Phentermine
(brand names Adipex-P®, Ionamin®)Read phentermine prescription information
Quick Summary
Speaking scientific English, phentermine, or, being more specific - Oral Phentermine Hydrochloride (HCL), is a phenethylamine (sympathomimetic family) used as an appetite suppressant in conjunction with diet, exercise, and behavior therapy for the short-term management of exogenous obesity.
In plain English this means that phentermine is a fast and effective way to get rid of extra pounds (or kilograms, whatever you prefer) in short term with no need for extra efforts than carefully following the doctor or pharmacist-provided instructions (as well as the ones given below) and combining the phentermine-based obesity treatment course with the diet, exercise and behavior therapy which I assume you have already got used to. You should also remember that not only Phentermine, but your lively faith and strong will are the primary keys to success on the way to the effective weight loss!
In regards to phentermine packaging, phentermine may be sold as an immediate release formulation (brand name Adipex), or as a slow-release resin (brand names Ionamin® and Duromine® in Australia and New Zealand). Three forms of phentermine are available in the market: tables, capsules, and resin capsules.
Read below to get ready for the short-term weight loss course with help of phentermine.
Historical Facts about Phentermine
You may be interested to know that phentermine was at first introduced as one of two drugs in the Fen-Phen, another obesity fighter medication which was very popular in the world market mid-ninetieth of the previous century. The other component of Fen-Phen accompanying phentermine was fenfluramine (also known as dexfenfluramine), which was reported as valvular heart disease and pulmonary hypertension producer and withdrawn from the U.S. market in 1997.
Phentermine was not reported as a harmful medicine, so it is now available by itself in most countries including the United States.
Phentermine At Work
Scientists insist that phentermine, as the most of the other prescribed medications, works with neurotransmitters in the brain (specifically, the hypothalamus gland - a region of the brain that controls the autonomic nervous system, regulating sleep cycles, body temperature, appetite, etc) to decrease patient's appetite. The neurotransmitters signal a fight-or-flight response in the body which actually puts a halt to the hunger signal. As a result of this activity, phentermine causes appetite loss because the brain does not receive the hunger messages.
In complex scientific terms, for those who really want to know more about phentermine and its effects, we can say that phentermine is a centrally-acting stimulant by its chemical structure related to amphetamines, which stimulates neuron bundles to release a specific group of neurotransmitters (known as catecholamines), including dopamine, epinephrine (you know this as adrenalin), and norepinephrine (noradrenaline). The anoretic activity seen with these compounds would seem likely because to this effect on Central Nervous System, which corresponds to the current knowledge about Central Nervous System and feeding behavior. For you to know, this mechanism of action is the same as other stimulant appetite suppressants, for example diethypropion or phendimetrazine.
What You Should Know Before Using Phentermine
First of all, you should be aware of the fact that some medicines that you already take or medical conditions may interact with phentermine, and not always in a positive way. Contact your doctor and consult them or a pharmacist of all prescription and over-the-counter medicine that you are taking to make sure the phentermine will be of help.
If you plan on taking phentermine, you must be very selective in taking other drugs. For example, you should definitely inform your doctor if you take the medicines listed below before start using phentermine, in order to avoid dangerous consequences:
- Amantadine (the other name is Symmetrel)
- Amphetamines
- Caffeine (also known as NoDoz)
- Chlophedianol (Ulone)
- Cocaine
- Medicine for asthma and other breathing problems
- Medicine for colds, sinus problems, or hay fever or other allergies (including nose drops or sprays)
- Methylphenidate (also known as Ritalin)
- Nabilone (Cesamet)
The names of other medications that you should let your doctor know about before using phentermine include guanadrel, guanethidine, furazolidone, fenfluramine, and dexfenfluramine.
Your doctor must also know if you are using other diet pills or selective serotonin reuptake inhibitors, as they are not always "compatible" with phentermine; for example, Celexa (citalopram), Luvox (fluvoxamine), Zoloft (sertraline), Prozac (fluoxetine), and Paxil (paroxetine).
Pelmoline (the brand name Cyler) in conjunction with phentermine may increase the stimulant effects of the central nervous system, take this into account. The mentioned stimulant effects include irritability, nervousness, trembling or shaking, and trouble in sleeping.
