Firdapse

About Firdapse

• Firdapse received Food and Drug Administration (FDA) approval on November 28, 2018, marking it as the first FDA-approved treatment for LEMS.
• Firdapse is an oral medication which belongs to the family called a potassium channel blocker. 
• It is used to treat LEMS in adults and pediatric patients aged six and older. 
• LEMS is a rare autoimmune disorder. In LEMS, the immune system mistakenly attacks the neuromuscular junction, disrupting the communication between nerve cells and muscle cells. 
• This condition is most frequently associated with cancer, particularly small cell lung cancer, often appearing before or alongside the cancer diagnosis. However, it can also be linked to other autoimmune diseases. 
• Firdapse tablet, meant for oral use, contain 10mg of Amifampridine (equivalent to 18.98mg amifampridine phosphate) along with inactive components such as calcium stearate, colloidal silicon dioxide, and microcrystalline cellulose.

Strength: 

Galafold tablets are delivered in a strength of 10mg respectively, for oral consumption.

Recommended Dosage:

To ensure proper use of Firdapse, follow your doctor’s prescribed regimen, and if your dose is less than 5mg or you have difficulty swallowing tablets, consult the detailed Instructions for Use to prepare a suspension. Do not alter your dose without your doctor’s guidance, and if you miss a dose, skip it and take the next scheduled dose without doubling up. 

Firdapse tablets can be split if needed and can be taken with or without food. Avoid combining with other medications that increase seizure risk, and in the case of an overdose, promptly contact your doctor or seek emergency medical attention at the nearest hospital.

• Administer this medication orally in divided doses, usually 3 to 4 times daily. The initial recommended dosage for adults and pediatric patients weighing 45kg or more is between 15mg to 30mg per day, split into multiple doses. 
• You can increase the dosage by 5mg daily every 3 to 4 days, with a maximum single dose of 20mg and a daily maximum of 80mg. 
• For pediatric patients under 45kg, start with 5mg to 15mg daily, divided into doses, and increase by 2.5mg daily every 3 to 4 days. 
• In cases of renal impairment (CLcr 15 to 90 mL/min), start with the lowest recommended daily dosage.
• The maximum single dose is 10mg, and the daily maximum is 40mg. Adjust the initial daily dosage for patients with renal impairment, hepatic impairment, or known N-Acetyltransferase 2 (NAT2) poor metabolizers to the lowest recommended level. 
• If necessary, a 1mg/mL suspension can be prepared for patients who need dose adjustments less than 5mg increments or have difficulty swallowing or require a feeding tube.

Important:

Make sure not to miss any Firdapse doses. If you do miss one, take it as soon as possible, but if your next dose is near, skip the missed dose and stick to your regular schedule; never double up. Keep your doctor informed about all your medications, including over-the-counter drugs, herbs, and vitamins, as some may interact with Firdapse, potentially causing severe side effects. If you have questions or concerns about this medication, discuss them with your doctor. Following these instructions diligently is essential to maximize the medicine’s benefits and minimize the risk of side effects.

Warnings & Precautions

• Firdapse has the potential to induce hypersensitivity reactions, including the severe condition of anaphylaxis. If such a reaction occurs, immediate discontinuation of Firdapse is essential, and prompt initiation of appropriate medical treatment is warranted. 
• This medication should not be administered to individuals who have demonstrated hypersensitivity to amifampridine phosphate, other aminopyridines, or any of the tablet’s inactive ingredients. 
• Furthermore, Firdapse should be avoided in patients with a history of seizures, as it may trigger seizure activity. Physicians should carefully consider discontinuation or dosage reduction of Firdapse in patients who experience seizures during treatment.
• Exercise caution when prescribing Firdapse to patients with renal or hepatic impairment. No specific dosage recommendation is available for patients with end-stage renal disease. 
• Before consuming this medicine inform your doctor if you are pregnant or plan to become pregnant. It is not known if Firdapse will harm your unborn baby. You and your doctor will decide if you should take Firdapse while you are pregnant. 
• Notify your doctor if you are breastfeeding or plan to breastfeed because it is unknown  whether Firdapse passes into your breast milk. Talk to your doctor about the best way to feed your baby while taking Firdapse. 
• Caution is advised when using Firdapse with drugs that lower seizure threshold, as it may increase the risk of seizures. Additionally, the use of drugs with cholinergic effects, such as cholinesterase inhibitors, alongside Firdapse may enhance cholinergic effects and raise the potential for adverse reactions.

Common Firdapse Side Effects:

• Shortness of breath or trouble breathing
• Swelling of your throat or tongue
• Hives
• Tingling around the mouth, tongue, face, fingers, toes, and other body parts
• Upper respiratory infection
• Stomach pain
• Nausea
• Diarrhea
• Headache
• Increased liver enzymes
• Back pain
• High blood pressure
• Muscle spasms 

Use in Specific Population

• Firdapse is safe and effective for treating LEMS in pediatric patients aged 6 and older, supported by various evidence sources. Its use in children under 6 is not established. 
• Clinical studies in elderly individuals were limited, but available data did not show significant differences in responses compared to younger patients. 
• However, when dosing elderly patients, caution is recommended, typically starting at the lower end of the dosing range due to potential age-related factors.

Storage and Handling

Before handling Galafold tablets, ensure your hands are clean by washing them with soap and water. Avoid touching the tablet with wet hands. If you accidentally touch a tablet with wet hands, make sure your hands are completely dry before handling the tablet again.