Details for Patent: 8,168,664

Title:	Metaxalone products, method of manufacture, and method of use
Abstract:	Disclosed herein are methods of using metaxalone. In one embodiment, the method comprises determining that a patient in need metaxalone therapy is taking a substance that is a n inhibitor or an inducer of a cytochrome p450 isozyme, wherein the cytochrome P450 is CYP1A2, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, or CYP3A4, and adjusting administration to the patient of metaxalone or the substance to avoid an adverse event associated with metaxalone. In another embodiment, the method comprises informing a user that metaxalone is metabolized by a cytochrome p450 isozyme, wherein the cytochrome P450 is CYP1A2, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, or CYP3A4. Also included are articles of manufacture comprising a container containing a dosage form of metaxalone, wherein the container is associated with published material informing that metaxalone affects activity of a cytochrome p450 isozyme. Also disclosed are a method of treatment and a method of manufacturing a metaxalone product.
Inventor(s):	Roberts; Richard H. (Lakewood, NJ), Du; Jie (Lansdale, PA), Davis; Matthew W. (Erwinna, PA)
Assignee:	Mutual Pharmaceutical Company, Inc. (Philadelphia, PA)
Filing Date:	May 21, 2010
Application Number:	12/784,738
Claims:	1. A method administering metaxalone to a patient in need of a skeletal muscle relaxant, comprising determining that a substance that is a known inducer or a known inhibitor of a cytochrome P450 isozyme (CYP) selected from CYP2C8, CYP2C9, and CYP2C19 is administered to a patient in need of a skeletal muscle relaxant; and administering a dose of metaxalone greater than a standard dose if a known inducer of the CYP is administered to the patient or administering a dose less than the standard dose of metaxalone if a known inhibitor of the CYP is administered to the patient. 2. The method of 1, wherein the standard dose of metaxalone is 800 mg. 3. The method of claim 1, further comprising determining a frequency per day at which the dose is administered to the patient. 4. The method of claim 1, further comprising monitoring plasma concentration of metaxalone in the patient to determine if the patient is at risk of a subtherapeutic outcome or of a metaxalone toxicity. 5. The method of claim 1 wherein the patient in need of a skeletal muscle relaxant has a musculoskeletal condition. 6. The method of claim 3, wherein if the patient is taking a known inducer of the CYP a daily dosing regimen of metaxalone administered to the patient consists of a daily amount of metaxalone greater than that provided by a standard metaxalone daily dosing regimen consisting of 800 mg, three or four times daily, or if the patient is taking a known inhibitor of the CYP a daily dosing regimen of metaxalone administered to the patient consists of a daily amount of metaxalone less than that provided by the standard metaxalone daily dosing regimen. 7. The method of claim 1, wherein the selected CYP is CYP2C8 and a known inducer of the selected CYP is administered to the patient. 8. The method of claim 1, wherein the selected CYP is CYP2C9 and a known inducer of the selected CYP is administered to the patient. 9. The method of claim 1, wherein the selected CYP is CYP2C19. 10. The method of claim 1, wherein the selected CYP is CYP2C9 or CYP2C19, the method further comprising: determining the patient has a poor metabolizer phenotype for the selected CYP. 11. A method of using metaxalone to treat a musculoskeletal condition, comprising: administering metaxalone to a human patient with a musculoskeletal condition; administering to the patient an active agent that is a substrate of a cytochrome p450 isozyme (CYP) selected from CYP1A2, CYP2B6, CYP2C9, CYP2C19, and CYP2D6; determining the patient has increased plasma concentration of the active agent during administration with metaxalone; and altering dosing of the active agent during administration with metaxalone based on the determined increased plasma concentration of the active agent. 12. The method of claim 11, wherein the active agent has a narrow therapeutic index. 13. The method of claim 11, wherein the selected CYP is CYP2B6, CYP2C9, CYP2C19, or CYP2D6, the method further comprising: determining the patient has a poor metabolizer phenotype for the selected CYP. 14. A method of using metaxalone to treat a musculoskeletal condition, comprising: administering metaxalone to a human patient with a musculoskeletal condition; administering to the patient an active agent that is a substrate of a cytochrome p450 (CYP) selected from CYP1A2 and CYP3A4; determining the patient has a decreased plasma concentration of the active agent during administration with metaxalone; and altering dosing of the active agent during administration with metaxalone based on the determined decreased plasma concentration of the active agent. 15. The method of claim 14, wherein the active agent has a narrow therapeutic index. 16. The method of claim 14, wherein the selected CYP is CYP1A2. 17. The method of claim 14, wherein the selected CYP is CYP3A4. 18. The method of claim 11, wherein the selected CYP is CYP1A2. 19. The method of claim 11, wherein the selected CYP is CYP2B6. 20. The method of claim 11, wherein the selected CYP is CYP2C9. 21. The method of claim 11, wherein the selected CYP is CYP2C19. 22. The method of claim 11, wherein the selected CYP is CYP2D6. 23. The method of claim 1, wherein the selected CYP is CYP2C8 and a known inhibitor of the selected CYP is administered to the patient. 24. The method of claim 1, wherein the selected CYP is CYP2C9 and a known inhibitor of the selected CYP is administered to the patient.