Medically reviewed by Drugs.com. Last updated on Sep 23, 2020.
Uses of Phentermine Capsules and Tablets:
- It is used to treat obesity.
What do I need to tell my doctor BEFORE I take Phentermine Capsules and Tablets?
- If you have an allergy to phentermine or any other part of this medicine (phentermine capsules and tablets).
- If you are allergic to this medicine (phentermine capsules and tablets); any part of this medicine (phentermine capsules and tablets); or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.
- If you have ever had any of these health problems: Heart disease like heart failure or a heartbeat that is not normal, drug abuse, high blood pressure, or stroke.
- If you have any of these health problems: Glaucoma, agitation, anxiety, or overactive thyroid.
- If you are on dialysis, talk with your doctor.
- If you have taken certain drugs for depression or Parkinson's disease in the last 14 days. This includes isocarboxazid, phenelzine, tranylcypromine, selegiline, or rasagiline. Very high blood pressure may happen.
- If you are taking any of these drugs: Fluoxetine, fluvoxamine, paroxetine, or sertraline.
- If you are taking or will be taking another drug like this one.
- If you are taking any other drug (prescription or OTC, natural product) for weight loss.
- If you are pregnant or may be pregnant. Do not take this medicine (phentermine capsules and tablets) if you are pregnant.
- If you are breast-feeding. Do not breast-feed while you take this medicine (phentermine capsules and tablets).
This is not a list of all drugs or health problems that interact with this medicine (phentermine capsules and tablets).
Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take this medicine (phentermine capsules and tablets) with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.
What are some things I need to know or do while I take Phentermine Capsules and Tablets?
- Tell all of your health care providers that you take this medicine (phentermine capsules and tablets). This includes your doctors, nurses, pharmacists, and dentists.
- Avoid driving and doing other tasks or actions that call for you to be alert until you see how this medicine (phentermine capsules and tablets) affects you.
- People who take drugs for weight loss like this medicine (phentermine capsules and tablets) may have a higher chance of having raised pressure in the lungs. This is rare but is often deadly. Talk with your doctor.
- Do not take this medicine (phentermine capsules and tablets) for longer than you were told by your doctor.
- If you have been taking this medicine (phentermine capsules and tablets) for a long time or at high doses, it may not work as well and you may need higher doses to get the same effect. This is known as tolerance. Call your doctor if this medicine (phentermine capsules and tablets) stops working well. Do not take more than ordered.
- If you have been taking this medicine (phentermine capsules and tablets) for many weeks, talk with your doctor before stopping. You may want to slowly stop this medicine (phentermine capsules and tablets).
- This medicine may be habit-forming; avoid long-term use. Tell your doctor if you have a history of drug or alcohol abuse.
- This medicine may cause unsafe heart-related side effects. Tell your doctor if you have any heart disease.
- Check blood pressure and heart rate as the doctor has told you.
- If you have high blood sugar (diabetes), talk with your doctor.
- Follow the diet and workout plan that your doctor told you about.
- Talk with your doctor before you drink alcohol.
- Do not give to a child younger than 17 years of age.
- This medicine may cause harm to the unborn baby if you take it while you are pregnant. If you are pregnant or you get pregnant while taking this medicine (phentermine capsules and tablets), call your doctor right away.
How is this medicine (Phentermine Capsules and Tablets) best taken?
Use this medicine (phentermine capsules and tablets) as ordered by your doctor. Read all information given to you. Follow all instructions closely.
- Take this medicine (phentermine capsules and tablets) early in the day to prevent sleep problems.
- Take before or after breakfast as your doctor has told you.
What do I do if I miss a dose?
- Take a missed dose as soon as you think about it.
- If it is close to the time for your next dose, skip the missed dose and go back to your normal time.
- Do not take 2 doses at the same time or extra doses.
What are some side effects that I need to call my doctor about right away?
WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:
- Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
- Signs of high blood pressure like very bad headache or dizziness, passing out, or change in eyesight.
- Change in how you act.
- Chest pain or pressure or a fast heartbeat.
- A heartbeat that does not feel normal.
- Mood changes.
- Shortness of breath.
- Swelling on legs or feet.
What are some other side effects of Phentermine Capsules and Tablets?
All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:
- Feeling nervous and excitable.
- Dry mouth.
- Not able to sleep.
- Bad taste in your mouth.
- Lowered interest in sex.
- Not able to get or keep an erection.
These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.
You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.
If OVERDOSE is suspected:
If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.
How do I store and/or throw out Phentermine Capsules and Tablets?
- Store at room temperature.
- Store in a dry place. Do not store in a bathroom.
- Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
- Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.
Consumer information use
- If your symptoms or health problems do not get better or if they become worse, call your doctor.
- Do not share your drugs with others and do not take anyone else's drugs.
- Some drugs may have another patient information leaflet. Check with your pharmacist. If you have any questions about this medicine (phentermine capsules and tablets), please talk with your doctor, nurse, pharmacist, or other health care provider.
- If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.
Frequently asked questions
More about phentermine
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- Drug class: anorexiants
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