Sodium Phosphate Dibasic Heptahydrate / Sodium Phosphate Monobasic Monohydrate

What it is and how it works

A hypertonic solution of dibasic and monobasic sodium phosphate. It draws water into the rectum and colon by osmosis, distending the bowel and stimulating peristalsis, usually producing evacuation within 2–5 minutes.

Indications

Relief of occasional constipation and bowel cleansing before rectal examination, sigmoidoscopy, radiography or surgery, and before or after childbirth.

Dosage and administration (summary)

Adults: one standard enema (usually about 118–133 mL) administered rectally as a single dose; do not exceed one enema in 24 hours unless directed by a doctor.

Contraindications

Suspected bowel obstruction or perforation, paralytic ileus, megacolon, inflammatory bowel disease with active inflammation, congestive heart failure, significant renal impairment, dehydration, and young children.

Warnings and precautions

Retention or repeated use can cause serious hyperphosphataemia, hypocalcaemia, hypernatraemia, dehydration and acute phosphate nephropathy; risk is higher in the elderly and in those with renal impairment or taking diuretics, ACE inhibitors or angiotensin II receptor antagonists. Rectal bleeding or failure to evacuate requires medical assessment.

Pregnancy

May be used occasionally in pregnancy when clinically appropriate.

Storage and supply

Store below 25 °C.

Source: reference summary prepared from the EU SmPC/EPAR, BNF and WHO Model Formulary. The approved product information in Iran governs.