Most patients who take phentermine will experience a dry mouth. To minimize this sensation, make sure that you drink plenty of water, which for most people should be 60-100 ounces per day.
Some patients will experience mild constipation. Again, keeping your fluid intake high can prevent this. If you are reaching your water goals and still struggling, you can take 2 tablespoons of milk of magnesia morning and night until the constipation subsides. Another option is to use polyethylene glycol powder (Miralax). Dissolve 17g in 8 ounces of water or another beverage daily until the constipation subsides.
All stimulants can potentially raise your blood pressure. If this happens, it is generally mild. If you take medication for high blood pressure, keep a blood pressure journal that has 3 weekly readings. This will help the providers to know how your blood pressure is doing at home and at work. If you don’t own a blood pressure cuff, you can check it at just about any pharmacy. When your weight significantly drops, expect your blood pressure to come down also. This may require taking you off your blood pressure medication.