ferrous fumarate
Femiron, Feostat, Fumasorb, Fumerin, Hemocyte, Ircon, Ircon-FA, Neo-Fer ◆, Nephro-Fer, Novofumar ◆, Palafer ◆, Span-FF

Available forms
Available without a prescription. Ferrous fumarate is 30% elemental iron.
Capsules (extended-release): 325 mg
Drops: 45 mg/0.6 ml
Suspension: 100 mg/5 ml
Tablets: 63 mg, 195 mg, 200 mg, 324 mg, 325 mg, 350 mg
Tablets (chewable): 100 mg

Indications and dosages
 Iron-deficiency states. Adults: 50 to 100 mg P.O. of elemental iron, t.i.d. Adjust dosage gradually, as needed and tolerated.
Children: 4 to 6 mg/kg P.O. daily divided into three doses.
Elderly patients: May need higher doses because reduced gastric secretions and achlorhydria may lower capacity for iron absorption.

Pharmacodynamics
Hematinic action: Ferrous fumarate replaces iron, an essential component in the formation of hemoglobin.

Pharmacokinetics
Absorption: Absorbed from the entire length of the GI tract, but primary absorption sites are the duodenum and proximal jejunum. Up to 10% of iron is absorbed by healthy individuals; patients with iron-deficiency anemia may absorb up to 60%. Enteric coating and some extended-release formulas have decreased absorption because they’re designed to release iron past the points of highest absorption; food may decrease absorption by 40% to 60%.
Distribution: Transported through GI mucosal cells directly into the blood, where it’s immediately bound to a carrier protein, transferrin, and transported to the bone marrow for incorporation into hemoglobin. Iron is highly protein-bound.
Metabolism: Liberated by the destruction of hemoglobin but is conserved and reused by the body.
Excretion: Healthy people lose only small amounts of iron daily. Men and postmenopausal women lose about 1 mg daily, and premenopausal women about 1.5 mg daily. The loss usually occurs in nails, hair, feces, and urine; trace amounts are lost in bile and sweat.

Contraindications and precautions
Contraindicated in patients receiving repeated blood transfusions and patients with primary hemochromatosis or hemosiderosis, hemolytic anemia unless iron-deficiency anemia is also present, peptic ulcer disease, regional enteritis, and ulcerative colitis. Use cautiously on long-term basis.

Interactions
Drug-drug. Antacids, aluminum-containing phosphate binders, cholestyramine, cimetidine, vitamin E: Decreases ferrous fumarate absorption. Separate doses by 1- to 2-hour intervals.
Chloramphenicol: Increases response to iron therapy. Monitor patient carefully.
Doxycycline: May interfere with ferrous fumarate absorption even when doses are separated. Avoid use together.
L-thyroxine: May decrease L-thyroxine absorption. Separate doses by at least 2 hours. Monitor thyroid function.
Levodopa, methyldopa: May decrease absorption of these drugs. Monitor patient carefully.
Penicillamine: Decreases penicillamine absorption. Separate doses by at least 2 hours.
Quinolones: Decreases quinolone absorption. Monitor patient closely.
Tetracycline: Inhibits absorption of both drugs. Give tetracycline 3 hours after or 2 hours before iron supplement.
Vitamin C: Increases iron absorption. May be used as a beneficial drug interaction.
Drug-herb. Black cohosh, chamomile, feverfew, gossypol, hawthorn, nettle, plantain, St. John’s wort: Decreased iron absorption. Discourage use together.
Drug-food. Cereals, cheese, coffee, eggs, milk, tea, whole-grain breads, yogurt: May impair oral iron absorption. Discourage use together.

Adverse reactions
GI: nausea, epigastric pain, vomiting, constipation, diarrhea, black stools, anorexia.
Other: temporary staining of teeth (with suspension and drops).

Effects on lab test results
None reported.

Overdose and treatment
The lethal dose of iron is between 200 and 250 mg/kg; fatalities have occurred with lower doses. Signs and symptoms may follow ingestion of 20 to 60 mg/kg. Between 30 minutes and 8 hours after ingestion, patient may experience lethargy, nausea, vomiting, green and then tarry stools, weak and rapid pulse, hypotension, dehydration, acidosis, and coma. If death doesn’t immediately ensue, symptoms may clear for about 24 hours. At 12 to 48 hours, symptoms may return, accompanied by diffuse vascular congestion, pulmonary edema, shock, seizures, anuria, and hyperthermia. Death may follow.
 Treatment requires immediate support of airway, breathing, and circulation. In conscious patient with intact gag reflex, induce emesis with ipecac; otherwise, empty stomach by gastric lavage. Follow emesis with lavage, using a 1% sodium bicarbonate solution, to convert iron to the less irritating, poorly absorbed form (phosphate solutions have been used but carry hazard of other adverse effects). Take abdominal X-ray to determine continued presence of excess iron; if serum iron levels exceed 350 mg/dl, deferoxamine may be used for systemic chelation.
 Survivors are likely to sustain organ damage, including pyloric or antral stenosis, hepatic cirrhosis, CNS damage, and intestinal obstruction.

Special considerations
• Ferrous fumarate blackens feces and may interfere with tests for occult blood in the stool; the guaiac test and orthotoluidine test may yield false-positive results, but the benzidine test usually isn’t affected.
• Iron overload may decrease uptake of technetium 99m and thus interfere with skeletal imaging.
• Drug may cause dark-colored stools.
Breast-feeding patients
• Iron supplements are commonly recommended for breast-feeding women; no adverse effects have been documented.
Pediatric patients
• Iron overdose may be fatal in children; treat immediately.
Geriatric patients
• Because iron-induced constipation is common in elderly patients, stress proper diet or prescribe a stool softener.

Patient education
 ALERTWarn patient to store drug securely away from children.
• Instruct patient to take tablets with orange juice or water but not with milk or antacids.
• Explain that patient may mix liquid forms in water or juice.
• Instruct patient not to crush or chew sustained-release forms.
• Tell patient to take suspension with straw to direct drops to back of throat.

Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE THREATENING.
◆ Canada only
◇ Unlabeled clinical use