K-Phos Original

Phosphates are used as dietary supplements for patients who are unable to get enough phosphorus in their regular diet, usually because of certain illnesses or diseases. Phosphate is the drug form (salt) of phosphorus. Some phosphates are used to make the urine more acid, which helps treat certain urinary tract infections. Some phosphates are used to prevent the formation of calcium stones in the urinary tract.

Injectable phosphates are to be administered only by or under the supervision of your health care professional. Some of these oral preparations are available only with a prescription. Others are available without a prescription; however, your health care professional may have special instructions on the proper dose of this medicine for your medical condition. You should take phosphates only under the supervision of your health care professional.

Your health care professional should check your progress at regular visits to make sure that this medicine does not cause unwanted effects.

Do not take iron supplements within 1 to 2 hours of taking this medicine. To do so may keep the iron from working properly.

For patients taking potassium phosphate-containing medicines:

• Check with your health care professional before starting any strenuous physical exercise, especially if you are out of condition and are taking other medication. Exercise and certain medicines may increase the amount of potassium in the blood.

For patients on a potassium-restricted diet:

• This medicine may contain a large amount of potassium. If you have any questions about this, check with your health care professional.
• Do not use salt substitutes and low-salt milk unless told to do so by your health care professional. They may contain potassium.

For patients on a sodium-restricted diet:

• This medicine may contain a large amount of sodium. If you have any questions about this, check with your health care professional.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• Confusion
• convulsions (seizures)
• decrease in amount of urine or in frequency of urination
• fast, slow, or irregular heartbeat
• headache or dizziness
• increased thirst
• muscle cramps
• numbness, tingling, pain, or weakness in hands or feet
• numbness or tingling around lips
• shortness of breath or troubled breathing
• swelling of feet or lower legs
• tremor
• unexplained anxiety
• unusual tiredness or weakness
• weakness or heaviness of legs
• weight gain

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

• Diarrhea
• nausea or vomiting
• stomach pain

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

For all uses of this medicine:

• Tell all of your health care providers that you take K-Phos Original. This includes your doctors, nurses, pharmacists, and dentists.
• Have blood work checked as you have been told by the doctor. Talk with the doctor.
• If you are taking a salt substitute that has potassium, potassium-sparing diuretics, or potassium, talk with your doctor.
• Do not take antacids that have aluminum, magnesium, or calcium in them with this medicine.
• Tell your doctor if you are pregnant or plan on getting pregnant. You will need to talk about the benefits and risks of using K-Phos Original while you are pregnant.
• Tell your doctor if you are breast-feeding. You will need to talk about any risks to your baby.

For lowering the urine's pH:

• If you have kidney stones, you may pass old stones when this medicine is started. Talk with your doctor.

This product is contraindicated in patients with infected phosphate stones; in patients with severely impaired renal function (less than 30% of normal) and in the presence of hyperphosphatemia and hyperkalemia.

Gastrointestinal upset (diarrhea, nausea, stomach pain, and vomiting) may occur with the use of potassium phosphate. Also, bone and joint pain (possible phosphate-induced osteomalacia) could occur. The following adverse effects may be observed with potassium administration: irregular heartbeat; dizziness; mental confusion; weakness or heaviness of legs; unusual tiredness; muscle cramps; numbness, tingling, pain, or weakness in hands or feet; numbness or tingling around lips; shortness of breath or troubled breathing.

Two tablets dissolved in 6-8 oz. of water 4 times daily with meals and at bedtime. For best results, let the tablets soak in water for 2 to 5 minutes, or more if necessary, and stir. If any tablet particles remain undissolved, they may be crushed and stirred vigorously to speed dissolution.

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

• Loose stools (diarrhea).
• Upset stomach or throwing up.
• Stomach pain.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-FDA-1088. You may also report side effects at http://www.fda.gov/medwatch.

Some side effects of K-Phos Original may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

Applies to potassium phosphate: intravenous solution

Along with its needed effects, potassium phosphate may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking potassium phosphate:

• Burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
• chest pain or discomfort
• confusion
• dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
• fast, slow, or irregular heartbeat
• muscle cramps in the hands, arms, feet, legs, or face
• no muscle tone or movement
• numbness and tingling around the mouth, fingertips, or feet
• pounding or rapid pulse
• shortness of breath
• unusual tiredness or weakness
• weakness and heaviness of the legs

Due to the high risk of hyperkalemia and hyperphosphatemia, chronic potassium phosphate therapy is generally not required nor recommended for patients with renal dysfunction.

Potassium is readily removed by hemodialysis. A dialysate potassium concentration should be chosen that will reduce serum potassium to 4.0 mEq/L based on the fractional dialyzer urea clearance (Kt/V) required. In the average patient requiring hemodialysis, the predialysis potassium is usually 5 to 6 mEq/L. Using a Kt/V of 1.0, a dialysate potassium of 2.0 mEq/L will result in end dialysis serum potassium levels ranging from 3.5 to 3.8 mEq/L. If the patient is extremely acidotic at the start of hemodialysis, correction of acidosis may cause an abrupt reduction in serum potassium, necessitating the need for hourly serum potassium measurements to decrease the risk of hypokalemia and possible cardiac arrhythmias.

Phosphate is removed by hemodialysis. The hemodialysis clearance of phosphate averages 100 to 150 mL/min over blood flow rates ranging from 150 to 400 mL/min for a typical hollow fiber dialyzer.

Potassium is readily removed by peritoneal dialysis. While potassium-free dialysate is usually used for the initial peritoneal dialysis exchanges, potassium is sometimes added during long periods of cycling (24 to 48 hours) at a concentration equivalent to the desired serum concentration.

Phosphate is removed by peritoneal dialysis. In one study, over a 10-hour total exchange time with 1.5% to 2.6% glucose solutions, the peritoneal dialysate to plasma ratio of phosphate increased from 0.6 to 1.0. The peritoneal dialysis clearance rate of phosphate over this 10 hour interval averaged 12 mL/min at 2-hours and 3 mL/min at 10 hours.