Saxenda and PPIs (Omeprazole, Pantoprazole): Drug Interaction Guide

What the Saxenda label actually says

Section 7.1 of the Saxenda prescribing information says liraglutide 'has the potential to impact the absorption of concomitantly administered oral medications,' and that in clinical pharmacology trials liraglutide did not affect the absorption of the tested oral medicines to any clinically relevant degree [1]. The same section asks for monitoring for potential consequences of delayed absorption [1]. It names no individual drug, PPI or otherwise [1].

The esomeprazole label adds nothing about liraglutide. Its interaction section covers antiretrovirals, warfarin, methotrexate, CYP2C19 substrates such as clopidogrel, citalopram and cilostazol, digoxin, tacrolimus, drugs that depend on gastric acidity to be absorbed, CYP2C19 or CYP3A4 inducers such as St. John's wort and rifampin, and some diagnostic tests [2]. Liraglutide is not listed [2].

The two labels together establish something narrow: the Saxenda label names no individual interacting drug or PPI, and discusses oral medicines as a class with advice to monitor [1]. The esomeprazole label's interaction tables do not include liraglutide [2].

How liraglutide is metabolized

Saxenda is injected under the skin once daily. Peak concentration arrives about 11 hours after a dose, more than 98% of the drug is protein bound, and the half-life is about 13 hours [1]. The Saxenda label says liraglutide is metabolized like a large protein, without a specific organ of elimination, and intact liraglutide is not found in urine or feces [1]. It does not identify CYP2C19 or any other CYP enzyme as a clearance route [1].

Does slowed gastric emptying change how a PPI is absorbed?

Esomeprazole comes as a delayed-release capsule and a delayed-release oral suspension [2]. The Saxenda label says the emptying delay may affect oral drug absorption in principle, that the tested oral drugs showed no clinically relevant effect, and that it asks for monitoring for consequences of delayed absorption [1].

What is known is how the PPI itself behaves. PPIs reduce stomach acid by binding the parietal cell H+/K+ ATPase, and the acid suppression lasts far longer than the plasma half-life (omeprazole 0.5 to 1 hour, pantoprazole about 1 hour, esomeprazole 1 to 1.5 hours) because the binding to the enzyme is prolonged [2].

Where the two drugs can look alike: stomach side effects

In the Saxenda adult trials (3,384 on Saxenda, 1,941 on placebo, up to 56 weeks at 3 mg daily), nausea occurred in 39.3% versus 13.8%, diarrhea in 20.9% versus 9.9%, constipation in 19.4% versus 8.5%, vomiting in 15.7% versus 3.9%, and dyspepsia in 9.6% versus 2.7% [1]. About 68% of Saxenda-treated patients versus 39% on placebo reported any gastrointestinal disorder, and nausea became less frequent as treatment continued [1].

The esomeprazole label lists headache, diarrhea, nausea, flatulence, abdominal pain, constipation and dry mouth as the most common adult adverse reactions, each above 1% [2]. Nausea, diarrhea, constipation and abdominal pain appear on both lists [1][2]. Neither label describes an additive interaction between liraglutide and a PPI [1][2].

Reflux and heartburn on Saxenda

Gastroesophageal reflux disease is listed as an adverse reaction in the Saxenda adult trials at 4.7% versus 1.7% on placebo, along with eructation 4.5% versus 0.2%, abdominal distension 4.5% versus 3%, and flatulence 4% versus 2.5% [1].

Saxenda starts at 0.6 mg daily for one week and increases at weekly intervals (1.2 mg, 1.8 mg, 2.4 mg, then 3 mg daily from week 5) to reduce the risk of gastrointestinal adverse reactions [1].

Severe gastroparesis

PPIs reduce stomach acid by acting on the gastric proton pump, while Saxenda delays gastric emptying [1][2]. The Saxenda label states that use is associated with gastrointestinal adverse reactions, sometimes severe, and that Saxenda is not recommended in patients with severe gastroparesis [1].

Practical points

The Saxenda label says the injection may be given once daily at any time of day without regard to meals [1]. The esomeprazole label lists 20 mg or 40 mg once daily for several adult indications, including erosive esophagitis, and 20 mg once daily for symptomatic GERD [2]. A review describes PPIs as having short plasma half-lives and requiring meal-associated dosing [3].

The PPI class warnings in the esomeprazole label include hypomagnesemia reported rarely with prolonged treatment, B12 malabsorption with daily use longer than 3 years, C. difficile diarrhea and bone fracture based on observational studies, and fundic gland polyps with use beyond a year [2]. American Gastroenterological Association best practice advice says every patient taking a PPI should have the ongoing indication for it reviewed regularly [4].