Phentermine is a drug that helps people suffering from obesity to lose weight. It provides for stable and efficient weight loss at the same time reducing food cravings. Taking phentermine in the evening can cause insomnia. Its best to use it 10-14 hours before going to bed. The most commonly recommended routine involves taking phentermine about 30 minutes before having breakfast. As your health care provider if you can take this medicine with some food. This drug is intended for short-term treatment, usually up to 6 weeks. This has to do with the fact phentermine can be addictive for some people. Extreme tiredness and depression are possible symptoms of a sudden withdrawal. To make sure they do not occur you will need to try gradual withdrawal. Your doctor will tell you how to take less and less of this medicine to provide for efficient weight loss. The following mild side effects are sometimes possible when phentermine is taken: diarrhea, feeling anxious, tremors, itching, nervousness, headache, unpleasant taste in your mouth, dry mouth, dizziness, trouble sleeping, and constipation. There is no need to get worried if you develop the symptoms mentioned, as they are not considered to be serious and tend to be short-lived. More serious side effects are also possible. They can include any of the following: unusual thoughts or behavior, buzzing in the ears, chest pain, blurred vision, swelling, high blood pressure, confusion, shortness of breath, uneven heartbeats, fast heartbeat, rapid weight gain, and seizure. If you notice any other side effects, make sure you report them to your doctor as well, since every person’s reactions may be quite different. If you have a history of drug or alcohol abuse, seizure disorder, overactive thyroid or some other thyroid disorder, anxiety disorder, diabetes, glaucoma, heart disease, or arteriosclerosis, make sure your doctor knows about it when prescribing this medicine. These medical conditions may require a dose adjustment or your condition will be monitored for side effects. Additional tests may be required or you will not be able to take this medication at all in some of the cases mentioned. Never take more of phentermine than prescribed by your doctor, as an overdose is possible. The following are the symptoms of an overdose: rapid breathing, fainting, nausea, vomiting, restlessness, hallucinations, stomach pain, hallucinations, tremors, seizure, confusion, aggressiveness, light-headedness, irregular heartbeat, diarrhea, and confusion. Seek emergency medical help if you have taken too much of phentermine, either intentionally or accidentally. Phentermine is not supposed to be taken for longer than several weeks. Make sure you discuss your individual treatment schedule with your health care provider to avoid taking more of phentermine or using it for longer than prescribed. Never give this medicine to your children and other people that do not have a prescription, as dangerous health reactions are possible in them.