Slow FE 160mg CR Tablets
WARNING: Accidental overdose of drugs that have iron in them is a leading cause of deadly poisoning in children younger than 6 years of age. Keep away from children. If this drug is taken by accident, call a doctor or poison control center right away. @ COMMON USES: It is used to aid diet needs.It is used to treat or prevent low iron in the body.It may be given to you for other reasons. Talk with the doctor.
Drug Class
Antianemic agent
Pharmacologic Class
Mineral supplement; Iron preparation
Pregnancy Category
Category A
FDA Approved
Jan 1970
DEA Schedule
Not Controlled
Overview
What is this medicine?
Slow FE is an iron supplement used to treat or prevent iron deficiency anemia. Iron is a vital mineral that your body needs to make red blood cells, which carry oxygen throughout your body. This controlled-release tablet is designed to release iron slowly, which may help reduce stomach upset.
How to Use This Medicine
Taking Your Medication Correctly
To get the most benefit from your medication, take it exactly as directed by your doctor. Carefully read all the information provided with your prescription and follow the instructions closely. For optimal effectiveness, take this medication on an empty stomach. However, if it causes stomach upset, you may take it with food. Certain foods, such as eggs, whole grain bread, cereal, dairy products, coffee, and tea, may interfere with the medication's effectiveness. If you experience stomach upset, consult your doctor about the best way to take this medication with food.
If you need to take antacids, discuss with your doctor or pharmacist whether you should take them at a different time than your medication.
Administration Instructions
Swallow the medication whole; do not chew, break, or crush it.
Take the medication with a full glass of water.
Storing and Disposing of Your Medication
Store your medication at room temperature, protected from light, and in a dry place. Avoid storing it in a bathroom. Keep all medications in a safe location, out of the reach of children and pets. Dispose of unused or expired medications properly. Do not flush them down the toilet or pour them down the drain unless instructed to do so. If you have questions about disposing of your medication, consult your pharmacist. You may also want to check if there are drug take-back programs in your area.
Missing a Dose
If you miss a dose, take it as soon as you remember. However, if it is close to the time for your next dose, skip the missed dose and resume your regular schedule. Do not take two doses at the same time or take extra doses.
To get the most benefit from your medication, take it exactly as directed by your doctor. Carefully read all the information provided with your prescription and follow the instructions closely. For optimal effectiveness, take this medication on an empty stomach. However, if it causes stomach upset, you may take it with food. Certain foods, such as eggs, whole grain bread, cereal, dairy products, coffee, and tea, may interfere with the medication's effectiveness. If you experience stomach upset, consult your doctor about the best way to take this medication with food.
If you need to take antacids, discuss with your doctor or pharmacist whether you should take them at a different time than your medication.
Administration Instructions
Swallow the medication whole; do not chew, break, or crush it.
Take the medication with a full glass of water.
Storing and Disposing of Your Medication
Store your medication at room temperature, protected from light, and in a dry place. Avoid storing it in a bathroom. Keep all medications in a safe location, out of the reach of children and pets. Dispose of unused or expired medications properly. Do not flush them down the toilet or pour them down the drain unless instructed to do so. If you have questions about disposing of your medication, consult your pharmacist. You may also want to check if there are drug take-back programs in your area.
Missing a Dose
If you miss a dose, take it as soon as you remember. However, if it is close to the time for your next dose, skip the missed dose and resume your regular schedule. Do not take two doses at the same time or take extra doses.
Lifestyle & Tips
- Take on an empty stomach (1 hour before or 2 hours after meals) for best absorption, if tolerated. If stomach upset occurs, take with food, but avoid dairy products, tea, coffee, and whole grains.
- Take with a source of Vitamin C (e.g., orange juice, a vitamin C tablet) to enhance iron absorption.
- Do not lie down for at least 10 minutes after taking the tablet to prevent esophageal irritation.
- Avoid taking with antacids, calcium supplements, or certain medications (see interactions) within 2-4 hours.
- Expect dark or black stools, which is a normal and harmless side effect of iron supplements.
