Potassium Chloride Extended-Release Capsules

Potassium Chloride Extended-release Capsules, USP, 8 mEq and 10 mEq

are oral dosage forms of microencapsulated potassium chloride

containing 600 and 750 mg, respectively, of potassium chloride

USP equivalent to 8 and 10 mEq of potassium.

Dispersibility of potassium chloride (KCl) is accomplished by

microencapsulation and a dispersing agent. The resultant flow characteristics

of the KCl microcapsules and the controlled release of K+

ions by the microcapsular membrane are intended to avoid the possibility

that excessive amounts of KCl can be localized at any point

on the mucosa of the gastrointestinal tract.

Each crystal of KCl is microencapsulated by a process with an insoluble

polymeric coating which functions as a semi-permeable membrane;

it allows for the controlled release of potassium and chloride

ions over an eight-to-ten-hour period. Fluids pass through the

membrane and gradually dissolve the potassium chloride within the

micro-capsules. The resulting potassium chloride solution slowly

diffuses outward through the membrane. Potassium Chloride

Extended-release Capsules, USP, 8 mEq and 10 mEq are electrolyte

replenishers. The chemical name of the active ingredient is potassium

chloride and the structural formula is KCl. Potassium chloride

USP occurs as a white, granular powder or as colorless crystals. It

is odorless and has a saline taste. Its solutions are neutral to litmus.

It is freely soluble in water and insoluble in alcohol.

The inactive ingredients are, ethylcellulose, FD&C blue #1, FD&C red

# 40, gelatin, sodium lauryl sulfate, titanium oxide and triacetin.

Potassium ion is the principal intracellular

cation of most body tissues. Potassium ions participate in a

number of essential physiological processes, including the maintenance

of intracellular tonicity, the transmission of nerve impulses,

the contraction of cardiac, skeletal, and smooth muscle, and the

maintenance of normal renal function.

The intracellular concentration of potassium is approximately 150 to

160 mEq per liter. The normal adult plasma concentration is 3.5 to

5 mEq per liter. An active ion transport system maintains this gradient

across the plasma membrane.

Potassium is a normal dietary constituent and under steady-state

conditions the amount of potassium absorbed from the gastrointestinal

tract is equal to the amount excreted in the urine. The usual

dietary intake of potassium is 50 to 100 mEq per day.

Potassium depletion will occur whenever the rate of potassium loss

through renal excretion and/or loss from the gastrointestinal tract

exceeds the rate of potassium intake. Such depletion usually develops

slowly as a consequence of therapy with diuretics, primary or secondary

hyperaldosteronisms, diabetic ketoacidosis, or inadequate replacement

of potassium in patients on prolonged parenteral nutrition.

Depletion can develop rapidly with severe diarrhea, especially if

associated with vomiting. Potassium depletion due to these causes

is usually accompanied by a concomitant loss of chloride and is

manifested by hypokalemia and metabolic alkalosis. Potassium

depletion may produce weakness, fatigue, disturbances of cardiac

rhythm (primarily ectopic beats), prominent U-waves in the electrocardiogram,

and in advanced cases, flaccid paralysis and/or

impaired ability to concentrate urine.

If potassium depletion associated with metabolic alkalosis cannot

be managed by correcting the fundamental cause of the deficiency,

e.g., where the patient requires long-term diuretic therapy, supplemental

potassium in the form of high potassium food or potassium

chloride may be able to restore normal potassium levels.

In rare circumstances (e.g., patients with renal tubular acidosis)

potassium depletion may be associated with metabolic acidosis and

hyperchloremia. In such patients potassium replacement should be

accomplished with potassium salts other than the chloride, such as

potassium bicarbonate, potassium citrate, potassium acetate, or

potassium gluconate.

BECAUSE OF REPORTS OF INTESTINAL

AND GASTRIC ULCERATION AND BLEEDING WITH CONTROLLEDRELEASE

POTASSIUM CHLORIDE PREPARATIONS, THESE DRUGS

SHOULD BE RESERVED FOR THOSE PATIENTS WHO CANNOT TOLERATE

OR REFUSE TO TAKE LIQUID OR EFFERVESCENT POTASSIUM

PREPARATIONS OR FOR PATIENTS IN WHOM THERE IS A

PROBLEM OF COMPLIANCE WITH THESE PREPARATIONS.

1. For the treatment of patients with hypokalemia with or without

metabolic alkalosis, in digitalis intoxications, and in patients with

hypokalemic familial periodic paralysis. If hypokalemia is the result

of diuretic therapy, consideration should be given to the use of a

lower dose of diuretic, which may be sufficient without leading to

hypokalemia.

