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Neurologia I Neurochirurgia Polska Jun 2024Lambert-Eaton myasthenic syndrome (LEMS) is an ultrarare neuromuscular disease with a triad of symptoms: muscle paresis, dysautonomy, and areflexia. Amifampridine is the...
INTRODUCTION
Lambert-Eaton myasthenic syndrome (LEMS) is an ultrarare neuromuscular disease with a triad of symptoms: muscle paresis, dysautonomy, and areflexia. Amifampridine is the symptomatic treatment of LEMS.
AIM OF STUDY
To assess the effectiveness and safety of treatment in the real world.
MATERIAL AND METHODS
14 patients with non-neoplastic LEMS treated with amifampridine were enrolled in the study (female 42.9%, mean age 48.8 ± 11.4 years). The patients were assessed using the Quantitative Myasthenia Gravis (QMG) scale, QMG limb domain (LD) score, spirometry, Hand Grip Strength (GRIP) test, and repetitive nerve stimulation study (RNS) at baseline and at the end of follow-up. Diagnostic delay since first symptoms was from seven months up to 22 years. Treatment delay ranged from one to 26 years. The patients were treated and reevaluated after 21.1 ± 12.0 weeks (range 13-48).
RESULTS
All of the patients improved in QMG score. Mean improvement was 5.1 ± 2.0 (range 1-8) points (p < 0.001) and this showed no correlation with the duration of the disease before treatment (p = 0.477). 85.7% of patients (N = 12) improved ≥ 3 points (clinically meaningful) in QMG. 78.6% of the patients improved in QMG LD (mean 2.2 ± 1.6 points (p < 0.001)). Also, forced vital capacity (FVC) improved after treatment (p = 0.031). Mean improvement in GRIP test was 7.0 ± 7.1 kg in the right hand and 5.2 ± 7.5 kg in the left hand (p < 0.001). In RNS before treatment, facilitation ( > 100%) was observed in 78.6% (N = 11) of patients, and was higher before treatment (p < 0.001). Compound muscle action potential (CMAP) amplitude was higher after treatment (p < 0.001). Mean increase of CMAP amplitude was 2.1 ± 1.6 times. In 64.3% (N = 9) of patients lowering of corticosteroid dose was achieved.
CONCLUSIONS
Amifampridine is an effective treatment in non-neoplastic LEMS patients, regardless of disease duration. The treatment is well-tolerated and allows to reduce dose of corticosteroids in the majority of patients.
PubMed: 38935421
DOI: 10.5603/pjnns.99335 -
Cureus May 2024Lambert-Eaton myasthenic syndrome (LEMS) is an autoimmune neuromuscular disorder caused by pathogenic autoantibodies directed against voltage-gated calcium channels...
Lambert-Eaton myasthenic syndrome (LEMS) is an autoimmune neuromuscular disorder caused by pathogenic autoantibodies directed against voltage-gated calcium channels present on the presynaptic nerve terminal. For LEMS patients refractory to initial symptomatic treatment with amifampridine, immunomodulatory therapy with intravenous immunoglobulin (IVIG) is often utilized. However, in the authors' review of literature, the utility of subcutaneous immunoglobulin (SCIG) in the treatment of LEMS has been scarcely reported. Here, we present a unique case of non-paraneoplastic LEMS managed with SCIG with excellent clinical response and improvement on electromyography. SCIG therapy may be a reasonable alternative for patients with LEMS who do not tolerate the intravenous formulation.
PubMed: 38903354
DOI: 10.7759/cureus.60773 -
Saudi Medical Journal Jun 2024To shed some light on a potential therapeutic modality that may facilitate resolution of botulism symptoms, namely 3,4-diaminopyridine (3,4-DAP).
OBJECTIVES
To shed some light on a potential therapeutic modality that may facilitate resolution of botulism symptoms, namely 3,4-diaminopyridine (3,4-DAP).
METHODS
In Riyadh, Saudi Arabia, we recently encountered a foodborne botulism outbreak that, luckily, was discovered early. In Prince Sultan Military Medical city, we admitted, during a period of approximately 3 weeks, 15 probable cases, 2 of which were excluded due to more likely alternative diagnoses. We report in this case series 13 highly suspected cases of botulism that we encountered during the outbreak.
RESULTS
A total of 12 out of 13 patients required intensive care unit (ICU) admission, one of which required intubation. Symptoms included cranial nerve palsies, gastrointestinal symptoms, limb and respiratory muscle weakness. Patients showed clinical improvement when received botulinum antitoxin and 3,4-DAP if given early in the course of the disease.
CONCLUSION
Early admisntration of 3,4-DAP may facilitate recovery and prevent disease progression. Larger prospective trials should be carried out to confirm that.
Topics: Humans; Botulism; Disease Outbreaks; Male; Saudi Arabia; Adult; Female; Middle Aged; Amifampridine; Botulinum Antitoxin; Young Adult
PubMed: 38830658
DOI: 10.15537/smj.2024.45.6.20240419 -
Scientific Reports May 20244-aminopyridine (4AP) is a potassium (K) channel blocker used clinically to improve walking in people with multiple sclerosis (MS). 4AP binds to exposed K channels in...