- Constipation is a common side effect; increase fluid intake, dietary fiber, and consider a stool softener if needed.
Available Forms & Alternatives
Available Strengths:
Dosing & Administration
Adult Dosing
Standard Dose:
1 tablet (160 mg ferrous sulfate, equivalent to 50 mg elemental iron) orally once daily
Dose Range:
50 - 100 mg
Condition-Specific Dosing:
ironDeficiencyAnemia:
1 tablet (50 mg elemental iron) orally once daily, or as directed by physician. Doses up to 100-200 mg elemental iron per day may be used for severe deficiency, but Slow FE is typically a once-daily formulation.
Pediatric Dosing
Neonatal:
Not established (specific Slow FE formulation)
Infant:
Not established (specific Slow FE formulation)
Child:
Not established (specific Slow FE formulation); elemental iron dosing for children varies by weight and indication (e.g., 3-6 mg/kg/day for treatment, 1-2 mg/kg/day for prophylaxis). Slow FE is generally not recommended for pediatric use due to fixed dose and risk of overdose.
Adolescent:
Not established (specific Slow FE formulation); generally adult dosing may apply for older adolescents, but individual assessment is crucial.
Dose Adjustments
Renal Impairment:
Mild:
No specific adjustment needed, but monitor iron levels to avoid overload.
Moderate:
No specific adjustment needed, but monitor iron levels to avoid overload. Use with caution in patients with chronic kidney disease not on dialysis, as iron overload can occur.
Severe:
No specific adjustment needed, but monitor iron levels to avoid overload. Use with caution in patients with chronic kidney disease not on dialysis, as iron overload can occur.
Dialysis:
Oral iron may be used, but IV iron is often preferred for patients on hemodialysis due to poor oral absorption and high iron requirements. Monitor iron parameters closely.
Hepatic Impairment:
Mild:
No specific adjustment needed.
Moderate:
No specific adjustment needed, but use with caution in patients with severe liver disease due to potential for iron accumulation.
Severe:
No specific adjustment needed, but use with caution in patients with severe liver disease due to potential for iron accumulation.
Pharmacology
Mechanism of Action
Iron is an essential component of hemoglobin, myoglobin, and various enzymes. It is necessary for oxygen transport and utilization, cellular respiration, and numerous metabolic processes. Ferrous sulfate provides a readily absorbable form of iron to replenish depleted iron stores and support erythropoiesis.
Pharmacokinetics
Absorption:
Bioavailability:
5-10% (highly variable, increases to 10-30% in iron deficiency)
Tmax:
Approximately 2-4 hours (for immediate release; controlled release formulations like Slow FE have a more prolonged absorption profile, leading to a delayed and flattened Tmax)
FoodEffect:
Food, especially dairy products, tea, coffee, and whole grains, can significantly decrease iron absorption. Ascorbic acid (Vitamin C) enhances absorption. Controlled-release formulations may be less affected by food than immediate-release forms, but still generally recommended to take on an empty stomach if tolerated.
Distribution:
Vd:
Not applicable (iron is an endogenous substance, distributed throughout the body, primarily bound to transferrin in plasma and stored as ferritin/hemosiderin in tissues)
ProteinBinding:
>90% (bound to transferrin)
CnssPenetration:
Limited (does not readily cross the blood-brain barrier in significant amounts)
Elimination:
HalfLife:
Not applicable (iron is conserved and recycled in the body; elimination is minimal)
Clearance:
Minimal (primarily through shedding of cells from the GI tract, skin, and urinary tract)
ExcretionRoute:
Feces (unabsorbed iron), urine, sweat, desquamated cells
Unchanged:
Not applicable (iron is an element)
Pharmacodynamics
OnsetOfAction:
Therapeutic effects on hemoglobin levels are typically observed within 3-4 weeks of consistent therapy.
PeakEffect:
Maximum increase in hemoglobin usually occurs after 2-3 months of therapy.
DurationOfAction:
Effects persist as long as iron stores are maintained; treatment duration often 3-6 months to replete stores.
