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Suprenza

Generic name: phentermine

Brand names: Adipex-P, Lomaira, Suprenza

Last updated November 3, 2026 0 views
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What is Suprenza?

Suprenza is like an amphetamine. This medicine activates the central nervous system (nerves and brain), which raises your heart rate and blood pressure while reducing your appetite.

Suprenza is used along with diet and exercise to help treat obesity, especially in people who have risk factors like high blood pressure, high cholesterol, or diabetes.

Suprenza may also be used for reasons not mentioned in this medication guide.

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How should I take Suprenza?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Use the medicine exactly as directed.

Suprenza is usually taken before breakfast or 1 to 2 hours after breakfast. Follow your doctor's dosing instructions very carefully.

Never use Suprenza in larger amounts or for longer than prescribed. Taking more of this medication will not make it more effective and can cause serious, life-threatening side effects.

Suprenza is for short-term use only. The effects of appetite suppression may wear off after a few weeks.

Suprenza may be habit-forming. Misuse can cause addiction, overdose, or death. Selling or giving away Suprenza is against the law.

Call your doctor at once if you think this medicine is not working as well, or if you have not lost at least 4 pounds within 4 weeks.

Do not stop using Suprenza suddenly, or you could have unpleasant withdrawal symptoms. Ask your doctor how to safely stop using this medicine.

Store at room temperature away from moisture and heat. Keep the bottle tightly closed when not in use.

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Warnings

You should not use Suprenza if you have glaucoma, an overactive thyroid, severe heart problems, uncontrolled high blood pressure, advanced coronary artery disease, extreme agitation, or a history of drug abuse.

Do not use this medicine if you have taken an MAO inhibitor in the past 14 days, such as isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, or tranylcypromine.

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Before taking this medicine

You should not use Suprenza if you are allergic to it, or if you have:

  • a history of heart disease (coronary artery disease, heart rhythm problems, congestive heart failure, stroke);
  • severe or uncontrolled high blood pressure;
  • overactive thyroid;
  • glaucoma;
  • extreme agitation or nervousness;
  • a history of drug abuse; or
  • if you take other diet pills.

Do not use Suprenza if you have used an MAO inhibitor in the past 14 days. A dangerous drug interaction could occur. MAO inhibitors include isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, tranylcypromine, and others.

Weight loss during pregnancy can harm an unborn baby, even if you are overweight. Do not use Suprenza if you are pregnant. Tell your doctor right away if you become pregnant during treatment.

You should not breast-feed while using Suprenza.

Tell your doctor if you have ever had:

  • heart disease or coronary artery disease;
  • a heart valve disorder;
  • high blood pressure;
  • diabetes (your diabetes medication dose may need to be adjusted); or
  • kidney disease.

Suprenza is not approved for use by anyone younger than 16 years old.

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Suprenza side effects

Get emergency medical help if you have signs of an allergic reaction: hives; trouble breathing; swelling of your face, lips, tongue, or throat.

Suprenza may cause serious side effects. Call your doctor right away if you experience:

  • shortness of breath, even with mild activity;
  • chest pain, feeling like you might faint;
  • swelling in your ankles or feet;
  • fast or fluttering heartbeats;
  • shaking, feeling restless, trouble sleeping;
  • unusual changes in mood or behavior; or
  • high blood pressure--severe headache, blurred vision, pounding in your neck or ears, anxiety, nosebleed.

Common side effects of Suprenza may include:

  • itching;
  • dizziness, headache;
  • dry mouth, bad taste;
  • diarrhea, constipation, stomach pain; or
  • increased or decreased interest in sex.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

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What happens if I miss a dose?

Take the medicine as soon as you can, but if you miss a dose and it is late in the day, skip the missed dose. Do not take two doses at the same time.

This section was rewritten for readability and reviewed for meaning.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. An overdose of Suprenza can be fatal.

Overdose symptoms may include confusion, panic, hallucinations, extreme restlessness, nausea, vomiting, diarrhea, stomach cramps, feeling tired or depressed, irregular heartbeats, weak pulse, seizure, or slow breathing (breathing may stop).

