Take this medication exactly as it was prescribed for you. Do not take the medication in
larger amounts, or take it for longer than recommended by your doctor. Follow the directions on
your prescription label.
It is best to take phentermine on an empty stomach before breakfast, or at least 10 to
14 hours before bedtime.
Do not take more phentermine for an increased effect. Taking too much
of this medication can cause serious, life-threatening side effects.
Do not crush, chew, break, or open an extended-release capsule. Swallow the pill
whole. It is specially made to release medicine slowly in the body. Breaking or opening the pill
would cause too much of the drug to be released at one time.
Phentermine should be taken only for a short time, such as a few weeks.
Taking high doses of phentermine over long periods of time can cause severe skin
problems, sleep problems (insomnia), personality changes, and feeling hyperactive or irritable.
Stop taking phentermine if you have increased hunger or if you otherwise think the
medication is not working properly.
You may have withdrawal symptoms when you stop using phentermine after a long
period of use. Do not stop using the medication suddenly without first talking to your doctor.
You may need to use less and less before you stop the medication completely.
Do not take phentermine in the evening because it may cause sleep problems (insomnia).
Store this medication at room temperature away from moisture and heat.
Keep track of how many pills have been used from each new bottle of this medicine.
Phentermine is a drug of abuse and you should be aware if any person in the household is using
this medicine improperly or without a prescription.
What happens if I miss a dose?
Take the missed dose as soon as you remember. If it is almost time for your next dose,
skip the missed dose and take the medicine at your next regularly scheduled time. Do
not take extra medicine to make up the missed dose.
What happens if I overdose?
Seek emergency medical attention if you think you have used too much of this
medication. An overdose of phentermine can be fatal.
Overdose symptoms may include confusion, hallucinations, feeling restless or aggressive,
nausea, vomiting, diarrhea, stomach pain, irregular heartbeat, tremors, rapid breathing, confusion,
hallucinations, feeling light-headed, fainting, or seizure (convulsions).
What should I avoid while taking phentermine?
Avoid drinking alcohol. It can increase some of the side effects of phentermine.
Phentermine can cause side effects that may impair your thinking or reactions. Be
careful if you drive or do anything that requires you to be awake and alert.
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