Converting from Victoza to Trulicity involves switching between two glucagon-like peptide-1 (GLP-1) receptor agonists used to manage type 2 diabetes mellitus. Whilst both medications work through similar mechanisms to improve glycaemic control, the transition from daily Victoza injections to once-weekly Trulicity offers potential benefits in treatment adherence and convenience. This conversion requires careful medical supervision, as there is no direct dose equivalence between these agents. Healthcare professionals must consider individual patient factors, monitor blood glucose levels closely during the transition period, and provide comprehensive education about the new injection regimen to ensure safe and effective diabetes management.

Understanding Victoza and Trulicity: Key Differences

Both Victoza (liraglutide) and Trulicity (dulaglutide) belong to a class of medications called glucagon-like peptide-1 (GLP-1) receptor agonists, used primarily for managing type 2 diabetes mellitus. These medicines work by mimicking the action of the naturally occurring hormone GLP-1, which stimulates insulin secretion in response to food intake, suppresses glucagon release, slows gastric emptying, and promotes satiety. This multifaceted mechanism helps improve glycaemic control whilst potentially supporting weight management.

The principal difference between these two agents lies in their dosing frequency and formulation. According to the Summary of Product Characteristics (SmPC), Victoza requires once-daily subcutaneous injection, typically administered at any time of day regardless of meals, using a pre-filled pen device. The dose is gradually titrated from 0.6 mg daily up to a maximum of 1.8 mg daily, depending on individual glycaemic response and tolerability. In contrast, Trulicity offers the convenience of once-weekly administration, available in pre-filled single-dose pens containing 0.75 mg, 1.5 mg, 3 mg, or 4.5 mg. This reduced injection frequency often appeals to patients seeking simplified treatment regimens.

Both medications have demonstrated cardiovascular benefits in landmark clinical trials, with evidence supporting reduced risk of major adverse cardiovascular events. Notably, the LEADER trial showed cardiovascular benefit with liraglutide in patients with established cardiovascular disease, while the REWIND trial demonstrated dulaglutide's cardiovascular benefits in a broader population including those with cardiovascular risk factors.

According to NICE guidance (NG28), GLP-1 receptor agonists are not routinely recommended as second-line therapy. They are considered in specific contexts, such as part of triple therapy where weight loss is a priority or when insulin is not appropriate, and for people with established cardiovascular disease if SGLT2 inhibitors are not suitable. The choice between daily and weekly formulations often depends on patient preference, lifestyle considerations, and individual response to therapy. Both agents are licensed in the UK and available through NHS prescription when clinically appropriate.

Why Switch from Victoza to Trulicity?

Healthcare professionals may recommend converting from Victoza to Trulicity for several clinically valid reasons, with improved treatment adherence being amongst the most common. The reduction from daily to weekly injections can significantly enhance medication compliance, particularly for patients who struggle with the burden of daily administration or those managing multiple chronic conditions requiring frequent dosing schedules. Research suggests that simplified regimens may improve long-term adherence, which directly correlates with better glycaemic outcomes and reduced diabetes-related complications.

Patient preference and quality of life considerations frequently drive switching decisions. Many individuals find weekly injections less intrusive to their daily routines, reducing the psychological burden associated with diabetes management. This can be particularly beneficial for working professionals, frequent travellers, or those who experience injection-site anxiety. The single-dose pen design of Trulicity also eliminates the need for dose selection, potentially reducing administration errors and simplifying the injection process for patients with dexterity issues or visual impairment.

Clinical factors may also necessitate conversion. Some patients experience persistent gastrointestinal side effects with daily liraglutide, though individual responses to different GLP-1 receptor agonists vary considerably. Additionally, if glycaemic targets remain unmet despite optimal Victoza dosing, switching to higher-dose Trulicity formulations (up to 4.5 mg weekly) may provide enhanced efficacy, as demonstrated in the AWARD-11 trial. Cost considerations and formulary restrictions within certain NHS Integrated Care Boards (ICBs) may also influence prescribing decisions, though individual clinical appropriateness should always take precedence over formulary considerations.

It is important to note that switching between GLP-1 receptor agonists should always occur under medical supervision, with individualised assessment of potential benefits, risks, and patient-specific factors guiding the decision-making process.

How to Convert from Victoza to Trulicity Safely

Converting from Victoza to Trulicity requires careful planning and medical oversight to ensure patient safety and maintain glycaemic stability. There is no direct dose equivalence between these medications due to differences in their molecular structure, pharmacokinetics, and dosing schedules. The transition should be managed by a healthcare professional experienced in diabetes care, typically a GP with special interest in diabetes, practice nurse, or specialist diabetes team.

