Elevated Liver Enzymes One of the classic signs of Lyme disease is alcohol intolerance. This suggests that the liver is an important site in the progression of Lyme disease. Some patients have experienced elevated liver enzymes while taking Flagyl. If it is a side effect then perhaps an alternative nitroimidazole would be an option. If it is a consequence of killing Lyme in the liver the elevated enzyme level may be part and parcel of effective treatment.
More work needs to be done.
In a similar way the nitroimidazoles may affect the peripheral nervous system. Peripheral neuropathy, typically manifest as numbness of the feet, has been recorded as a side effect of Flagyl treatment. It may be so, but equally it may be a consequence of treating Lyme-infected nerves. The reports of Flagyl-induced peripheral neuropathy came only in recent years. It seems, just seems, that tinidazole is not so likely to cause peripheral neuropathy.