Phendimet SR

Phendimet SR®PDM (Phendimet SR tartrate) is indicated in the management of exogenous obesity as a short term adjunct (a few weeks) in a regimen of weight reduction based on caloric restriction in patients with an initial body mass index (BMI) of 30 kg/m2 or higher who have not responded to appropriate weight reducing regimen (diet and/or exercise) alone. Below is a chart of Body Mass Index (BMI) based on various heights and weights. BMI is calculated by taking the patient's weight, in kilograms (kg), divided by the patient's height, in meters (m), squared. Metric conversions are as follows: pounds ÷ 2.2 = kg; inches x 0.0254 = meters.

Phendimet SR tartrate is indicated for use as monotherapy only.

Phendimet SR (Phendimet SR) is a sympathomimetic amine, which is similar to an amphetamine. It is also known as an "anorectic" or "anorexigenic" drug. Phendimet SR stimulates the central nervous system (nerves and brain), which increases your heart rate and blood pressure and decreases your appetite.

Phendimet SR is used as a short-term supplement to diet and exercise in the treatment of obesity.

Phendimet SR may also be used for purposes not listed in this medication guide.

Usual Adult Dose: 1 tablet (35 mg) b.i.d. or t.i.d., one hour before meals.

Dosage should be individualized to obtain an adequate response with the lowest effective dosage. In some cases, 1/2 tablet (17.5 mg) per dose may be adequate. Dosage should not exceed 2 tablets t.i.d.

How supplied

Each single-scored, yellow, round tablet contains 35 mg Phendimet SR tartrate. Tablets are supplied in bottles of 100 (NDC 46672-138-10) and in bottles of 1000 (NDC 46672-138-11).

Each single-scored, blue, unimprinted round tablet contains 35 mg Phendimet SR tartrate. Tablets are supplied in bottles of 100 (NDC 46672-057-10) and in bottles of 1000 (NDC 46672-057-11).

Storage

Store at controlled room temperature 15°-30°C (59°-86°F).

Dispense in tight containers with child-resistant closures.

Manufactured by: Mikart, Inc., Atlanta, GA 30318. Rev. 05/96.

See also:
What is the most important information I should know about Phendimet SR?

Weight loss during pregnancy can harm an unborn baby, even if you are overweight. Do not use Phendimet SR if you are pregnant.

Phendimet SR may cause blurred vision or impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert and able to see clearly.

Phendimet SR may be habit-forming and should be used only by the person for whom it was prescribed. Keep the medication in a secure place where others cannot get to it.

Do not stop using Phendimet SR suddenly after long-term use, or you could have unpleasant withdrawal symptoms. Ask your doctor how to avoid withdrawal symptoms when you stop using Phendimet SR.

Do not crush, chew, break, or open the extended-release capsule. Swallow it whole. Breaking or opening the pill may cause too much of the drug to be released at one time.

Use Phendimet SR sustained-release capsules as directed by your doctor. Check the label on the medicine for exact dosing instructions.

• Take Phendimet SR sustained-release capsules about 30 to 60 minutes before the morning meal, unless your doctor tells you otherwise.
• Swallow Phendimet SR sustained-release capsules whole. Do not break, crush, or chew before swallowing.
• If you miss a dose of Phendimet SR sustained-release capsules, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.

Ask your health care provider any questions you may have about how to use Phendimet SR sustained-release capsules.

Phendimet SR 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.

How to use Phendimet SR

Take the immediate-release form of this medication by mouth, usually 2 to 3 times a day 1 hour before meals or as directed by your doctor. Taking this medication late in the day may cause trouble sleeping (insomnia).

The sustained-release form of Phendimet SR is usually taken once a day 30 - 60 minutes before the morning meal. Swallow this medication whole. Do not crush, chew, or break the capsules. Doing so can destroy the long action of the drug and may increase side effects.

The dosage is based on your medical condition and response to therapy. Your doctor will adjust the dose to find the best dose for you. Use this medication regularly and exactly as prescribed in order to get the most benefit from it. To help you remember, take it at the same time(s) each day.

Phendimet SR is usually taken for only a few weeks at a time. It should not be taken with other appetite suppressants. The possibility of serious side effects increases with longer use of this medication and use of this drug along with certain other diet drugs.

