Diethylpropion
Diethylpropion is an older stimulant-type appetite suppressant tablet. The label describes it as a short-term add-on to diet, for a few weeks. It is a Schedule IV controlled drug.
Diethylpropion (known as Tenuate)
Also searched as: Tenuate, diethylpropion hydrochloride.
Educational information. This page does not give dosing instructions or tell you what to take. Ask a prescriber about your own care.
In plain English
Diethylpropion is an older appetite-suppressant tablet related to amphetamines. In the U.S. it is a Schedule IV controlled substance, approved only as a short-term add-on to a reduced-calorie diet. The label describes short-term as a few weeks.
The label is modest about the benefit. In the short trials it cites, people on the drug lost more than people on placebo by some fraction of a pound a week on average, with large differences between people. Longer trials exist. In a 69-person trial in Brazil, people on diethylpropion lost 9.8% of body weight over 6 months versus 3.2% on placebo. In a 156-person trial in Mexico, the loss was 7.7 kg versus 1.1 kg over 6 months. Both ran longer than the few weeks the label describes.
It is not for people with pulmonary hypertension, advanced hardening of the arteries, an overactive thyroid, glaucoma, severe high blood pressure, agitation, or a history of drug misuse, or during or within 14 days of an MAOI antidepressant. The label says to continue only if weight loss in the first 4 weeks is satisfactory.
Brand names and products
A generic name identifies the drug itself. A brand name identifies one company's product. One drug can come in several products with different forms and approved uses, so the brand name often tells you more about what a prescription is for.
A separate brand page for this medicine has not been added to the atlas yet. Other names on record: Tenuate, diethylpropion hydrochloride. The forms table below lists its approved use.
Approved and investigational. Diethylpropion is FDA-approved as a short-term add-on for weight reduction. Longer use, or use with other weight-loss drugs, is outside what the label describes.
How it works
Diethylpropion is a sympathomimetic amine, a stimulant-type medicine whose label notes similarities to amphetamines. It lowers appetite through effects on the nervous system, and it can raise blood pressure and heart rate. The part of the label read here does not give a complete explanation of how it lowers appetite.
Forms and approval status
| Form | How it is taken | U.S. status |
|---|---|---|
| Diethylpropion hydrochloride tablets (generic) | Three times daily before meals on the immediate-release label. Short-term use only, per the label. It should not be combined with other weight-loss drugs. | Approved in the U.S. as a short-term add-on (a few weeks) to a reduced-calorie diet for adults with a BMI of 30 or more who have not responded to diet and exercise alone. It is approved as the only weight-loss medicine in use, not alongside others. It is a Schedule IV controlled substance. DailyMed lists immediate-release and extended-release tablets from several generic makers; only the immediate-release 25 mg label from KVK-Tech was read here. |
What the trials found
These are group averages from published trials in adults without diabetes unless stated. See how to read trial numbers before comparing.
Diethylpropion 12-month trial (Brazil)
Average change in body weight. Every bar uses one scale, 0 to 25 percent.
- People studied
- 69 otherwise healthy adults with obesity in São Paulo, Brazil, all given a low-calorie diet
- Length
- 26 weeks
- Compared with
- Placebo for 6 months, then everyone took diethylpropion for another 6 months without blinding. The amount was 50 mg twice a day
- What was measured
- Average change in body weight at 6 months
- Analysis approach
- Not stated in the abstract
- Other results
- At month 12, people on diethylpropion since the start had lost 10.6%. People switched from placebo at month 6 had lost 7.0%. The difference between groups at month 12 was not significant (P = 0.07).
- Safety
- No differences were seen in blood pressure, pulse, electrocardiogram or psychiatric ratings. Dry mouth and insomnia were the most frequent side effects.
- Limits
- A small trial at one center in a carefully selected group, as the authors note. Only the first 6 months were placebo-controlled. The 6-month and 12-month durations are longer than the few weeks the U.S. label describes, and 50 mg twice a day is not the schedule on the immediate-release label. Group averages do not predict one person's result.
Sources: Cercato C 2009
Safety
Based on the FDA-approved label for KVK-Tech immediate-release 25 mg tablets. The official label is the controlling source for warnings. The points below are a summary and may be incomplete.
Boxed warning and label notes
- Diethylpropion hydrochloride tablets (generic): No boxed warning was found on the label that was read.
Warnings labels describe
- Not for people with pulmonary hypertension, advanced hardening of the arteries, an overactive thyroid, glaucoma, severe high blood pressure, agitated states, a history of drug misuse, or known allergy to this class of drug. Not for use during or within 14 days of an MAOI antidepressant.
- Not for use with other appetite-suppressing drugs, and not recommended in people who used any such drug in the past year.
- Related to amphetamines, with a risk of dependence and withdrawal. Rare psychosis and hallucinations are reported. It can impair driving and machinery use.
- Pulmonary hypertension: the label cites a case-control study linking appetite-suppressant use beyond 3 months to a 23-fold higher risk. Stop if there is breathlessness on exertion, chest pain, fainting or swelling.
- Heart-valve disease has been rarely reported. The label suggests considering a baseline heart evaluation and does not recommend use with a known murmur or valve disease.
- Continue only if weight loss in the first 4 weeks is satisfactory. Do not exceed the stated amount to overcome tolerance.
Most common in trials
- Dry mouth
- Insomnia
- Nervousness, dizziness or headache
- Nausea, constipation or diarrhea
- Raised blood pressure or a fast heartbeat
Less common but serious
- Pulmonary hypertension (rare)
- Heart-valve disease (rare)
- Psychosis or hallucinations (rare)
- Seizures in some people with epilepsy
- Dependence and withdrawal
- Low blood counts, such as low white blood cells (listed on the label)
What is still unknown
- How well it works beyond the label's few weeks. Two 6-month trials show weight loss, but they are small, and the label itself says the total benefit beyond diet alone is unknown.
- Long-term safety, including pulmonary hypertension risk with use beyond 3 months.
- Differences between brands and between immediate-release and extended-release tablets. Only one immediate-release label was read here.
- How it compares with phentermine or newer medicines. No head-to-head trial is summarized here.
Compiled from public information: FDA-approved labels, manufacturer websites, ClinicalTrials.gov and published journal articles. Sources are listed at the bottom of this page.
Sources
- Diethylpropion hydrochloride tablets, 25 mg immediate-release: prescribing information KVK-Tech, Inc., on DailyMed (U.S. National Library of Medicine). FDA-approved label, May 2024 listing. Official FDA label on DailyMed
- DailyMed: current FDA drug labels U.S. National Library of Medicine. Regulator
- A randomized double-blind placebo-controlled study of the long-term efficacy and safety of diethylpropion in the treatment of obese subjects Cercato C, et al. Int J Obes (Lond). 2009;33(8):857-865. PMID 19564877. Funding: Not stated in the abstract. Journal article
- Six-month efficacy and safety of amfepramone in obese Mexican patients: a double-blinded, randomized, controlled trial Soto-Molina H, et al. Int J Clin Pharmacol Ther. 2015;53(7):541-549. PMID 26073353. Funding: Not stated in the abstract. Journal article