Safety & Warnings
Side Effects
Serious Side Effects: Seek Medical Help Right Away
Although rare, this medication can cause severe and potentially life-threatening side effects. If you experience any of the following symptoms, contact your doctor or seek immediate medical attention:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Fever
Black, tarry, or bloody stools
Vomiting blood or coffee ground-like material
Other Possible Side Effects
Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other unusual symptoms that bother you or do not go away, contact your doctor:
Constipation
Diarrhea
Stomach pain
Upset stomach
Vomiting
Decreased appetite
Change in stool color to green
Stomach cramps
Reporting Side Effects
This list is not exhaustive, and you may experience other side effects. If you have questions or concerns, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch. Your doctor can provide medical advice about side effects.
Although rare, this medication can cause severe and potentially life-threatening side effects. If you experience any of the following symptoms, contact your doctor or seek immediate medical attention:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Fever
Black, tarry, or bloody stools
Vomiting blood or coffee ground-like material
Other Possible Side Effects
Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other unusual symptoms that bother you or do not go away, contact your doctor:
Constipation
Diarrhea
Stomach pain
Upset stomach
Vomiting
Decreased appetite
Change in stool color to green
Stomach cramps
Reporting Side Effects
This list is not exhaustive, and you may experience other side effects. If you have questions or concerns, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch. Your doctor can provide medical advice about side effects.
Seek Immediate Medical Attention If You Experience:
- Severe stomach pain or cramps
- Vomiting (especially if blood is present or looks like coffee grounds)
- Diarrhea (especially if bloody)
- Fever
- Unusual tiredness or weakness
- Pale skin (worsening)
- Shortness of breath (worsening)
- Signs of allergic reaction (rash, itching, swelling, severe dizziness, trouble breathing)
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
Certain health conditions, including:
+ Having too much iron in your body (iron overload)
+ Anemia caused by a factor other than low iron levels
If you are currently taking another medication that contains iron
This list is not exhaustive, and it is crucial to discuss all your medications and health conditions with your doctor. Please provide your doctor and pharmacist with a comprehensive list of:
All prescription and over-the-counter (OTC) medications you are taking
Any natural products or vitamins you are using
Your health problems, including any medical conditions or allergies
Before starting, stopping, or changing the dose of any medication, including this one, you must consult with your doctor to ensure your safety. It is vital to verify that it is safe to take this medication with all your other medications and health conditions.
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
Certain health conditions, including:
+ Having too much iron in your body (iron overload)
+ Anemia caused by a factor other than low iron levels
If you are currently taking another medication that contains iron
This list is not exhaustive, and it is crucial to discuss all your medications and health conditions with your doctor. Please provide your doctor and pharmacist with a comprehensive list of:
All prescription and over-the-counter (OTC) medications you are taking
Any natural products or vitamins you are using
Your health problems, including any medical conditions or allergies
Before starting, stopping, or changing the dose of any medication, including this one, you must consult with your doctor to ensure your safety. It is vital to verify that it is safe to take this medication with all your other medications and health conditions.
Precautions & Cautions
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. Regular blood tests will be necessary, as directed by your doctor, to monitor your condition. Be sure to discuss any concerns or questions with your doctor.
Please note that this medication may interfere with certain laboratory tests. To ensure accurate results, notify all your healthcare providers and laboratory personnel that you are taking this drug.
To avoid potential risks, adhere to the prescribed dosage and frequency of this medication. Do not exceed the recommended dose or take it more often than instructed.
If you have a known allergy to tartrazine (FD&C Yellow No. 5), consult your doctor before taking this medication, as some products may contain this ingredient.
This medication can affect the absorption of other drugs. If you are taking other medications, consult your doctor or pharmacist to determine if you need to take them at a different time to minimize interactions.
If you are pregnant, planning to become pregnant, or breastfeeding, inform your doctor. It is crucial to discuss the potential benefits and risks of this medication to both you and your baby to make an informed decision.
