Our coverage of the range of gastrointestinal medications continues with this look at the different types of laxatives. The Nursing Pharmacology video series follows along with our Pharmacology Second Edition Flashcards, which are intended to help RN and PN nursing students study for nursing school exams, including the ATI, HESI, and NCLEX.
Pharmacology - Nursing Flashcards
When you see this Cool Chicken, that indicates one of Cathy's silly mnemonics to help you remember. The Cool Chicken hints in these articles are just a taste of what's available across our Level Up RN Flashcards for nursing students!
Constipation
Laxatives are often prescribed to treat constipation. When a patient has constipation, it's important to provide additional teaching on how they can prevent constipation, rather than just administering laxatives. Preventative measures include increasing fluid and fiber intake. Encourage the patient to get up and move around as increasing their mobility can also help to stimulate peristalsis, the contraction of the stomach muscles and other muscles in the GI tract that move food along, which allows for digestion and bowel evacuation.
Stool softeners - docusate sodium (Colace), docusate calcium (Kaopectate)
Stool softeners, which include docusate sodium and docusate calcium, are medications used to treat and prevent constipation.
Stool softeners mode of action
Stool softeners work by drawing water into the stool, which helps to soften the stool.
Stool softeners side effects
Side effects of stool softeners like Colace and Kaopectate can include mild cramping and diarrhea.
Stool softeners patient teaching
When administering stool softeners like docusate sodium and docusate calcium, encourage the patient to take this medication with a full glass of water.
The doc said if you ate more fiber, you wouldn’t need docusate to soften your stool!
Bulk forming laxatives - psyllium (Metamucil), methylcellulose
Bulk forming laxatives include psyllium and methylcellulose. These are medications used for constipation, as well as to prevent straining and to help manage chronic watery diarrhea.
Bulk forming laxatives mode of action
The mode of action of these bulk forming laxatives is to combine with water in the intestines to soften the stool and increase its bulk.
Bulk forming laxatives side effects
Side effects of bulk-forming laxatives like psyllium and methylcellulose can include mild cramping, as well as nausea or vomiting.
Bulk forming laxatives patient teaching
Hydration is very important when administering all laxatives — encourage the patient to take psyllium or methylcellulose with a full glass of water, then have them drink another glass of water after that.
Stimulant laxatives - bisacodyl (Dulcolax), sennosides (Senokot)
Stimulant laxatives, which include bisacodyl and sennosides, are medications used for constipation, as well as for bowel prep prior to a surgery or procedure.
Stimulant laxatives mode of action
Stimulant laxatives like bisacodyl and sennosides work by stimulating peristalsis, which causes bowel evacuation.
Stimulant laxatives side effects
The side effects of stimulant laxatives like bisacodyl and sennosides can include cramping, nausea, and vomiting.
Stimulant laxatives patient teaching
Stimulant laxatives are another medication that should be administered with a full glass of water. The patient should also increase their fiber and fluid intake. And they should increase their mobility to promote regularity.
Bisacodyl will help you do your “Business” (BM).
Osmotic laxatives - magnesium hydroxide, magnesium citrate, lactulose, polyethylene glycol (MiraLax)
Osmotic laxatives, which include magnesium hydroxide, magnesium citrate, lactulose, and polyethylene glycol (also known as Miralax), are another type of medication used to treat constipation, as well as to prep the bowel prior to a surgery or procedure.
Osmotic laxatives mode of action
Osmotic laxatives work by drawing water into the intestine from the surrounding tissues — a process known as osmosis. This helps soften stools and make them easier to pass. This type of laxative also stimulates peristalsis.
Osmotic laxatives side effects
Side effects of osmotic laxatives can include cramping, bloating, and diarrhea.
Magnesium hydroxide or magnesium citrate are known to cause hypermagnesemia, elevated magnesium levels. Symptoms of hypermagnesemia include hypotension (low blood pressure), respiratory depression, and cardiac arrest. This means it is important to monitor the patient's magnesium levels if they're on one of these two medications.
Lactulose as treatment of hepatic encephalopathy
Lactulose, another osmotic laxative, may be used for the treatment of hepatic encephalopathy, a brain disorder caused by a buildup of ammonia in the body. When a patient has liver dysfunction, their body cannot eliminate toxins, including ammonia. That ammonia can flow through the bloodstream into the brain, where it affects brain function, often causing confusion.
Administering lactulose helps to lower the pH in the colon, which in turn promotes the excretion of ammonia resulting in lower ammonia levels.
Lactulose will cause you to “lose” stool as it gets rid of excess ammonia from the body.