Toxicity of gadolinium-based contrast agents can generally be classified as acute (short term) and chronic (longer term) and include¹:
- Acute allergic-like reactions
- Acute physiologic reaction
- Chronic kidney injury (called nephrogenic systemic fibrosis)
Additionally, there is evidence that a small amount of contrast agent is retained in various tissues of the body (including the brain), for years¹, or potentially for life. The health effects of this gadolinium remain unknown.
Chronic kidney injury after gadolinium administration is overwhelmingly seen among individuals with pre-existing kidney disease¹.
There is some experimental evidence in animal models and retrospective review of patient data that suggests adequate intravenous hydration may decrease the risk of kidney injury².
However, for individuals without kidney disease, I can find no evidence that hydration, either IV or oral, would have any clear effect on any adverse effects of gadolinium.