A MAN ended up in hospital after weight loss jabs seemingly sent his metabolism into overdrive.
The obese 62-year-old, who had type 1 diabetes, shed 5.7st (36kg) in less than six months while taking tirzepatide – sold under the brand name Mounjaro.
But he soon began experiencing heart palpitations, excessive sweating, a fever, confusion and hand tremors, so took himself to A&E.
Tests revealed the patient had developed atrial fibrillation – an irregular and often rapid heartbeat sometimes described as a ‘silent killer’ as it does not always have symptoms and can be fatal.
Doctors also discovered he had thyrotoxicosis – when the thyroid gland produces excess hormones.
This can have life-threatening consequences, the NHS warns.
Writing in the medical journal JAMA Internal Medicine, doctors called for anyone taking tirzepatide or other slimming jabs to be monitored more closely to prevent “adverse events”.
They said: “We recommend evaluating patients using tirzepatide closely (every four to six weeks initially) for assessment of therapy response, adverse events, and possible dose adjustment of other concomitant medications.”
The patient, who has not been named, initially weighed 20.8st (132kg) and had a BMI of 44.4 – putting him in the obese category.
He was prescribed 2.5mg of tirzepatide per week for obesity, as well as 200-μg of levothyroxine daily and insulin injections to control his hypothyroidism and diabetes.
Doctors suggested he increase his tirzepatide dose every four weeks as tolerated, and to return to the clinic for a follow-up.
The man missed his appointment due to living seasonally in different states, but still upped his dose to 10mg a week.
When he started suffering symptoms, his BMI had dropped to 31.2 – still considered obese – and he had lost 5.7st (36kg).
“After further investigation, the origin of atrial fibrillation was determined to be thyrotoxicosis in the context of rapid weight loss from tirzepatide,” doctors said.
Tirzepatide, made by Eli Lilly, is a drug that works on two different hormonal receptors – glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP).
It works by helping people feel full for longer and slowing how quickly food moves through their digestive systems.
Weight loss jabs are a hot media topic at the moment, with hundreds of success stories from people who shed the pounds.
In March 2023, the NHS announced it would make Wegovy, a drug made by Danish firm Novo Nordisk, available on prescription to thousands of obese Brits.
It contains the drug semaglutide, which is said to have helped reality star Kim Kardashian and Twitter boss Elon Musk lose weight.
Wegovy, which helped a third of people reduce their weight by 20 per cent in trials, is now available from pharmacies like Boots.
How do they work?
The jabs work by suppressing your appetite, making you eat less and therefore lose weight.
To do this, semaglutide mimics the role of a natural hormone, called GLP-1.
GLP-1 is part of the signalling pathway that tells your body you have eaten, and prepares it to use the energy that comes from your food.
London GP and founder of wellgoodwellbeing.com, Dr Zoe Watson, said: “Your body naturally produces an appetite regulating hormone called glucagon-like peptide-1.
“These jabs work by regulating your appetite, which can lead to eating fewer calories and losing weight.”
Aren’t they diabetes drugs?
Semaglutide, the active drug in Wegovy, was originally sold under the name Ozempic specifically for diabetes patients.
But people started noticing it helped suppress their appetites, stopping them eating as much and helping them shed the pounds.
Novo Nordisk then developed Wegovy, which contains the same chemical but at higher doses specifically to aid weight loss.
Wegovy is not prescribed for diabetes patients.
Can I get them?
Wegovy is offered on prescription to obese adults given specialist weight loss treatment.
The NHS currently also offers a similar drug called Saxenda, or liraglutide.
Both are only available on Tier 3 and Tier 4 weight management services, which means you have to be referred to weight management clinics led by experts.
GPs can’t prescribe them on their own either, Dr Watson said.
The jabs have to be taken as part of an overall programme to help with lifestyle changes and psychological support to get the best effect from the medication prescribed.
Despite being approved for use, supply of Wegovy on the NHS has been postponed indefinitely because of a surge in worldwide demand.
Supply was also halved in the US because of the skyrocketing demand.
Are there any risks?
Like all medicines, the jabs do not come without side effects.
Around half of people taking the drug experience gut issues, including sickness, bloating, acid reflux, constipation and diarrhoea.
Dr Sarah Jarvis, GP and clinical consultant at patient.info, said: “One of the more uncommon side effects is severe acute pancreatitis, which is extremely painful and happens to one in 500 people.”
Other uncommon side effects include altered taste, kidney problems, allergic reactions, thyroid tumours, gallbladder problems and hypoglycemia.
What other options are there?
Mounjaro (brand name for tirzepatide) also came onto the market in early 2024.
Like Wegovy, tirzepatide stems from a drug originally designed to treat diabetes.
The weekly injection helped overweight people drop more than two stone in 18 months.
It is available with to order with a prescription online from pharmacies including Superdrug and LloydsPharmacy Online Doctor.
It works in a similar way to Wegovy and Saxenda, but is more effective.
Dr Mitra Dutt from LloydsPharmacy says: “Based on clinical trials, 96 per cent of people were able to lose more than five per cent of their body fat using Mounjaro. In similar trials, 84 per cent of people lost more than five per cent of their body weight on Wegovy, and 60 per cent on Saxenda.
“Mounjaro works by activating two hormonal receptors (GIP and GLP-1), which enhance insulin production, improve insulin sensitivity, and work to decrease food intake.”
Tirzepatide is similar to celebrity-endorsed Ozempic and Wegovy, which have been hailed as “miracle” off-label weight loss drugs.
Research shows overweight people dropped more than two stone in 18 months when on the drug.
Patients managed to shave off an average of 15.7 per cent of their body weight in 72 weeks.
It was five times as much as the three per cent among those just trying diet and exercise.
Tirzepatide is available in the UK to treat type 2 diabetes and obesity, but patients need to meet certain criteria.
While effective for many people, there is a dark side to these drugs.
UK health chiefs are investigating 20 deaths reported as potentially linked to the injections, and the curiosity to try the ‘quick fix‘ has driven some to turn to the black market for skinny jabs, which can leave people seriously unwell.
They also come with a long list of potential side effects, including nausea, diarrhoea, constipation, headaches, dizziness, vomiting, abdominal pain, fatigue, flatulence and acid reflux.
