MERIDIA
Clinical safety rating: caution
Comprehensive clinical and safety monograph for MERIDIA (MERIDIA).
Sibutramine is a serotonin-norepinephrine reuptake inhibitor (SNRI) that inhibits the reuptake of serotonin and norepinephrine in the hypothalamus, enhancing satiety and increasing energy expenditure.
| Metabolism | Primarily metabolized by cytochrome P450 3A4 (CYP3A4) to active metabolites desmethylsibutramine and didesmethylsibutramine; also metabolized by CYP2C19 and CYP2B6 to a lesser extent. |
| Excretion | Primarily hepatic (CYP3A4 metabolism) with renal excretion of metabolites; ~80% of dose excreted in urine (mainly as M1 and M2 metabolites) and ~10% in feces. |
| Half-life | Sibutramine: 1.1 hours; active metabolites M1 and M2: 14-16 hours (terminal half-life). Steady-state achieved within 4 days. |
| Protein binding | Sibutramine: 97% bound to albumin and alpha-1-acid glycoprotein (AAG); M1 and M2: 94% bound. |
| Volume of Distribution | Sibutramine: 6.5 L/kg; large Vd indicates extensive tissue distribution. |
| Bioavailability | Oral: 77% (sibutramine) due to first-pass metabolism; extensive biotransformation to active metabolites. |
| Onset of Action | Oral: Appetite suppression typically within 1-3 hours after a single dose. |
| Duration of Action | Supports once-daily dosing; clinical effect persists for 24 hours due to active metabolites. |
10–15 mg orally once daily, titrated to 15 mg maximum after 4 weeks if inadequate weight loss.
| Dosage form | CAPSULE |
| Renal impairment | Contraindicated in severe renal impairment (CrCl <30 mL/min). No adjustment required for mild to moderate impairment (CrCl ≥30 mL/min). |
| Liver impairment | Contraindicated in Child-Pugh class B or C cirrhosis. No adjustment recommended for Child-Pugh class A; monitor carefully. |
| Pediatric use | Not recommended for use in pediatric patients (<16 years) due to lack of safety and efficacy data. |
| Geriatric use | Use caution in elderly patients, especially those with hypertension, history of stroke, or cardiovascular disease; no specific dose adjustment, but monitor blood pressure and heart rate closely. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for MERIDIA (MERIDIA).
| Breastfeeding | Excreted in breast milk; M/P ratio 0.6. Consider risk of infant tachycardia and hypertension; use only if benefit outweighs risk. |
| Teratogenic Risk | Pregnancy Category C. First trimester: animal studies show increased risk of neural tube defects; insufficient human data. Second and third trimesters: potential for fetal growth restriction and maternal hypertension. Avoid use in pregnancy. |
| Fetal Monitoring |
■ FDA Black Box Warning
Sibutramine is contraindicated in patients with a history of coronary artery disease, congestive heart failure, arrhythmias, or stroke due to an increased risk of major adverse cardiovascular events, including non-fatal myocardial infarction and non-fatal stroke.
| Serious Effects |
["History of coronary artery disease (e.g., angina, history of MI)","Congestive heart failure","Arrhythmias","Stroke or transient ischemic attack","Uncontrolled hypertension (>145/90 mmHg)","Concomitant use of MAOIs or within 14 days of discontinuation","Concomitant use of other centrally acting appetite suppressants","Known hypersensitivity to sibutramine","Pregnancy and lactation","Severe eating disorders (e.g., anorexia nervosa, bulimia nervosa)"]
| Precautions | ["Increased risk of major adverse cardiovascular events (non-fatal MI, non-fatal stroke) in patients with pre-existing cardiovascular disease.","Monitor blood pressure and heart rate; sibutramine can cause sustained increases in both.","Avoid use in patients with uncontrolled hypertension.","Risk of serotonin syndrome when co-administered with other serotonergic drugs.","Potential for drug interactions with CYP3A4 inhibitors/inducers.","Not recommended for use in patients with severe hepatic or renal impairment."] |
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| Monitor maternal blood pressure, heart rate, and weight. Monitor fetal growth via ultrasound if used inadvertently. |
| Fertility Effects | May impair ovulation due to weight loss; reversible upon discontinuation. |