Homocystinuria

Homocystinurias (463)
Homocystinurias are three biochemically  and clinically distinct disorders each characterized
 by increased  concentration of sulfur-containg amino acid , homocysteine , in blood and urine.
The most common form results from markedly reduced catalying a key step in transsulfuration
pathway by which methionine is converted to cysteine.

Depending on the underlying disorder , some patients with each of the homocysteinuria show chemical
and in some instances clinical improvement  following adminstration of specific improvements
following administreration of specific vitamin supplements (pyrodoxine, folate, or cobalamin )

Adverse reactions-

Nausea  , GI distress,  diarrhea,  aspirated the powder, caused odor, 
questionalble pscychological changes, unspecified problem

Special Precautions
Pregnancy-    betaine can cause fetal harm when administered  to a pregnant woman or can
affect reproductive capacity. Give to  pregnant woman only if clearly needed

Lactation- excrcise caution when administering to a nursing woman

Children- Majority of case studies of homocytinuria patients treated with betaine have been
pediatric patients.  Patients have been treated successfully without adverse efects within the
first months or years of life  with dosage greater than or equal to 6g/day  with resultant
biochemical and clinical improvement 

Indication-
Homocystinuria

Dosage-
The usual dosage in adults and pediatric patients is 6g/day  administred orally in divided doses
of 3g twice daily.
Dosages upto 20g/day have been necessar to control homocysteine levels in some patients
In pediatric patric patients less than 3 years of age dosage may be started at 100mg/kg/day
and then increased weekly by 1oomg/kg/day  increments.

Dosage in all patients can be gradually increased until plasma homocysteine levels is undetectable
or present only in small amounts.

Measure prescribed amount with the measuring scoop provided ( one level 1.7ml scoop is equal
to 1g betaine anhydrous powder ) and then dissolve in 120ml to 180ml ( 4 to 6 0z )  of water for
immediate ingestion

1. Shake bottle before removing cap

2. Measure with scoop provided.

3.One level scoop ( 1.7ml ) is equivalent to 1g betaine anhydrous powder. Measure the number
  of scoops your physician has precscribed

4. Mix with 120 to 180 ( 4 to 60 oz ) of water until completely dissolved  then drink immediately

5. Always replace the cap tightly after using . Protect from moisture. Do not use if powder does not
   completely dissolve or gives a colored solution.

Pharmacology-
Betaine acts as methyl group donor in the remethylation of homocysteine to methionine  in patients
with momocystinuria. As a result toxic blood levels of momocysteine are reduced in these patients,
usually 20% to 30% or less of pre-treatment levels.

Elevated homocysteine blood levels are associated with clinical problems such as cardiovascular
thrombosis, osteoporosis, skelatal abnormalites and optic lens dislocation 

Pregnancy-  
Betaine can cause fetal harm when administered  to a pregnant woman or can
affect reproductive capacity. Give to  pregnant woman only if clearly needed

Lactation-
Exercise caution when administering to a nursing woman

Children-
Majority of case studies of homocystinuria patients treated with betaine have been
pediatric patients.  Patients have been treated successfully without adverse efects within the
first months or years of life  with dosage greater than or equal to 6g/day  with resultant
biochemical and clinical improvement