Meliglix (Sitagliptin)

Sitagliptin, marketed as Meliglix, acts on the incretin pathway to improve blood glucose regulation in type 2 diabetes.

• Type 2 diabetes mellitus: improves glycaemic control as monotherapy or in combination with other antidiabetic agents.
• Adjunct to diet and exercise: enhances the effect of lifestyle modifications on glucose levels.
• Combination with metformin: provides additional HbA1c reduction when used together.

• Sitagliptin selectively inhibits the enzyme dipeptidyl peptidase‑4 (DPP‑4), which degrades the incretin hormones GLP‑1 and GIP. By blocking DPP‑4, sitagliptin increases circulating levels of these hormones, leading to glucose‑dependent stimulation of insulin secretion and suppression of glucagon release, thereby lowering post‑prandial and fasting blood glucose concentrations. This effect occurs only when blood glucose is elevated, minimizing risk of hypoglycaemia, making it suitable for many patients.

Sitagliptin may be associated with several adverse reactions, which are categorized by frequency.

Common Side Effects

• Nausea: mild to moderate stomach upset.
• Headache: transient cranial discomfort.
• Nasopharyngitis: inflammation of the nasal passages and throat.
• Diarrhoea: loose stools, usually self‑limiting.

Serious or Rare Side Effects

• Pancreatitis: severe abdominal pain with elevated enzymes.
• Severe allergic reactions: rash, angioedema, or anaphylaxis.
• Joint pain: unexplained arthralgia that may be disabling.
• Stevens‑Johnson syndrome: rare but life‑threatening skin eruption.

When prescribing sitagliptin, clinicians should consider several precautionary measures to ensure patient safety.

• Renal impairment: assess kidney function and adjust dose or avoid use in severe cases.
• Hepatic impairment: use with caution and monitor liver enzymes.
• History of pancreatitis: avoid sitagliptin due to risk of recurrence.
• Elderly patients: monitor for hypoglycaemia, especially when combined with insulin or sulfonylureas.
• Concomitant medications: review for potential drug interactions before initiating therapy.
• Store at ambient temperature: keep below 25 °C in the original packaging, protected from moisture.

Sitagliptin can interact with other medicines, requiring attention to avoid reduced efficacy or increased toxicity.

Major Interactions (Avoid)

• Insulin or sulfonylureas: combined use may cause significant hypoglycaemia; avoid unless closely supervised.
• Strong CYP3A4 inhibitors (e.g., ketoconazole, clarithromycin): may increase sitagliptin plasma levels and risk of adverse effects.

Moderate Interactions (Monitor Closely)

• Rifampin: induces metabolism and may lower sitagliptin exposure, reducing effectiveness.
• ACE inhibitors or ARBs: monitor renal function and potassium levels when used together.
• Diuretics: observe for changes in blood glucose and electrolytes.