- ACRONYMS AND DEFINITIONS
- ER - Extended-release
- IR - Immediate-release
- ODT - Orally-disintegrating tablet
- Phen - Phentermine
- APPETITE SUPPRESSANTS
Benzphetamine IR (Didrex®)
Dosage forms
Tablet
- 50 mg
Dosing
Weight loss
- Starting: 25 - 50 mg once daily
- Maintenance: 25 - 50 mg one to three times a day
- Max: 150 mg/day
- Take midmorning
Generic / Price
- YES/$Other
- DEA Schedule III
- Tablets are scored so they may be cut in two
Diethylpropion IR (Tenuate®)
Dosage forms
Tablet
- 25 mg
Dosing
Weight loss
- Dosing: 25 mg three times a day
- Max: 100 mg/day
- Take one hour before meals
- A midevening dose may be added to overcome night hunger
Generic / Price
- YES/$Other
- DEA Schedule IV
- Usual starting dose is 25 mg three times a day before meals
- May take a fourth dose midevening to overcome night hunger
Diethylpropion ER (Tenuate Dospan®)
Dosage forms
Tablet, extended-release
- 75 mg
Dosing
Weight loss
- Dosing: 75 mg once daily
- Max: 75 mg once daily
- Take midmorning
Generic / Price
- YES/$Other
- DEA Schedule IV
- Do not cut, chew, or crush tablet
Phendimetrazine IR (Bontril® PDM)
Dosage forms
Tablet
- 35 mg
Dosing
Weight loss
- Dosing: 35 mg two to three times a day
- Max: 210 mg/day (2 tablets 3 times a day)
- Take one hour before meals
Generic / Price
- YES/$Other
- DEA Schedule III
- In some cases, half a tablet (17.5 mg) per dose may be adequate
- Tablets are scored so they may be cut in two
Phendimetrazine ER (Bontril®)
Dosage forms
Capsule, extended-release
- 105 mg
Dosing
Weight loss
- Dosing: 105 mg once daily
- Max: 105 mg once daily
- Take 30 - 60 minutes before morning meal
Generic / Price
- YES/$Other
- DEA Schedule III
Phentermine IR (Adipex-P®)
Dosage forms
Tablet
- 37.5 mg
Capsule
- 15 mg
- 30 mg
- 37.5 mg
Dosing
Weight loss
- Dosing: 37.5 mg once daily
- Max: 37.5 mg once daily
- Tablet can be split and given twice a day
- May take before breakfast or 1-2 hours after breakfast
Generic / Price
- YES/$Other
- DEA Schedule IV
- For some patients, half tablet (18.75 mg) daily may be adequate
- In some cases, it may be desirable to give half tablets (18.75 mg) two times a day
- Tablets are scored so that they may be cut in two
Phentermine IR (Lomaira™)
Dosage forms
Tablet
- 8 mg
Dosing
Weight loss
- Dosing: 1 tablet three times a day 30 minutes before meals
- Max: 8 mg three times a day
- Take 30 minutes before meals
- Tablet may be halved for 4 mg dose
Generic / Price
- NO/$Other
- DEA Schedule IV
- Tablets are scored so that they may be halved
Phentermine (Suprenza™)
Dosage forms
Tablet, orally-disintegrating
- 15 mg
- 30 mg
- 37.5 mg
Dosing
Weight loss
- Dosing: 15 - 37.5 mg once daily
- Max: 37.5 mg once daily
- May be taken without regard to food
Generic / Price
- NO/$$$$Other
- DEA Schedule IV
- Place tablet on tongue where it will dissolve, then swallow with or without water
Qsymia® (phentermine + topiramate)
Dosage forms
Capsule
- Phentermine : Topiramate
- 3.75 : 23 mg
- 7.5 : 46 mg
- 11.25 : 69 mg
- 15 : 92 mg
Dosing
Weight loss
- Starting: 3.75/23 mg once daily for 14 days
- Maintenance: 7.5/46 mg once daily
- Max: 15/92 mg once daily
- May be taken without regard to food. Take in the morning.
