HIGHLIGHTS OF PRESCRIBING INFORMATION
These highlights do not include all the information needed to use Cystadane safely and effectively.  See full prescribing information for Cystadane.
Cystadane (betaine anhydrous for oral solution) powder
Initial U.S. Approval: 1996
Indications and Usage for Cystadane
Cystadane is a methylating agent indicated for the treatment of homocystinuria to decrease elevated homocysteine blood levels.  Included within the category of homocystinuria are (1):
Cystathionine beta-synthase (CBS) deficiency
5,10-methylenetetrahydrofolate reductase (MTHFR) deficiency
Cobalamin cofactor metabolism (cbl) defect
Cystadane Dosage and Administration
Usual dose in adult and pediatric patients is 6 grams per day, administered orally in divided doses of 3 grams two times a day.(2)
In children less than 3 years of age, may initiate dosing at 100 mg/kg/day, divided in twice daily doses, and then increased weekly by 50 mg/kg increments.(2)
Dose can be gradually increased until plasma total homocysteine is undetectable or present only in small amounts.(2)
Monitor patient response by plasma homocysteine levels.(2)
Prescribed amount of Cystadane should be measured with the measuring scoop provided and then dissolved in 4 to 6 ounces of water, juice, milk, or formula, or mixed with food for immediate ingestion.(2)
Dosage Forms and Strengths
Powder for oral solution available in bottles containing 180 grams of betaine anhydrous.(3)
Contraindications
None (4)
Warnings and Precautions
Hypermethioninemia:  Cystadane may worsen elevated plasma methionine concentrations in patients with CBS deficiency.  Cerebral edema has been reported in patients receiving Cystadane.( 5.1)
Monitoring:  Monitor plasma methionine concentrations in patients with CBS deficiency.  Keep plasma methionine concentrations below 1,000 mmol/L through dietary medication and, if necessary, a reduction of Cystadane dose. ( 5.1)
Adverse Reactions
Most common adverse reactions (incidence > 2%) were nausea and gastrointestinal distress, based on physician survey.
To report SUSPECTED ADVERSE REACTIONS, contact Rare Disease Therapeutics at 1-615-399-0700, or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch
USE IN SPECIFIC POPULATIONS
Pregnancy: Animal reproduction studies have not been conducted with Cystadane.  Use only if clearly needed.(8.1)
Nursing women: It is not known whether Cystadane is excreted in human milk.  Use only if clearly needed.(8.3)
Pediatrics: Pediatric patients ranging in age from 24 days to 17 years have been treated with Cystadane.  Children younger than 3 years of age may benefit from dose titration.
See 17 for PATIENT COUNSELING INFORMATION.
Revised: April 2010
FULL PRESCRIBING INFORMATION: CONTENTS*

1    INDICATIONS AND USAGE
2    DOSAGE AND ADMINISTRATION
      2.1    Dosage              
      2.2    Administration
3    DOSAGE FORMS AND STRENGTHS
4    CONTRAINDICATIONS
5    WARNINGS AND PRECAUTIONS
      5.1    Hypermethioninemi