sibutramine

Sibutramine is no longer available in the U.S. because of the risk of serious cardiovascular problems in some people who take it.

Sibutramine is indicated for the management of obesity, including weight loss and maintenance of weight loss, and should be used in conjunction with a reduced-calorie diet. Sibutramine is recommended for obese patients with an initial body mass index ≥ 30 kg/m2, or ≥ 27 kg/m2 in the presence of other risk factors (e.g., diabetes, dyslipidemia, controlled hypertension).

Sibutramine assists with weight loss by altering neurotransmitters within the brain. Neurotransmitters are chemicals that are produced and released by nerves to communicate with other nerves. Released neurotransmitters may attach to other nerves or they may be taken up again by the nerves that release them, a process termed reuptake. Sibutramine blocks the reuptake of the neurotransmitters dopamine, norepinephrine, and serotonin. Blocking the reuptake of neurotransmitters alters the balance of neurotransmitters within the nerve cells and thereby affects nerve function and interaction.

Patients taking sibutramine may achieve a 5-10% reduction from their baseline weight. Additionally, sibutramine-assisted weight loss has been accompanied by improvement in blood lipids (e.g, cholesterol). Sibutramine was approved by the FDA in 1997.

What brand names are available for sibutramine?

Meridia

Is sibutramine available as a generic drug?

No

Do I need a sibutramine prescription?

Yes

WARNING

Sibutramine substantially increases blood pressure and/or pulse rate in some patients. Regular monitoring of blood pressure and pulse rate is required when prescribing sibutramine.

In placebo-controlled obesity studies, sibutramine 5 to 20 mg once daily was associated with mean increases in systolic and diastolic blood pressure of approximately 1 to 3 mm Hg relative to placebo, and with mean increases in pulse rate relative to placebo of approximately 4 to 5 beats per minute. Larger increases were seen in some patients, particularly when therapy with sibutramine was initiated at higher doses.

Blood pressure and pulse should be measured before starting therapy with sibutramine and should be monitored at regular intervals thereafter. For patients who experience a sustained increase in blood pressure or pulse rate while receiving sibutramine, either dose reduction or discontinuation should be considered. MERIDIA should be given with caution to those patients with a history of hypertension, and should not be given to patients with uncontrolled or poorly controlled hypertension.

Common side effects

In general, sibutramine is well-tolerated. The most common side effects have been:

• constipation,
• inability to sleep,
• headache,
• dry mouth,
• abdominal pain,
• acne,
• rash,
• chest pain,
• anxiety,
• joint pain,
• back pain,
• excitation,
• depression,
• sweating,
• dizziness,
• drowsiness,
• changes in taste,
• irregular or painful menstrual periods,
• flu-like syndrome,
• increased cough,
• muscle pain,
• nausea,
• vomiting,
• neck pain,
• nervousness,
• palpitations,
• tingling of the extremities,
• sore throat, and
• sinus congestion.

Abnormal liver tests have been reported in 1 in 60 persons who receive sibutramine.

Other important side effects include:

• depression,
• psychosis,
• mania,
• suicidal thoughts and
• suicide

However, it has not been established that sibutramine caused these events. If any of these events occur during treatment, sibutramine probably should be discontinued.

Sibutramine is taken once daily, generally in the morning. Therapy usually is started with one 10mg tablet per day. The dose may be increased to 15mg by the physician after several weeks to achieve the desired effect. Doses of up to 60mg have been studied. Sibutramine may be taken with or without food.

Sibutramine must be converted in the liver to its active form. This conversion is inhibited by ketoconazole (Nizoral), cimetidine (Tagamet), and erythromycin (Erytab, Eryc, Ilosone), and the use of these drugs can result in decreased conversion and effectiveness of sibutramine. Several other drugs may have a similar effect. These other drugs include clarithromycin (Biaxin), danazol (Danocrine), diltiazem (Cardizem, Tiazac, Dilacor), fluconazole (Diflucan), fluoxetine (Prozac), itraconazole (Sporanox), propoxyphene (Darvon), troleandomycin (Tao) and verapamil (Verelan, Covera, Calan, Isoptin).

In patients receiving one of the drugs from a class of drugs known as selective serotonin reuptake inhibitors (SSRIs), for example, fluoxetine (Prozac), fluvoxamine (Luvox), paroxetine (Paxil), sertraline (Zoloft)--at the same time as monoamine oxidase inhibitor drugs (MAO inhibitors), there have been reports of serious reactions (serotonin syndrome). The serotonin syndrome may include one or more of the following: agitation, anxiety, dizziness, confusion, excessive sweating, disorientation, painful joints, vomiting, hyperexcitement, fever, loss of coordination, loss of consciousness, shivering, fast heart rate, tremor, and weakness. As discussed previously, sibutramine, like SSRIs, blocks the reuptake of serotonin and may also cause serotonin syndrome. Therefore, sibutramine should not be used with MAO inhibitors, and there should be at least a 2-week interval between stopping an MAO inhibitor and starting sibutramine. Similarly, there should be at least a 2-week interval after stopping sibutramine and starting an MAO inhibitor. Serotonin syndrome also has been reported with the use of SSRIs at the same time as medications used for migraines such as sumatriptan (Imitrex), zolmitriptan (Zomig), and dihydroergotamine (DHE), as well as dextromethorphan (found in many cough medications such as Robitussin-DM), meperidine (Demerol), pentazocine (Talwin) and fentanyl (Duragesic), or lithium (Eskalith). Therefore, these drugs should not be used with sibutramine.

No adequate studies with sibutramine have been done in pregnant women. The use of sibutramine during pregnancy, therefore, is not recommended. Women who could become pregnant should use adequate contraception while taking sibutramine.

It is unknown whether sibutramine or its active products accumulate in breast milk. Sibutramine, therefore, is not recommended for nursing mothers.

Capsules: 5mg (blue and yellow); 10mg (blue and white); 15mg (white and yellow)

Capsules should be stored at 25°C (77°F). Brief periods at higher or lower temperatures, i.e., 15-30°C (59-86°F) are permitted. The medication should be stored in a tight, light-resistant container. The capsules should be protected from heat and moisture.