- Evaluate weight loss after 12 weeks on 7.5/46 mg dose. If patient has not lost ≥ 3% of baseline body weight, discontinue or increase to next highest dose by giving 11.25/69 mg for 14 days, then 15/92 mg once daily.
- If patients have not lost ≥ 5% of baseline body weight after 12 weeks on 15/92 mg dose, then discontinue
- When discontinuing 15/92 mg dose, take every other day for 1 week to avoid precipitating seizure
- 3.75/23 mg and 11.25/69 mg doses are for titration purposes only
Generic / Price
- NO/$$$$Other
- DEA Schedule IV
- Topiramate is a seizure medication. See topiramate for more.
- Topiramate has been associated with an increased risk of birth defects, and Qsymia should not be given to pregnant women or women who may become pregnant. Pregnancy testing is recommended before therapy and monthly during therapy along with effective contraception. Providers and pharmacies must register with the Qsymia REMS program in order to prescribe or dispense Qsymia.
- Kidney disease dosing
- Benzphetamine
- Pharmacokinetics are not well-defined
- Manufacturer makes no specific recommendations [14]
- Diethylpropion
- Diethylpropion is excreted in the urine
- Kidney disease would be expected to affect diethylpropion clearance
- The manufacturer recommends caution in kidney disease, but makes no specific dosage recommendations [7]
- Phendimetrazine
- Major route of elimination is by the kidneys
- Kidney disease would be expected to affect phendimetrazine clearance
- The manufacturer makes no specific dosage recommendations in kidney disease [15]
- Phentermine
- Phentermine is excreted in the urine
- Kidney disease would be expected to affect phentermine clearance
- The manufacturer makes no specific dosage recommendations in kidney disease [12]
- Liver disease dosing
- Benzphetamine
- Pharmacokinetics are not well-defined
- Manufacturer makes no specific recommendations [14]
- Diethylpropion
- The metabolism of diethylpropion is not well-defined
- Diethylpropion has not been studied in patients with significant liver disease
- The manufacturer makes no specific dosage recommendations in liver disease [7]
- Phendimetrazine
- The metabolism of phendimetrazine is not well-defined
- Phendimetrazine has not been studied in patients with significant liver disease
- The manufacturer makes no specific dosage recommendations in liver disease [15]
- Phentermine
- The metabolism of phentermine is not well-defined
- Phentermine has not been studied in patients with significant liver disease
- The manufacturer makes no specific dosage recommendations in liver disease [12]
- DRUG INTERACTIONS
- NOTE: Drug interactions presented here are NOT all-inclusive. Other interactions may exist. The interactions presented here are meant to encompass commonly prescribed medications and/or interactions that are well-documented. Always consult your physician or pharmacist before taking medications concurrently. CLICK HERE for more information on drug interactions.
- All sympathomimetic amines
- MAO inhibitors - MAO inhibitors should not be taken within 14 days of sympathomimetic amines. When taken together, severe hypertension may occur.
- Medications that work in the central nervous system - any medication that works in the central nervous system (ex. antidepressants, antipsychotics, seizure medications, insomnia drugs, bipolar medications, etc.) may potentially be affected by the stimulant properties of sympathomimetic amines
- Serotonergic medications - Case reports of serotonin syndrome have been reported in patients taking stimulants with other serotonergic medications
- Metabolism and clearance
- The metabolism of sympathomimetic amines is not well-defined
- PRICE ($) INFO
Pricing legend
- $ = 0 - $50
- $$ = $51 - $100
- $$$ = $101 - $150
- $$$$ = > $151
- Pricing based on one month of therapy at standard dosing in an adult
- Pricing based on information from GoodRX.com®
- Pricing may vary by region and availability
- BIBLIOGRAPHY
- 1 - PMID 11493122
- 2 - PMID 19564877
- 3 - PMID 15526396
- 4 - PMID 7471128
- 5 - PMID 17066505
- 6 - Phentermine package insert
- 7 - Diethylpropion package insert
- 8 - PMID 11104741
- 9 - PMID 10713017
- 10 - PMID 20920040
- 11 - PMID 9731087
- 12 - Suprenza PI
- 13 - PMID 21481449
- 14 - Didrex PI
- 15 - Bontril PI