We highly recommend that you avoid taking phentermine at the same time with Monoamine Oxidase (MAO) inhibitors - phentermine taken in conjunction with them or less than 14 days after taking a MAO inhibitor may result in extremely high blood pressure. Again, let your doctor know and ask for advice. Here is a short list for you to know for sure what is meant under the term Monoamine Oxidase (MAO) Inhibitors: Furoxone (furazolidone), Nardil (phenelzine), Eldepryl (selegiline), Marplan (isocarboxazid), Matulane (procarbazine), Parnate (tranylcypromine).
Another warning relates to tricyclic antidepressants - using them with phentermine may result in high blood pressule or irregular heartbeat. For your reference, tricyclic antidepressants include: Elavil (amitriptyline), Anafranil (clomipramine), Asendin (amoxapine), Sinequan (doxepin), Aventyl (nortriptyline), Surmontil (trimipramine), Asendin (amoxapine), and others.
Never forget to inform your doctor of any other medical conditions, allergies, pregnancy, or breast-feeding before taking phentermine. Below we provide a comprehensive list of contraindications (refer to cautions section below for more details), but in general use of phentermine is not recommended if you have a history of heart conditions, brain or spinal cord disorders, atherosclerosis, high blood pressure, glaucoma, or hyperthyroidism.
If something of these relate to you, do not forget to contact your doctor or pharmacist if you have any questions or concerns about using phentermine.
Phentermine Usage Directions
The phentermine usage directions provided below are specific only to the average doses. The actual recommended dose of phentermine could be different for different patients. We strongly recommend that you follow the directions for using phentermine provided by your doctor or as noted on phentermine package.
FDA recommends that phentermine is used short-term (not more than 12 weeks), and its usage is combined with "non-pharmacological" approaches to weight loss such as healthy dieting and exercise. At other side, the recommendations which limit phentermine use for short-term treatment are sometimes controversial. The one reason of limiting phentermine use is drug tolerance: phentermine may loose its appetite suppressing effects if the body adjusts to this drug. On the other side, statistics shows that phentermine stayed effective evein in a 36 week trial (as noted in PMID 11054601).
Phentermine should be taken on an empty stomach, once daily, before breakfast or 2 hours after breakfast, depending on directions given by your doctor. These requirements are set due to the risk of insomnia, so it is generally recommended that phentermine is taken at specified time range. Swallow whole; do not break, crush, or chew tablets before swallowing. As phentermine may disrupt normal sleep patterns, make sure you take a dose at least 10 to 14 hours before the bedtime. If you are taking more than one dose of phentermine per day, take the last dose approx. 4-6 hours before you go to the bed.
Oral dosage form for adults (under age 60):
- Capsules - 15 to 37.5 mg phentermine once a day before breakfast or 1 up to 2 hours after breakfast;
- Tablets - 15 to 37.5 mg phentermine once a day before breakfast or 1 up to 2 hours after breakfast. Your doctor may also tell you to take 15 to 37.5 mg phentermine in divided doses one-half hour before meals, instead of taking one dose per day;
- Resin (Capsules) - 15 to 30 mg phentermine once a day before breakfast.
Oral dosage form for adults (age 60 and over):
Depending on your health conditions, it could be necessary for you to take the reduced dosage of phentermine. Please consult your physician to know for sure.
Oral dosage form for infants and children (under age 16):
Phentermine is not recommended for children under age 16.
General phentermine usage instructions, which you should definitely take care of, are the following:
- Take phentermine only as it is directed by your doctor or a pharmacist;
- Avoid taking more phentermine than prescribed (refer to cautions section for more details);
- Avoid overdose (do not take phentermine more often than prescribed);
- Avoid taking phentermine for longer time than your doctor ordered.
In case you miss a dose of phentermine, go take it ASAP (even make the day longer if it would be necessary to satisfy the above requirements). However, if it is afternoon, do not hesitate to skip the missed dose and go back to your regular dosing schedule starting the following day. And never double dose of phentermine - keep yourself out of danger.
