Sitafit 500 Tablet

Combination of a DPP-4 inhibitor and metformin for adults with type 2 diabetes, with diet and exercise, when metformin alone is not enough or to replace separate tablets. May be combined with a sulphonylurea, insulin or a glitazone.

Adults: one tablet twice daily with meals — sitagliptin 50 mg + metformin 500 mg, 850 mg or 1,000 mg, chosen according to the current metformin dose.

Maximum: sitagliptin 100 mg + metformin 2,000 mg daily.

• Extended-release forms (50/1,000 or 100/1,000) once daily with the evening meal.
• Kidney function eGFR 30–45: sitagliptin 50 mg/day and metformin maximum 1,000 mg/day; below 30: contraindicated.
• Not for children under 18.

• Type 1 diabetes, diabetic ketoacidosis
• eGFR below 30 ml/min
• Conditions causing acidosis or low oxygen: severe infection, dehydration, shock, recent heart attack, severe heart or lung failure
• Liver failure, heavy alcohol use
• Before iodinated contrast or major surgery (stop temporarily)
• Allergy to sitagliptin or metformin

Common: nausea, diarrhoea, stomach pain, wind, metallic taste, loss of appetite, headache, nasopharyngitis.

Less common: low blood sugar (with sulphonylureas or insulin), constipation, itching.

Rare but serious: lactic acidosis (emergency), pancreatitis (severe persistent stomach pain), severe skin reactions and bullous pemphigoid, angioedema, joint pain, vitamin B12 deficiency with long use.

• Check kidney function at least yearly.
• Stop and seek help for severe persistent abdominal pain.
• Hold during dehydrating illness and before contrast scans or surgery.
• Check B12 with long-term use.

Insulin is preferred in pregnancy. Not recommended while breastfeeding.

• Iodinated contrast (stop before and 48 hours after)
• Alcohol (lactic acidosis)
• Sulphonylureas, insulin (low sugar — their doses may need lowering)
• Digoxin (slight rise with sitagliptin)
• Diuretics, NSAIDs, ACE inhibitors (kidney effects); steroids (raise sugar)
• Cimetidine, dolutegravir (raise metformin levels)

Lactic acidosis is the main danger (metformin) — emergency treatment; haemodialysis removes metformin.

Store below 30°C, dry.