2. For the prevention of hypokalemia in patients who would be at

particular risk if hypokalemia were to develop e.g., digitalized

patients or patients with significant cardiac arrhythmias, hepatic cirrhosis

with ascites, states of aldosterone excess with normal renal

function, potassium-losing nephropathy, and certain diarrheal states.

The use of potassium salts in patients receiving diuretics for

uncomplicated essential hypertension is often unnecessary when

such patients have a normal dietary pattern and when low doses of

the diuretic are used. Serum potassium should be checked periodically,

however, and if hypokalemia occurs, dietary supplementation

with potassium-containing foods may be adequate to control milder

cases. In more severe cases, and if dose adjustment of the diuretic

is ineffective or unwarranted, supplementation with potassium salts

may be indicated.

Potassium supplements are contraindicated

in patients with hyperkalemia since a further increase in serum

potassium concentration in such patients can produce cardiac

arrest. Hyperkalemia may complicate any of the following conditions:

chronic renal failure, systemic acidosis such as diabetic acidosis,

acute dehydration, extensive tissue breakdown as in severe

burns, adrenal insufficiency, or the administration of a potassiumsparing

diuretic (e.g., spironolactone, triamterene, amiloride) (see

OVERDOSAGE).

Controlled-release formulations of potassium chloride have produced

esophageal ulceration in certain cardiac patients with

esophageal compression due to an enlarged left atrium. Potassium

supplementation, when indicated in such patients, should be given

as a liquid preparation.

All solid oral dosage forms of potassium chloride are contraindicated

in any patient in whom there is structural, pathological (e.g., diabetic

gastroparesis) or pharmacologic (use of anticholinergic

agents or other agents with anticholineric properties at sufficient

doses to exert anticholinergic effects) cause for arrest or delay in

capsule passage through the gastrointestinal tract.

Hyperkalemia (see OVERDOSAGE)

In patients with impaired mechanisms for excreting potassium, the

administration of potassium salts can produce hyperkalemia and

cardiac arrest. This occurs most commonly in patients given potassium

by the intravenous route but may also occur in patients given

potassium orally. Potentially fatal hyperkalemia can develop rapidly

and be asymptomatic. The use of potassium salts in patients with

chronic renal disease, or any other condition which impairs potassium

excretion, requires particularly careful monitoring of the serum

potassium concentration and appropriate dosage adjustments.

Interaction with Potassium-Sparing Diuretics

Hypokalemia should not be treated by the concomitant administration

of potassium salts and a potassium-sparing diuretic (e.g.,

spironolactone, triamterene, or amiloride), since the simultaneous

administration of these agents can produce severe hyperkalemia.

Interaction with Angiotensin Converting Enzyme Inhibitors

Angiotensin converting enzyme (ACE) inhibitors (e.g., captopril,

enalapril) will produce some potassium retention by inhibiting

aldosterone production. Potassium supplements should be given to

patients receiving ACE inhibitors only with close monitoring.

Gastrointestinal Lesions

Solid oral dosage forms of potassium chloride can produce ulcerative

and/or stenotic lesions of the gastrointestinal tract. Based on

spontaneous adverse reaction reports, enteric coated preparations

of potassium chloride are associated with an increased frequency of

small bowel lesions (40 - 50 per 100,000 patient years) compared

to sustained-release wax matrix formulations (less than one per

100,000 patient years). Because of the lack of extensive marketing

experience with microencapsulated products, a comparison

between such products and wax matrix or enteric coated products

is not available. Potassium Chloride Extended-release Capsules,

USP, 8 mEq and 10 mEq are microencapsulated capsules formulated

to provide a controlled rate of release of microencapsulated

potassium chloride and thus to minimize the possibility of high local

concentration of potassium near the gastrointestinal wall.

Prospective trials have been conducted in normal human volunteers

in which the upper gastrointestinal tract was evaluated by endoscopic

inspection before and after one week of solid oral potassium chloride

therapy. The ability of this model to predict events occurring in

usual clinical practice is unknown. Trials which approximated usual

clinical practice did not reveal any clear differences between the wax

matrix and microencapsulated dosage forms. In contrast, there was

a higher incidence of gastric and duodenal lesions in subjects receiving

a high dose of a wax matrix controlled-release formulation under

conditions which did not resemble usual or recommended clinical

practice (i.e., 96 mEq per day in divided doses of potassium chloride

administered to fasted patients, in the presence of an anticholinergic

drug to delay gastric emptying). The upper gastrointestinal lesions

observed by endoscopy were asymptomatic and were not accompanied

by evidence of bleeding (hemoccult testing). The relevance of

these findings to the usual conditions (i.e., non-fasting, no anticholinergic

agent, smaller doses) under which controlled-release

potassium chloride products are used is uncertain; epidemiologic

studies have not identified an elevated risk, compared to microencapsulated

products, for upper gastrointestinal lesions in patients

receiving wax matrix formulations. Potassium Chloride Extendedrelease

Capsules, USP, 8 mEq and 10 mEq should be discontinued

immediately and the possibility of ulceration, obstruction or perforation

considered if severe vomiting, abdominal pain, distention, or

gastrointestinal bleeding occur.

