Home Drug Guide Canagliflozin and Metformin Hydrochloride

Drug Guide

Generic Name

Canagliflozin and Metformin Hydrochloride

Brand Names Invokana, Vokanamet

Classification

Therapeutic: Antidiabetic agent

Pharmacological: SGLT2 inhibitor and Biguanide combination

FDA Approved Indications

  • Type 2 Diabetes Mellitus

Mechanism of Action

Canagliflozin inhibits the sodium-glucose co-transporter 2 (SGLT2) in the proximal renal tubules, reducing glucose reabsorption and increasing urinary glucose excretion. Metformin decreases hepatic glucose production, decreases intestinal absorption of glucose, and improves insulin sensitivity.

Dosage and Administration

Adult: Initial dose of canagliflozin 100-300 mg once daily; metformin dose adjusted according to renal function and tolerability, usually starting at 500 mg twice daily

Pediatric: Not approved for pediatric use

Geriatric: Start at lower doses due to renal function considerations, monitor renal function regularly

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

Hepatic Impairment: Use with caution; contraindicated in severe hepatic impairment

Pharmacokinetics

Absorption: Canagliflozin is well absorbed; food does not affect absorption

Distribution: High plasma protein binding for canagliflozin; extensive distribution for metformin

Metabolism: Canagliflozin is metabolized minimally; metformin undergoes negligible metabolism

Excretion: Renally excreted; canagliflozin 50-60% unchanged in urine, metformin 90% in urine

Half Life: Canagliflozin approximately 10.6 hours; metformin approximately 17.6 hours

Contraindications

  • Renal impairment (eGFR <30 mL/min/1.73 m²)
  • Metabolic acidosis
  • Hypersensitivity to components

Precautions

  • Risk of ketoacidosis, urinary tract infections, hypotension, dehydration, and lactic acidosis (metformin)

Adverse Reactions - Common

  • Genital mycotic infections (Common)
  • Urinary tract infections (Common)
  • Hypoglycemia when combined with insulin or insulin secretagogues (Less common)

Adverse Reactions - Serious

  • Lactic acidosis (metformin) (Rare)
  • Ketoacidosis (Rare)
  • Severe urinary tract infections or Fournier's gangrene (Rare)

Drug-Drug Interactions

  • Diuretics, ACE inhibitors, ARBs (risk of hypotension or renal function decline)
  • Other hypoglycemic agents (risk of hypoglycemia)

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor blood glucose, renal function, signs of dehydration or infections

Diagnoses:

  • Risk for hypoglycemia
  • Risk for urinary tract infection
  • Risk for lactic acidosis

Implementation: Administer with meals, monitor renal function regularly, educate patient about signs of adverse effects

Evaluation: Assess glycemic control, renal function, and patient adherence

Patient/Family Teaching

  • Take medication with food to reduce gastrointestinal side effects.
  • Maintain hydration; report symptoms of dehydration, urinary infections, or ketoacidosis.
  • Monitor blood glucose regularly.
  • Avoid excessive alcohol intake.
  • Be aware of symptoms of lactic acidosis: unusual weakness, fatigue, muscle pain, difficulty breathing.

Special Considerations

Black Box Warnings:

  • Lactic acidosis (metformin)

Genetic Factors: N/A

Lab Test Interference: May interfere with serum creatinine and blood glucose assessments

Overdose Management

Signs/Symptoms: Severe hypoglycemia, lactic acidosis, dehydration signs

Treatment: Discontinue medication, supportive care, manage hydration, and correct acidosis if present

Storage and Handling

Storage: Store at room temperature, 20-25°C, 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.