The history of phentermine shows the strengths and weaknesses of the regulatory system for medication. When this drug was first submitted to the FDA for approval in the late 1950s, medical science was still adjusting to the development of technology.
Clinical trials were conducted but, by modern standards, they were relatively crude. Thus, the standards of “safety” and “effectiveness” applied were lower than those in force today.
Once approved, the FDA does not require the manufacturer to conduct new efficacy trials. It is left to the monitoring system to judge whether there are safety issues.
One of the ways in which the FDA protects the public is to invite all hospitals and medical professionals to submit reports of adverse side-effects for all drugs on the market. It would be better if this was a mandatory system but, as it stands, it does give the FDA some evidence of trends in the safety of classes of drugs. It tends to be only the more serious side-effects that are reported.
Although there are some question marks over the use of the class of amphetamines, the FDA has never had sufficient evidence of adverse side-effects in the use of phentermine to justify instructing the manufacturer to withdraw it. Because it is significantly cheaper than the other appetite suppressants, it dominates the market.
Independently, the FDA approved Fenfluramine. Several hospitals and general practitioners experimented and found that combining Fenfluramine with Phentermine appeared to produce good results. This became known as Fen-Phen.
The combination of two independently approved drugs did not need FDA approval. It is always open to physicians to prescribe two or more drugs at the same time. In just a few years, this became the cocktail of choice among those wishing to lose weight.
In 1996, the FDA approved Dexfenfluramine, and a new partner for phentermine was born. Then evidence emerged of damage to heart valves. The FDA stepped in and both Fenfluramine and Dexfenfluramine were withdrawn from the U.S. market. There was never been any suggestion that phentermine itself is a danger to the cardiovascular system.
As an aside, it is noted that there is a new off-label combination of phentermine with Prozac. The use of Prozac is said to delay the onset of tolerance for the phentermine. There are no current reports of problems in this combination.
What is phentermine?
Phentermine is one of the classes of amphetamine drugs. It is used as an appetite suppressant, prescribed together with a change in diet, light exercise, and counseling to help people reduce their weight.
The guidelines used by healthcare professionals are to limit access to this drug. There are two consequences. Prescriptions should only be given to people who are at risk of serious medical problems because of their excess weight.
This means individuals already have a high body mass index (BMI) and so are at risk, or they already have problems with high cholesterol and hypertension. Further, because of the risk of side-effects, phentermine should only be used for short periods of time.
Although this drug can be obtained through the internet without a prescription, people should always follow the instructions given by the online pharmacist. The best course is to lose weight slowly and stay safe.
The human body builds up a tolerance for this drug fairly quickly and it will seem to become less effective. Never give in to the temptation to increase the dosage without first discussing it with your physician.
It is important to note that, in many countries around the world including the U.S., this drug is a controlled substance. This affects the way you should keep the drug and whether you should carry it around with you outside the home.
How does phentermine work?
Phentermine is one of the classes of amphetamine drugs and it is designed to affect one specific group of neurotransmitters (the chemicals that carry messages around the brain). There are two competing explanations for how phentermine suppresses appetite.
The first is that it modifies the messages from the stomach to trick people into believing that they are full. Under normal circumstances, it takes about half an hour for the stomach to signal it is full. When using this drug, the message may be sent more continuously.
Thus, people do not feel hungry and so eat less. The second explanation is that it triggers the fight-or-flight mechanism. When people experience fear, the body releases adrenaline. This gets people ready to run away or fight if the danger proves real. To make sure all the senses are available for scanning the surrounding environment, hunger is suppressed. There must be no distractions if people are to survive.
How to use phentermine
This drug is usually only available on prescription. The fact that online pharmacies will supply it on the basis of the answers given to a medical questionnaire should not give you a false sense of security. You should read all the information supplied on the label and in the packaging.
Even more importantly, all users should strictly follow all the instructions given by the online pharmacist. That way, everyone stays safe.
If you are prescribed a once-daily version, take the dose in the morning before breakfast. Should you forget to take it one morning, it is very important not to take it after midday. Leave the dose until the following day.
If you are on a schedule taking three or sometimes four per day, aim to take each tablet at least thirty minutes before a meal. You should also allow at least five hours between the last dose for the day and your usual bedtime.
In the event you forget to take a dose, never double up when you remember. It is not advisable to play catch-up. Never crush the tablet. Swallow it whole with plenty of water.
Finally, never take this drug in larger doses nor for longer than prescribed. There are real risks of side-effects if people exceed the dose directed by their pharmacist.
This drug should be kept in a cool, dry place. The steam from a shower in the bathroom or from cooking in a kitchen can affect the drug. Security is important. Keep this drug in a safe place well out of the reach of any children. No-one under the age of 16 years should take this drug unless it is approved by a doctor.
