Hi Mary

I have the same curiosity with you, only my case is in the Thymol Turbidity Test (2 times high when the others are normal).

Indirect Bilirubin is the result of total bilirubin minus direct bilirubin. Therefore, if your total bilirubin is low or your direct bilirubin is too high you can get negative result for your indirect bilirubin.

I got this reference from webMD website, perhaps it is proper for your curiosity:

Medications that may lower bilirubin levels include vitamin C (ascorbic acid), phenobarbital, and theophylline (Elixophyllin).

Caffeine, which can lower bilirubin levels.

I don't know the range in your laboratory, but I think your direct bilirubin is quite high (the normal range should be 0.1-0.3, however, this can be different in each laboratory). Perhaps you can discuss again with your doctor to make your peace of mind.

wish you good health

sincerely