Phentermine/topiramate, sold under the brand name Qsymia, is a
combination drug
A combination drug or a fixed-dose combination (FDC) is a medicine that includes two or more active ingredients combined in a single dosage form. Terms like "combination drug" or "combination drug product" can be common shorthand for a FDC prod ...
of
phentermine
Phentermine ( phenyl- tertiary-butyl amine), with several brand names including Ionamin and Sentis, is a medication used together with diet and exercise to treat obesity. It is taken by mouth for up to a few weeks at a time, after which the ben ...
and
topiramate
Topiramate, sold under the brand name Topamax among others, is a carbonic anhydrase inhibitor medication used to treat epilepsy and prevent migraines. It has also been used in alcohol dependence. For epilepsy this includes treatment for gener ...
used to treat
obesity
Obesity is a medical condition, sometimes considered a disease, in which excess body fat has accumulated to such an extent that it may negatively affect health. People are classified as obese when their body mass index (BMI)—a person's ...
.
It is used together with dietary changes and exercise.
[ If less than 3% weight loss is seen after 3 months it is recommended the medication be stopped.][ The weight loss is modest.][https://www.qsymia.com/pdf/prescribing-information.pdf ] Effects on heart related health problems or death is unclear.[
Common side effects include tingling, dizziness, trouble sleeping, and constipation.][ Serious side effects may include suicide, abuse.]pregnancy
Pregnancy is the time during which one or more offspring develops (gestation, gestates) inside a woman, woman's uterus (womb). A multiple birth, multiple pregnancy involves more than one offspring, such as with twins.
Pregnancy usually occur ...
.[ ]Phentermine
Phentermine ( phenyl- tertiary-butyl amine), with several brand names including Ionamin and Sentis, is a medication used together with diet and exercise to treat obesity. It is taken by mouth for up to a few weeks at a time, after which the ben ...
is a stimulant and appetite suppressant
An anorectic or anorexic is a drug which reduces appetite, resulting in lower food consumption, leading to weight loss. By contrast, an appetite stimulant is referred to as orexigenic.
The term is (from the Greek ''ἀν-'' (an-) = "without" ...
.Topiramate
Topiramate, sold under the brand name Topamax among others, is a carbonic anhydrase inhibitor medication used to treat epilepsy and prevent migraines. It has also been used in alcohol dependence. For epilepsy this includes treatment for gener ...
is an anticonvulsant that has weight loss side effects.[ In October 2012, approval was denied in Europe, due to concerns regarding safety.]
Medical uses
In clinical trials, people treated with the highest dose of phentermine/topiramate ER in combination with a program of diet and exercise lost 10% to 11% of their body weight compared to 1% to 2% for those who received placebo.placebo
A placebo ( ) is a substance or treatment which is designed to have no therapeutic value. Common placebos include inert tablets (like sugar pills), inert injections (like saline), sham surgery, and other procedures.
In general, placebos can af ...
.orlistat
Orlistat, sold under the brand name Xenical among others, is a medication used to treat obesity. Its primary function is preventing the absorption of fats from the human diet by acting as a lipase inhibitor, thereby reducing caloric intake. It ...
, and naltrexone/bupropion
Naltrexone/bupropion, sold under the brand name Contrave among others, is a fixed-dose combination medication for the management of chronic obesity in adults in combination with a reduced-calorie diet and increased physical activity. It contains ...
) and also reduced blood pressure.
Adverse effects
In clinical trials, the most common adverse events which occurred at a rate ≥5% and ≥1.5 times placebo included paraesthesia (tingling in fingers/toes), dizziness, altered taste, insomnia
Insomnia, also known as sleeplessness, is a sleep disorder in which people have trouble sleeping. They may have difficulty falling asleep, or staying asleep as long as desired. Insomnia is typically followed by daytime sleepiness, low energy, ...
, constipation
Constipation is a bowel dysfunction that makes bowel movements infrequent or hard to pass. The stool is often hard and dry. Other symptoms may include abdominal pain, bloating, and feeling as if one has not completely passed the bowel movement ...
, and dry mouth
Xerostomia, also known as dry mouth, is dryness in the mouth, which may be associated with a change in the composition of saliva, or reduced salivary flow, or have no identifiable cause.
This symptom is very common and is often seen as a side eff ...
.
Pregnancy
Phentermine and topiramate can cause fetal harm. Data from pregnancy registries and epidemiology studies indicate that a fetus exposed to topiramate in the first trimester of pregnancy has an increased risk of oral clefts (cleft lip with or without cleft palate).
Risk evaluation and mitigation strategy
Phentermine and topiramate was approved with a risk evaluation and mitigation strategy (REMS) program to ensure that benefits of treatment outweigh the risks. Because of the teratogenic risk associated with phentermine/topiramate ER therapy, phentermine/topiramate ER is distributed via certified pharmacies.
Contraindications
Phentermine/topiramate ER is contraindicated in pregnancy, glaucoma, hyperthyroidism, during or within 14 days of taking monoamine oxidase inhibitors, and in patients with hypersensitivity or idiosyncrasy to sympathomimetic amines. Phentermine/topiramate ER can cause an increase in resting heart rate.
History
Phentermine and topiramate was developed by Vivus
Vivus () is a small pharmaceutical company headquartered in Campbell, California, working in obesity, sleep, and sexual health. Vivus is developing an erectile dysfunction drug, Avanafil, that has completed Phase 3 clinical trials. The drug has b ...
, a California pharmaceutical company.
In December 2009 VIVUS, Inc. submitted a new drug application (NDA) to the FDA and on March 1, 2010, VIVUS, Inc. announced that the FDA accepted the NDA for review.
In October 2010, the FDA announced its decision to not approve phentermine/topiramate ER in its current form and issued a Complete Response Letter to VIVUS due to lack of long-term data and concerns about side effects including elevated heart rate, major adverse cardiovascular events, and birth defects.
In January 2011, the FDA expressed concerns about the potential for phentermine/topiramate ER to cause birth defect
A birth defect, also known as a congenital disorder, is an abnormal condition that is present at birth regardless of its cause. Birth defects may result in disabilities that may be physical, intellectual, or developmental. The disabilities ca ...
s and requested that Vivus assess the feasibility of analyzing existing healthcare databases to determine the historical incidence of oral cleft in offspring of women treated with topiramate for migraine prophylaxis (100 mg).
In October 2011, VIVUS resubmitted the NDA to the FDA with responses to the issues addressed in the CRL and the FDA accepted the NDA in November 2011.
On September 18, 2012, Qsymia became available on the US market.[
]
References
External links
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{{DEFAULTSORT:Phentermine Topiramate
Anorectics
Combination drugs
Antiobesity drugs