Hypotonia is a state of low muscle tone (the amount of tension or resistance to stretch in a muscle), often involving reduced muscle strength. Hypotonia is not a specific medical disorder, but a potential manifestation of many different diseases and disorders that affect motor nerve control by the brain or muscle strength. Hypotonia is a lack of resistance to passive movement, whereas muscle weakness results in impaired active movement. Central hypotonia originates from the central nervous system, while peripheral hypotonia is related to problems within the spinal cord, peripheral nerves and/or skeletal muscles. Severe hypotonia in infancy is commonly known as floppy baby syndrome. Recognizing hypotonia, even in early infancy, is usually relatively straightforward, but diagnosing the underlying cause can be difficult and often unsuccessful. The long-term effects of hypotonia on a childs development and later life depend primarily on the severity of the muscle weakness and the nature of the cause. Some disorders have a specific treatment but the principal treatment for most hypotonia of idiopathic or neurologic cause is physical therapy and/or occupational therapy for remediation. Hypotonia is thought to be associated with the disruption of afferent input from stretch receptors and/or lack of the cerebellum’s facilitatory efferent influence on the fusimotor system, the system that innervates intrafusal muscle fibers thereby controlling muscle spindle sensitivity. On examination a diminished resistance to passive movement will be noted and muscles may feel abnormally soft and limp on palpation. Diminished deep tendon reflexes also may be noted.
Ixabepilone (INN; also known as azaepothilone B, codenamed BMS-247550) is a pharmaceutical drug developed by Bristol-Myers Squibb as a chemotherapeutic medication for cancer. History
Ixabepilone is a semi-synthetic analog of epothilone B, a natural chemical compound produced by Sorangium cellulosum. Epothilone B itself could not be developed as a pharmaceutical drug because of poor metabolic stability and pharmacokinetics. Ixabepilone was designed through medicinal chemistry to improve upon these properties. Pharmacology
Much like Taxol, Ixabepilone acts to stabilize microtubules. It is highly potent, capable of damaging cancer cells in very low concentrations, and retains activity in cases where tumor cells are insensitive to taxane type drugs. Approval
On October 16, 2007, the U.S. Food and Drug Administration approved ixabepilone for the treatment of aggressive metastatic or locally advanced breast cancer no longer responding to currently available chemotherapies. In November 2008, the EMEA has refused a marketing authorisation for Ixabepilone.Ixabepilone is administered through injection, and is marketed under the trade name Ixempra. Clinical uses
Ixabepilone, in combination with capecitabine, has demonstrated effectiveness in the treatment of metastatic or locally advanced breast cancer in patients after failure of an anthracycline and a taxane.It has been investigated for use in treatment of non-Hodgkins lymphoma. In pancreatic cancer phase two trial it showed some promising results (used alone). Combination therapy trials are ongoing. References
External links
Ixempra product website
Ixempra prescribing information