硫酸第一鉄

動物種別の用量

投与経路

禁忌

• Hemosiderosis
• Hemochromatosis
• Hemolytic anemias
• Known hypersensitivity to iron products
• Gastrointestinal ulcerative diseases (relative contraindication due to GI irritation)

有害事象

• Mild gastrointestinal upset (nausea, vomiting)
• Black or dark-colored feces (normal and harmless)
• Constipation or diarrhea

薬物相互作用

• Antacids · May bind to iron and decrease oral absorption; administer at least two hours apart.
• Calcium (Oral) · May bind to iron and decrease oral absorption; administer at least two hours apart.
• Chloramphenicol · May delay the response to iron administration; avoid using in patients with iron deficiency anemia.
• Fluoroquinolones (e.g., enrofloxacin) · Iron may significantly reduce the absorption of oral fluoroquinolones; administer at least two hours apart.
• H2-Receptor Antagonists (e.g., famotidine) · Increased gastric pH may decrease iron absorption.
• Penicillamine · Iron can decrease the efficacy of penicillamine by decreasing its absorption; space doses as far apart as possible.
• Proton-Pump Inhibitors (e.g., omeprazole) · Increased gastric pH may decrease iron absorption.
• Tetracyclines · Oral iron preparations can bind to orally administered tetracyclines, decreasing the absorption of both compounds.
• Thyroxine · Iron may reduce the absorption of oral thyroxine; administer at least two hours apart.
• Vitamin C (Ascorbic Acid) · May enhance the gastrointestinal absorption of iron.

モニタリング

• Clinical efficacy (resolution of anemia signs)
• Hemograms (CBC)
• Serum iron (Normal: Dogs 80-180 mcg/dL, Cats 70-140 mcg/dL)
• Total iron binding capacity (TIBC) (Normal: Dogs 280-340 mcg/dL, Cats 270-400 mcg/dL)
• Serum transferrin saturation

過量投与

Ingestion of iron-containing products can result in **life-threatening toxicity**. As little as 400 mg of elemental iron can be fatal in a child. **Clinical Signs of Toxicity:** * **Phase 1 (30 mins to several hours):** Acute gastrointestinal irritation, distress, vomiting (possibly hemorrhagic), abdominal pain, and diarrhea. * **Phase 2 (12-48 hours):** The patient may appear asymptomatic, but this can be a deceptive latent phase. * **Phase 3:** Peripheral vascular collapse, hypotension, cyanosis, pulmonary edema, fulminant hepatic failure, coma, and death. * **Long-term Sequelae:** Animals that survive may exhibit gastric scarring, strictures, and persistent digestive disturbances. **Treatment:** * Must be handled as an absolute emergency. * **Decontamination:** Empty the stomach using gastric lavage with a large bore tube (avoid emetics if hemorrhagic vomiting is already present). Lavage with tepid water or 1-5% sodium bicarbonate solution. * Oral milk of magnesia may help bind the drug in the GI tract. * **Antidote:** **Deferoxamine** is a specific chelating agent used to bind absorbed iron. * **Supportive Care:** IV fluids for shock, treatment of acidosis, prophylactic antibiotics, oxygen, and management of coagulation abnormalities or seizures.