Metabolic Acidosis

Hypokalemia in patients with metabolic acidosis should be treated

with an alkalinizing potassium salt such as potassium bicarbonate,

potassium citrate, potassium acetate, or potassium gluconate.

One of the most severe adverse effects is

hyperkalemia (see CONTRAINDICATIONS, WARNINGS, AND OVERDOSAGE).

Gastrointestinal bleeding and ulceration have been

reported in patients treated with Potassium Chloride Extendedrelease

Capsules, USP, 8 mEq and 10 mEq (see CONTRAINDICATIONS

and WARNINGS). In addition to gastrointestinal bleeding and

ulceration, perforation and obstruction have been reported in

patients treated with other solid KCl dosage forms, and may occur

with Potassium Chloride Extended-release Capsules, USP, 8 mEq

and 10 mEq. The most common adverse reactions to the oral potassium

salts are nausea, vomiting, flatulence, abdominal discomfort,

and diarrhea. These symptoms are due to irritation of the gastrointestinal

tract and are best managed by taking the dose with meals,

or reducing the amount taken at one time. Skin rash has been

reported rarely with potassium preparations.

The administration of oral potassium salts to persons

with normal excretory mechanisms for potassium rarely causes

serious hyperkalemia. However, if excretory mechanisms are

impaired or if potassium is administered too rapidly intravenously,

potentially fatal hyperkalemia can result (see CONTRAINDICATIONS

and WARNINGS). It is important to recognize that hyperkalemia is

usually asymptomatic and may be manifested only by an increased

serum potassium concentration (6.5-8.0 mEq/L) and characteristic

electrocardiographic changes (peaking of T-waves, loss of P-waves,

depression of ST segment, and prolongation of the QT interval).

Late manifestations include muscle paralysis and cardiovascular

collapse from cardiac arrest (9-12 mEq/L).

Treatment measures for hyperkalemia include the following: (1)

elimination of foods and medications containing potassium and of

any agents with potassium-sparing properties; (2) intravenous

administration of 300 to 500 mL/hr of 10% dextrose solution containing

10 to 20 units of crystalline insulin per 1,000 mL; (3) correction

of acidosis, if present, with intravenous sodium bicarbonate;

(4) use of exchange resins, hemodialysis, or peritoneal dialysis. In

treating hyperkalemia, it should be recalled that in patients who have

been stabilized on digitalis, too rapid a lowering of the serum potassium

concentration can produce digitalis toxicity.

The usual dietary intake of potassium

by the average adult is 50 to 100 mEq per day. Potassium

depletion sufficient to cause hypokalemia usually requires the loss

of 200 or more mEq of potassium from the total body store.

Dosage must be adjusted to the individual needs of each patients.

The dose for the prevention of hypokalemia is typically in the range

of 20 mEq per day. Doses of 40 to 100 mEq per day or more are

used for the treatment of potassium depletion. Dosage should be

divided if more than 20 mEq per day is given such that no more than

20 mEq is given in a single dose. Because of the potential for gastric

irritation (see WARNINGS), Potassium Chloride Extendedrelease

Capsules, USP, 8 mEq and 10 mEq should be taken with

meals and with a full glass of water or other liquid.

Patients who have difficulty swallowing capsules may sprinkle the

contents of the capsule onto a spoonful of soft food. The soft food,

such as applesauce or pudding, should be swallowed immediately

without chewing and followed with a glass of cool water or juice to

ensure complete swallowing of the microcapsules. The food used

should not be hot and should be soft enough to be swallowed without

chewing. Any microcapsule/food mixture should be used immediately

and not stored for future use.

Potassium Chloride Extended-release Capsules, USP, 10 mEq are dark

blue opaque capsules, imprinted with Andrx logo on the cap and 560

on the body, each containing 750 mg microencapsulated potassium

chloride (equivalent to 10 mEq K) in blisterpacks of 30 (NDC 0615-1318-39),

blisterpacks of 31 (NDC 0615-1318-31), blisterpacks of 15 (NDC 0615-1318-05).

Store at controlled room temperature, 20° - 25°C (68° - 77°F).

[See USP.]

Dispense in tight container.

Manufactured by:

Watson Laboratories, Inc.

Corona, CA 92880 USA

Distributed by:

Watson Pharma, Inc.

Corona, CA 92880 USA

Rev. date: 10/09 192064

Potassium Chloride ER Capsules,

USP 10mEq K (750 mg)