Monobasic sodium phosphate + Dibasic sodium phosphate


Generic Medicine Info
Indications and Dosage
Oral
Bowel evacuation before investigational procedures
Adult: Available preparation:
Monobasic sodium phosphate 1.102 g (as monohydrate) and dibasic sodium phosphate 0.398 g (as anhydrous) tab

For cleansing of bowel in preparation for colonoscopy: Night before the procedure: 4 tab taken with at least 240 mL of water or clear liq every 15 minutes for a total of 20 tab. Day of the procedure (starting 3-5 hours prior to procedure): 4 tab taken with at least 240 mL of water or clear liq every 15 minutes for a total of 12 tab.

Oral
Bowel decontamination before surgery, Bowel evacuation before investigational procedures
Adult: Available preparation:
Monobasic sodium phosphate 18.8 g (as 24.4 g monobasic sodium phosphate dihydrate) and dibasic sodium phosphate 4.3 g (as 10.8 g dibasic disodium phosphate dodecahydrate) per 45 mL oral solution

45 mL solution diluted in 120 mL of cold water for 2 doses. Each dose should be followed by 1 full glass (240 mL) of water. For morning appointment, doses are given at 7 am then at 7 pm on the day before the procedure. For afternoon appointment, 1st dose is given at 7 pm on the night before the procedure then at 7 am on the day of the procedure. Dosage recommendations may vary among countries and individual products (refer to specific product guideline).

Rectal
Bowel evacuation before investigational procedures, Constipation
Adult: Available preparations:
Monobasic sodium phosphate 21.4 g (as dihydrate) and dibasic sodium phosphate 9.4 g (as dodecahydrate) per 118 mL delivered dose of 133 mL enema bottle
Monobasic sodium phosphate 19 g and dibasic sodium phosphate 7 g (as heptahydrate) per 118 mL delivered dose of 133 mL enema bottle

1 bottle once daily or as directed.
Child: Available preparation:
Monobasic sodium phosphate 9.5 g and dibasic sodium phosphate 3.5 g (as heptahydrate) per 59 mL delivered dose of 66 mL enema bottle

2-<5 years 1/2 bottle daily as single dose; 5-11 years 1 bottle daily as single dose, or as directed; ≥12 years Same as adult dose. Dosage recommendations may vary among countries or individual products (refer to specific product guideline).
Renal Impairment
Contraindicated.
Contraindications
Ascites, primary hyperparathyroidism associated with hypercalcaemia, known or suspected gastrointestinal obstruction, congenital or acquired megacolon, gastrointestinal perforation, ileus, active inflammatory bowel disease, CHF or uncontrolled heart failure, hypomotility syndrome (e.g. scleroderma, hypothyroidism), imperforate anus, toxic colitis; presence of nausea, vomiting and stomach pain; unstable angina pectoris, biopsy-proven or history of acute phosphate nephropathy (tab). Patient who has undergone gastric bypass surgery (tab). Renal impairment. Concomitant use with other Na phosphate-based purgative or enema products.
Special Precautions
Patient with pre-existing electrolyte disturbances, increased risk for underlying renal impairment, risk factors for electrolyte disturbances (e.g. gastric retention, inability to take adequate oral fluid, hypertension); hypotension with clinical impact or associated with hypovolaemia, acute MI or history of MI, arrhythmia or with risk factors (e.g. cardiomyopathy, prolonged QT interval, history of uncontrolled arrhythmias), conditions predisposing to hypomotility disorder, diabetes; risk factors for seizure (e.g. history of seizure, receiving agents that lower seizure threshold such as TCA), impaired gag reflex or other swallowing difficulties (tab). Debilitated patients. Children (enema) and elderly. Pregnancy and lactation.
Adverse Reactions
Significant: Increased Na and phosphate levels and decreased Ca and K levels resulting in hypernatraemia, hyperphosphataemia, hypocalcaemia, hypokalaemia, and acidosis; single or multiple aphthoid-like punctiform lesions in the rectosigmoid region, hypersensitivity reactions (e.g. rash, angioedema, anaphylaxis, urticaria, throat tightness). Rarely, QT prolongation, arrhythmia, generalised tonic-clonic seizures, acute phosphate nephropathy, nephrocalcinosis, renal failure.
Gastrointestinal disorders: Abdominal pain or distension, diarrhoea, nausea, vomiting; erythematous gastritis-like lesions and/or superficial gastric ulcerations with necrotising base (tab).
General disorders and administration site conditions: Asthenia, chills, chest pain.
Nervous system disorders: Dizziness, headache.
Potentially Fatal: Dehydration, severe electrolyte disturbances (particularly in elderly).
Patient Counseling Information
Ensure adequate hydration before, during the preparation, and after the procedure. This drug may cause dizziness which may be due to dehydration, if affected, do not drive or operate machinery.
Monitoring Parameters
Monitor electrolyte levels, Ca levels, phosphorus levels, BUN, creatinine (in patients who may be at increased risk of nephropathy) at baseline and post-procedure; ECG (in patients at increased risks of prolonged QT or arrhythmias).
Overdosage
Symptoms: Hyperphosphataemia with hypocalcaemia, hypernatraemia and acidosis; dehydration, hypotension, bradycardia, tachycardia, tachypnoea, dyspnoea, convulsions, paralytic ileus, anxiety, pain, cardiac arrest, shock, respiratory failure. Management: Symptomatic treatment. Electrolyte and fluid replacement therapy may be necessary for the treatment of electrolyte imbalance. Administration of IV Ca gluconate 10% may be required.
Drug Interactions
Increased risk of acute phosphate nephropathy with antihypertensives (e.g. ACE inhibitors, angiotensin receptor blockers, Ca channel blockers), diuretics, NSAIDs. May decrease lithium levels. May delay or prevent the absorption of orally administered agents (e.g. oral contraceptives, antibiotics, antidiabetics, antiepileptics).
Potentially Fatal: Concomitant administration of other Na phosphate-based purgatives or enema products may result in acute phosphate nephropathy.
Action
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, thereby producing distension, promoting peristalsis and subsequently, evacuation of the bowel.
Synonyms: monobasic sodium phosphate: sodium dihydrogen phosphate; dibasic sodium phosphate: disodium phosphate.
Onset: Within 0.5-6 hours (oral); 2-5 minutes (rectal).
Duration: 1-3 hours (tab).
Pharmacokinetics:
Absorption: Approx 1-20% is absorbed from gastrointestinal tract (oral); probably minimal colonic absorption (rectal).
Excretion: Oral: Via faeces.
Chemical Structure

