Educational guide
Adipex-P: Uses, Side Effects & Dosage | Healio
Topics Adipex-P Brand Names Adipex-P, Ionamin, Pro-Fast Generic Name phentermine HCl Phonetic Name (FEN-ter-meen) Clinical Uses Phentermine is used with a doctor-approved exercise, behavior change, and reduced-calorie diet program to help you lose weight. It i
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Topics
Adipex-P
Brand Names
Adipex-P, Ionamin, Pro-Fast
Generic Name
phentermine HCl
Phonetic Name
(FEN-ter-meen)
Clinical Uses
Phentermine is used with a doctor-approved exercise, behavior change, and reduced-calorie diet program to help you lose weight. It is used by certain overweight people, such as those who are obese or have weight-related medical problems. Losing weight and keeping it off can lessen the many health risks that come with obesity, including heart disease, diabetes, high blood pressure, and a shorter life. It is not known how this medication helps people to lose weight. It may work by decreasing your appetite, increasing the amount of energy used by your body, or by affecting certain parts of the brain. This medication is an appetite suppressant and belongs to a class of drugs called sympathomimetic amines.
Dosage and Administration
Preparations
- 37.5 mg Brand(s): * Adipex-P(R) (C-IV), Gate Tablets
- 37.5 mg Brand(s): * Adipex-P(R) (C-IVscored), Gate
Administration Notes
Take this medication by mouth as directed by your doctor, usually once a day, 1 hour before breakfast or 1 to 2 hours after breakfast. If needed, your doctor may adjust your dose to take a small dose up to 3 times a day. Carefully follow your doctor's instructions. Taking this medication late in the day may cause trouble sleeping (insomnia). If you are using sustained-release capsules, the dose is usually taken once a day before breakfast or at least 10 to 14 hours before bedtime. Swallow the medication whole. Do not crush or chew sustained-release capsules. Doing so can release all of the drug at once, increasing the risk of side effects. If you are using the tablets made to dissolve in the mouth, the dose is usually taken once a day in the morning, with or without food. First, dry your hands before handling the tablet. Place your dose on top of the tongue until it dissolves, then swallow it with or without water. The dosage and length of treatment are based on your medical condition and response to treatment. Your doctor will adjust the dose to find the best dose for you. Discuss the risks and benefits, and the length of phentermine treatment, with your doctor. To get the most benefit, take this medication regularly, exactly as prescribed, and for as long as directed by your doctor. To help you remember, take it at the same time(s) each day. Caffeine can increase the side effects of this medication. Avoid drinking large amounts of beverages containing caffeine (coffee, tea, colas), eating large amounts of chocolate, or taking nonprescription products that contain caffeine. If you suddenly stop using this medication, you may have withdrawal symptoms (such as depression, severe tiredness). To help prevent withdrawal, your doctor may lower your dose slowly. Withdrawal is more likely if you have used phentermine for a long time or in high doses. Tell your doctor or pharmacist right away if you have withdrawal. Though it helps many people, this medication may sometimes cause addiction. This risk may be higher if you have a substance use disorder (such as overuse of or addiction to drugs/alcohol). Do not increase your dose, take it more often, or use it for a longer time than prescribed. Properly stop the medication when so directed. This medication may stop working well after you have been taking it for a few weeks. Talk with your doctor if this medication stops working well. Do not increase the dose unless directed by your doctor. Your doctor may direct you to stop taking this medication.
Missed Dose Instructions
If you miss a dose, take it as soon as you remember. If it is near the time of the next dose or late in the evening, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.
Label Warnings
Warning: Do not use if you are pregnant, suspect that you are pregnant, or while breastfeeding. Consult your doctor or pharmacist. This drug may impair the ability to operate a vehicle, vessel (e.g., boat), or machinery. Use care until you become familiar with its effects. May cause dizziness
Indications
- weight loss management for obese patient (body mass index 30 or greater)
- weight loss management for overweight patient with bmi 27 to 29 and weight-related comorbidity
Phentermine is used with a doctor-approved exercise, behavior change, and reduced-calorie diet program to help you lose weight. It is used by certain overweight people, such as those who are obese or have weight-related medical problems. Losing weight and keeping it off can lessen the many health risks that come with obesity, including heart disease, diabetes, high blood pressure, and a shorter life. It is not known how this medication helps people to lose weight. It may work by decreasing your appetite, increasing the amount of energy used by your body, or by affecting certain parts of the brain. This medication is an appetite suppressant and belongs to a class of drugs called sympathomimetic amines.
