Saline Cathartics are inorganic, poorly absorbed salts. When you put salt in the intestinal lumen, osmotic pressure increases, which pulls water toward it and creates more bulk. With more bulk we have increased motility and peristalsis takes place. These can work very fast, in a matter of 30 minutes to 3 hours. They can be used if someone needs quick relief or if someone needs their body to be cleared out before a radiologic exam. These drugs are habit forming. If a person takes these drugs day in and day out, they can’t have a bowel movement without it. They would have to ween themselves off of it.
- Inorganic, poorly absorbed salts
- Increases osmotic pressure which increases water in intestinal lumen
- Increases bulk which increases motility
- Onset: 30 minutes to 3 hours
- Use: Acute constipation or prepare for exam
- Side Effect: Diarrhea, habit forming
Examples
Milk of Magnesia: most commonly used in the hospital, usually given at night so there’s a bowel movement in the morning.
Magnesium Citrate: used before a GI procedure to evacuate the intestinal tract. It looks like a carbonated soda bottle that’s flavored. The only problem with it is that it’s loaded with salt so it’s tough to consume. The best thing to do with your patients to make it as palatable as possible is to refrigerate it. The colder it is the more palatable it will be.
Epsom Salt: Good for feet soaking, but it’s also a salt laxative.
Golytely: It’s a gallon jug with a powder in it. You could put some flavor packets in it to make it taste better. You tell the patient to drink a glass of this every 15 minutes and they will be “going lightely” constantly.
Polyethylene glycol 3350 (MiraLax): This can be bought OTC and it’s chemically closely related to golytely. This comes in a powder you have to mix yourself. It’s not used before a procedure, it’s just used as a laxative.