phosphate/biphosphate

Osmotically active in the lumen of the GI tract.
Produces laxative effect by causing water retention and stimulation of peristalsis.
Stimulates motility and inhibits fluid and electrolyte absorption from the small intestine.

Therapeutic effects:

Relief of constipation.
Emptying of the bowel.

Pharmacokinetics ⬆ ⬇

Absorption: 1–20% of rectally administered sodium and phosphate may be absorbed; some absorption follows oral administration.

Distribution: Unknown.

Metabolism/Excretion: Excreted by the kidneys.

Half-Life: Unknown.

Time/Action Profile ⬆ ⬇

(laxative effect)

ROUTE	ONSET	PEAK	DURATION
PO	0.5–3 hr	unknown	unknown
Rect	2–5 min	unknown	unknown

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity;
Abdominal pain, nausea, or vomiting, especially when associated with fever or other signs of an acute abdomen;
Severe renal or cardiovascular disease;
Intestinal obstruction;
OB: Not recommended for use at term;
OsmoPrep: HF, ascites, unstable angina, acute colitis, toxic megacolon, or hypomotility syndrome;
Pedi: Children <2 yr.

Use Cautiously in:

Excessive or chronic use (may lead to dependence);
Renal or cardiovascular disease, dehydration or concurrent use of diuretics or other drugs known to alter electrolytes (correct abnormalities prior to administration);
Dehydration, renal dysfunction, bowel obstruction, active colitis, or concurrent use of diuretics, ACE inhibitors, ARBs, or NSAIDs (↑ risk of acute phosphate nephropathy);
OB: May cause sodium retention and edema;
Geri: May be more sensitive to effects.

Adv. Reactions/Side Effects ⬆ ⬇

CV: ARRHYTHMIAS

GI: cramping, nausea, colonic aphtous ulcerations, ischemic colitis, OsmoPrepabdominal bloating, abdominal pain, vomiting

F and E: hyperphosphatemia, hypocalcemia, hypokalemia, sodium retention

GU: renal dysfunction

Neuro: Visicoldizziness, headache

Interactions ⬆ ⬇

Drug-drug:

OsmoPrep: Concurrently administered oral medications may not be absorbed due to rapid peristalsis and diarrhea.

Route/Dosage ⬆ ⬇

Each Fleet Enema contains 4.4 g sodium/118 mL

Bowel Cleansing

PO (Adults ): OsmoPrep: evening before colonoscopy: 4 tablets every 15 min (with at least 8 oz of water) for a total of 20 tablets; on morning of colonoscopy starting 3–5 hr before procedure, 4 tablets every 15 min (with at least 8 oz of clear liquids), for a total of 12 tablets; should not be repeated in less than 7 days.

Constipation

PO (Adults ): 15 mL as single dose.
PO (Children 5–9 yr): 7.5 mL as single dose.
Rect (Adults and Children >12 yr): 118 mL Fleet Enema.
Rect (Children >2 yr): ½of the adult dose.

Availability ⬆ ⬇

(Generic available)

Oral solution: 0.9 g dibasic sodium phosphate and 2.4 g monobasic sodium biphosphate/5 mL
Enema: 7 g dibasic sodium phosphate and 19 g monobasic sodium biphosphate/118 mL
Tablets (OsmoPrep): 1.5 g

Assessment ⬆ ⬇

Assess patient for fever, abdominal distention, presence of bowel sounds, and usual pattern of bowel function.
Assess color, consistency, and amount of stool produced.
May rarely cause arrhythmias. Monitor patients with underlying cardiovascular disease, renal disease, bowel perforation, misuse or overdose.

Lab Test Considerations:

May cause ↑ serum sodium and phosphorus levels, ↓ serum calcium and potassium levels, and acidosis. Electrolyte changes are transient, self-limiting, do not require treatment, and are not usually associated with adverse clinical events.

Implementation ⬆ ⬇

Do not administer at bedtime or late in the day.
PO: Administer on an empty stomach for more rapid results. Mix dose in at least ½ glass cold water. May be followed by carbonated beverage or fruit juice to improve flavor.
- See Route and Dosage section for dosing of OsmoPrep.
- Osmoprep: Do not drink any red—or purple-colored liquids.
Position patient on left side with knee slightly flexed. Insert prelubricated tip about 2 inches into rectum, aiming toward the umbilicus. Gently squeeze bottle until empty. Discontinue if resistance is met, because perforation may occur if contents are forced into rectum.

Patient/Family Teaching ⬆ ⬇

Advise patient that laxatives should be used only for short-term therapy. Avoid using more than 1 dose of OTC laxatives/day. Long-term therapy may cause electrolyte imbalance and dependence.
Caution patient on sodium restriction that this product has a high sodium content.
Advise patient not to take oral form of this medication within 2 hr of other medications.
Encourage patient to use other forms of bowel regulation, such as increasing bulk in the diet, fluid intake, and mobility. Normal bowel habits may vary from 3 times/day to 3 times/wk.
Advise patient to notify health care professional if unrelieved constipation, rectal bleeding, or symptoms of electrolyte imbalance (muscle cramps or pain, weakness, dizziness, and so forth) occur.

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