All about Firdapse(amifampridine)

Firdapse, pronounced FIR-dapse, is a groundbreaking medication designed to address Lambert-Eaton myasthenic syndrome (LEMS) in both adults and pediatric patients aged six and above. This oral tablet falls under the drug class of Cholinergic muscle stimulants, showcasing its distinctive mechanism and effectiveness in managing this rare autoimmune disease.

Manufacture and FDA Approval

Manufactured with precision by Amicus Therapeutics, Firdapse (amifampridine) undergoes a meticulous production process adhering to stringent quality standards. This commitment to excellence ensures a reliable and effective treatment option for individuals in need. Firdapse received approval from the U.S. Food and Drug Administration (FDA) on November 28, 2018, marking a significant milestone in the field of rare disease therapeutics.

What is Firdapse?

Firdapse, with its generic name amifampridine phosphate, is more than a medication; it’s a beacon of hope for those grappling with Lambert-Eaton myasthenic syndrome. This oral tablet functions as a nonspecific, voltage-dependent, potassium (K+) channel blocker, offering a targeted approach to address the challenges posed by LEMS.

Indication

Firdapse, a potassium channel blocker, is specifically indicated for the treatment of Lambert-Eaton myasthenic syndrome (LEMS) in adults and pediatric patients aged 6 years and older.

What is Lambert-Eaton myasthenic syndrome? 

Lambert-Eaton myasthenic syndrome (LEMS) is a rare autoimmune disorder that primarily affects the neuromuscular junction—the point where nerve cells and muscles communicate. In individuals with LEMS, the immune system mistakenly targets and attacks the voltage-gated calcium channels in nerve endings. These channels play a crucial role in signaling between nerve cells and muscle cells. 

Common symptoms of Lambert-Eaton myasthenic syndrome include muscle weakness, particularly in the legs and hips, difficulty with movement, and fatigue. The severity of symptoms can vary among individuals, and they may improve with rest.

Diagnosis involves a combination of clinical evaluation, electromyography (EMG) to assess muscle response to nerve signals, and antibody testing to detect the presence of autoantibodies targeting calcium channels.

Dosage Information

The recommended dosage of Firdapse tablet depends on the patient’s weight and ranges from 15mg to 30mg daily, administered in divided doses. It’s crucial to follow the prescribed dosage regimen to optimize the therapeutic benefits while minimizing potential side effects.

Benefits

The benefits of Firdapse are profound for individuals grappling with certain neuromuscular disorders. By improving nerve-to-muscle communication, Firdapse aids in alleviating symptoms and enhancing overall quality of life.

Warnings and Precautions

Seizures:

Firdapse has the potential to induce seizures, with occurrences noted in patients without a seizure history at the recommended doses. The incidence is approximately 2%, and many affected patients were either taking medications or had underlying medical conditions that could have lowered the seizure threshold. Seizures may be dose-dependent. In the event of a seizure during treatment, consideration should be given to discontinuing or reducing the dose of Firdapse. Importantly, Firdapse is contraindicated in individuals with a history of seizures.

Hypersensitivity:

Clinical trials have not reported hypersensitivity reactions or anaphylaxis associated with Firdapse administration. Although anaphylaxis has been documented in patients taking another aminopyridine, it may occur with Firdapse. If anaphylaxis is observed, Firdapse administration should be halted, and appropriate therapeutic measures initiated.

Firdapse in Specific Populations

• During pregnancy, Firdapse may harm the fetus based on animal data. Consult with healthcare professionals for guidance.
• There is insufficient data regarding the presence of Firdapse in human milk, its impact on the breastfed infant, or its effects on milk production. 
• The safety and effectiveness of Firdapse in treating Lambert-Eaton myasthenic syndrome (LEMS) have been confirmed in pediatric patients aged 6 years and older. 
• In individuals with renal impairment, it is advisable to commence Firdapse at the lowest recommended initial daily dosage, with close monitoring for potential adverse reactions.

Adverse Reactions

The common adverse reactions (occurring in more than 10% of patients) associated with Firdapse tablet include:

• Paresthesia
• Upper respiratory tract infection
• Abdominal pain
• Nausea
• Diarrhea
• Headache
• Elevated liver enzymes
• Back pain
• Hypertension
• Muscle spasms

Vigilance and open communication with healthcare professionals can help manage and mitigate these effects effectively.

Conclusion

In conclusion, Firdapse marks a significant milestone in rare disease therapeutics, addressing LEMS with precision and FDA approval. Its role reflects the continuous dedication to understanding rare diseases, providing hope and enhancing the quality of life for those affected.

FAQ

How does Firdapse work?

Firdapse operates as a potassium channel blocker, specifically targeting voltage-dependent potassium channels. By blocking these channels, it increases the release of acetylcholine, a neurotransmitter, improving neuromuscular transmission and addressing the disrupted communication between nerves and muscles in LEMS.

What are the common side effects of Firdapse?

The most common adverse reactions (occurring in more than 10% of patients) include paresthesias (burning or prickling sensations), upper respiratory tract infections, abdominal pain, nausea, diarrhea, headache, elevated liver enzymes, back pain, hypertension, and muscle spasms.

Is Firdapse safe during pregnancy and breastfeeding?

Based on animal data, Firdapse may cause fetal harm, and its safety during breastfeeding is unknown. It is essential to consult with a healthcare professional regarding the potential risks and benefits in these situations.

Are there any drug interactions with Firdapse?

Firdapse may interact with drugs that lower the seizure threshold and other medications with cholinergic effects. It is crucial to inform the healthcare provider about all current medications to avoid potential interactions.

How should Firdapse be stored?

Store Firdapse at room temperature (20°C-25°C or 68°F-77°F), away from moisture and heat. Discard any unused medication before the expiration date.

How to buy Firdapse online?

Obtaining Firdapse online has become increasingly accessible. To procure this medication, which is exclusively available in the US and Europe, you can contact the SANSFRO team or similar companies that specialize in importing medicines from these regions.

What is the Firdapse price?

Firdapse price depends on various product specifications and factors. For precise pricing information, please get in touch with our Patient Support Team at ‎(+91) 9315705373 or email us at help@sansfro.com. Our team can provide you with accurate and current cost details for Firdapse in the Indian market after importation.

Reference

1. https://www.accessdata.fda.gov/drugsatfda_docs/label/2022/208078s008lbl.pdf
2. https://www.drugs.com/Firdapse.html