Pharmacist’s Guide To Phentermine (Adipex)

In the United States, there are around 3.6 million prescriptions for phentermine (Adipex), a prescription medication that is used to decrease appetite and help you lose weight in combination with a low-calorie diet and frequent exercise. Studies have found that the average weight loss expected from the drug is approximately 5% of your initial body weight

Specifically, it is a short-term tool for the management of obesity alongside other conditions such as diabetes, high cholesterol, and high blood pressure. It is typically taken three times a day, 30-minutes before meals. It also comes as a single dose taken daily in the morning. This medication is most effective when combined with a low-calorie diet and behavior modification counseling. When on this medication therapy, weight and waist circumference should be monitored by your prescriber every month for the first 3 months and then at 3-month intervals to check for progress. 

Read on below to learn more about this important medication. 

How does it work? 

Phentermine works by stimulating the central nervous system (specifically the hypothalamus) to release norepinephrine, a stress hormone and neurotransmitter that is part of your fight-or-flight response. Activating this response then reduces your sense of appetite and hunger. 

What are the possible side effects? 

Phentermine (Adipex) can cause dry mouth, a bad taste in your mouth, headache, insomnia, constipation, diarrhea, and changes in libido. It can also cause drowsiness, so please avoid any activities that require mental alertness (such as driving and/or operating any machinery). 

Phentermine should be avoided if you have an amphetamine allergy, as this drug is in the same class. Although uncommon, taking this with that allergy may cause allergic reactions such as rash, hives, and photosensitivity. 

Can phentermine (Adipex) be addictive?  

Currently, phentermine (Adipex) is considered a Schedule IV controlled substance by the DEA. That’s because there is the potential for abusing or misusing this medication, which works in a similar way to other substances like methamphetamine. This is why phentermine is typically prescribed on a short-term basis. However, despite the consideration of this drug as potentially addictive, it does appear that the risk is low. If you have any concerns about phentermine becoming habit-forming for you, please reach out to your doctor and/or pharmacist. 

Is it safe to drink alcohol while taking phentermine (Adipex)?

We do not recommend drinking alcohol while taking this medication. That’s because alcohol can make the side effects of phentermine more likely to occur and, if they do occur, then it can make them more extreme. 

What are some helpful pharmacist tips? 

It is not safe to take phentermine if you are pregnant, planning on conceiving, or breastfeeding, so make sure to keep your doctor informed of your plans. Another useful tip would be to avoid taking this medication late in the evening to prevent sleep problems.

Missed doses: Take a missed dose as soon as you think about it, but If it is close to the time for your next dose, skip the missed dose and go back to your normal routine. It is important that you do not take 2 doses at the same time or extra doses. 

Read more:

All Your Questions About Azithromycin (Zithromax), Answered
Our pharmacists break down exactly what Zithromax is, how it works, and …
What is Misoprostol (Cytotec)?
Cytotec is an important medication used mostly commonly to prevent stomach ulcers.
Type 2 Diabetes 101: What to know for new patients
To help you get your treatment started, our pharmacists answered some of …
Is Your Antidepressant Screwing Up Your Sex Life? Try These 7 Expert Strategies
Whether you’ve been taking meds for years or have just started during …
Dr. James Kim

Leave a Reply