This medication may cause withdrawal reactions, especially if it has been used regularly for a long time or in high doses. In such cases, withdrawal symptoms (such as depression, severe tiredness) may occur if you suddenly stop using this medication. To prevent withdrawal reactions, your doctor may reduce your dose gradually. Consult your doctor or pharmacist for more details, and report any withdrawal reactions right away.

Rarely, abnormal drug-seeking behavior (addiction) is possible with this medication. Do not increase your dose, take it more frequently, 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 while. 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.

See also:
What other drugs will affect Phendimet SR?

Acebrophylline: May enhance the stimulatory effect of CNS Stimulants. Avoid combination

Alcohol (Ethyl): May enhance the adverse/toxic effect of Phendimet SR. Monitor therapy

Alkalinizing Agents: May decrease the excretion of Amphetamines. Management: Consider alternatives to using amphetamines and alkalinizing agents in combination. If these agents must be used together, patients should be monitored closely for excessive amphetamine effects. Consider therapy modification

Amifampridine: Agents With Seizure Threshold Lowering Potential may enhance the neuroexcitatory and/or seizure-potentiating effect of Amifampridine. Monitor therapy

Ammonium Chloride: May decrease the serum concentration of Amphetamines. This effect is likely due to an enhanced excretion of amphetamines in the urine. Monitor therapy

Antacids: May decrease the excretion of Amphetamines. Monitor therapy

Antihistamines: Amphetamines may diminish the sedative effect of Antihistamines. Monitor therapy

Antihypertensive Agents: Amphetamines may diminish the antihypertensive effect of Antihypertensive Agents. Monitor therapy

Antipsychotic Agents: May diminish the stimulatory effect of Amphetamines. Monitor therapy

Ascorbic Acid: May decrease the serum concentration of Amphetamines. Monitor therapy

AtoMOXetine: May enhance the hypertensive effect of Sympathomimetics. AtoMOXetine may enhance the tachycardic effect of Sympathomimetics. Monitor therapy

BuPROPion: May enhance the neuroexcitatory and/or seizure-potentiating effect of Agents With Seizure Threshold Lowering Potential. Monitor therapy

Cannabinoid-Containing Products: May enhance the tachycardic effect of Sympathomimetics. Exceptions: Cannabidiol. Monitor therapy

Carbonic Anhydrase Inhibitors: May decrease the excretion of Amphetamines. Exceptions: Brinzolamide; Dorzolamide. Monitor therapy

Cocaine (Topical): May enhance the hypertensive effect of Sympathomimetics. Management: Consider alternatives to use of this combination when possible. Monitor closely for substantially increased blood pressure or heart rate and for any evidence of myocardial ischemia with concurrent use. Consider therapy modification

CYP2D6 Inhibitors (Moderate): May increase the serum concentration of Amphetamines. Monitor therapy

CYP2D6 Inhibitors (Strong): May increase the serum concentration of Amphetamines. Exceptions: FLUoxetine; PARoxetine. Monitor therapy

Doxofylline: Sympathomimetics may enhance the adverse/toxic effect of Doxofylline. Monitor therapy

Esketamine: May enhance the hypertensive effect of CNS Stimulants. Monitor therapy

Ethosuximide: Amphetamines may diminish the therapeutic effect of Ethosuximide. Amphetamines may decrease the serum concentration of Ethosuximide. Monitor therapy

Gastrointestinal Acidifying Agents: May decrease the serum concentration of Amphetamines. Monitor therapy

Guanethidine: May enhance the arrhythmogenic effect of Sympathomimetics. Guanethidine may enhance the hypertensive effect of Sympathomimetics. Monitor therapy

Iobenguane Radiopharmaceutical Products: Amphetamines may diminish the therapeutic effect of Iobenguane Radiopharmaceutical Products. Management: Discontinue all drugs that may inhibit or interfere with catecholamine transport or uptake for at least 5 biological half-lives before iobenguane administration. Do not administer these drugs until at least 7 days after each iobenguane dose. Avoid combination

