Precautions when taking phentermine

What to tell your doctor before taking phentermine

The presence of other medical problems may affect the use of phentermine (or other appetite suppressants).

Please inform your doctor if you suffer from, or have suffered from:

  • Advanced Atherosclerosis
  • Alcohol Abuse (or history of)
  • Allergies - Inform your doctor if you have ever had any unusual or allergic reaction to:
  • Phentermine
  • Amphetamine
  • Dextroamphetamine
  • Ephedrine
  • Epinephrine
  • Isoproterenol
  • Metaproterenol
  • Methamphetamine
  • Norepinephrine
  • Phenylephrine
  • Phenylpropanolamine
  • Pseudoephedrine
  • Terbutaline
  • Other appetite suppressants
  • Dyes
  • Food preservatives
  • Diabetes Mellitus (sugar diabetes) - It may be necessary to change the amount of insulin or oral anti-diabetic medicine that you take.
  • Drug Abuse or Dependence (or history of) - Dependence on phentermine may be more likely to develop.
  • Family History of Mental Illness - Mental depression or other mental illness may be more likely to occur.
  • Glaucoma
  • Hyperthyroidism (over-active thyroid) - phentermine may worsen the condition.
  • Kidney Disease - The chance of serious side effects may increase due to higher blood levels of phentermine.
  • Mental Illness
  • Moderate to Severe Hypertension (high blood pressure)
  • Symptomatic Cardiovascular Disease
  • The use of a Monoamine Oxidase (MAO) inhibitor within the last 2 weeks

Pregnancy - It is not known if phentermine causes birth defects in humans. Prior to taking this medication, tell your doctor if you are pregnant or attempting to become pregnant.

Phentermine Contraindications

Alcohol - Alcohol may increase unwanted side effects of dizziness, therefore, it is advisable to limit alcohol use while taking phentermine (or other appetite suppressants).

Diabetes - Phentermine may affect blood sugar levels. If you are diabetic and notice a change in the results of your urine or blood sugar test, or if you have any questions or concerns, please consult your doctor.

Hyperthyroidism (over-active thyroid) - Phentermine (or other appetite suppressants) may worsen the condition.

Kidney disease - The chance of serious side effects may increase due to higher blood levels of phentermine.

Driving and hazardous work - Phentermine (or other appetite suppressants) may cause some people to feel a false sense of well-being or to become dizzy, lightheaded, drowsy, or less alert than normal. Do NOT drive or engage in hazardous work until you know how the medicine affects you.

Surgery, dental treatment, or emergency treatment - Taking phentermine in conjunction with medicines that are used during surgery or dental or emergency treatments may cause serious side effects. Prior to surgery or treatment, inform the doctor or dentist that you are using this medicine.

Medications that may react with phentermine

Certain medicines should never be used together, however, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary.

When you are taking phentermine (or other appetite suppressants), it is especially important that you inform your doctor if you are taking any of the following:

  • Amantadine, i.e. - Symmetrel
  • Amphetamines
  • Caffeine, i.e. - NoDoz
  • Chlophedianol, i.e. - Ulone
  • Cocaine
  • Medicine for asthma or other breathing problems
  • Medicine for colds, sinus problems, or hay fever or other allergies (including nose drops or sprays)
  • Methylphenidate, i.e. - Ritalin
  • Nabilone - i.e. Cesamet

Other diet pills or Selective Serotonin Reuptake Inhibitors (SSRIs), such as:

  • Citalopram, i.e. - Celexa
  • Fluvoxamine, i.e. - Luvox
  • Sertraline, i.e. - Zoloft
  • Fluoxetine, i.e. - Prozac
  • Paroxetine, i.e. - Paxil

Pemoline, i.e. - Cyler - These medicines in conjunction with Sympathomimetic appetite suppressants may increase the central nervous system (CNS) stimulant effects, such as irritability, nervousness, trembling or shaking, or trouble in sleeping.

Monoamine Oxidase (MAO) inhibitors - phentermine (or any other appetite suppressant) taken in conjunction with or less than 14 days after taking a monoamine oxidase (MAO) inhibitor may suddenly provoke extremely high blood pressure.

Monoamine Oxidase (MAO) inhibitors include:

  • Furazolidone, i.e.- Furoxone
  • Phenelzine, i.e. - Nardil
  • Selegiline, i.e. - Eldepryl
  • Isocarboxazid, i.e.- Marplan
  • Procarbazine, i.e.- Matulane
  • Tranylcypromine, i.e. - Parnate

Tricyclic antidepressants - Using these medicines with Sympathomimetic appetite suppressants may cause high blood pressure or irregular heartbeat.

Tricyclic antidepressants include:

  • Amitriptyline, i.e. - Elavil
  • Clomipramine, i.e. - Anafranil
  • Amoxapine, i.e. - Asendin
  • Doxepin, i.e. - Sinequan
  • Nortriptyline, i.e.- Aventyl
  • Trimipramine, i.e. - Surmontil
  • Amoxapine, i.e. - Asendin
  • Desipramine, i.e.- Pertofrane
  • Imipramine, i.e. - Tofranil
  • Protriptyline, i.e. - Vivactil

Children and the over 60's

Adults age 60 and over - There is no specific information comparing the use of appetite suppressants in the elderly with use in other age groups. Therefore, it may not be known if they work in exactly the same way they do in younger adults, or if they cause different side effects or problems in older people.

Adverse reactions may be more likely and more severe in older patients, especially when taken in combination with drugs that act on the central nervous system.

Breast feeding - Use of phentermine (or other appetite suppressants) while breast-feeding is NOT recommended; it may pass into breast milk, causing unwanted effects in nursing babies. Please consult your doctor for advice.

Infants and children - Phentermine (or other appetite suppressants) are NOT recommended for use by children under age 18. Studies on appetite suppressants have been done only in adult patients, and there is no specific information comparing use of Sympathomimetic appetite suppressants in children with use in other age groups.

How to store phentermine

Keep this and all medications out of children's reach.

Store away from heat and direct light.

Do NOT store in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.

Do NOT keep outdated medicine past the expiration date. Discarded medicine should be kept out of children's reach.

> For answers to Frequently Asked Questions see our FAQs section

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