Weight loss medications: Nursing pharmacology

Definitions & Key takeaways

Weight loss medications can help manage obesity in the short term, and include anorexiants, sympathomimetic medications, lipase inhibitors, GLP-1 receptor agonists, and opioid antagonists with atypical antidepressants. However, clients can experience different side effects depending on the medication taken, such as agitation, anxiety, oily rectal leakage, headaches, dizziness, and abdominal pain. Weight loss medications are contraindicated in individuals with a history of stroke, seizures, and psychiatric conditions like anorexia nervosa, depression, and bipolar disorder.

When caring for a client prescribed weight loss medication, a nursing assessment should be done to establish a baseline for weight, BMI, and vital signs. Client education is a crucial aspect of care, with a focus on safe self-administration of the medication, recognizing and reporting side effects, and adhering to any lifestyle modifications recommended by the healthcare provider, such as changes in diet and exercise.

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Introduction0:00–0:20

Weight loss medications can be used for the short-term management of obesity, and include anorexiants, sympathomimetic medications, lipase inhibitors, glucagon-like peptide-1 or GLP-1 receptor agonists, as well as opioid antagonists combined with atypical antidepressants.Starting with anorexiants, the most commonly used are benzphetamine and diethylpropion, which are taken orally.

Anorexiants0:20–0:47

These medications are believed to decrease appetite by stimulating the release of dopamine and norepinephrine in the satiety center of the brain, which is located in the hypothalamic and limbic areas.
As a result, these neurotransmitters ultimately increase the feeling of satiety and decrease the perception of hunger.Then, there are sympathomimetic medications, among which the most commonly used one for weight loss is phentermine, which is taken orally.

Sympathomimetic medications0:47–1:16

Once administered, phentermine is absorbed into the bloodstream, and travels to the brain. Here, it works at the synaptic cleft by inhibiting the reuptake of the neurotransmitters dopamine and norepinephrine.
This results in an increased concentration of these neurotransmitters within the synaptic cleft, ultimately decreasing the perception of hunger.Moving on, lipase inhibitors include orlistat, which is taken orally.

Lipase inhibitors1:16–1:31

This medication acts in the gastrointestinal tract by inhibiting the absorption of fats, causing them to get excreted in the feces.Next are GLP-1 receptor agonists, which are primarily used as oral antidiabetic medications, and mainly include liraglutide that is administered through subcutaneous injection.

GLP-1 receptor agonists1:31–1:56

The way liraglutide works is by acting on the stomach to slow gastric emptying. This leads to an increase in the feeling of satiety after eating.
In addition, this medication can act in the brain to suppress appetite. Finally, weight loss medications include opioid antagonists like naltrexone, which is generally combined with an atypical antidepressant, namely bupropion.

Opioid antagonists and atypical antidepressants1:56–2:33

These medications are taken together orally. The way bupropion works is by stimulating proopiomelanocortin or POMC neurons in the hypothalamus to release hormones that increase energy output and decrease appetite.
Now, POMC neurons are inhibited by opioids. So, then comes naltrexone, which binds strongly to opioid receptors without activating them, thereby letting POMC neurons stay stimulated longer by bupropion.
Now, clients taking weight loss medications can often experience side effects, which depends on the medication taken. Side effects commonly associated with anorexiants are agitation, anxiety, irritability, and difficulty sleeping.

Side effects2:33–5:18

Less commonly, clients can also experience heart palpitations, systemic or pulmonary hypertension, as well as valvular heart disease.
Next, sympathomimetic medications like phentermine can often cause side effects like hyperactivity, irritability, and insomnia.
Some clients may also experience gastrointestinal side effects, like nausea, vomiting, diarrhea or constipation. Also, clients often develop tachycardia and palpitations, while some may present hypertension or even arrhythmias.
Finally, it’s important to note that unlike other sympathomimetic medications, phentermine’s risk for potential abuse and dependence is considered insignificant.
On the other hand, side effects of lipase inhibitors include oily rectal leakage and steatorrhea, meaning fatty, greasy, floating, voluminous, and terribly smelling stools, often associated with flatus, fecal urgency or incontinence.
Clients can also experience nausea, vomiting, or abdominal cramping, and some may even develop acute liver failure! In addition, clients with diabetes mellitus may present with hypoglycemia.
Now, the most common side effects of GLP-1 receptor agonists include headaches, dizziness, and weakness, associated with nausea, vomiting, and diarrhea.
In addition, these medications can cause injection site reactions like pruritus, and less frequently, renal impairment and acute pancreatitis.
In addition, GLP-1 receptor agonists have a boxed warning for increasing the risk of thyroid cancer development. Finally, when combined with other anti-diabetic medications, GLP-1 receptor agonists can cause hypoglycemia.
The last weight loss medication are opioid antagonists combined with atypical antidepressants. Now, these opioid antagonists can cause side effects like dizziness, as well as abdominal pain, nausea, vomiting, diarrhea, and flatulence, while some clients can even present with gastrointestinal perforation.
On the other hand, due to their excitatory effects, atypical antidepressants can often cause vision and hearing disturbances, headaches, agitation, insomnia, dizziness, and confusion, as well as tremors, and even seizures, which is particularly important in clients with a history of seizures or eating disorders.
In addition, these medications have a boxed warning for causing suicidal thoughts. Other common and more serious side effects include hypertension, tachycardia, palpitations, and even arrhythmias.As far as contraindications go, weight loss medications should also be avoided in clients with a history of stroke, seizures, or psychiatric conditions like anorexia nervosa, depression, and bipolar disorder.

