Key takeaways
Diethylpropion and phentermine (Adipex-P) are both sympathomimetic medications used for weight management in people with obesity. They work by suppressing appetite and are intended for short-term use. Diethylpropion is available as immediate-release and extended-release tablets, while phentermine comes in tablets, capsules, and orally disintegrating tablets. Diethylpropion is typically taken three times a day or once daily in the extended-release form, whereas phentermine is usually taken once daily, but can be taken twice daily depending on the form. Both medications are controlled substances due to their potential for misuse and dependence. Common side effects of diethylpropion include nausea, dry mouth, and trouble sleeping, while phentermine may cause dry mouth, headache, and constipation. Both medications should not be combined with other weight loss medications or taken within 14 days of monoamine oxidase inhibitors (MAOIs). Diethylpropion is not recommended for people over 65 or those with heart or kidney problems, while phentermine should be avoided in people with serious heart issues.
