This drug is used in people who cannot get enough phosphorus from their diets. Phosphorus is a natural body mineral that is needed for the body to work normally. It is needed for building and keeping strong bones. It also helps control the amount of calcium in the body and urine.

How to use Phos-NaK Oral
Open the packet and mix the powder in one-third of a glass (2.5 ounces or 75 milliliters) of water or other liquid such as juice. Stir the mixture well before taking all of it. Take this medication by mouth, usually 4 times a day with meals and at bedtime or as directed by your doctor.
Dosage is based on your medical condition and response to treatment.
Take this medication regularly in order to get the most benefit from it. To help you remember, take it at the same times each day.
Take this medication 2 to 3 hours before or after taking any products containing magnesium, aluminum, or calcium. Some examples include quinapril, didanosine, vitamins/minerals, and antacids. Dairy products (e.g., milk, yogurt), calcium-enriched juice, iron, and zinc are also included. These products bind with phosphate, preventing its full absorption.
If your doctor has recommended that you follow a special diet, it is very important to follow the diet to get the most benefit from this medication and prevent serious side effects. Do not take other supplements/vitamins unless ordered by your doctor.
If you are unsure about how to take this medication, ask your doctor or pharmacist.

Nausea, vomiting, diarrhea, headache, dizziness, or stomach/abdominal pain may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.
If your doctor has directed you to use this medication, remember that he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
When this medication is first started, there is a chance an old kidney stone will be passed. Tell your doctor immediately if you develop any symptoms of a kidney stone passing, including: painful/frequent urination, sudden/severe pain in the side/back/abdomen, blood in the urine.
Tell your doctor immediately if any of these unlikely but serious side effects occur: bone/joint pain, muscle cramps, swelling ankles/feet, sudden weight gain, fast/irregular heartbeat, change in the amount of urine, tingling/numbness of the hands/feet/lips, confusion, seizures, unusual weakness/tiredness, shortness of breath.
A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.
This is not a complete list of possible side effects. If you notice other side effects not listed above, contact your doctor or pharmacist.
In the US -
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before taking this medication, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have: high phosphate/potassium/sodium levels, adrenal gland problems (e.g., Addison\'s disease), infection due to kidney stones, severe kidney disease.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: bone problems (e.g., rickets, osteomalacia), kidney disease (including kidney stones), heart disease (e.g., heart failure), high blood pressure, a certain hormone problem (hypoparathyroidism), a certain muscle problem (myotonia congenita), liver disease, severe loss of body water (dehydration), too much body water (e.g., swelling of arms/legs, fluid in the lungs), severe burns/wounds, swelling of the pancreas (pancreatitis), late pregnancy problems (pre-eclampsia), a diet restricted in sodium or potassium.
This medication contains sodium. Consult your doctor for more information if you are on a salt-restricted diet or if increased salt intake could worsen your condition (e.g., congestive heart failure).
During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.
It is not known whether this drug passes into breast milk. Consult your doctor before breast-feeding.

See also How to Use section.
Your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor or pharmacist first.
Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use, especially of: corticosteroids (e.g., prednisone), digoxin, drugs that are affected by acid levels in the urine (e.g., amphetamines, chlorpropamide, methadone), medications that may increase potassium levels (e.g., eplerenone, ACE inhibitors such as lisinopril, ARBs such as valsartan, potassium-sparing diuretics/\"water pills\" such as amiloride/spironolactone/triamterene, birth control pills containing drospirenone), potassium supplements/salt substitutes.
This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist.

If overdose is suspected, contact your local poison control center or emergency room immediately. US residents can call the US National Poison Hotline at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: severe diarrhea, muscle spasms.

NOTES:
Do not share this medication with others.
Laboratory and/or medical tests (e.g., calcium/phosphorus/potassium/sodium levels, kidney function) should be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.

MISSED DOSE:
If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.

STORAGE:
Store at room temperature between 59-86 degrees F (15-30 degrees C) away from heat and moisture. Do not store in the bathroom. Keep all medicines away from children and pets.
Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.
Information last revised May 2010. Copyright(c) 2010 First Databank, Inc.