Iobenguane Radiopharmaceutical Products: CNS Stimulants may diminish the therapeutic effect of Iobenguane Radiopharmaceutical Products. Management: Discontinue all drugs that may inhibit or interfere with catecholamine transport or uptake for at least 5 biological half-lives before iobenguane administration. Do not administer these drugs until at least 7 days after each iobenguane dose. Avoid combination

Ioflupane I 123: Amphetamines may diminish the diagnostic effect of Ioflupane I 123. Monitor therapy

Iohexol: Agents With Seizure Threshold Lowering Potential may enhance the adverse/toxic effect of Iohexol. Specifically, the risk for seizures may be increased. Management: Discontinue agents that may lower the seizure threshold 48 hours prior to intrathecal use of iohexol. Wait at least 24 hours after the procedure to resume such agents. In nonelective procedures, consider use of prophylactic anticonvulsants. Consider therapy modification

Iomeprol: Agents With Seizure Threshold Lowering Potential may enhance the adverse/toxic effect of Iomeprol. Specifically, the risk for seizures may be increased. Management: Discontinue agents that may lower the seizure threshold 48 hours prior to intrathecal use of iomeprol. Wait at least 24 hours after the procedure to resume such agents. In nonelective procedures, consider use of prophylactic anticonvulsants. Consider therapy modification

Iopamidol: Agents With Seizure Threshold Lowering Potential may enhance the adverse/toxic effect of Iopamidol. Specifically, the risk for seizures may be increased. Management: Discontinue agents that may lower the seizure threshold 48 hours prior to intrathecal use of iopamidol. Wait at least 24 hours after the procedure to resume such agents. In nonelective procedures, consider use of prophylactic anticonvulsants. Consider therapy modification

Methenamine: May decrease the serum concentration of Amphetamines. This effect is likely due to an enhanced excretion of amphetamines in the urine. Monitor therapy

Monoamine Oxidase Inhibitors: May enhance the hypertensive effect of Amphetamines. While linezolid and tedizolid may interact via this mechanism, management recommendations differ from other monoamine oxidase inhibitors. Refer to monographs specific to those agents for details. Avoid combination

Multivitamins/Fluoride (with ADE): May decrease the serum concentration of Amphetamines. More specifically, the ascorbic acid (vitamin C) in many multivitamins may decrease amphetamine concentrations. Monitor therapy

Multivitamins/Minerals (with ADEK, Folate, Iron): May decrease the serum concentration of Amphetamines. Monitor therapy

Multivitamins/Minerals (with AE, No Iron): May decrease the serum concentration of Amphetamines. Specifically, vitamin C may impair absorption of amphetamines. Monitor therapy

Opioid Agonists: Amphetamines may enhance the analgesic effect of Opioid Agonists. Monitor therapy

Ozanimod: May enhance the hypertensive effect of Sympathomimetics. Management: Concomitant use of ozanimod with sympathomimetic agents is not recommended. If combined, monitor patients closely for the development of hypertension, including hypertensive crises. Consider therapy modification

PHENobarbital: Amphetamines may decrease the serum concentration of PHENobarbital. Monitor therapy

Phenytoin: Amphetamines may decrease the serum concentration of Phenytoin. Monitor therapy

Quinolones: Amphetamines may enhance the cardiotoxic effect of Quinolones. Monitor therapy

Selective Serotonin Reuptake Inhibitors (Strong CYP2D6 Inhibitors): Amphetamines may enhance the serotonergic effect of Selective Serotonin Reuptake Inhibitors (Strong CYP2D6 Inhibitors). This could result in serotonin syndrome. Selective Serotonin Reuptake Inhibitors (Strong CYP2D6 Inhibitors) may increase the serum concentration of Amphetamines. Management: Monitor for increased amphetamine toxicities, including signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability) when these agents are combined. Monitor therapy

Serotonergic Agents (High Risk): Amphetamines may enhance the serotonergic effect of Serotonergic Agents (High Risk). This could result in serotonin syndrome. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) when these agents are combined. Exceptions: Amitriptyline; Amoxapine; ClomiPRAMINE; Desipramine; Dothiepin; Doxepin (Systemic); Doxepin (Topical); FLUoxetine; Imipramine; Isocarboxazid; Linezolid; Lofepramine; Melitracen [INT]; Methylene Blue; Moclobemide; Nortriptyline; PARoxetine; Phenelzine; Protriptyline; Tranylcypromine; Trimipramine. Monitor therapy