Contraindications and cautions5:18–6:14

In addition, anorexiants and sympathomimetics are contraindicated in clients with severe arteriosclerosis, symptomatic cardiovascular disease, and moderate to severe hypertension.
Anorexiants, sympathomimetics, and lipase inhibitors are also contraindicated during pregnancy, while other weight loss medications should be used with caution.
Lipase inhibitors are also contraindicated in clients with cholestasis and chronic malabsorption syndrome. Additional precautions should be taken in breastfeeding clients, elderly clients, and children.
Other important precautions include glaucoma, hyperthyroidism, hepatic or renal disease, and a history of tobacco smoking or substance abuse.
Now, when your client is diagnosed with obesity and is prescribed a lipase inhibitor like orlistat, first perform a baseline assessment including their current nutritional habits, weight, BMI, waist circumference and vital signs.

Nursing considerations & client education6:14–8:32

Then, review recent laboratory test results including renal and hepatic function, blood glucose, thyroid panel, and lipid panel.
Lasty, confirm a negative pregnancy test for clients assigned female at birth that can become pregnant.Next, explain how the medication can help them to lose weight when combined with lifestyle modifications that include regular physical activity as tolerated, decreased alcohol intake, and a reduced-calorie, low-fat diet.
In addition, encourage them to consume a well-balanced diet that contains complex carbohydrates, fruits, vegetables, and lean sources of protein.
Remind them to distribute their fat intake equally between each meal, and instruct them to take their medication three times each day with meals that contain fat.
Be sure they understand that if they miss a meal, or if their food has no fat content, they should not take a dose of their medication.
Additionally, let them know that their medication makes it hard for their body to absorb certain fat-soluble vitamins, so advise them to take the prescribed multivitamin at least two hours before or after they take their orlistat.
Then, teach your client about some of the side effects they could experience, including oily rectal leakage, steatorrhea, flatus, as well as fecal urgency or incontinence.
Let them know that these symptoms can be reduced with decreased dietary fat intake. Then, prompt them to notify their healthcare provider if they experience symptoms of hepatotoxicity, including nausea, abdominal pain, anorexia, dark-colored urine, or yellowing of the skin or eyes; as well as symptoms of cholelithiasis, including sudden abdominal pain that gets stronger, and which sometimes can be felt around their right shoulder or between their shoulder blades.Finally, while your client is taking a lipase inhibitor like orlistat, be sure to monitor hepatic function, as well as the development of side effects.
Be sure to evaluate for the desired therapeutic response of decreased weight, BMI, and waist circumference, while maintaining optimal nutritional intake.
Alright, as a quick recap...Weight loss medications can be used for the short-term management of obesity, and include anorexiants, sympathomimetic medications, lipase inhibitors, GLP-1 receptor agonists, as well as opioid antagonists combined with atypical antidepressants.

Review8:32–9:59

Now, clients taking weight loss medications experience a variety of side effects, depending on the medication taken, including agitation, anxiety, irritability, and difficulty sleeping with anorexiants; hyperactivity, irritability, and insomnia with sympathomimetic medications; oily rectal leakage and steatorrhea with lipase inhibitors; headaches, dizziness, and weakness with GLP-1 receptor agonists; and lastly, dizziness, abdominal pain, nausea, and vomiting with opioid antagonists.
As far as contraindications go, all weight loss medications should be avoided in clients with a history of stroke, seizures, or psychiatric conditions like anorexia nervosa, depression, and bipolar disorder.
When caring for a client prescribed a weight loss medication, nursing considerations include performing a baseline assessment, as well as monitoring for side effects and the desired therapeutic effects.
Client teaching is focused on safe self-administration, as well as learning to recognize side effects, and when to notify the healthcare provider.
Weight loss medications: Video, Uses, Mechanism | Osmosis