Micro-K 8meq CR Capsules
It is used to treat or prevent low potassium levels.
Drug Class
Electrolyte replacement; Potassium supplement
Pharmacologic Class
Mineral/Electrolyte
Pregnancy Category
Category C
FDA Approved
Jan 1970
DEA Schedule
Not Controlled
Overview
What is this medicine?
Potassium chloride is a mineral supplement used to prevent or treat low levels of potassium in your blood. Potassium is very important for your heart, muscles, and nerves to work properly.
How to Use This Medicine
Taking Your Medication Correctly
To ensure you get the most benefit from your medication, follow these steps:
Take your medication exactly as directed by your doctor.
Read all the information provided with your medication and follow the instructions carefully.
Take your medication with or immediately after a meal.
Swallow your medication with a full glass of water.
Swallow the medication whole; do not chew, break, or crush it.
Do not suck on the medication.
If you have trouble swallowing, consult your doctor for guidance.
If you need to, you can sprinkle the contents of the capsule onto applesauce or another soft food. However, do not chew the mixture. Swallow it immediately and follow with a glass of water or juice.
Avoid mixing the medication with hot food.
After preparing your dose, take it right away. Do not store it for later use.
Storing and Disposing of Your Medication
To maintain the effectiveness and safety of your medication:
Store it at room temperature, protected from light.
Keep it in a dry place.
Do not store your medication 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 by your pharmacist or healthcare provider.
Check with your pharmacist for guidance on the best way to dispose of your medication. You may also want to explore drug take-back programs in your area.
What to Do If You Miss a Dose
If you miss a dose of your medication:
Take the missed dose as soon as you remember.
If it is close to the time for your next scheduled dose, skip the missed dose and continue with your regular dosing schedule.
* Do not take two doses at the same time or take extra doses to make up for a missed dose.
To ensure you get the most benefit from your medication, follow these steps:
Take your medication exactly as directed by your doctor.
Read all the information provided with your medication and follow the instructions carefully.
Take your medication with or immediately after a meal.
Swallow your medication with a full glass of water.
Swallow the medication whole; do not chew, break, or crush it.
Do not suck on the medication.
If you have trouble swallowing, consult your doctor for guidance.
If you need to, you can sprinkle the contents of the capsule onto applesauce or another soft food. However, do not chew the mixture. Swallow it immediately and follow with a glass of water or juice.
Avoid mixing the medication with hot food.
After preparing your dose, take it right away. Do not store it for later use.
Storing and Disposing of Your Medication
To maintain the effectiveness and safety of your medication:
Store it at room temperature, protected from light.
Keep it in a dry place.
Do not store your medication 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 by your pharmacist or healthcare provider.
Check with your pharmacist for guidance on the best way to dispose of your medication. You may also want to explore drug take-back programs in your area.
What to Do If You Miss a Dose
If you miss a dose of your medication:
Take the missed dose as soon as you remember.
If it is close to the time for your next scheduled dose, skip the missed dose and continue with your regular dosing schedule.
* Do not take two doses at the same time or take extra doses to make up for a missed dose.
Lifestyle & Tips
- Take with food or immediately after a meal to reduce stomach upset.
- Swallow the capsule whole; do not crush, chew, or suck on the capsule, as this can cause irritation or ulceration of the esophagus.
- If you have trouble swallowing the capsule, some formulations allow sprinkling the contents on soft food (e.g., applesauce) and swallowing immediately without chewing. Check specific product instructions.
- Avoid salt substitutes that contain potassium unless advised by your doctor.
- Report any signs of severe stomach pain, black/tarry stools, or vomiting blood immediately.
