Effects of laparoscopic sleeve gastrectomy on simvastatin absorption

The Need of Dosing Adjustment for Simvastatin in Obese Patients Post Bariatric Surgery- Laparoscopic Sleeve Gastrectomy (LSG)

PHASE4 · National University Hospital, Singapore · NCT03571802

This study is testing how laparoscopic sleeve gastrectomy affects the way the body absorbs simvastatin, a cholesterol-lowering medication, in people who are having this surgery and already take statins.

Quick facts

PhasePHASE4
Study typeInterventional
Enrollment10 (estimated)
Ages21 Years and up
SexAll
SponsorNational University Hospital, Singapore (other)
Drugs / interventionstocilizumab, imatinib
Locations1 site (Singapore)
Trial IDNCT03571802 on ClinicalTrials.gov

What this trial studies

This study investigates how laparoscopic sleeve gastrectomy (LSG) affects the pharmacokinetics of simvastatin, a commonly used medication for lowering cholesterol. It aims to understand changes in the drug's systemic exposure following the surgical procedure, as LSG alters gastrointestinal physiology, potentially impacting drug absorption. The study will include participants who are scheduled for LSG and are currently taking statins, focusing on the changes in bioavailability of simvastatin post-surgery. This research addresses a gap in the literature regarding the pharmacokinetics of simvastatin in the context of bariatric surgery.

Who should consider this trial

Good fit: Ideal candidates are adults aged 21 and above who are scheduled for laparoscopic sleeve gastrectomy and are currently taking statins.

Not a fit: Patients who are pregnant or taking medications that significantly affect simvastatin pharmacokinetics will not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to optimized simvastatin dosing for patients undergoing LSG, improving lipid management post-surgery.

How similar studies have performed: While there have been studies on the pharmacokinetics of other statins post-bariatric surgery, this specific investigation into simvastatin is novel and has not been previously explored.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Planned for laparoscopic sleeve gastrectomy at National University Hospital
* Taking statin
* Aged 21 or above

Exclusion Criteria:

* Patient on concomitant treatment with medications/ food/ herbal supplements that may affect the pharmacokinetics of simvastatin: boceprevir, conivaptan, cyclosporine, efavirenz, mitotane, tocilizumab, rifamycin, amiodarone, amlodipine, aprepitant, azithromycin, colchicine, fenofibrate, imatinib, raltegravir, ranolazine, teriflunomide, ticagrelor, fusidic acid, protease inhibitors, telaprevir, telithromycin, gemfibrozil, erythromycin, clarithromycin, carbamazepine, rifampicin, ketoconazole, fluconazole, itraconazole, voriconanzole, diltiazem, verapamil, dexamethasone, prednisolone, phenytoin, ritonavir, indinavir, nelfinavir, bosentan, telithromycin, nefazodone, St John's wort, orlistat, sibutramine and other strong CYP 3A4 inhibitors/ inducers
* Pregnant ladies

Where this trial is running

Singapore

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Obesity, Hyperlipidemias, pharmacokinetics, simvastatin, bariatric surgery, laparoscopic sleeve gastrectomy

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.