Please note that this medication may interfere with certain laboratory tests. To ensure accurate results, notify all your healthcare providers and laboratory personnel that you are taking this drug.
To avoid potential risks, adhere to the prescribed dosage and frequency of this medication. Do not exceed the recommended dose or take it more often than instructed.
If you have a known allergy to tartrazine (FD&C Yellow No. 5), consult your doctor before taking this medication, as some products may contain this ingredient.
This medication can affect the absorption of other drugs. If you are taking other medications, consult your doctor or pharmacist to determine if you need to take them at a different time to minimize interactions.
If you are pregnant, planning to become pregnant, or breastfeeding, inform your doctor. It is crucial to discuss the potential benefits and risks of this medication to both you and your baby to make an informed decision.
Overdose Information
Overdose Symptoms:
- Severe stomach pain
- Nausea
- Vomiting (may be bloody or look like coffee grounds)
- Diarrhea
- Drowsiness
- Pale or bluish lips/skin
- Weak, rapid pulse
- Low blood pressure
- Shallow breathing
- Seizures
- Coma
What to Do:
Iron overdose is a medical emergency. Seek immediate medical attention. Call 911 or Poison Control at 1-800-222-1222. Keep iron supplements out of reach of children.
Drug Interactions
Contraindicated Interactions
- Hemochromatosis
- Hemosiderosis
- Hemolytic anemia (unless iron deficiency is also present)
- Porphyria cutanea tarda
Major Interactions
- Tetracyclines (e.g., doxycycline, minocycline): Decreased absorption of both iron and tetracycline. Separate by 2-3 hours.
- Fluoroquinolones (e.g., ciprofloxacin, levofloxacin): Decreased absorption of both iron and fluoroquinolone. Separate by 2-6 hours.
- Levothyroxine: Decreased absorption of levothyroxine. Separate by at least 4 hours.
- Bisphosphonates (e.g., alendronate, risedronate): Decreased absorption of bisphosphonates. Separate by at least 30 minutes (or as per bisphosphonate instructions).
- Mycophenolate mofetil: Decreased absorption of mycophenolate. Avoid concomitant use if possible, or monitor closely.
- Antacids (e.g., aluminum hydroxide, magnesium hydroxide): Decreased iron absorption due to increased gastric pH. Separate by 2-4 hours.
- Proton Pump Inhibitors (PPIs) (e.g., omeprazole, pantoprazole): Decreased iron absorption due to increased gastric pH. Consider alternative iron formulations or IV iron if long-term PPI use is necessary.
- H2-receptor antagonists (e.g., ranitidine, famotidine): Decreased iron absorption due to increased gastric pH. Separate by 2-4 hours.
Moderate Interactions
- Penicillamine: Decreased absorption of penicillamine. Separate by at least 2 hours.
- Chloramphenicol: May delay response to iron therapy.
- Vitamin E: May impair iron utilization, though clinical significance is debated.
- Zinc supplements: High doses of zinc may interfere with iron absorption. Separate dosing.
Minor Interactions
- Calcium supplements: May slightly decrease iron absorption. Separate dosing if possible.
- Dietary fiber, phytates (in whole grains, legumes), oxalates (in spinach, rhubarb), phosphates (in dairy): Can reduce iron absorption. Advise taking iron on an empty stomach or with vitamin C-rich foods.
Monitoring
Baseline Monitoring
Hemoglobin (Hb) and Hematocrit (Hct)
Rationale: To assess the severity of anemia and establish baseline for treatment efficacy.
Timing: Prior to initiation of therapy
Serum Ferritin
Rationale: To assess body iron stores. Low ferritin is indicative of iron deficiency.
Timing: Prior to initiation of therapy
Transferrin Saturation (TSAT) and Total Iron Binding Capacity (TIBC)
Rationale: To further characterize iron status and differentiate iron deficiency from other anemias.
Timing: Prior to initiation of therapy
Routine Monitoring
Hemoglobin (Hb) and Hematocrit (Hct)
Frequency: Every 3-4 weeks initially, then every 1-3 months until target levels are reached and maintained.