There are also some who may be tempted to take the drug for the wrong reason. Never agree to share your drug with anyone else, and make sure that people with problems of addiction cannot get access to your supply of this drug. It is good practice to keep a count of the number of tablets. If you become aware that some of the tablets are missing, take action to identify who has taken them and whether the drug is being abused.
Always warn a dentist or doctor that you are taking phentermine if you go for treatment. There can be serious interactions between different drugs and it is very important that medical and dental professionals know all the facts before treating you.
Contraindications and warnings
If you are overweight, there is a temptation to take several diet medications at the same time. You should not mix phentermine with anything else unless it is specifically approved by your doctor.
In particular, do not take phentermine at the same time as fenfluramine.
Some years ago, this combination was called Phen-Fen and it was considered a safe and effective treatment. Unfortunately, evidence emerged over time that continued use caused damage to the valves of the heart.
The combination marketed by the manufacturer was withdrawn from the market on safety grounds. Similarly, the combination with dexfenfluramine can produce pulmonary hypertension — a dangerous rise in blood pressure in the lungs which can be fatal.
If you experience pain in your chest, find it difficult to breathe, faint and your ankles swell, this is an emergency and you should get immediate treatment.
One of the side-effects of phentermine is drowsiness and a slowing in reaction times. It is therefore unsafe to drive or to operate any machine requiring you to be alert. This side-effect is more likely if you have also consumed alcohol. It is better to avoid drinking any alcohol, even in low concentrations, at any time during your course of treatment or in the days immediately after finishing.
More generally, you should recognize that phentermine is a controlled substance. You should not start to take this drug if you have a history of problems with alcohol or other drugs.
You should also discuss the issues if any member of your close family has problems with addiction. If this drug is abused, i.e. you take too much or you take it for too long, it can be habit-forming. This means you will experience withdrawal symptoms when you try to stop. It is not advisable to stop suddenly.
Your doctor will guide you through a slow reduction in the daily dose so that your body slowly grows used to the absence of phentermine. You should be prepared for unpleasant side-effects during this time.
What should you tell your physician?
Starting with the possible drug interactions, you must tell your doctor if you have ever had an allergic reaction to any drug in the amphetamine class or to a drug that stimulates the central nervous system.
In particular, you should not begin taking phentermine if you are also currently taking an antidepressant in the Monoamine Oxidase Inhibitor (MAOI) class. Be careful because MAOIs are sometimes used to help people quit smoking. You must allow at least 14 days to pass before starting phentermine.
This allows the MAOI to wash out of your body. For similar reasons, do not mix phentermine with antidepressants that increase the levels of serotonin in your brain.
If you take medication to relieve high blood pressure such as Ismelin, you should discuss the risks with your doctor. Diabetics should also take care.
If you are talking through the risks and benefits of phentermine with your own healthcare professional, there will be access to your medical records. But if you are buying phentermine online, you must be honest and disclose whether you suffer from any of the following:
- arteriosclerosis or any other disease of the vascular system;
- high blood pressure or heart disease;
- hyperthyroidism, i.e. an overactive thyroid;
- epilepsy or any other disorder causing seizures;
- high levels of anxiety or panic; or
- problems with your eyesight including glaucoma.
It may be that there are potential problems with drug interactions or that the phentermine will cause the existing problems to grow worse.
Finally, it is wise to tell your doctor if you are planning to become or you are actually pregnant. There is a lack of information about the effects of phentermine on the unborn child. However, there is some evidence that phentermine enters breast milk so do not use this drug while you are breastfeeding.
What side-effects can occur?
No matter how carefully medical researchers test a drug, there will always be a very small percentage of people who suffer some type of adverse side-effect. It is impossible to make a drug that is completely safe for everyone.
That said, the FDA would not authorize the release of a drug on to the market if there was evidence of any major problem. The most common side-effects are always mild and pass quickly. You should only seek advice or help if mild symptoms last an unexpectedly long time or grow more serious. The more common symptoms include:
- a dryness or bad taste in the mouth;
- an upset stomach;
- constipation or diarrhea;
- a loss of interest in sex or actual impotence;
- dizziness or loss of concentration; or
- increased anxiety, restlessness and disturbance of sleep patterns, sometimes associated with a feeling of euphoria.
If you have any of the following symptoms, this is more serious and it justifies you seeking immediate help:
- a rash, usually associated with extreme itchiness, difficulty in breathing and swelling of the neck and face — symptoms of an allergic reaction to the drug;
- pain in the chest;
- fast or erratic heartbeat;
- a tremor in or swelling of the arms and legs; or
- strange and erratic behavior.
Is phentermine for you?
The answer to this question is complicated because it is not a black-and-white medical issue. Each individual will have to come up with their own answer based on their priorities. So let us take it one step at a time.
- As a matter of principle, it is always better if you can solve your health problems without having to rely on drugs. Once you come to depend on medication or treatment, this is a long-term cost that can weigh down your family budget.