If you think that phentermine is not working properly after you have taken it for a few weeks, please consult your doctor. It is strictly recommended that you do not increase the dose.
Phentermine Storage Requirements
Phentermine package must be stored at room temperature in a tightly-closed container, far away from heat and light. Please do not store it in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down. Never keep outdated medicine past the expiration date. Keep it out of reach of children.
Cautions
Never exceed the recommended dose and never take phentermine for longer than you are instructed without checking with your doctor. These both factors may cause serious side effects. Do not forget to keep all doctor or laboratory appointments while you are using phentermine. If you plan to begin taking any new medicine after the phentermine, either prescription or over-the-counter, you should definitely check with your doctor or pharmacist.
Avoid driving, operating machinery, or doing anything else that may be dangerous until you understand how you react to phentermine. Remember that if you are going to have any medical or dental treatments, emergency care, or surgery, tell the doctor or dentist that you are using phentermine.
Women should know that if they plan to become pregnant, they must discuss the benefits and risks of using phentermine during pregnancy with their doctor. The science has no conclusion if phentermine is excreted in breast milk, so avoid breast-feeding while taking this medicine.
Actually, as it had been already mentioned in "what you should know before using phentermine" section above, the presence of other medical problems may affect the use of phentermine. If you suffer from or have suffered from one or more of the problems listed below, please inform your doctor before start taking phentermine:
- Advanced atherosclerosis;
- Alcohol abuse - alcohol may increase unwanted side effects of dizziness; we recommend limiting alcohol use during the phentermine (or other diet pills) usage period;
- Allergies, or allergic reactions to phentermine, amphetamine, dextroamphetamine, ephedrine, epinephrine, isoproterenol, metaproterenol, methamphetamine, norepinephrine, phenylephrine, phenylpropanolamine, pseudoephedrine, terbutaline, other appetite suppressants, dyes, food, or preservatives;
- Diabetes (sugar diabetes) - it is possible that phentermine will 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. In case of diabetes it may be necessary to change the amount of insulin or oral antidiabetic medicine that you take;
- Drug Abuse or Dependence - 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;
- 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;
- Pregnancy - phentermine has not been shown to cause birth defects in humans. Prior to taking this medication, tell your doctor if you are pregnant or attempting to become pregnant;
- 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, please inform the doctor or dentist that you are using phentermine.
It is necessary to mention that phentermine may have unwanted side effects in the following cases as well:
- Driving and Hazardous Work - phentermine (or other diet pills) may cause some people to feel a false sense of well-being or to become dizzy, lightheaded, drowsy, or less alert than normal. Please avoid driving or engaging in hazardous work until you know how phentermine affects you.
- Infants and Children - phentermine (or other appetite suppressants) are not recommended for use by children under age 16. Studies on appetite suppressants have been done only in adult patients, and there is no specific information comparing use of phentermine in children with use in other age groups.
Side Effects of Phentermine
In general, phentermine is relatively well tolerated. The scientists had discovered that side effects produced by phentermine may include restlessness, nervousness, difficulty sleeping, dry mouth, tachycardia, and increased alertness, but the incidence and magnitude of these appear to be less than with the amphetamines. According to the fact that phentermine acts through sympathomimetic pathways, it can also increase the blood pressure and heart rate. Palpitations and insomnia may not be an exception as well. And, finally, for those people who, regardless to the numerous warnings, take phentermine on a long-term basis, phentermine may develop euphoria and a psychological addiction to it.
However, if mentioned above symptoms continue or are bothersome, immediately check with your doctor. In case you notice other effects of phentermine not listed above, please contact your doctor, nurse, or pharmacist.
Overdosage Effects of Phentermine
If you take too much phentermine, it may cause unwanted effects or become habit-forming, but generally it is unlikely for an overdose of Phentermine to be life-threatening. For you to know, symptoms of overdose may include restlessness, tremor, rapid breathing, confusion, nausea, vomiting, diarrhea, and stomach cramps.
Regardless to the relative safety of phentermine, once you suspect or know for sure of the overdose, the first thing to do must be to contact your local poison control center or emergency room immediately to solve this problem as soon as possible. Remember that self-treatment of phentermine overdose is never an option.