Because of the variability in severity and progression of the disease, doctors will not be able to give a definite prognosis. A period of experimentation with different treatment regimens is likely to be necessary in order to discover the most appropriate treatment regimen for a given patient. Epidemiology
In 1982 Lewis et al. reported a group of patients with a chronic asymmetrical sensorimotor neuropathy mostly affecting the arms with multifocal involvement of peripheral nerves. Also in 1982 Dyck et al reported a response to prednisolone to a condition they referred to as chronic inflammatory demyelinating polyradiculoneuropathy. Parry and Clarke in 1988 described a neuropathy which was later found to be associated with IgM autoantibodies directed against GM1 gangliosides. This latter condition was later termed multifocal motor neuropathy This distinction is important because multifocal motor neuropathy responds to intravenous immunoglobulin alone, while chronic inflammatory demyelinating polyneuropathy responds to intravenous immunoglobulin, steroids and plasma exchange. It has been suggested that multifocal motor neuropathy is distinct from chronic inflammatory demyelinating polyneuropathy and that Lewis-Sumner syndrome is a distinct variant type of chronic inflammatory demyelinating polyneuropathy.The Lewis-Sumner form of this condition is considered a rare disease with only 50 cases reported up to 2004. A total of 90 cases had been reported by 2009. Vaccine injury compensation for CIDP
The National Vaccine Injury Compensation Program has awarded money damages to patients who came down with CIDP after receiving one of the childhood vaccines listed on the Federal Governments vaccine injury table.
Selexipag, sold under the brand name Uptravi, is a medication developed by Actelion for the treatment of pulmonary arterial hypertension (PAH). Selexipag and its active metabolite, ACT-333679 (or MRE-269, the free carboxylic acid), are agonists of the prostacyclin receptor, which leads to vasodilation in the pulmonary circulation. It is taken by mouth or administered intravenously. Contraindications
In Europe, use of selexipag together with strong inhibitors of the liver enzyme CYP2C8, such as gemfibrozil, is contraindicated because it increases concentrations of selexipag twofold, and its active metabolite 11-fold, potentially leading to more adverse effects. Adverse effects
The adverse effects of selexipag are similar to those of intravenous prostacyclins used for pulmonary arterial hypertension. Common side effects include headache and jaw pain. An increased risk for hyperthyroidism has also been noted in people taking selexipag. Pharmacology
Mechanism of action
Selexipag and its active metabolite ACT-333679 act on the prostacyclin receptor of lung tissue, with the latter being 37-fold more potent. They are selective for the prostacyclin receptor. Binding to this receptor leads to three major effects: increased vasodilation of the arteries, decreased cell proliferation and inhibition of platelet aggregation, all beneficial in the treatment of pulmonary arterial hypertension. Pharmacokinetics
Selexipag is quickly absorbed from the gut and hydrolyzed in the intestines and the liver to ACT-333679 by carboxylesterases. Absolute bioavailability is about 49%, most likely because of a high first-pass effect. Highest concentrations in the blood plasma are reached after one to three hours for selexipag and after three to four hours for the active metabolite.