Liraglutide
MetabolicAlso known as Victoza, Saxenda
GLP-1 receptor agonist, dosed daily rather than weekly. FDA approved.
How it works
97% homologous to human GLP-1. Protraction comes from self-association at the injection site plus plasma protein binding, a different mechanism from semaglutide's albumin binding, and it produces a much shorter half-life.
In the body
Shape of a single dose, modelled as one compartment with first-order absorption. The peak is normalised to 100% because bioavailability and volume of distribution are not published for most of these compounds.
13 hours after subcutaneous dosing. Short enough that each daily dose rises and falls almost completely.
What happens, and when
- 0 min, 8 hAbsorbing from the depot.
- 8 h, 14 hPeak plasma levels, 8 to 12 hours in.
- 14 h, 24 hFalling steeply. Roughly a quarter of peak remains by hour 24.
- 24 h, 2 dEssentially cleared. There is almost no accumulation between daily doses.
Doses
Saxenda tops out at 3 mg daily; Victoza at 1.8 mg.
Saxenda escalation to 3 mg
Saxenda prescribing information, Table 1 · 16 weeks total
- wk 1600 mcg1 week
- wk 21.2 mg1 week
- wk 31.8 mg1 week
- wk 42.4 mg1 week
- wk 5, 163 mg12 weeks
If more than 3 days have passed since the last dose, the label says to restart at 0.6 mg and escalate again.
Side effects
- Nausea, vomiting, diarrhoea, constipation
- Injection site reactions
- Gallbladder disease
- Pancreatitis, uncommon
Cautions
- Boxed warning: thyroid C-cell tumours in rodents. Contraindicated with a personal or family history of medullary thyroid carcinoma or MEN 2.
- Caution with insulin or sulfonylureas.
Status
FDA approved as Victoza (type 2 diabetes) and Saxenda (weight management).
Reference information for personal record-keeping. Not medical advice, and not a recommendation to use any of these compounds.