Who might reasonably benefit, and who should avoid it?
IV therapy has a reasonable rationale for people with a laboratory-confirmed deficiency, a malabsorption condition, dehydration after illness, or iron deficiency that oral treatment has not corrected. It is inappropriate or hazardous for several groups, including people with kidney or heart failure, fluid-overload risk, certain electrolyte disorders, or a history of infusion reactions.
The following situations are where an intravenous route has a defensible clinical justification. In every case the justification comes from a diagnosis, not from a general wish to feel better.
- A deficiency confirmed on blood tests where the oral route has failed or is not tolerated
- Malabsorption conditions such as pernicious anaemia, coeliac disease, inflammatory bowel disease, or after bariatric or bowel surgery
- Dehydration following vomiting, diarrhoea or heat illness where drinking fluids is not enough
- Iron-deficiency anaemia where oral iron has been ineffective or poorly tolerated
- Situations where a prescriber has decided a medicine must be given intravenously
The list below is the part that most promotional pages omit. Giving fluid and solutes into a vein is not a neutral act, and some people are put at real risk by it.
A responsible assessment should include current medical conditions, medicines and supplements already being taken, allergy history, and — where the intention is to correct a deficiency — blood tests that actually demonstrate the deficiency exists. An infusion aimed at a nutrient nobody has measured is treating an assumption.