Compounding Hotline

Pharmacy Times, Volume 0, 0

COMPOUNDINGHOTLINE

Martin A. Erickson, III, RPh

Q

Do you have any information (or a recipe) on vancomycin

enemas? Our gastrointestinal (GI) specialist wrote an order

for them for a patient with extensive pseudomembranous colitis.

A

Anecdotal reports of the use of vancomycin enemas as

alternative treatment for this condition indicate positive

results.The vancomycin HCl has generally been compounded as

500 mg in 1000 mL of 0.9% sodium chloride for injection. Other

reports of use of these retention enema formulations varied from

1 g of vancomycin HCl in 1000 mL of 0.9% sodium chloride for

injection q6h to 500 mg vancomycin HCl in 500 mL 0.9% sodium

chloride for injection bid. The solution should be freshly prepared,

if no preservative is present.

Q

I have a 2-month-old patient who has maple syrup urine

disease. The physician wants the patient to have 300 mg of

thiamine (vitamin B1) each day. Currently, the mom and dad are

trying to dissolve 3 x 100-mg tablets in water. Do you have a formula

for preparing thiamine suspension?

A

Thiamine HCl occurs as colorless-to-white crystals or as a

white crystalline powder, has a bitter taste, and is soluble

approximately 1 g in 1 mL of water. In solution, it is incompatible

with reducing agents such as sulfites; the resultant molecular

cleavage increases with increased pH. Also, reports that it

degrades in the presence of amino acids in solution with thiosulfites

have been found. When the concentration of sulfite did not

exceed 0.05%, thiamine was more stable. The drug is well

absorbed from the GI tract, following oral administration.

The US Pharmacopeia has an official monograph for an elixir

of thiamine HCl, but, because this patient is a child, it seems reasonable

to suggest compounding an aqueous solution and to

suggest the use of a syrup, such as simple syrup, as a base for

the preparation. After compounding the thiamine HCl in syrup,

the pH should be adjusted to less than 4 with HCl.

E-mail your compounding questions to

compounding@pharmacytimes.com