4-aminopyridine (4AP) is a potassium (K) channel blocker used clinically to improve walking in people with multiple sclerosis (MS). 4AP binds to exposed K channels in demyelinated axons, reducing the leakage of intracellular K and enhancing impulse conduction. Multiple derivatives of 4AP capable of blocking K channels have been reported including three radiolabeled with positron emitting isotopes for imaging demyelinated lesions using positron emission tomography (PET). However, there remains a demand for novel molecules with suitable physicochemical properties and binding affinity that can potentially be radiolabeled and used as PET radiotracers. In this study, we introduce 3-fluoro-5-methylpyridin-4-amine (5Me3F4AP) as a novel trisubstituted K channel blocker with potential application in PET. 5Me3F4AP has comparable potency to 4AP and the PET tracer 3-fluoro-4-aminopyridine (3F4AP). Compared to 3F4AP, 5Me3F4AP exhibits comparable basicity (pK = 7.46 ± 0.01 vs. 7.37 ± 0.07, P-value = 0.08), greater lipophilicity (logD = 0.664 ± 0.005 vs. 0.414 ± 0.002, P-value < 0.0001) and higher permeability to an artificial brain membrane (P = 88.1 ± 18.3 vs. 31.1 ± 2.9 nm/s, P-value = 0.03). 5Me3F4AP is also more stable towards oxidation in vitro by the cytochrome P450 enzyme CYP2E1 (IC = 36.2 ± 2.5 vs. 15.4 ± 5.1, P-value = 0.0003); the enzyme responsible for the metabolism of 4AP and 3F4AP. Taken together, 5Me3F4AP has promising properties as a candidate for PET imaging warranting additional investigation.
Topics: Potassium Channel Blockers; Humans; Positron-Emission Tomography; 4-Aminopyridine; Amifampridine
PubMed: 38750155
DOI: 10.1038/s41598-024-61465-w -
The American Journal of Emergency... Jun 20243,4-Aminopyridine or Amifampridine belongs to the aminopyridine class of drugs which is used to treat multiple sclerosis and Lambert-Eaton Myasthenic Syndrome (LEMS)....
3,4-Aminopyridine or Amifampridine belongs to the aminopyridine class of drugs which is used to treat multiple sclerosis and Lambert-Eaton Myasthenic Syndrome (LEMS). Aminopyridine pharmaceuticals inhibit presynaptic potassium channels. This increases available acetylcholine in the nerve cleft which leads to improved strength in this patient population. While overdoses have been reported of 4-Aminopyridine, no case reports of acute 3.4-Aminopyridine overdose are currently available. A 67 year old man presented to the emergency department 30 min after ingesting 100 mg of amifampridine in a suicide attempt. Within an hour of ingestion he experienced tachycardia, tachypnea, hypertension and tremor. The patient then started to experience seizures and had a cardiac arrest 3 h after the ingestion. The patient achieved return of spontaneous circulation but proceeded to have refractory seizures. Despite significant and escalating doses of anti-epileptic medications, the patient continued to have seizures until 18 h after ingestion. His anti-epileptic medications were weaned over the following days and he had no more seizures. This is a report of a novel overdose of 3,4-Aminopyridine, a medication that belongs to the aminopyridine class of pharmaceuticals that have been well used for many years. Aminopyridine overdoses are commonly thought to carry low morbidity and mortality; however, our patient had both a cardiac arrest and refractory status epilepticus. Ultimately, this case suggests that patients who overdose on 3,4-Aminopyridine could become critically ill and their presentation may be far more severe than that of other medications of the same class.
Topics: Humans; Male; Aged; Drug Overdose; Status Epilepticus; Potassium Channel Blockers; Amifampridine; Suicide, Attempted; Anticonvulsants
PubMed: 38693021
DOI: 10.1016/j.ajem.2024.04.023 -
Cureus Jan 2024After a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, approximately 10-20% of patients are affected by the post-COVID syndrome (PCS). This...
After a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, approximately 10-20% of patients are affected by the post-COVID syndrome (PCS). This condition leads to a variety of functional complaints, including symptoms of fatigue. To date, there is still no adequate treatment option. Five patients are presented, including the self-observation of one of the authors, in whom the administration of amifampridine as an "off-label use" led to a normalization of the unphysiologically increased need for sleep with a simultaneous increase in the Bell score. This effect was confirmed in a double-blind discontinuation trial (the medication was discontinued on a trial basis) in two of the patients. The five patients, who were previously unable to lead a normal life due to their fatigue symptoms, were able to return to everyday life after treatment with amifampridine. This offers hope to millions of affected patients.