Available Forms & Alternatives
Available Strengths:
Generic Alternatives:
Dosing & Administration
Adult Dosing
Standard Dose:
20-100 mEq/day in 1-2 divided doses
Dose Range:
20 - 100 mg
Condition-Specific Dosing:
hypokalemia_prevention:
20 mEq/day
mild_moderate_hypokalemia:
40-80 mEq/day
severe_hypokalemia:
Higher doses may be required, often initiated intravenously with careful monitoring
Pediatric Dosing
Neonatal:
Not established (use with extreme caution, consult specialist)
Infant:
Weight-based dosing (e.g., 2-3 mEq/kg/day in divided doses), consult specific guidelines
Child:
Weight-based dosing (e.g., 2-3 mEq/kg/day in divided doses, max 100 mEq/day), consult specific guidelines
Adolescent:
Similar to adult dosing, based on severity and weight, consult specific guidelines
Dose Adjustments
Renal Impairment:
Mild:
Use with caution, monitor serum potassium closely
Moderate:
Reduce dose significantly or avoid, monitor serum potassium closely
Severe:
Contraindicated due to high risk of hyperkalemia
Dialysis:
Contraindicated in most cases, unless specifically indicated for hypokalemia and under strict monitoring
Hepatic Impairment:
Mild:
No specific adjustment needed, monitor serum potassium
Moderate:
No specific adjustment needed, monitor serum potassium
Severe:
No specific adjustment needed, monitor serum potassium (renal function is primary concern)
Pharmacology
Mechanism of Action
Potassium is the major intracellular cation and is essential for the maintenance of intracellular tonicity, nerve impulse transmission, cardiac contraction, skeletal and smooth muscle contraction, and maintenance of normal renal function. It is involved in many enzymatic reactions and plays a role in carbohydrate metabolism and protein synthesis. Potassium chloride supplements replace depleted potassium stores.
Pharmacokinetics
Absorption:
Bioavailability:
Well absorbed (nearly 90% from GI tract)
Tmax:
Approximately 4-6 hours for extended-release formulations
FoodEffect:
Food may delay absorption but generally enhances tolerability and reduces GI upset; recommended to take with food.
Distribution:
Vd:
Approximately 0.5 L/kg (reflects total body water)
ProteinBinding:
Negligible
CnssPenetration:
Limited (primarily extracellular, but essential for neuronal function)
Elimination:
HalfLife:
Not applicable (homeostatically regulated, but renal excretion is rapid)
Clearance:
Primarily renal (glomerular filtration and tubular secretion)
ExcretionRoute:
Renal (90%), Fecal (10%)
Unchanged:
Nearly 100%
Pharmacodynamics
OnsetOfAction:
Hours (for oral extended-release to achieve steady state)
PeakEffect:
4-8 hours (for extended-release)
DurationOfAction:
12-24 hours (due to extended-release formulation)
Safety & Warnings
Side Effects
Urgent Side Effects: Seek Medical Help Right Away
While rare, some people may experience severe and potentially life-threatening side effects when taking this medication. If you notice 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
Signs of high potassium levels, including:
+ Abnormal heartbeat
+ Confusion
+ Weakness, lightheadedness, or dizziness
+ Feeling like passing out
+ Numbness or tingling
+ Shortness of breath
Slow heartbeat
Chest pain or pressure
Signs of bowel problems, such as:
+ Black, tarry, or bloody stools
+ Fever
+ Mucus in the stools
+ Vomiting blood or coffee ground-like vomit
+ Severe stomach pain, constipation, or diarrhea
Abdominal swelling
Other Possible Side Effects
Like all medications, this drug can cause side effects. Many people may not experience any side effects or only minor ones. If you notice any of the following side effects or any other symptoms that bother you or do not go away, contact your doctor:
Stomach pain or diarrhea
Upset stomach or vomiting
* Gas
This is not an exhaustive list of possible side effects. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
While rare, some people may experience severe and potentially life-threatening side effects when taking this medication. If you notice 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
Signs of high potassium levels, including:
+ Abnormal heartbeat
+ Confusion
+ Weakness, lightheadedness, or dizziness
+ Feeling like passing out
+ Numbness or tingling
+ Shortness of breath
Slow heartbeat
Chest pain or pressure
Signs of bowel problems, such as:
+ Black, tarry, or bloody stools
+ Fever
+ Mucus in the stools
+ Vomiting blood or coffee ground-like vomit
+ Severe stomach pain, constipation, or diarrhea
Abdominal swelling
Other Possible Side Effects
Like all medications, this drug can cause side effects. Many people may not experience any side effects or only minor ones. If you notice any of the following side effects or any other symptoms that bother you or do not go away, contact your doctor:
Stomach pain or diarrhea
Upset stomach or vomiting
* Gas
This is not an exhaustive list of possible side effects. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Symptoms of too much potassium (hyperkalemia): unusual tiredness, muscle weakness, tingling in hands or feet, slow or irregular heartbeat, confusion, paralysis.
- Symptoms of stomach irritation/ulceration: severe stomach pain, nausea, vomiting, black or tarry stools, blood in vomit.
