Sitagliptin

What is sitagliptin?

Sitagliptin is a prescription-only oral medicine used to help manage type 2 diabetes mellitus. It belongs to a class of medications called DPP-4 inhibitors (dipeptidyl peptidase-4 inhibitors). Sitagliptin helps regulate blood sugar levels and is commonly sold under the brand name Januvia, though generic versions are also available[1]. 

What is sitagliptin used for?

Sitagliptin is prescribed to[1]: 

• Lower blood sugar levels in adults with type 2 diabetes 

• Improve blood sugar control when used alone or with other diabetes medicines such as metformin, sulphonylureas, thiazolidinediones (glitazones), or insulin 

How does sitagliptin work?

Sitagliptin works by[1]: 

• Increasing the amount of insulin released after meals 

• Reducing the amount of glucose produced by the liver. It achieves this by blocking the DPP-4 enzyme, which normally breaks down incretin hormones. These hormones help regulate blood sugar in response to meals. 

Who can take sitagliptin?

Sitagliptin is suitable for most adults with type 2 diabetes. It is not recommended for people with type 1 diabetes or diabetic ketoacidosis. Speak to your doctor first if you[1]: 

• Have severe kidney problems (dose adjustments may be required) 

• Are under 18 (not approved for use in this age group) 

• Are a heavy drinker or are dependent on alcohol 

• Are pregnant, trying to get pregnant, or breastfeeding 

• Have gallstones or high levels of triglycerides in your blood 

• Have had pancreatitis, bullous pemphigoid, or allergic reactions to sitagliptin 

Please tell your doctor or pharmacist about any conditions you may have or medication you take before you start treatment, and always follow the instructions in the Patient Information Leaflet[2]. 

What is the typical dosage of sitagliptin?

 Sitagliptin tablets (25 mg, 50 mg, 100 mg) are dosed based on kidney function: 100 mg once daily (normal kidney function, eGFR ≥50 mL/min), 50 mg once daily (moderate kidney impairment, eGFR 30–<50 mL/min), 25 mg once daily (severe kidney impairment, eGFR <30 mL/min). Always follow your doctor’s or pharmacist’s instructions. 

How do you take sitagliptin?

Take once a day, at the same time each day. It can be taken with or without food – swallow the tablet whole with water[1]. 

Can you stop taking sitagliptin?

Do not stop taking sitagliptin without speaking to your doctor or pharmacist. Stopping suddenly may cause your blood sugar to rise, increasing the risk of diabetes complications[1]. 

What do you do if you take too much sitagliptin?

If you take more than prescribed: Contact your doctor or pharmacist immediately. Overdose may cause mild symptoms like nausea or, rarely, low blood sugar if combined with other diabetes medicines. 

What do you do if you forget to take sitagliptin

If you forget to take your dose[1]: 

• Take it as soon as you remember 

• If it’s nearly time for your next dose, skip the missed one 

• Do not take two doses at once 

What medicines can’t you take with sitagliptin?

Caution is needed with some medications, including[1]: 

• Digoxin – your doctor may monitor levels 

• Other diabetes medicines – may increase the risk of hypoglycaemia 

• Fungal medicines like ketoconazole or itraconazole 

• Ritonavir for HIV and AIDS 

• Antibiotics like clarithromycin 

Always inform your doctor or pharmacist about all medications and supplements you take before you start a new medicine, and follow the instructions in the Patient Information Leaflet[2]. 

What are the side effects of sitagliptin?

The most common side effects include[1]: 

• Headache 

• Upper respiratory tract infections 

• Stomach pain 

• Nausea 

• Hypoglycaemia (or hypos) - not often, but can occur if taken with other diabetes medicines 

Serious but rare side effects[1]: 

• Pancreatitis (seek immediate help if you have severe stomach pain) 

• Bullous pemphigoid (a blistering skin condition) 

• Allergic reactions (rash, itching, swelling, or breathing difficulties) 

You should contact your GP if you experience any of these symptoms. In rare cases, the medicine may cause a serious allergic reaction (anaphylaxis). You should call 999 or visit A&E immediately if you believe this is happening[1]. 

Symptoms of anaphylaxis include[1]:  

• Difficulty breathing  

• Tightness in throat and chest  

• Swelling of the tongue or throat  

• Feeling faint or dizzy  

• Blue/grey skin or lips  

• Loss of consciousness 

If you experience any side effects, including those not listed, you are encouraged to report them via the Yellow Card Scheme or contact your doctor, pharmacist, or nurse. This information is intended as a summary for general awareness and does not replace professional medical advice. 

The information provided in the side effects section is not a comprehensive list of all possible side effects associated with this medication. For a complete list of side effects, please refer to the Patient Information Leaflet (PIL) provided with your medication or consult your healthcare professional[2]. 

Frequently asked questions about sitagliptin

Can sitagliptin cause low blood sugar or hypoglycaemia? 
It’s unlikely on its own, but possible when combined with other diabetes medications[1]. 

Can I drink alcohol while taking sitagliptin? 
Alcohol can affect blood sugar, so consult your doctor before drinking[1]. 

How long will I need to take sitagliptin? 
Usually long-term, depending on your blood sugar control and how you respond[1]. 

For the official NHS guide to sitagliptin, visit their website.