Hematinics — Iron Supplements and IV Iron (with pregnancy notes)
Iron therapy in pregnancy (practical overview)
- Oral iron is typically first-line for iron deficiency anemia in pregnancy when tolerated and absorption is adequate.
- IV iron is commonly used in pregnancy when oral iron is not tolerated, ineffective, malabsorption is suspected, or when more rapid repletion is needed (follow local protocol).
- Timing: many obstetric protocols preferentially use IV iron in the 2nd/3rd trimester unless urgency dictates otherwise.
- Alternate-day oral dosing: oral iron may be better absorbed when taken every other day (hepcidin-mediated effect) and can improve tolerability—use a regimen appropriate to the clinical scenario.
Safety (iron poisoning)
Accidental overdose of iron-containing products is a leading cause of fatal poisoning in children.
In the U.S., call Poison Help: 1-800-222-1222 (poisonhelp.org).
Oral iron therapy (commonly used in pregnancy)
Elemental iron varies by salt and product; confirm the specific product label. GI side effects are dose-related. Consider strategies to improve adherence/tolerance.
Absorption tip
Oral iron may be better absorbed when taken every other day rather than daily in some patients, and this can also reduce nausea/constipation.
Use a dosing plan that fits the severity of anemia, gestational age, and urgency of repletion.
| Medication | How used | Dose & administration (examples) | How supplied / notes |
|---|---|---|---|
|
Ferrous sulfate (OTC/Rx)
|
First-line oral iron for iron deficiency / iron deficiency anemia (including pregnancy) when tolerated. |
Typical adult/pregnancy regimens used clinically:
Administration pearls:
|
Tablets/capsules/liquids vary by brand. Verify elemental iron per unit. |
|
Ferrous gluconate (OTC/Rx)
|
Alternative oral iron salt; some patients tolerate better than ferrous sulfate. |
Dose to deliver a similar elemental iron target as ferrous sulfate.
Commonly used as PO daily or every other day depending on tolerance and urgency.
Elemental iron per tablet varies by product—confirm the label.
|
Multiple strengths; verify elemental iron per unit. |
|
Ferrous fumarate (OTC/Rx)
|
Higher elemental iron per tablet in many products; useful when fewer pills desired but may increase GI effects. | Dose to elemental iron target; consider every other day dosing if GI effects limit adherence. | Verify elemental iron per unit and formulation. |
|
Carbonyl iron (OTC)
|
Oral iron option; used when a different formulation is preferred. |
Product-specific. Many products are dosed to deliver ~45 mg elemental iron per dose,
taken daily or every other day as tolerated.
Confirm elemental iron and dosing on the product label.
|
OTC products vary widely. |
|
Polysaccharide-iron complex (Rx/OTC)
|
Oral iron alternative sometimes used when intolerance to iron salts occurs. | Product-specific; dose to the elemental iron goal (often daily or every other day). | Different products provide different elemental iron per capsule/teaspoon. |
Response check (oral iron) |
Assess adequacy of therapy and adherence. |
A commonly used clinical benchmark is a hemoglobin rise of about ~2 g/dL within ~3 weeks
when therapy is effective and taken.
Interpret with context (baseline severity, inflammation, hemoglobinopathy, ongoing blood loss).
|
If response is inadequate, reassess diagnosis, adherence, timing with food/meds, and consider IV iron. |
Intravenous (parenteral) iron therapy (commonly used in pregnancy when oral fails)
IV iron products differ substantially in dosing, dilution, infusion time, and monitoring requirements. Use product labeling (DailyMed) and institutional protocols.
| Medication | How used (summary) | Typical dose patterns (label-style summary) | How supplied / notes |
|---|---|---|---|
|
Iron sucrose (Venofer®)
|
IV iron commonly used clinically, including in pregnancy (often 2nd/3rd trimester) when oral iron is not tolerated or ineffective. | Often given in 100–200 mg increments per infusion, repeated until repletion (protocol-dependent). See detailed Venofer section below for a protocol-style example. | Commonly supplied as 20 mg/mL vials (vial sizes vary). |
|
Ferric carboxymaltose (Injectafer®)
|
Larger-dose IV iron option for rapid repletion when oral iron is not tolerated/ineffective (pregnancy use per protocol). | Typical label patterns include 750 mg IV x 2 doses separated by ≥7 days (total 1500 mg), or 15 mg/kg up to 1000 mg as a single dose (see label). | Follow label for dilution, infusion time, and monitoring. |
|
Ferric derisomaltose (Monoferric®)
|
Larger single-infusion option in many patients when oral iron is not tolerated/ineffective. | Label pattern commonly allows 1000 mg IV infusion over at least 20 minutes (weight-based for <50 kg; see label). | Verify concentration and infusion requirements per label. |
|
Ferumoxytol (Feraheme®)
|
Two-dose IV iron regimen; pregnancy use varies by institution. | Common label pattern: 510 mg IV then 510 mg IV 3–8 days later; infusion over ≥15 minutes (see label). | Follow label warnings and monitoring requirements. |
|
Sodium ferric gluconate (Ferrlecit®)
|
IV iron used mainly in hemodialysis settings per label; other uses per protocol. | Common label pattern: 125 mg IV per dialysis session administered per label. | Verify dilution/infusion instructions on label. |
|
Iron dextran (e.g., INFeD®)
|
IV iron option with higher hypersensitivity concern; many obstetric protocols prefer other formulations when available. | Dose individualized to iron deficit; follow label precautions and infusion rate limits. | Strong warnings apply; ensure emergency therapies available. |
Iron sucrose (Venofer®) — protocol-style details (example)
How used: Treatment of low blood levels of iron when IV therapy is indicated (e.g., intolerance to oral iron, malabsorption, need for faster repletion). Confirm indication and protocol.
Example dosing/administration (protocol-style):
- Treatment of low blood levels of iron in patients with chronic kidney disease, intestinal malabsorption, or intolerance to oral iron.
- 200 mg diluted in a maximum of 100 mL 0.9% Sodium Chloride given as a slow IV infusion administered over at least 30 minutes, one to three times per week (protocol-dependent) until cumulative repletion dose reached.
- First dose observation strategy (protocol-dependent): start slowly and observe closely for reactions. If no adverse reaction (hives, wheezing, SOB, hypotension), continue to complete infusion.
- Do not dilute to concentrations below 1 mg/mL.
- Observe during and for at least 30 minutes after each dose per label/policy.
How supplied (typical):
- Commonly supplied as 20 mg elemental iron/mL vials (vial sizes vary by NDC).
If a reaction occurs
Non-Allergic/Fishbane Reaction
Flushing, nausea, dizziness
Severe Reactions (Hypersensitivity/Anaphylaxis)
Signs of severe anaphylaxis (difficulty breathing, severe hypotension, hives)
References (selected)
- DailyMed (NIH): Prescribing information for listed iron products (see drug-specific links above).
- CDC: Recommendations to prevent and control iron deficiency in the United States. MMWR Recomm Rep. 1998;47(RR-3):1–29.
- ACOG guidance on anemia/iron deficiency in pregnancy (use the most current ACOG Practice Bulletin and updates used by your service).
- Alternate-day dosing concept: oral iron absorption may improve with every-other-day dosing due to hepcidin dynamics (clinical practice varies; tailor to patient and severity).