Iron / Anemia Agents

Every red blood cell carries hemoglobin, and hemoglobin needs iron at its core to grab oxygen in the lungs and release it to tissues. When iron runs low — from blood loss (menstruation, GI bleeding), poor intake, malabsorption, or pregnancy — the body makes small, pale, oxygen-poor red cells: iron-deficiency anemia, the most common anemia worldwide. Fatigue, pallor, and shortness of breath follow.

Iron therapy simply restores the supply so the marrow can build normal hemoglobin. The whole nursing story is about getting the iron absorbed (oral) or giving it safely (IV) — and setting expectations about the harmless but alarming side effects.

Iron is absorbed best in its ferrous (Fe²⁺) form in an acidic environment, so the rules of oral iron all serve absorption: take it on an empty stomach (1 h before or 2 h after food) when tolerated, and pair it with vitamin C (which keeps iron in the absorbable ferrous state). Conversely, antacids, dairy, calcium, tea/coffee, and whole grains reduce absorption and must be separated.

Absorption is deliberately limited by the gut, so most swallowed iron passes through — which is exactly why the stool turns dark/black (harmless) and why unabsorbed iron irritates the bowel, causing nausea and constipation. Replenishing stores is slow: therapy continues for months even after hemoglobin normalizes.

When oral iron isn’t tolerated, isn’t absorbed (e.g., after bariatric surgery, IBD), or the deficit is large (CKD, heavy loss), IV iron is used. Its main hazard is hypersensitivity/infusion reactions — from flushing and hypotension up to rare anaphylaxis — so a test dose/slow infusion and monitoring are standard.

A separate, critical fact for pediatric nursing: iron is a leading cause of fatal poisoning in young children. Colorful tablets look like candy; overdose causes severe GI bleeding, shock, and liver failure. The antidote is the chelator deferoxamine, and iron products carry pediatric-overdose warnings — store them out of reach.