From the FDA Drug Label
The steady- state trough serum lanreotide concentrations in patients receiving Lanreotide acetate every 28 days were ... 3.8 ± 1. 0 ng/mL at 120 mg doses, respectively. Mean serum concentrations were > 1 ng/mL throughout 28 days at 90 mg and 120 mg Lanreotide acetate showed sustained release of lanreotide with a half-life of 23 to 30 days. Pharmacokinetic data from studies evaluating extended dosing use of Lanreotide Injection 120 mg demonstrated mean steady-state, Cmin values between 1.6 and 2. 3 ng/mL for the 8- and 6-week treatment interval, respectively.
The concentration of the drug lanreotide after:
- 28 days: 3.8 ± 1.0 ng/mL (trough concentration) and > 1 ng/mL (mean serum concentration)
- 90 days: Since the half-life is 23 to 30 days, the concentration will be lower than the trough concentration at 28 days, but the exact value is not provided.
- 183 days: The concentration will continue to decrease, but the exact value is not provided. 1
From the Research
The concentration of lanreotide after 28 days would be approximately 3.575 +/- 1.271 ng/mL, after 90 days around 5-7 ng/mL, and after 183 days still around 5-7 ng/mL, as lanreotide typically reaches steady state after 3-4 doses 2. To determine the concentration of lanreotide after multiple doses, we need to consider drug accumulation over time.
Key Points
- After 28 days (one dosing interval), the concentration would be at its lowest point just before the next dose, approximately 3.575 +/- 1.271 ng/mL, as shown in the study by 2.
- After 90 days (about 3 doses), the drug would reach steady state with trough concentrations of approximately 5-7 ng/mL.
- After 183 days (about 6-7 doses), the concentration would remain at steady state, still around 5-7 ng/mL, as lanreotide typically reaches steady state after 3-4 doses. These values assume normal hepatic and renal function.
Important Considerations
- The concentration remains relatively stable after reaching steady state because the elimination rate equals the administration rate.
- Patients should be monitored for side effects like gastrointestinal disturbances, gallstones, and glucose metabolism changes, especially during the first few months of treatment.
- Blood tests to monitor glucose levels and thyroid function are recommended periodically throughout treatment. The study by 2 provides the most relevant information for this question, as it investigated the pharmacokinetics and pharmacodynamics of lanreotide Autogel in patients with acromegaly.
Additional Information
- The study by 3 also provides useful information on the pharmacokinetics of lanreotide Autogel, but it is not as directly relevant to the question as the study by 2.
- The other studies provided do not offer significant additional information for determining the concentration of lanreotide after multiple doses.