Sibutramine: May enhance the adverse/toxic effect of Centrally Acting Weight Loss Agents. Avoid combination

Solriamfetol: Sympathomimetics may enhance the hypertensive effect of Solriamfetol. Sympathomimetics may enhance the tachycardic effect of Solriamfetol. Monitor therapy

Solriamfetol: CNS Stimulants may enhance the hypertensive effect of Solriamfetol. CNS Stimulants may enhance the tachycardic effect of Solriamfetol. Monitor therapy

Sympathomimetics: May enhance the adverse/toxic effect of other Sympathomimetics. Monitor therapy

Tedizolid: May enhance the hypertensive effect of Sympathomimetics. Tedizolid may enhance the tachycardic effect of Sympathomimetics. Monitor therapy

Tricyclic Antidepressants: May enhance the adverse/toxic effect of Amphetamines. Tricyclic Antidepressants may potentiate the cardiovascular effects of Amphetamines. Amphetamines may enhance the serotonergic effect of Tricyclic Antidepressants. This could result in serotonin syndrome. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) and increased cardiovascular effects when these agents are combined. Monitor therapy

Urinary Acidifying Agents: May decrease the serum concentration of Amphetamines. Monitor therapy

See also:
What are the possible side effects of Phendimet SR?

Applies to Phendimet SR: oral capsule, oral capsule extended release, oral tablet

As well as its needed effects, Phendimet SR (the active ingredient contained in Phendimet SR) may cause unwanted side effects that require medical attention.

Major Side Effects

If any of the following side effects occur while taking Phendimet SR, check with your doctor immediately:

Rare

• Seeing, hearing, or feeling things that are not there
• severe mental changes

• Anxiety
• burning while urinating
• chest pain or discomfort
• decreased ability to exercise
• difficult or painful urination
• dizziness
• dry mouth
• fainting
• fast, irregular, pounding, or racing heartbeat or pulse
• feeling of warmth
• headache
• hyperventilation
• increased need to urinate
• irritability
• nausea
• numbness or tingling in the arms or legs
• pain or discomfort in the arms, jaw, back, or neck
• passing urine more often
• redness of the face, neck, arms, and occasionally, upper chest
• restlessness
• shakiness in the legs, arms, hands, or feet
• shortness of breath
• sweating
• swelling of the feet or lower legs
• trembling or shaking of the hands or feet
• trouble with breathing
• trouble with sleeping
• trouble with thinking, speaking, or walking
• vomiting
• weakness

If any of the following symptoms of overdose occur while taking Phendimet SR, get emergency help immediately:

Symptoms of overdose:

• Abdominal or stomach cramps
• blurred vision
• change in consciousness
• convulsions
• diarrhea
• discouragement
• dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
• fast, slow, or irregular heartbeat
• feeling sad or empty
• lack of appetite
• lightheadedness
• loss of consciousness
• loss of interest or pleasure
• overactive reflexes
• panic
• physical attempt to injure
• pounding in the ears
• rapid breathing
• sweating
• tiredness
• trouble with concentrating
• unusual tiredness or weakness
• violent actions

Minor Side Effects

Some Phendimet SR side effects may not need any medical attention. As your body gets used to the medicine these side effects may disappear. Your health care professional may be able to help you prevent or reduce these side effects, but do check with them if any of the following side effects continue, or if you are concerned about them:

Incidence not known:

• Decreased interest in sexual intercourse
• difficulty having a bowel movement (stool)
• inability to have or keep an erection
• increased in sexual ability, desire, drive, or performance
• increased interest in sexual intercourse
• loss in sexual ability, desire, drive, or performance
• sleeplessness
• stomach pain
• unable to sleep

Phendimet SR is a weight loss medication. Phendimet SR is chemically related to amphetamines and is a Schedule III drug under the Convention on Psychotropic Substances. In the United States, Phendimet SR is a Schedule III controlled substance under the Uniform Controlled Substances Act of 1970.