Monobasic sodium phosphate + Dibasic sodium phosphate

Oral
Mild osmotic laxative for bowel evacuation and cleansing

Oral
Mild osmotic laxative for bowel evacuation and cleansing

Rectal
Constipation, Mild osmotic laxative for bowel evacuation and cleansing

Severe: Contraindicated.

Hypercalcaemia, acute phosphate nephropathy (biopsy proven), CHF, ascites, GI obstruction, decreased bowel motility, inflammatory bowel disease (e.g. severe active ulcerative colitis), paralytic ileus, anorectal stenosis, imperforate anus, toxic megacolon, toxic colitis, Hirschsprung’s disease, appendicitis, intestinal perforation, rectal bleeding, dehydration, gastric bypass or stapling surgery. Severe renal impairment.

Patient w/ CV disorder (e.g. heart failure, HTN, heart disease, acute MI, unstable angina, cardiomyopathy, arrhythmias); rectal ulcers/fissures, colostomy; pre-existing electrolyte imbalance, hypovolaemia, severe chronic constipation, gastric retention, impaired gag reflex; history and risk of seizures. Mild to moderate renal impairment. Elderly or debilitated patients, childn. Pregnancy and lactation.

Significant: Electrolyte disorders (e.g. hypernatraemia, hyperphosphataemia, hypophosphataemia, hypokalaemia, hypocalcaemia), dehydration, QT prolongation, seizures, fluid loss, hypovolaemia.
Nervous: Dizziness, headache, asthenia.
CV: Oedema.
GI: Nausea, vomiting, diarrhoea, abdominal pain/distention, bloating (oral); rectal bleeding, irritation, pain, stinging.
Resp: Chest pain.
Others: Chills.
Potentially Fatal: Rarely, acute phosphate nephropathy, nephrocalcinosis, severe electrolyte disorders (oral).

IV/PO: C

Drink sufficient liq before, during and after therapy. This drug may cause dizziness due to dehydration, if affected, do not drive or operate machinery.

Monitor electrolyte balance and renal function, ECG prior and during therapy.

Symptoms: Dehydration, hypotension, tachycardia, bradycardia, tachypnoea, cardiac arrest, shock, resp failure, dyspnoea, paralytic ileus, anxiety, pain, hypernatraemia, hyperphosphataemia, hypokalaemia, hypocalcaemia, acidosis. Management: Symptomatic treatment. Initiate electrolyte correction and fluid replacement therapy immediately. Admin of Ca gluconate may be necessary.

Reduced absorption w/ Ca, Fe, Mg salts, sucralfate. Increased risk of seizures w/ TCA. Increased risk for hyperphosphataemia w/ vit D. Reduced therapeutic effect w/ lithium. Increased risk of ectopic calcification w/ Ca supplements or Ca-containing antacids. Increased risk of hyperkalaemia w/ K phosphates.
Potentially Fatal: Enhanced nephrotoxicity w/ diuretics, ACE inhibitors, NSAIDs.

Description: Monobasic sodium phosphate and dibasic sodium phosphate are osmotic laxatives. They exert osmotic effect in the small intestine by drawing water into the lumen of the gut producing distention and peristalsis and eventually, evacuation of bowel.
Onset: W/in 30 min to 6 hr (oral); w/in 2-5 min (rectal).
Pharmacokinetics:
Absorption: Approx 1-20% is absorbed from GI tract (oral).
Excretion: Via faeces.

Store below 25°C.

Laxatives, Purgatives

Anon. Saline Laxatives. AHFS Clinical Drug Information [online]. Bethesda, MD. American Society of Health-System Pharmacists, Inc. https://www.ahfscdi.com. Accessed 14/09/2017.

Anon. Sodium Phosphates. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 14/09/2017.

Buckingham R (ed). Phosphate. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 14/09/2017.

Osmoprep Tablet (Salix Pharmaceuticals, Inc.). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 14/09/2017.

Ready-To-Use Enema (Rugby Laboratories, Inc.). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 15/09/2017.