Niferex: Uses, Dosage & Side Effects

What Is Niferex and What Is It Used For?

Niferex is a form of iron taken by mouth for the treatment of, or prevention of, iron deficiency. Each capsule contains 567.7 mg of iron(II) glycine sulfate complex, equivalent to 100 mg of elemental ferrous iron (Fe²⁺). Iron is an essential mineral that plays a critical role in oxygen transport through hemoglobin in red blood cells and in energy transfer throughout the body.

The capsules are enteric-coated, meaning they do not release their contents in the stomach. Instead, the iron is delivered to the small intestine (duodenum and jejunum), where it is absorbed most efficiently. This design reduces the gastrointestinal side effects commonly associated with oral iron preparations, such as nausea and stomach pain, while also enhancing bioavailability.

Iron deficiency is the most prevalent nutritional deficiency worldwide, affecting an estimated 1.2 billion people according to the World Health Organization. It is particularly common among women of reproductive age, pregnant women, young children, and individuals with chronic blood loss. When iron stores are depleted, the body cannot produce sufficient hemoglobin, leading to iron deficiency anemia — a condition characterized by fatigue, pallor, weakness, shortness of breath, and impaired cognitive function.

Niferex is indicated for the treatment of established iron deficiency, whether or not anemia is present, and for the prevention of iron deficiency in at-risk populations such as pregnant women, regular blood donors, and patients with chronic conditions that increase iron requirements. It is available over-the-counter in some pack sizes and by prescription in others, depending on the country of purchase.

Niferex is approved and marketed in several European countries under different brand names, including Ferro sanol duodenal (Germany, Greece, Spain) and Obsidan (Poland). It is manufactured by Aesica Pharmaceuticals GmbH on behalf of UCB Pharma GmbH.

What Should You Know Before Taking Niferex?

Before starting Niferex, it is essential to understand who should not take this medication, what precautions to observe, and which conditions require special monitoring. Although Niferex is available without a prescription in certain formulations, iron supplementation should ideally be guided by blood tests confirming iron deficiency, as excessive iron intake can be harmful.

Contraindications

Do not use Niferex if any of the following apply to you:

• Allergy to the active ingredient — hypersensitivity to iron(II) glycine sulfate complex or any of the excipients listed in the composition section.
• Esophageal stricture — narrowing of the esophagus that could cause the capsule to become lodged.
• Hemochromatosis — a hereditary condition causing excessive iron accumulation in organs, potentially leading to liver damage, heart disease, and diabetes.
• Iron-overloading conditions — including thalassemia, chronic hemolysis, and other hemoglobinopathies where repeated red blood cell destruction releases excessive iron.
• Iron utilization disorders — such as sideroblastic anemia or lead poisoning anemia, where the body cannot incorporate iron into hemoglobin properly.
• Repeated blood transfusions — each unit of transfused blood contains approximately 200–250 mg of iron, which accumulates over time.
• Children under 6 years of age or children weighing less than 20 kg should not take Niferex capsules.

Warnings and Precautions

Talk to your healthcare provider before using Niferex if you have any of the following conditions, as they may require careful monitoring or dose adjustments:

• Gastrointestinal diseases — including inflammatory bowel disease (Crohn's disease, ulcerative colitis), esophageal stricture, intestinal stricture, diverticular disease, gastritis, or gastric and duodenal ulcers. Iron can irritate the mucosal lining and worsen these conditions.
• Chronic kidney disease requiring erythropoietin — in patients with renal failure, oral iron absorption is significantly reduced. Intravenous iron is generally preferred in this population.
• Impaired liver function or alcohol dependency — these conditions can alter iron metabolism and increase the risk of iron overload.
• Unexplained anemia or iron deficiency in elderly patients — the underlying cause of blood loss (e.g., gastrointestinal malignancy, peptic ulcer disease) should be thoroughly investigated before starting iron supplementation.

Pregnancy and Breastfeeding

There are no known risks associated with using Niferex during pregnancy or breastfeeding. Iron supplementation is commonly recommended during pregnancy to meet the increased iron demands of both the mother and the developing fetus. The WHO recommends daily iron supplementation for pregnant women in areas where anemia prevalence is high. However, you should always consult your healthcare provider before starting any medication during pregnancy or while breastfeeding to determine the appropriate dose for your individual needs.