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 symptoms you experienced.
If you have high potassium levels in your blood.
If you are currently taking any of the following medications: Amiloride, Eplerenone, Spironolactone, or Triamterene.
If you have any of the following health conditions:
+ A bowel blockage or obstruction
+ A slow-moving gastrointestinal (GI) tract
+ Slow stomach emptying or gastric clearance
+ Heart disease accompanied by esophageal problems
+ If you are taking other medications classified as anticholinergics, such as Ipratropium or Oxybutynin. If you are unsure whether any of your medications fall into this category, consult your doctor.
Please note that this list is not exhaustive, and it is crucial to discuss all your medications (including prescription, over-the-counter, natural products, and vitamins) and health problems with your doctor and pharmacist. This will help ensure your safety while taking this medication. Never start, stop, or adjust the dosage of any medication without first consulting 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 symptoms you experienced.
If you have high potassium levels in your blood.
If you are currently taking any of the following medications: Amiloride, Eplerenone, Spironolactone, or Triamterene.
If you have any of the following health conditions:
+ A bowel blockage or obstruction
+ A slow-moving gastrointestinal (GI) tract
+ Slow stomach emptying or gastric clearance
+ Heart disease accompanied by esophageal problems
+ If you are taking other medications classified as anticholinergics, such as Ipratropium or Oxybutynin. If you are unsure whether any of your medications fall into this category, consult your doctor.
Please note that this list is not exhaustive, and it is crucial to discuss all your medications (including prescription, over-the-counter, natural products, and vitamins) and health problems with your doctor and pharmacist. This will help ensure your safety while taking this medication. Never start, stop, or adjust the dosage of any medication without first consulting your doctor.
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.
To minimize the risk of severe side effects, it is crucial to adhere to the prescribed dosage and not exceed the amount recommended by your doctor. If you follow a low-salt diet or use a salt substitute, consult with your doctor to discuss any potential interactions.
If you are pregnant, planning to become pregnant, or are breastfeeding, notify your doctor immediately. You and your doctor will need to carefully weigh the benefits and risks of this medication to both you and your baby.
To minimize the risk of severe side effects, it is crucial to adhere to the prescribed dosage and not exceed the amount recommended by your doctor. If you follow a low-salt diet or use a salt substitute, consult with your doctor to discuss any potential interactions.
If you are pregnant, planning to become pregnant, or are breastfeeding, notify your doctor immediately. You and your doctor will need to carefully weigh the benefits and risks of this medication to both you and your baby.
Overdose Information
Overdose Symptoms:
- Muscle weakness (flaccid paralysis)
- Paresthesias (tingling or numbness)
- Bradycardia (slow heart rate)
- Hypotension (low blood pressure)
- Cardiac arrhythmias (irregular heartbeats, including ventricular fibrillation and asystole)
- ECG changes (peaked T waves, prolonged PR interval, widened QRS complex, loss of P wave, sine wave pattern)
What to Do:
Seek immediate medical attention. Call 911 or Poison Control at 1-800-222-1222. Treatment may involve IV calcium (for cardiac stability), IV insulin and glucose, sodium bicarbonate, diuretics, or dialysis.
