Victoza® and low blood sugar

Why the background medicine matters

Liraglutide raises insulin release only when blood glucose is high, and that effect fades as glucose approaches normal. ^[1] A single dose did not blunt the glucagon response that the body uses to correct a low. ^[1] The European summary puts it simply: during low blood sugar, liraglutide reduces insulin secretion and does not impair glucagon secretion. ^[2]

Sulfonylureas and insulin work differently, pushing glucose down whatever its level. That is why section 5.4 of the US label warns that adults who combine Victoza® with insulin, or with a medicine that pushes the pancreas to release insulin such as a sulfonylurea, can face more lows, severe ones included. ^[1] Europe lists hypoglycaemia as common overall and very common with a sulfonylurea. ^[2]

Adult trial results by combination

Table 2 of the US label shows four 26-week placebo-controlled trials, each with a different background. ^[1] “Needed help” means another person had to treat the low. Severe lows were rare overall: 8 adults on Victoza® needed help across the five glycemic control trials, 7.5 events per 1,000 patient-years, and 7 of the 8 were taking a sulfonylurea. ^[1]

What Europe, Canada and LEADER add

The European summary gives event rates: severe lows about 0.02 per patient-year when liraglutide was combined with a sulfonylurea, against 0.001 with other tablets. ^[2] Canada reports that minor lows in LEAD-2, on metformin, affected 0.8% to 3.3% on Victoza® against 16.9% on glimepiride, which itself raises the risk. ^[3]

LEADER followed 9,340 adults with type 2 diabetes and high cardiovascular risk for 3.5 to 5 years. Severe lows occurred in 114 people on liraglutide and 153 on placebo, a rate ratio of 0.69, and were concentrated in people using insulin or a sulfonylurea. ^[2][3][4] A follow-up analysis found that people who had a severe low had longer-standing diabetes, more heart failure and kidney disease and more insulin use, and were more likely to have a cardiovascular event or die, especially soon after the low. ^[4] The authors note that cause and effect remain unclear. ^[4]

Children and teenagers

This is where Victoza® differs most from the adult picture. In patients aged 10 and older, the label says low blood sugar was more frequent with Victoza® regardless of insulin or metformin use. ^[1] In the 26-week trial with a 26-week extension, 21.2% of young people on Victoza®, mean age 14.6, had a reading below 54 mg/dL with or without symptoms; no severe episodes occurred. ^[1][5]

Canada splits the minor lows by background treatment, and Europe gives the rate: 0.58 events per patient-year on liraglutide against 0.29 on placebo, rising to 1.82 against 0.91 in those using insulin. ^[2][3] Canada recommends extra glucose monitoring for young people when Victoza® is added, partly because some lows cause no symptoms. ^[3]

The signs to know

The Victoza® Medication Guide lists dizziness or light-headedness, blurred vision, anxiety or irritability, slurred speech, hunger, confusion or drowsiness, weakness, headache, a fast heartbeat, sweating, shakiness and feeling jittery. ^[1] The European leaflet adds cold sweat, cool pale skin and difficulty concentrating, and says signs can come on suddenly. ^[2] MedlinePlus explains that a reading below 70 mg/dL counts as low, that more serious symptoms tend to appear below 54 mg/dL, and that some people feel nothing until a low is severe. ^[6]

Lows can also happen during sleep. NIDDK lists crying out or nightmares and sweating enough to dampen pyjamas or sheets as possible signs. ^[7]

Why it might happen

Label-supported: the main driver is the partner medicine. The label says the risk may be lowered by reducing the dose of a sulfonylurea or insulin, and Europe says the dose reduction should be considered when Victoza® is added. ^[1][2]

Everyday contributors described by NIDDK: eating too little carbohydrate, skipping or delaying meals, fasting for a procedure, more physical activity than usual, alcohol without food and illness that stops you eating. ^[7] Decreased appetite and nausea, both common on Victoza®, can make some of these more likely. ^[1]

In people without diabetes medicines, MedlinePlus lists alcohol, severe kidney or liver failure, hormone deficiencies and some other medicines among causes. ^[6]

Before you start and during a low

• Before the first dose, the Medication Guide wants a conversation with your provider on recognising and handling lows, and on any insulin or sulfonylurea you use. ^[1]
• Europe says glucose self-monitoring is not needed to adjust Victoza® itself, but is needed to adjust a sulfonylurea or insulin, especially at the start. ^[2]
• MedlinePlus says treatment of a low may include juice or another sugary drink, food or glucose tablets, and that some people are given glucagon for severe lows; your provider should teach you which to use. ^[6]
• NIDDK advises carrying a fast-acting source of sugar, eating something when you drink alcohol and teaching family or coworkers how to use glucagon if you have it. ^[7]
• Driving: Europe and Canada ask you to take care to avoid a low while driving or using machines, especially with a sulfonylurea or insulin. ^[2][3]

Victoza® is a registered trademark of Novo Nordisk A/S. PepLabo is not affiliated with or endorsed by Novo Nordisk A/S.