Iron is excreted in breast milk in small amounts. Supplementation with Niferex during lactation is considered safe and may help replenish maternal iron stores depleted during pregnancy and childbirth.

Children

Niferex capsules should not be used in children under 6 years of age or in children weighing less than 20 kg. For children aged 6 years and older who weigh at least 20 kg, a dose of 1 capsule daily is generally appropriate. Adolescents with pronounced iron deficiency and a body weight of at least 50 kg may receive higher doses as directed by their physician.

Driving and Operating Machinery

Niferex does not affect the ability to drive or operate machinery. No special precautions are needed.

Sodium Content

Niferex contains less than 1 mmol (23 mg) of sodium per capsule and is therefore considered essentially sodium-free. This is relevant for patients on sodium-restricted diets.

How Does Niferex Interact with Other Drugs?

Iron supplements have extensive interactions with other medications, primarily because iron forms insoluble complexes with many drugs in the gastrointestinal tract, reducing the absorption of both the iron and the interacting medication. Understanding these interactions is critical for ensuring the effectiveness of all your treatments. Always inform your healthcare provider about every medication, supplement, and herbal product you are taking.

Major Interactions

The following interactions are clinically significant and require careful management:

Other Important Interactions

Food and Drink Interactions

Niferex should not be taken with food. Certain substances in food can form insoluble complexes with iron, dramatically reducing absorption. The key dietary interactions include:

• Phytates — found in cereals, whole grains, legumes, and nuts. Phytic acid is one of the most potent inhibitors of non-heme iron absorption.
• Oxalates — present in spinach, rhubarb, beets, and chocolate.
• Phosphates — abundant in dairy products, processed foods, and carbonated beverages.
• Polyphenols and tannins — found in coffee, tea (especially black tea), red wine, and cocoa. These can reduce iron absorption by up to 60–90%.
• Calcium — present in milk, cheese, yogurt, and calcium-fortified foods. Calcium inhibits both heme and non-heme iron absorption.

Allow at least 2 hours between consuming any of these products and taking Niferex. Taking Niferex on an empty stomach (e.g., first thing in the morning, or between meals) provides the best absorption.

What Is the Correct Dosage of Niferex?

Always take Niferex exactly as described in the patient information leaflet or as directed by your healthcare provider. The maximum daily dose should not exceed 5 mg of elemental iron per kilogram of body weight. For example, a person weighing 60 kg should not take more than 300 mg (3 capsules) per day.

Adults

Children

Elderly

No specific dose adjustment is required for elderly patients. However, in older adults presenting with iron deficiency anemia of unknown origin, the underlying cause (particularly gastrointestinal blood loss from conditions such as peptic ulcer disease, colorectal cancer, or angiodysplasia) must be thoroughly investigated before starting iron supplementation. The standard adult dosing applies.

How to Take Niferex

• Swallow the capsule whole with plenty of water. Do not chew the capsule, as this will destroy the enteric coating and cause the iron to be released in the stomach.
• Take on an empty stomach for optimal absorption — either first thing in the morning before breakfast, or between two main meals.
• If swallowing is difficult, the capsule may be opened: carefully pull apart the two capsule halves over a bowl, shake out the granules onto a spoon, and swallow them. Follow with a drink of water.
• Space doses evenly throughout the day if taking more than one capsule daily.

Missed Dose

If you forget to take a dose of Niferex, do not take a double dose to make up for the missed one. Simply skip the missed dose and continue with your regular schedule. If you miss several doses, you may need to extend your overall treatment duration slightly. Consult your healthcare provider if you are frequently forgetting doses.

Overdose

Symptoms of iron overdose develop in stages and may include:

• Early phase (0–6 hours): restlessness, severe abdominal pain, nausea, vomiting (possibly blood-stained), and diarrhea. Stools may appear dark or tarry.
• Latent phase (6–24 hours): deceptive apparent improvement where symptoms temporarily subside.
• Systemic toxicity (12–48 hours): shock, metabolic acidosis, convulsions, Cheyne-Stokes respiration (alternating deep and shallow breathing), loss of consciousness, pulmonary edema, liver failure, and potentially death.

