Home Drug Guide Metformin Hydrochloride and Sitagliptin Phosphate

Drug Guide

Generic Name

Metformin Hydrochloride and Sitagliptin Phosphate

Brand Names Jentadueto, Janumet

Classification

Therapeutic: Antidiabetic agent

Pharmacological: Combination of biguanide and DPP-4 inhibitor

FDA Approved Indications

  • Type 2 diabetes mellitus, to improve glycemic control

Mechanism of Action

Metformin decreases hepatic glucose production and increases insulin sensitivity; Sitagliptin inhibits DPP-4 enzyme, increasing incretin levels, which increase insulin synthesis and release, and decrease glucagon secretion.

Dosage and Administration

Adult: Typically one tablet twice daily with meals, dosage varies based on patient response

Pediatric: Not approved for pediatric use

Geriatric: Start with lower doses considering reduced renal function

Renal Impairment: Adjust dose based on renal function, contraindicated if eGFR below 30 mL/min/1.73 m²

Hepatic Impairment: Use with caution, contraindicated in severe hepatic disease

Pharmacokinetics

Absorption: Well absorbed, peak plasma levels in 1-4 hours

Distribution: Widely distributed, low protein binding

Metabolism: Metformin not metabolized; Sitagliptin minimally metabolized

Excretion: Renal excretion primarily for both drugs

Half Life: Metformin ~17.6 hours, Sitagliptin ~12.4 hours

Contraindications

  • Renal impairment (eGFR <30 mL/min/1.73 m²)
  • Severe hepatic impairment
  • Acute or chronic metabolic acidosis

Precautions

  • Use with caution in elderly, dehydration, infections, or surgery

Adverse Reactions - Common

  • Gastrointestinal disturbances (nausea, diarrhea) (Common)
  • Upper respiratory tract infection (Common)

Adverse Reactions - Serious

  • Lactic acidosis (Rare but serious)
  • Pancreatitis (Rare)

Drug-Drug Interactions

  • Cationic drugs that affect renal function (e.g., diuretics, NSAIDs)

Drug-Food Interactions

N/A

Drug-Herb Interactions

  • St. John’s Wort (may decrease efficacy)

Nursing Implications

Assessment: Monitor renal function, blood glucose levels, and signs of hypoglycemia or lactic acidosis

Diagnoses:

  • Risk for hypoglycemia
  • Risk for lactic acidosis

Implementation: Administer with meals to reduce gastrointestinal side effects

Evaluation: Assess blood sugar control and renal function periodically

Patient/Family Teaching

  • Take medication with meals to reduce gastrointestinal upset
  • Inform provider of any signs of lactic acidosis (muscle pain, abnormal fatigue, hyperventilation)
  • Maintain hydration

Special Considerations

Black Box Warnings:

  • Lactic acidosis risk

Genetic Factors: None specific

Lab Test Interference: None

Overdose Management

Signs/Symptoms: Severe hypoglycemia or lactic acidosis

Treatment: Supportive care, hemodialysis in severe cases, discontinue medication immediately

Storage and Handling

Storage: Store at room temperature, away from moisture and light

Stability: Stable under recommended storage conditions

🛡️ 5 Critical Medication Safety Tips for Nurses

1

Triple-Check High-Risk Medications

Always have another nurse verify insulin, heparin, warfarin, and chemotherapy drugs. These "high-alert" medications cause the most serious errors. Check concentration, dose calculation, and pump settings twice.

2

Know Look-Alike, Sound-Alike Drugs

Common mix-ups: hydromorphone/morphine, Celebrex/Celexa, Zyprexa/Zyrtec. Always use BOTH generic and brand names, read labels twice, and use barcode scanning when available. One wrong letter can be fatal.

3

Assess Before AND After Giving Meds

Check vitals before cardiac meds, pain levels before analgesics, and blood glucose before insulin. Always reassess within 30 minutes to evaluate effectiveness and watch for adverse reactions.

4

Watch for Drug Interactions

Common dangerous combinations: warfarin + aspirin (bleeding), ACE inhibitors + potassium (hyperkalemia), digoxin + diuretics (toxicity). Always check drug interactions before administering new medications.

5

Educate Your Patients

Teach patients medication names, purposes, major side effects, and what to report. Informed patients catch errors and improve compliance. Always encourage questions - an educated patient is a safer patient.

⚡ Remember: When in doubt, don't give it out! It's always safer to double-check than regret later.

⚠️ Medical Disclaimer

This drug guide is for educational purposes only and is NOT intended for clinical use. Always consult current prescribing information, healthcare providers, and institutional protocols before administering any medication. Do not use this information for patient care decisions.