Drug Interactions
Contraindicated Interactions
- Potassium-sparing diuretics (e.g., spironolactone, triamterene, amiloride)
- Eplerenone
Major Interactions
- ACE inhibitors (e.g., lisinopril, enalapril)
- Angiotensin Receptor Blockers (ARBs) (e.g., valsartan, losartan)
- Nonsteroidal Anti-inflammatory Drugs (NSAIDs) (e.g., ibuprofen, naproxen) - especially in patients with renal impairment
- Cyclosporine
- Tacrolimus
- Digoxin (potassium depletion increases digoxin toxicity, but hyperkalemia can reduce its effects)
Moderate Interactions
- Beta-blockers (may reduce potassium excretion)
- Heparin (may cause hyperkalemia)
- Succinylcholine (may cause acute hyperkalemia)
Monitoring
Baseline Monitoring
Serum Potassium
Rationale: To establish baseline and guide initial dosing
Timing: Prior to initiation
Renal Function (BUN, Creatinine, eGFR)
Rationale: To assess ability to excrete potassium and determine hyperkalemia risk
Timing: Prior to initiation
ECG (if severe hypokalemia or cardiac risk factors)
Rationale: To assess for cardiac manifestations of hypokalemia
Timing: Prior to initiation
Routine Monitoring
Serum Potassium
Frequency: Initially daily or every few days until stable, then weekly to monthly depending on patient stability and concomitant medications
Target: 3.5-5.0 mEq/L
Action Threshold: Below 3.5 mEq/L (increase dose), Above 5.0 mEq/L (reduce dose or discontinue), Above 5.5 mEq/L (urgent intervention)
Renal Function (BUN, Creatinine)
Frequency: Periodically, especially if renal function changes or interacting drugs are added
Target: Normal limits
Action Threshold: Significant increase in creatinine or decrease in eGFR (re-evaluate potassium dosing)
ECG
Frequency: As clinically indicated, especially if hyperkalemia is suspected or patient has cardiac symptoms
Target: Normal rhythm, no T wave peaking or QRS widening
Action Threshold: Peaked T waves, prolonged PR, widened QRS, absent P waves, sine wave (urgent intervention for hyperkalemia)
Symptom Monitoring
- Symptoms of hyperkalemia: muscle weakness, fatigue, paresthesias, bradycardia, irregular heartbeat, confusion, flaccid paralysis
- Symptoms of hypokalemia (if treatment is insufficient): muscle weakness, cramps, fatigue, constipation, palpitations, polyuria
Special Patient Groups
Pregnancy
Category C. Potassium is an essential electrolyte. Use during pregnancy only if clearly needed and the potential benefits outweigh the potential risks. Close monitoring of maternal potassium levels is crucial.
Trimester-Specific Risks:
First Trimester:
No specific data suggesting increased risk of congenital anomalies, but electrolyte balance is critical.
Second Trimester:
Generally considered safe if maternal potassium levels are monitored and maintained within normal range.
Third Trimester:
Generally considered safe if maternal potassium levels are monitored and maintained within normal range. Avoid hyperkalemia near term.
Lactation
Potassium is naturally present in breast milk. Supplemental potassium chloride is generally considered compatible with breastfeeding when used at therapeutic doses, as it is an essential electrolyte. Monitor infant for any signs of electrolyte imbalance, though unlikely.
Infant Risk:
Low risk. The amount transferred into breast milk is unlikely to cause adverse effects in a healthy, full-term infant.
Pediatric Use
Used in pediatric patients for hypokalemia, but dosing must be carefully calculated based on weight and severity of deficiency. Renal function must be assessed. Risk of hyperkalemia is higher in infants and young children due to smaller body mass and developing renal function. Close monitoring of serum potassium is essential.
Geriatric Use
Elderly patients are at increased risk of hyperkalemia due to age-related decline in renal function and increased likelihood of concomitant medications (e.g., ACE inhibitors, ARBs, NSAIDs) that impair potassium excretion. Lower starting doses and more frequent monitoring of serum potassium and renal function are recommended.
Clinical Information
Clinical Pearls
- Always take potassium chloride extended-release capsules with food or immediately after a meal to minimize gastrointestinal irritation and improve tolerability.
- Do NOT crush, chew, or suck on the capsules. This can lead to a rapid release of potassium, causing local irritation, ulceration, and potentially systemic hyperkalemia.
- Regular monitoring of serum potassium levels and renal function (BUN, creatinine) is critical, especially at initiation, dose changes, or in patients with renal impairment or on interacting medications.
- Advise patients to avoid salt substitutes containing potassium unless specifically instructed by their healthcare provider.
- Educate patients on the symptoms of hyperkalemia (e.g., muscle weakness, fatigue, irregular heartbeat) and to seek immediate medical attention if they occur.
- Consider alternative formulations (e.g., liquid solution) for patients who have difficulty swallowing capsules or are at high risk for esophageal ulceration.
Alternative Therapies
- Dietary potassium intake (e.g., bananas, oranges, potatoes, leafy greens)
- Intravenous potassium chloride (for severe or symptomatic hypokalemia, or when oral intake is not feasible)
Cost & Coverage
Average Cost:
$15 - $50 per 30 capsules (generic)
Generic Available:
Yes
Insurance Coverage:
Tier 1 or Tier 2 (for generic formulations)
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 information. If you have any questions or concerns about this 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 details about the medication, including the amount taken and the time it happened, to facilitate prompt and effective treatment.