Drug reference

Ferrous fumarate

Oral iron salt (haematinic) · Antianemic

Also known as Ferretts, Ferrimin 150

START

200 mg ferrous fumarate (≈65 mg elemental) once daily

TYPICAL MAX

~180–200 mg elemental iron/day

STOP IF

Iron overload, intolerable GI effects, or no response

WATCH

Hb/ferritin response; keep away from children (overdose)

CDSCO approvedOTCATC B03AA02

Dose laddermg/d

Renal dose adjustmenteGFR mL/min/1.73m²

KDIGO 2024 + manufacturer label

Pharmacokineticsplasma · t hours

ONSET: 3d · reticulocytosis
PEAK: 8w · Hb ~8 wk
t½: 36s · physiologic
DURATION: 1d · daily dosing

EXCRETION

No active excretion; loss via shed cells

route + CYP

INTERACTIONS

3 major

SEVERE in our sources

PREGNANCY

Safe and recommended where indicated.

FDA category + note

Top interactionssee all 12 →

BictegravirSevereDatabaseDDInter
DimercaprolSevereDatabaseDDInter
DolutegravirSevereDatabaseDDInter

Mechanism

Provides ferrous iron (Fe2+) for duodenal absorption to replenish iron stores for haemoglobin/myoglobin synthesis; ferrous fumarate is a high-elemental-iron salt (~33%).

Indications

Iron-deficiency anaemia (treatment)Prevention of iron deficiency (increased demand)

Dosing

Adult: Ferrous fumarate 200 mg (≈65 mg elemental iron) 1–3 times daily (or once-daily/alternate-day for tolerability and absorption).
Pediatric: 3–6 mg/kg/day elemental iron divided.
Renal adjustment: No adjustment for oral iron (consider IV iron in CKD).
Hepatic adjustment: No specific adjustment.
Geriatric: Once-daily/alternate-day often better tolerated.
Max dose: ~180–200 mg elemental iron/day (treatment)

Pharmacokinetics

Onset

Reticulocytosis ~3–10 days; Hb rise over weeks

Peak effect

Hb correction ~6–8 weeks

Duration

Dosing-dependent

Half-life

Not applicable (physiologic iron handling)

Bioavailability

~10–20% (food reduces; higher if deficient)

Protein binding

Transferrin-transported

Metabolism

Not metabolised (incorporated into haem)

Excretion

No active excretion; loss via shed cells

Contraindications

Iron overload (haemochromatosis, haemosiderosis)
Haemolytic anaemia without iron deficiency
Repeated transfusions
Hypersensitivity

Side effects

Common

ConstipationNausea/epigastric painBlack stoolsDiarrhoea

Serious

Acute iron overdose (children — potentially fatal)
GI ulceration (modified-release lodgement)
Iron overload (chronic excess)

Pregnancy & lactation

Pregnancy

Safe and recommended where indicated.

Lactation

Compatible with breastfeeding.

Drug interactions

Bictegravir

Severe

Database

Clinical effect not specified

Source: DDInter

Dimercaprol

Severe

Database

Clinical effect not specified

Source: DDInter

Dolutegravir

Severe

Database

Clinical effect not specified

Source: DDInter

Ciprofloxacin

Moderate

Textbook-cited

Therapeutic failure of the antibiotic.