Target: Hb: Normal range for age/sex (e.g., >12 g/dL for adult females, >13 g/dL for adult males); Hct: Normal range.
Action Threshold: If Hb does not increase by at least 1-2 g/dL after 3-4 weeks, re-evaluate diagnosis, adherence, and absorption.
Serum Ferritin
Frequency: Every 3 months or after Hb normalizes, to confirm repletion of iron stores.
Target: >50 mcg/L (some sources suggest >100 mcg/L for full repletion)
Action Threshold: If ferritin remains low after 3-6 months of therapy, investigate malabsorption or ongoing blood loss.
Adverse Effects (GI symptoms)
Frequency: Regularly, especially during initial weeks of therapy.
Target: Not applicable
Action Threshold: If severe or persistent GI upset, constipation, or diarrhea, consider dose reduction, alternative formulation, or taking with food (if not already).
Symptom Monitoring
- Fatigue
- Pallor (pale skin)
- Dyspnea (shortness of breath)
- Pica (craving for non-food items like ice, dirt)
- Restless legs syndrome
- Dizziness
- Headache
- Brittle nails
- Glossitis (sore tongue)
Special Patient Groups
Pregnancy
Iron supplementation is often necessary and recommended during pregnancy to meet increased maternal and fetal iron requirements and prevent iron deficiency anemia. Ferrous sulfate is a first-line treatment.
Trimester-Specific Risks:
First Trimester:
Generally safe and often recommended for prophylaxis or treatment of deficiency.
Second Trimester:
Increased iron requirements; continued supplementation is common.
Third Trimester:
Highest iron requirements; continued supplementation is common.
Lactation
Ferrous sulfate is considered safe for use during breastfeeding. Iron is a normal component of breast milk, and supplementation in the mother does not significantly increase infant exposure to iron beyond physiological levels.
Infant Risk:
Low risk to infant (L1)
Pediatric Use
Accidental overdose of iron-containing products is a leading cause of fatal poisoning in children under 6. Slow FE is a fixed-dose adult formulation and generally not recommended for children. Pediatric dosing of elemental iron should be carefully calculated based on weight and indication, and liquid formulations are often preferred for easier dose adjustment.
Geriatric Use
Generally safe for use in geriatric patients. However, older adults may be more prone to constipation, a common side effect of iron supplements. Monitor for gastrointestinal tolerance and adjust dose or formulation if necessary. Ensure adequate fluid and fiber intake.
Clinical Information
Clinical Pearls
- Slow FE's controlled-release formulation aims to reduce gastrointestinal side effects (e.g., nausea, constipation) compared to immediate-release ferrous sulfate, making it better tolerated for some patients.
- Always advise patients that iron supplements will cause dark or black stools, which is normal and not a cause for concern.
- Emphasize the importance of taking iron with Vitamin C (e.g., orange juice) to maximize absorption, and avoiding co-administration with calcium, antacids, or certain medications.
- Iron therapy for iron deficiency anemia typically requires 3-6 months of treatment to replete iron stores, even after hemoglobin levels normalize.
- If a patient experiences persistent or severe GI side effects, consider alternative iron salts (e.g., ferrous gluconate, ferrous fumarate), lower doses, or taking with a small amount of food (if not contraindicated by interactions).
Alternative Therapies
- Dietary iron intake (red meat, fortified cereals, leafy greens)
- Intravenous (IV) iron preparations (e.g., iron dextran, iron sucrose, ferric carboxymaltose) for severe deficiency, malabsorption, or intolerance to oral iron.
Cost & Coverage
Average Cost:
$10 - $30 per 30 tablets
Generic Available:
Yes
Insurance Coverage:
Tier 1 or OTC (often covered by FSA/HSA)
General Drug Facts
If your symptoms or health issues persist or worsen, it's essential to contact your doctor for further guidance. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so be sure to check with your pharmacist for more details. If you have any questions or concerns about your medication, don't hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek medical attention. When seeking help, be prepared to provide information about the medication taken, the amount, and the time it happened.