Avoid driving or hazardous activity until you know how Suprenza will affect you. Your reactions could be impaired.

Drinking alcohol with this medicine can cause side effects.

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What other drugs will affect Suprenza?

Taking Suprenza with other diet medications like fenfluramine (Phen-Fen) or dexfenfluramine (Redux) can lead to a rare but serious lung condition called pulmonary hypertension. Do not take this medicine with any other diet medications unless your doctor tells you to.

Many medications can interact with Suprenza. This includes both prescription and over-the-counter medicines, as well as vitamins and herbal products. Not all possible interactions are included here. Inform your doctor about all the medicines you are currently taking and any new medicines you start or stop using.

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Common questions about Suprenza

Why am I tired on Phentermine?
Fatigue or tiredness can come as a result of sleepless nights or following a period of over-stimulation, however, adverse effects of phentermine also include drowsiness, fatigue, and reduced energy levels. If you’re feeling fatigued or lacking in energy while taking phentermine and the problem persists, you should consult your doctor as it may be that you have an undiagnosed medical condition.
Is phentermine safe to use?
Phentermine is safe to use when taken as prescribed by your doctor. Make sure your doctor knows about all of the other medicines you take, as well as any medical problems you have. It should not be taken along with other weight loss drugs. Though rare, high blood pressure has been reported in some patients. Phentermine should not be taken if: You have cardiovascular disease You are taking or recently stopped taking drugs known as monoamine oxidase inhibitors You have hyperthyroidism You have glaucoma You have a history of drug abuse or agitation You are pregnant or nursing You are sensitive to or had a reaction to other stimulant drugs
How long does it take to start losing weight on phentermine?
Phentermine should be prescribed as part of a weight loss plan that also includes exercise, modifying behavior and reducing calories. Phentermine is usually taken for 12 weeks or less. Weight loss effects depend on the dose of phentermine taken, as well as diet, exercise and other factors.
How long does phentermine stay in your system?
Phentermine stays in your system for approximately 4 days after you take it. It takes about 20 hours for half of the drug to leave your system. Many things affect how long it takes a drug to leave your system. These include your age, diet, how well your kidneys and liver are working and other factors.
How to take phentermine for the best results?
Take phentermine as directed by your doctor. It is usually taken first thing in the morning, before breakfast. It may also be taken 1 to 2 hours after eating breakfast. Phentermine is not usually taken at night because it can cause insomnia.
Is Phentermine approved for weight loss?
Phentermine is a drug approved for weight loss as part of a regimen of exercise, calorie restriction and behavior modification. Phentermine may be prescribed for short-term treatment in people who have a body mass index (BMI) of 30 kg/m2 or greater. It may also be prescribed to people who have a BMI of 27 kg/m2 or greater with other risk factors, such as high blood pressure, diabetes or high cholesterol. Some of the adverse effects of phentermine may include: Heart palpitations Raised blood pressure A feeling of restlessness Headaches Dry mouth Diarrhea Constipation Hives A higher or lower libido
How does phentermine work?
Phentermine affects the brain’s neurotransmitters. It is thought to cause weight loss by suppressing appetite. The exact way phentermine works to cause weight loss is not known. Phentermine belongs to the class of drugs known as sympathomimetic amines. These are more commonly known as stimulant drugs.
What drugs can cause serotonin syndrome?
Common drug classes that can cause serotonin syndrome include selective serotonin reuptake inhibitors (SSRIs), monoamine oxidase inhibitors (MAOIs), and opioids like tramadol. Continue reading
Why is phentermine a controlled substance?
Phentermine is classified as a Schedule IV controlled substance by the DEA because it is a prescription stimulant medication with potential for abuse and dependence, though the risk is considered relatively low compared to other controlled substances. Continue reading

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Before you take this medicine: the information on this page is general and may not cover your personal circumstances. Read the label supplied with your medicine and ask a pharmacist or doctor if you are unsure, especially if you are pregnant, breastfeeding, taking other medicines or managing a long-term condition.
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