Saxenda (liraglutide) is a GLP-1 receptor agonist licensed for weight management and must be administered subcutaneously into fatty tissue beneath the skin. The medication is not approved for intravenous or intramuscular use, and the effects of accidental intravenous injection are unknown. If you suspect you have accidentally injected Saxenda into a vein, it is important to seek medical guidance promptly. This article explains what to do following a suspected accidental intravenous injection, symptoms to monitor, and how to inject Saxenda correctly to prevent such incidents. Proper injection technique and awareness of warning signs are essential for safe medication use.

What Happens If Saxenda Is Injected Into a Vein

Saxenda (liraglutide) is a glucagon-like peptide-1 (GLP-1) receptor agonist licensed for weight management in adults with a body mass index (BMI) of 30 kg/m² or greater, or 27 kg/m² or greater with weight-related comorbidities. It is specifically formulated and approved for subcutaneous injection only – meaning it should be administered into the fatty tissue layer beneath the skin.

According to the Saxenda Summary of Product Characteristics (SmPC), the medication must not be administered intravenously or intramuscularly. The safety and effects of intravenous administration are unknown and potentially harmful. Saxenda is designed to be absorbed gradually from subcutaneous tissue, with peak plasma concentrations occurring approximately 8–12 hours post-injection.

The pharmacological action of liraglutide involves stimulating insulin secretion in a glucose-dependent manner (which reduces the risk of hypoglycaemia when used alone), suppressing glucagon release, and slowing gastric emptying. If you believe you have accidentally injected Saxenda into a vein, it is advisable to seek medical guidance promptly, as the medication would not be delivered as intended and the effects of intravenous administration have not been established.

Immediate Steps After Accidental Intravenous Injection

If you suspect that you have accidentally injected Saxenda into a vein rather than subcutaneously, it is important to remain calm and take appropriate action. Do not attempt to inject another dose to compensate, as this could lead to medication overdose or duplication.

The first step is to monitor yourself closely for any unusual symptoms (detailed in the next section). Note the time of injection, the dose administered, and any immediate sensations such as pain or bleeding at the injection site. While the effects of accidental intravenous injection are not well-documented, it is prudent to err on the side of caution.

Contact your GP, NHS 111, or out-of-hours services for advice as soon as possible. Explain what has happened, including:

• The time and dose of the injection

• Whether you experienced immediate pain, rapid blood flow, or other unusual sensations during injection

• Any symptoms you are currently experiencing

If you develop severe symptoms such as difficulty breathing, chest pain, rapid heartbeat, severe dizziness, or loss of consciousness, call 999 immediately or attend your nearest Accident & Emergency department. These symptoms, while unlikely, would require urgent medical assessment.

Keep the Saxenda pen and packaging available for reference, as healthcare professionals may need to confirm the medication details. Apply gentle pressure if there is bleeding at the injection site, and dispose of the used needle safely in a sharps bin. Do not take additional doses of Saxenda or adjust other diabetes medications without professional guidance.

Symptoms and Warning Signs to Monitor

Following a suspected accidental intravenous injection of Saxenda, it is essential to monitor for both common side effects of the medication and any signs that might indicate an atypical response due to the route of administration.

Common side effects of Saxenda (when used correctly) include nausea, vomiting, diarrhoea, constipation, headache, and injection site reactions. These symptoms typically occur regardless of injection technique and are related to the medication's mechanism of action on the gastrointestinal system. If these symptoms are mild and consistent with your previous experience of Saxenda, they are less likely to be cause for immediate concern.

However, you should be vigilant for warning signs that may warrant urgent medical attention:

• Hypoglycaemia symptoms: Shakiness, sweating, confusion, rapid heartbeat, dizziness, or extreme hunger. While Saxenda alone rarely causes low blood sugar, the risk increases if you are taking insulin or sulfonylurea medications for diabetes. Contact your prescriber about possible dose adjustments of these medications if needed.

• Cardiovascular symptoms: Unusually rapid or irregular heartbeat (palpitations) or chest discomfort. GLP-1 receptor agonists like Saxenda can cause a modest increase in heart rate.

• Severe gastrointestinal symptoms: Intense abdominal pain, persistent vomiting, or signs of pancreatitis (severe upper abdominal pain radiating to the back). If you suspect pancreatitis, stop taking Saxenda and seek urgent medical attention.

• Gallbladder problems: Pain in the upper right abdomen, fever, or yellowing of the skin or eyes, which could indicate gallstones or gallbladder inflammation.

• Allergic or systemic reactions: Difficulty breathing, facial swelling, widespread rash, or feeling faint.

Maintain adequate hydration, especially if experiencing vomiting or diarrhoea, as dehydration could affect kidney function. Monitor your blood glucose levels if you have diabetes and access to a glucose meter. Record any readings outside your normal range and report these to your healthcare provider.

If you experience any suspected side effects, you can report them via the MHRA Yellow Card scheme (yellowcard.mhra.gov.uk).

How to Inject Saxenda Correctly and Safely

Proper injection technique is essential to ensure Saxenda is delivered subcutaneously as intended and to minimise the risk of complications, including accidental intravenous injection. The following guidance aligns with the manufacturer's instructions and Forum for Injection Technique (FIT UK) recommendations.

Preparation and injection site selection:

• Saxenda should be injected into areas with adequate subcutaneous fat: the abdomen (avoiding a 5cm radius around the navel), thigh, or upper arm.

• Rotate injection sites with each dose to reduce the risk of lipodystrophy (changes in fat tissue) and injection site reactions.

• Clean the injection site with an alcohol wipe if recommended by your healthcare provider, and allow the skin to dry completely.

Correct injection technique:

• Pinch the skin gently between your thumb and forefinger to lift the subcutaneous tissue away from underlying muscle. This creates a clear target for subcutaneous injection.

• Insert the needle at a 90-degree angle (or 45 degrees if you are very lean or injecting into an area with less fat).

• Inject slowly and steadily, keeping the needle in place for at least 6 seconds after pressing the dose button fully to ensure complete delivery.

• Release the skin pinch and withdraw the needle straight out.

Important safety points:

• Never inject into areas with visible veins, bruising, or broken skin.

• Do not inject into muscle – this can be avoided by using the pinch technique and appropriate needle angle.

• There is no need to aspirate (pull back on the plunger) when using pen injectors.

• Use a new needle for each injection and dispose of used needles in a sharps bin.

• If you see blood at the injection site after withdrawing the needle, apply gentle pressure with clean gauze. A small amount of bleeding is not necessarily indicative of intravenous injection.

• Never share your Saxenda pen with others, even if the needle is changed, due to infection risk.

If you are uncertain about your injection technique, request a demonstration from your GP practice nurse, diabetes specialist nurse, or pharmacist. Many NHS services offer injection training for patients starting Saxenda or other injectable medications. Proper training significantly reduces the risk of injection errors and improves treatment outcomes.

Frequently Asked Questions