PubMed: 38406122
DOI: 10.7759/cureus.52935 -
Dalton Transactions (Cambridge, England... Jan 2024The different behaviors of the drug amifampridine (AMP) against Mn(II), Cu(II), Zn(II) and Cd(II) metal ions, in the presence and absence of tris(2-aminoethyl)amine...
Complexation of drug amifampridine with Cu(II), Zn(II) and Cd(II) ions, and its dimerization with the magic of Mn(II) salts. Potential anti-COVID-19 and anticancer activities.
The different behaviors of the drug amifampridine (AMP) against Mn(II), Cu(II), Zn(II) and Cd(II) metal ions, in the presence and absence of tris(2-aminoethyl)amine (tren) was studied. The results showed that AMP successfully coordinates with Cu(II), Zn(II) and Cd(II) metal ions, but interestingly it undergoes an unexpected dimerization through a C-H activation in the presence of different Mn(II) salts. A four-coordinate complex of zinc(II), [Zn(AMP)Cl] (1), a binuclear complex of cadmium(II), [Cd(AMP)Cl] (2), three five-coordinate tren-based metal complexes, [Cu(tren)(AMP)](ClO) (8), [Zn(tren)(AMP)]Cl (9) and [Cd(tren)(AMP)](ClO) (10), three pyridinium salts, [AmpDimer]X (X = Cl, NO, ClO; (3, 4 & 5)), and also two four-coordinate metal complexes with this pyridinium cation, [Zn(AmpDimer)Cl] (6) and [Cd(AmpDimer)Cl] (7), were synthesized. All new compounds were characterized by elemental analysis and IR spectroscopy, and by H- and C-NMR spectroscopy (for 1, 2, 3, 6, 7, 9 & 10) and by X-ray crystal structure determinations (for 1, 3, 4, 5, 7, 8 & 10). Theoretical studies showed that the [M(tren)(AMP)] cations act as pH-sensitive drug carriers of AMP and release it upon protonation. The molecular docking studies on the interaction of AMP and the above complexes/salts with DNA and the proteins of SARS-CoV-2 showed that the synthesized complexes/salts have greater anticancer and anti-covid-19 activities than AMP alone.
Topics: Cadmium; Salts; Amifampridine; Coordination Complexes; Molecular Docking Simulation; Dimerization; Metals; Zinc; Ions
PubMed: 38099626
DOI: 10.1039/d3dt03281g -
The Journal of Pharmacology and... Jan 2024Botulinum neurotoxin (BoNT) is a potent protein toxin that causes muscle paralysis and death by asphyxiation. Treatments for symptomatic botulism are intubation and...
Botulinum neurotoxin (BoNT) is a potent protein toxin that causes muscle paralysis and death by asphyxiation. Treatments for symptomatic botulism are intubation and supportive care until respiratory function recovers. Aminopyridines have recently emerged as potential treatments for botulism. The clinically approved drug 3,4-diaminopyridine (3,4-DAP) rapidly reverses toxic signs of botulism and has antidotal effects when continuously administered in rodent models of lethal botulism. Although the therapeutic effects of 3,4-DAP likely result from the reversal of diaphragm paralysis, the corresponding effects on respiratory physiology are not understood. Here, we combined unrestrained whole-body plethysmography (UWBP) with arterial blood gas measurements to study the effects of 3,4-DAP, and other aminopyridines, on ventilation and respiration at terminal stages of botulism in mice. Treatment with clinically relevant doses of 3,4-DAP restored ventilation in a dose-dependent manner, producing significant improvements in ventilatory parameters within 10 minutes. Concomitant with improved ventilation, 3,4-DAP treatment reversed botulism-induced respiratory acidosis, restoring blood levels of CO, pH, and lactate to normal physiologic levels. Having established that 3,4-DAP-mediated improvements in ventilation were directly correlated with improved respiration, we used UWBP to quantitatively evaluate nine additional aminopyridines in BoNT/A-intoxicated mice. Multiple aminopyridines were identified with comparable or enhanced therapeutic efficacies compared with 3,4-DAP, including aminopyridines that selectively improved tidal volume versus respiratory rate and vice versa. In addition to contributing to a growing body of evidence supporting the use of aminopyridines to treat clinical botulism, these data lay the groundwork for the development of aminopyridine derivatives with improved pharmacological properties. SIGNIFICANCE STATEMENT: There is a critical need for fast-acting treatments to reverse respiratory paralysis in patients with botulism. This study used unrestrained, whole-body plethysmography and arterial blood gas analysis to show that aminopyridines rapidly restore ventilation and respiration and reverse respiratory acidosis when administered to mice at terminal stages of botulism. In addition to supporting the use of aminopyridines as first-line treatments for botulism symptoms, these data are expected to contribute to the development of new aminopyridine derivatives with improved pharmacological properties.
Topics: Mice; Humans; Animals; Botulism; Aminopyridines; Amifampridine; Acidosis, Respiratory; Botulinum Toxins, Type A; Paralysis; Respiration
PubMed: 37977816
DOI: 10.1124/jpet.123.001773