Use of many other prescription and non-prescription drugs, including nonsteroidal anti-inflammatory drugs (NSAIDs), lipid-lowering drugs, antibiotics, histamine receptor blockers (used to treat excess stomach acid production), antifungal agents, antidepressants, and hormones such as testosterone, can increase GGT levels
. Smoking can also increase GGT.
Gamma-glutamyl transferase (GGT) levels
may be used to determine the cause of an elevated alkaline phosphatase (ALP).