Chemical Structure Image
Monobasic sodium phosphate

Source: National Center for Biotechnology Information. PubChem Compound Summary for CID 23672064, Monosodium phosphate. https://pubchem.ncbi.nlm.nih.gov/compound/Monosodium-phosphate. Accessed Aug. 25, 2021.


Chemical Structure Image
Dibasic sodium phosphate

Source: National Center for Biotechnology Information. PubChem Compound Summary for CID 24203, Disodium hydrogen phosphate. https://pubchem.ncbi.nlm.nih.gov/compound/Disodium-hydrogen-phosphate. Accessed Aug. 25, 2021.

Storage
Oral solution, enema: Store below 25°C. Tab: Store between 15-30°C.
MIMS Class
Laxatives, Purgatives
ATC Classification
A06AG01 - sodium phosphate ; Belongs to the class of enemas. Used in the treatment of constipation.
A06AD17 - sodium phosphate ; Belongs to the class of osmotically acting laxatives.
References
Anon. Saline Laxatives. AHFS Clinical Drug Information [online]. Bethesda, MD. American Society of Health-System Pharmacists, Inc. https://www.ahfscdi.com. Accessed 09/07/2021.

Anon. Sodium Phosphates. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 09/07/2021.

Buckingham R (ed). Phosphate. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 09/07/2021.

Cleen Ready-to-Use 21.4 g/9.4 g Enema (Casen Recordati, S.L.). MHRA. https://products.mhra.gov.uk. Accessed 09/07/2021.

Coloclear 1,500 mg Tablets (Laboratories Mayoly Spindler). MHRA. https://products.mhra.gov.uk. Accessed 16/08/2021.

Fleet Enema (C.B. Fleet Company, Inc.). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed. Accessed 09/07/2021.

Fleet for Children Enema (C.B. Fleet Company, Inc.). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed. Accessed 09/07/2021.

Osmoprep Tablet (Salix Pharmaceuticals, Inc.). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed. Accessed 09/07/2021.

Pharmaco (NZ) Ltd. Phospho-Soda Oral Solution data sheet July 2017. Medsafe. http://www.medsafe.govt.nz. Accessed 09/07/2021.

Phospho-soda 24.4 g/10.8 g Oral Solution (Casen Recordati, S.L.). MHRA. https://products.mhra.gov.uk. Accessed 09/07/2021.

Disclaimer: This information is independently developed by MIMS based on Monobasic sodium phosphate + Dibasic sodium phosphate from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2021 MIMS. All rights reserved. Powered by MIMS.com
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