According to the Trulicity SmPC, the standard approach involves discontinuing Victoza and initiating Trulicity the following day. Most patients will commence Trulicity at the 0.75 mg weekly dose, with potential escalation to 1.5 mg, then 3 mg, and finally 4.5 mg at intervals of at least four weeks if additional glycaemic control is required and the lower dose is well tolerated. For patients previously stable on maximum-dose Victoza (1.8 mg daily) with suboptimal control, initiating at 1.5 mg weekly may be appropriate, though this decision should be individualised.

If a dose is missed, patients should administer it as soon as possible if there are at least 3 days (72 hours) until the next scheduled dose. If less than 3 days remain, the missed dose should be skipped and the next dose administered on the regularly scheduled day.

Blood glucose monitoring should be intensified during the transition period, particularly for the first two to four weeks. Patients should be advised to check their blood glucose levels more frequently, especially if they experience symptoms of hypoglycaemia or hyperglycaemia. Those taking concomitant sulfonylureas or insulin may require dose adjustments of these medications to minimise hypoglycaemia risk. Consider reducing sulfonylurea doses by approximately 50% and/or basal insulin by 10-20% at initiation, with close glucose monitoring.

Patients should receive comprehensive education about the new injection technique, including proper storage (refrigerated until first use, then may be kept at room temperature for up to 14 days), administration site rotation (abdomen, thigh, or upper arm), and the importance of injecting on the same day each week. A follow-up appointment should be scheduled within four to eight weeks to assess glycaemic response (reviewing HbA1c if appropriate), tolerability, and address any concerns. Patients should be provided with clear written information and contact details for their diabetes care team should questions or problems arise during the transition.

Caution is advised in patients with severe gastrointestinal disease (including gastroparesis) or a history of pancreatitis. Trulicity should be discontinued if pancreatitis is suspected and should not be restarted if pancreatitis is confirmed.

Managing Side Effects During the Transition

Gastrointestinal adverse effects represent the most common challenge when converting between GLP-1 receptor agonists. Nausea, vomiting, diarrhoea, and abdominal discomfort occur most frequently during treatment initiation or dose escalation, typically diminishing over two to four weeks as the body adapts to the medication. These effects result from the drugs' mechanism of slowing gastric emptying and affecting gastrointestinal motility.

To minimise gastrointestinal symptoms, patients should be advised to eat smaller, more frequent meals rather than large portions, avoid high-fat and spicy foods initially, and stay well hydrated. If nausea is problematic, short-term use of antiemetics may be considered, though with important restrictions. Domperidone should only be used for nausea/vomiting at the lowest effective dose for the shortest possible duration (typically maximum 7 days), and is contraindicated in those with cardiac conduction disorders, electrolyte abnormalities, or taking other QT-prolonging medications. Metoclopramide should be limited to a maximum of 5 days due to neurological side effect risks.

Injection-site reactions—including redness, itching, or mild swelling—occasionally occur but are generally self-limiting. Rotating injection sites with each dose and ensuring the medication reaches room temperature before injection can reduce discomfort. Patients should be reassured that minor injection-site reactions do not typically require treatment discontinuation.

Patients should be informed about the risk of gallbladder disease (cholelithiasis, cholecystitis) with GLP-1 receptor agonists and advised to seek medical review for persistent right-upper quadrant pain or jaundice.

More serious adverse effects require immediate medical attention. Patients should be counselled to stop treatment and seek urgent medical care if they experience: severe, persistent abdominal pain with or without vomiting (potentially indicating pancreatitis); signs of thyroid nodules or neck masses (thyroid C-cell tumours have been observed in animal studies, though the relevance to humans is unknown); symptoms of severe allergic reaction; or persistent vomiting leading to dehydration.

Regular monitoring of renal function is advisable, particularly in patients with pre-existing kidney disease, as dehydration from gastrointestinal side effects could potentially affect renal function. HbA1c should be reassessed approximately three months after conversion to evaluate glycaemic efficacy, with ongoing monitoring every three to six months thereafter according to individual clinical circumstances and NICE recommendations for type 2 diabetes management.

Patients and healthcare professionals are encouraged to report suspected adverse reactions via the MHRA Yellow Card scheme (yellowcard.mhra.gov.uk).

Frequently Asked Questions