3-hydroxy-4-aminopyridine, but neither of these metabolites is active.

• Cytochrome P2E1 is a significant enzyme responsible for the three-hydroxylation of Dalfampridine.

Elimination:

• The kidneys eliminate most of the dosage of Dalfampridine and its metabolites within one day (24 hours) of administration.

• 90 to 96 percent of the total dose of Dalfampridine is excreted in urine as an unchanged form, and about 0.5 percent is excreted in feces.

Half-life:

Dalfampridine's absolute half-life periods in immediate-release form and extended-release form are 3.5 hours and 5.47 hours, respectively.

Toxicity:

The Toxic overdose or lethal dose of 50 percent (LD50) orally in mice is determined to be 19 milligrams per kilogram and, in rats, is 21 milligrams per kilogram.

Adverse effects of dalfampridine:

The most common adverse effect experienced in people taking Dalfampridine is urinary tract infection.

Other adverse reactions that tend to occur in about one to ten percent of patients are as follows:

• Dizziness.

• Headache.

• Insomnia.

• Nausea.

• Asthenia (lack of energy or physical weakness).

• Multiple sclerosis relapse.

• Back pain.

• Balance disorder.

• Constipation.

• Dyspepsia.

• Drug and dose-related increased risk for seizures.

• Pharyngolaryngeal pain.

• Paresthesia.

Post-marketing reports:

• Seizures have been reported in 4.6 cases per 1000 patients in years of use.

• Vomiting.

• Vertigo.

What Are the Contraindications of Dalfampridine?

The use of the drug Dalfampridine is strictly contraindicated in these conditions.

• History of seizures.

• Moderate to severe degrees of renal impairment with creatinine clearance values less than 50 milliliters per minute.

• History of hypersensitivity or allergic reaction to Dalfampridine.

Specific considerations:

• Pediatric: The safety and efficacy of children younger than 18 years of age have not been determined.

• Geriatrics: The clinical research on Dalfampridine did not include an adequate number of people aged 65 and above to assess whether geriatric subjects show different responses than younger subjects. Analysis suggests that Dalfampridine clearance may be reduced with increasing age, but this does not necessarily require a dosage adjustment with age. The kidneys significantly excrete Dalfampridine with an increased risk of adverse reactions, especially seizures. As geriatric patients are more likely to have reduced renal function, it is crucial to determine the creatinine clearance in elderly patients before administration.

• Lactation: No data suggest the presence of Dalfampridine in human breast milk, its effects on the infant, or milk production. However, one should consider the health and developmental benefits of breastfeeding and estimate them against the clinical need for Dalfampridine and its potential adverse effects on the infant.

• Gender: An analysis suggests that female patients would be more likely to have increased and maximum Dalfampridine plasma concentration than males. Nevertheless, the eminence of these differences is substantially less and does not require any dosage modification.

• Pregnancy: No adequate data exist on the developmental risks and complications associated with the use of Dalfampridine in pregnant women. The administration of Dalfampridine to animals during pregnancy and lactation resulted in reduced offspring viability and progression with clinically appropriate doses.