Contraindications
- chronic heart failure
- coronary artery disease
- drug abuse
- glaucoma
- history of cerebrovascular accident
- hyperthyroidism
- lactation
- pregnancy
- severe uncontrolled hypertension
- tachyarrhythmia
- alcohol use disorder
- chronic kidney disease stage 4 (severe) GFR 15-29 mL/min
- diabetes mellitus
- kidney disease with reduction in glomerular filtration rate (GFR)
- mild hypertension
Common Adverse Effects
- Dysgeusia
- Insomnia
- Nervousness
- Xerostomia
- Acute abdominal pain
- Agitation
- Blurred vision
- Constipation
- Diarrhea
- Dizziness
- Dysuria
- Euphoria
- Flushing
- Headache disorder
- Libido changes
- Palpitations
- Skin rash
- Tachycardia
- Tremor
- Depression
- Dysphoric mood
- Erectile dysfunction
- Hyperhidrosis
- Increased urinary frequency
- Nausea
Serious Adverse Effects
- Hypertension
- Allergic dermatitis
- Cardiac arrhythmia
- Urticaria
- Cardiomyopathy
- Drug-induced psychosis
- Myocardial ischemia
- Pulmonary hypertension
- Valvular heart disease
Elderly Precautions
Pregnancy Precautions
Lactation Precautions
Pediatric Precautions
Drug Interactions
Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval. This drug should not be used with certain medications because very serious interactions may occur. If you are taking or have taken other appetite-suppressant drugs in the past year (such as diethylpropion, ephedra/ma huang), tell your doctor or pharmacist before starting this medication. Taking MAO inhibitors with this medication may cause a serious (possibly fatal) drug interaction. Avoid taking MAO inhibitors (isocarboxazid, linezolid, metaxalone, methylene blue, moclobemide, phenelzine, procarbazine, rasagiline, safinamide, selegiline, tranylcypromine) during treatment with this medication. Most MAO inhibitors should also not be taken for two weeks before treatment with this medication. Ask your doctor when to start or stop taking this medication. Some products that may interact with this drug are: high blood pressure medicine (such as guanethidine, methyldopa), phenothiazines (such as prochlorperazine, chlorpromazine), other stimulants (including amphetamines, methylphenidate, street drugs such as cocaine or MDMA/"ecstasy"). Tell your doctor or pharmacist if you are taking other products that cause drowsiness such as opioid pain or cough relievers (such as codeine, hydrocodone), alcohol, marijuana (cannabis), drugs for sleep or anxiety (such as alprazolam, lorazepam, zolpidem), muscle relaxants (such as carisoprodol, cyclobenzaprine), or antihistamines (such as cetirizine, diphenhydramine). Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely. Some products have ingredients that could raise your heart rate or blood pressure. Tell your pharmacist what products you are using, and ask how to use them safely (especially cough-and-cold products or diet aids). This medication may interfere with certain medical/lab tests (such as brain scan for Parkinson's disease), possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug.
Drug Interactions Table
Chemical Properties
Phentermine is an amphetamine congener that is used as an anorexigenic agent. Phentermine is available as the hydrochloride salt and as a cation exchange resin complex of sulfonated polystyrene. Phentermine hydrochloride occurs as a bitter, white, odorless, hygroscopic, crystalline powder and is soluble in water and in alcohol. Phentermine resin is a coarse granular substance and is practically insoluble in water.
Pharmacology
In experimental animals and in clinical studies in humans, phentermine apparently produces an anorexigenic effect and loss of weight. As with other amphetamine derivatives, no primary effect on appetite has been demonstrated with phentermine and it is probable that its anorexigenic action is secondary to CNS stimulation. In the past, it was suggested that combined therapy with phentermine, which inhibits uptake of norepinephrine and dopamine, and fenfluramine (no longer commercially available in the US), which affected serotoninergic mechanisms, may provide complementary anorexigenic affects; therefore, such combined therapy had been used in the management of obesity. In addition, while phentermine produced CNS stimulation, fenfluramine produced CNS depression. However, because of accumulated data on adverse effects associated with the drugs, fenfluramine hydrochloride (Pondimin(R)) and its dextrorotatory isomer dexfenfluramine hydrochloride (Redux(R)) were withdrawn from the US market in 1997. (See Cautions and also see Cautions, in the Amphetamines General Statement 28:20.04.)
Stability Information
Phentermine hydrochloride capsules and tablets should be stored in tight and well-closed containers, respectively, at a temperature less than 40degreesC, preferably at 15-30degreesC. Capsules containing phentermine as a resin complex should be stored in tight containers at 15-30degreesC.
Storage Requirements
Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets. Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.
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