First, lets start with what phentermine is. Phentermine is an appetite suppressant and a stimulant that can help increase metabolism. Of course, that is just music to most people’s ears who have struggled with weight loss: it will make me eat less and burn more calories! Unfortunately, nothing is that simple right? What we have found is that phentermine if used in conjunction with lifestyle changes such as diet and exercise can help obese and overweight individuals loose weight. However, short term use without changing your diet and starting an exercise regimen, usually only results in short term weight loss. Most of these people will gain all the weight back and maybe even a little more once they stop taking phentermine. Most providers that work with their patients on weight management will only prescribe phentermine for 3 months at a time. So, while phentermine can have some great results if properly used, it can also have dangerous results if abused or used improperly.
- One of the biggest concerns with phentermine is the risk of developing pulmonary hypertension. Pulmonary hypertension is a rare disease, but it can be fatal. People that take other diet medications with phentermine like fenfluramine (sold under the brand name Phen-Fen) can develop pulmonary hypertension.
- Phentermine has a lot of side effects. It can cause restlessness, headaches, dizziness, itching, diarrhea, change in libido, and sleep problems. Serious side effects can be substantial such as shortness of breath, chest pain, confusion or increasing your blood pressure to dangerously high levels. If you experience any of these severe symptoms, you must discontinue the medication immediately and see your provider. Drinking alcohol can intensify the side effects of phentermine. These should not be taken together.
- Phentermine can be very habit forming. There are many people that become reliant on phentermine for weight loss. Remember phentermine is a stimulant and in the same class of medications as cocaine and amphetamines. While cocaine and methamphetamines are much more potent releasers of norepinephrine and dopamine and therefore more addictive than phentermine, the potential for addiction is there.
- Long term phentermine use and sudden discontinuation can lead to withdrawal. The most common symptoms are exhaustion and depression. This is one of the main reasons we only use phentermine for short periods of time to aid in weight loss. If a person has taken it for long periods of time, their dose should be decreased gradually to avoid the symptoms of withdrawal.