- In most cases, you lose weight by dieting, exercising, and counseling. There is no magic formula. It all comes down to you. Given the first point, now add this to your calculation. If you eat less and change your lifestyle, you save money in your family budget.
- There is clear medical evidence that people who carry excess weight are more likely to suffer illness and disease as they grow older. Your life expectancy is significantly reduced if you have a body mass index (BMI) of 30 kg/m2 or higher.
- Physicians prefer not to prescribe any drug unless you are significantly overweight and you make a commitment to lifestyle changes and counseling. Let us be clear. Taking phentermine on its own will not reduce your weight. This drug is only effective when used in combination with eating smaller portions of more healthy food and introducing physical exercise into your life.
- Because there are problems if you take this drug in too high a dose or for too long, you have to have the will power to keep going with the diet and exercise during the times you stop taking the phentermine. If not, you will produce a yo-yo effect of weight loss/weight gain which is unhealthy and demoralizing.
- If you do not follow the instructions of your healthcare provider in the use of this drug, there is a real risk of addiction with all the medical and financial problems this brings.
The benefits of Phentermine
There are three major drugs competing in the market for appetite suppression and weight loss. The two modern drugs are still branded and so remain expensive. Phentermine, on the other hand, is long out of the period of patent protection and is therefore freely available as a generic.
This means that the price per tablet is always a fraction of that charged by the other manufacturers. So, as a simple matter of economics at a time when there is a serious risk of recession, the first and most obvious benefit of phentermine is the price. Whether you decide to buy locally in your neighborhood pharmacy or you buy online, you will pay less for phentermine.
The second benefit comes in the area of side-effects. None of the three competing drugs will reduce weight on their own. You have to invest the effort to diet and exercise to shed the pounds. So you want to have the drug that has the fewest side-effects. As you should realize from the length of time phentermine has been on the market, millions of people have been using it.
If there were serious problems in the use of this drug, they would soon have emerged and demand would have fallen. Yet, phentermine now commands more than half the market. The number of prescriptions recorded in each quarter build-up to a sold endorsement of the safety of this drug. Whereas one of the competing drugs is notorious for its embarrassing side-effect.
Is phentermine safe for children?
This has not been covered in clinical research to date. The primary reason is that, as one of the class of amphetamines and a controlled substance, it is not considered ethical to administer this drug to children to see how they react.
Whereas adults aware of the risks of addiction may decide that the benefits outweigh the risks, it is not proper to expose children to the risk of physical or psychological dependence. Thus, the standard precautionary principles apply.
It is not safe to administer this drug to a child under the age of 12 years. No matter how high the BMI and the health problems the child may be experiencing, using a drug of this kind is to be considered dangerous.
However, under proper medical supervision, very low doses up to three times per day at least half-an-hour before meals may be given to children over the age of 12 and under the age of 16 years.
Once the child has reached the age of 16 years, there should be sufficient physical and psychological maturity to take an adult dose calculated on the basis of body weight.
Phentermine brand name list
This can be a little confusing so a word of explanation is required. When a drug is first produced, the manufacturer protects the “recipe” with a patent and the name with a trademark.
These protections are territorial, i.e. they only apply with the territory of one country. Manufacturers then license others to make the drug in their own countries.
A name that works in one country may be inappropriate for others, so a part of this process of globalizing the drug involves different names for different countries. Fifty years ago, this was not a problem. Now that the internet can bring products from any country, you may see the one or more of the following offered for sale, remembering that the difference may be in geography or in a slightly different delivery system:
- Adipex P
- Phentermine Trenker
Phentermine + diet and exercise
To repeat the standard warning: taking phentermine on its own will not change your weight. It only works when combined with diet and physical exercise. The second warning is not to follow one of the fad diets. There is no scientific evidence that any of the latest, heavily advertised books has any real effect.
You should discuss the plan of action with your local healthcare provider. Hopefully, you can also talk with a nutritionist who will plan something positive for you given your age, current weight and health, lifestyle, and personal preferences.
Dieting is not simply a question of eating less, although smaller portions are a good thing in their own right. You need to change the type of food you eat so that it reduces the fat content and the number of calories. You should be aiming for net-loss calorie intake.
There is a scientific approach to calculating your minimum daily calorie needs. Once that number is established, you should then eat less than that. The idea is that your body will then burn the fat in your body to make up the lost intake. To increase the rate at which your body burns the stored fat, you should also increase your activity level. You can start with brisk walking and then move on to more demanding exercise.
As you eat less food of the type your body is used to, the stomach will signal “emptiness” to the brain. That is translated into hunger. This may not be something you have experienced.
Many people not only eat large meals but also snack during the day and so never feel hungry. Phentermine disrupts this message and leaves people able to eat less and not feel hunger pangs. With this drug’s help, you can keep your motivation going for longer and burn more stored fat.