lorcaserin BELVIQ
Class: 5HT2C AgonistFDA Indications: Chronic Weight Management
Off-Label Use: Obesity
Prescribing
FDA Schedule IVForms: 10mg tablet; 20mg XR capsule
Dose Range: 20 mg/day
Starting: IR tablet: 10 mg bid
XR capsure: 20 mg qd
Can be taken with or without food. No dose titration necessary.
Stopping: Taper not necessary.
Pharmacodynamics
1° MOA: Selectively activates 5HT2C receptors on anorexigenic pro-opiomelanocortin neurons in the hypothalamusTarget: 5HT2C agonist
Pharmacokinetics
t½: 11° TMAX: 1.5-2°Substrate of: 1A2, 2A6, 2B6, 2C19, 2D6, 3A4, FMO1
Inhibits: 2D6; Induces: ∅
Active Metabolites: ∅
DDIs
- - The risk of serotonin syndrome and neuroleptic malignant syndrome (NMS)-like reactions can occur if lorcaserin is used in combination with other serotonergic agents
- - as a substrate of numerous P450 pathways, coprescription with P450 inhibitors or inducers can ↑ or ↓ serum levels of lorcaserin, respectively as a 2D6 inhibitor it can increase levels of co-prescribed 2D6 substrates
Misc
- - approved for use in the treatment of obesity for adults with a BMI ≥30 or adults with a BMI of ≥27 who have at least one weight-related health condition, such as high blood pressure, type 2 diabetes, or high cholesterol
- - classified as a Schedule IV drug because it has psychedelic effects at higher than approved doses
- - a pilot trial comparing phentermine monotherapy, lorcaserin monotherapy, and a combination of both showed that the combination induced greater weight loss than either drug alone
- - lorcaserin's affinity for the 5-HT2C receptor is approximately 15-fold and 100-fold greater than its affinity for 5-HT2A and 5-HT2B, respectively
- - binding affinity is dose-dependent – when the maximum dose of 20 mg/day is exceeded, the binding becomes less selective for 5-HT2C and binds more to other serotonin receptors such as 5-HT2A
Special Populations
Category X—No reports describing the use of lorcaserin in human pregnancy have been located. The animal reproduction data suggest moderate risk, but the absence of human pregnancy experience prevents a better assessment of the embryo-fetal risk. However, the manufacturer classifies the drug as contraindicated in pregnancy because weight loss offers no potential benefit to a pregnant woman and may result in fetal harm.
No reports describing the use of lorcaserin during human lactation have been located. The molecular weight (about 197 for the free base), moderate (about 70%) plasma protein binding, and the long (about 11 hours) plasma half-life suggest that the drug will be excreted into breast milk. The effect of the exposure on a nursing infant is unknown.
The effect of lorcaserin in geriatric populations is unknown, as most patients in the three published clinical trials were 65 years of age or younger.12 No dose adjustments should be made based solely on age.
No dose adjustment necessary in patients with mild impairment. Use with caution in patients with moderate impairment. Not recommended in patients with severe impairment or end-stage renal disease.
No dose adjustment necessary in patients with mild to moderate impairment.