Treatment of iron overdose typically involves whole bowel irrigation, and in severe cases, administration of deferoxamine (an iron chelating agent) and intensive supportive care.

Treatment Duration

Your healthcare provider will determine how long you need to take Niferex based on your blood test results. As a general guide:

• Iron deficiency anemia: treatment typically lasts 10–20 weeks or longer, depending on the severity of the deficiency and the underlying cause.
• Replenishing iron stores: after hemoglobin levels have normalized, continued supplementation for an additional 3–6 months is often recommended to fully replenish ferritin (stored iron) levels.
• Prevention: duration varies according to the specific situation (pregnancy, blood donation, chronic hemodialysis, or planned autologous transfusion).

Regular blood tests (hemoglobin, serum ferritin, transferrin saturation) should be performed to monitor treatment response and determine when to stop supplementation.

What Are the Side Effects of Niferex?

Like all medicines, Niferex can cause side effects, although not everyone will experience them. Most side effects are gastrointestinal in nature and tend to improve as your body adjusts to the medication. The enteric coating of Niferex is specifically designed to reduce stomach irritation compared to non-coated iron preparations.

Dark stools: This is a completely normal and expected effect of oral iron therapy. The unabsorbed iron is excreted in the stool, giving it a dark or black appearance. This is harmless and should not be confused with gastrointestinal bleeding (melena). However, if you experience severe abdominal pain along with dark stools, contact your healthcare provider to rule out other causes.

Tooth discoloration: In rare cases, iron preparations can stain the teeth, particularly if the capsule is opened and the granules come into contact with tooth enamel. This discoloration typically disappears after stopping treatment. If it persists, it can be removed with an abrasive toothpaste or by professional dental cleaning.

If you experience side effects that are bothersome or do not resolve, speak with your healthcare provider. They may adjust your dose, suggest taking the medication with a small amount of food (noting this will reduce absorption), or recommend an alternative iron preparation.

How Should You Store Niferex?

Proper storage of Niferex is important to ensure the medication remains effective and safe throughout its shelf life. Follow these storage guidelines:

• Temperature: Store at or below 25°C (77°F). Do not freeze.
• Packaging: Keep capsules in the original blister packaging to protect from moisture and light.
• Child safety: Store out of sight and reach of children. Iron poisoning from accidental ingestion is a serious risk for young children.
• Expiry date: Do not use Niferex after the expiry date stated on the carton and blister packaging. The expiry date refers to the last day of the stated month.
• Disposal: Do not dispose of medications in household waste or wastewater. Ask your pharmacist about proper disposal methods to protect the environment.

What Does Niferex Contain?

Active substance: Iron(II) glycine sulfate complex. Each capsule contains 567.7 mg of the complex, equivalent to 100 mg of elemental ferrous iron (Fe²⁺).

Other ingredients in the iron granules:

• Ascorbic acid (vitamin C) — enhances iron absorption
• Microcrystalline cellulose
• Hypromellose
• Hydroxypropylcellulose
• Methacrylic acid-ethyl acrylate copolymer (1:1) dispersion 30% (Eudragit L 30 D-55) — the enteric coating that prevents stomach release
• Acetyltriethyl citrate
• Talc

Capsule shell:

• Bottom half: gelatin, titanium dioxide (E 171), red iron oxide (E 172), yellow iron oxide (E 172) — orange, opaque
• Top half: gelatin, titanium dioxide (E 171), red iron oxide (E 172), black iron oxide (E 172) — chocolate brown, opaque

Appearance: Hard enteric-coated gelatin capsule, approximately 21.7 mm × 7.5 mm, with a chocolate-brown opaque cap and an orange opaque body. The capsule contains grey-brown enteric-coated granules.

Available pack sizes: 30, 50, and 100 capsules (available without prescription); 90 and 500×1 capsules (prescription-only in some markets). Not all pack sizes may be marketed in every country.