Ask your doctor if he can prescribe plain old "lithium carbonate". It comes in tablets and/or capsules 300 mg ea (others available but this is standard).
Lithium is actually on the Table of Elements along with hydrogen & oxygen so you shouldn't be having these problems if you have been prescribed lithium. (He may not be marking that "generic" is ok also)
Good luck! I've been on lithium carbonate for 20 yrs with real success in eliminating the manias and deep dark depressions...