Metformin

INTRODUCTION

Indications

Management of type 2 diabetes mellitus; may be used with diet, insulin, or sulfonylurea oral hypoglycemics.

Action

Decreases hepatic glucose production. Decreases intestinal glucose absorption. Increases sensitivity to insulin. Therapeutic Effects: Maintenance of blood glucose.

Adverse Reactions/Side Effects

GI: abdominal bloating, diarrhea, nausea, vomiting, unpleasant metallic taste. Endo: hypoglycemia. F and E: LACTIC ACIDOSIS. Misc: ↓ vitamins B₁ and B₂ levels.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

• Monitor signs of lactic acidosis, especially during exercise. Signs include confusion, lethargy, stupor, shallow rapid breathing, tachycardia, hypotension, nausea, and vomiting. Notify physician immediately if these signs occur.

• Be alert for signs of hypoglycemia, especially during and after exercise. Common neuromuscular signs include anxiety; restlessness; tingling in hands, feet, lips, or tongue; chills; cold sweats; confusion; difficulty in concentration; drowsiness; excessive hunger; headache; irritability; nervousness; tremor; weakness; unsteady gait. Report persistent or repeated episodes of hypoglycemia to the physician.

• Report signs of vitamin B deficiencies, including neurologic disorders (agitation, confusion, paresthesias), skin lesions (cracked, dry lips, dermatitis), and cardiovascular problems (palpitations, tachycardia). Blood tests can confirm low vitamin B levels, and vitamin or dietary supplements may be needed to resolve this problem.

• Assess blood pressure periodically (See Appendix F). A sudden or sustained increase in blood pressure (hypertension) may indicate problems in diabetes management, and should be reported to the physician.

Interventions

• Implement aerobic exercise and endurance training programs to maintain optimal body weight, improve insulin sensitivity, and reduce the risk of macrovascular disease (heart attack, stroke) and microvascular problems (reduced blood flow to tissues and organs that causes poor wound healing, neuropathy, retinopathy, and nephropathy).

• Use caution during aerobic exercise and endurance conditioning because of an increased risk of lactic acidosis. Terminate exercise if patient exhibits untoward symptoms (chest pain, shortness of breath, etc.), or displays other criteria for exercise termination (See Appendix L).

• Provide a source of oral glucose (fruit juice, glucose gels/tablets, etc.) to treat mild hypoglycemia. Call for emergency assistance if symptoms persist or in cases of severe hypoglycemia. Emergency treatment typically consists of IV glucose, glucagon, or epinephrine.

Patient/Client-Related Instruction

• Encourage patient to monitor blood glucose before and after exercise and to adjust food intake to maintain normal glycemic levels.

• Emphasize the importance of adhering to nutritional guidelines and the need for periodic assessment of glycemic control (serum glucose and glycosylated hemoglobin levels) throughout the management of diabetes mellitus.

• Advise patient about symptoms of hyperglycemia (confusion, drowsiness; flushed, dry skin; fruit-like breath odor; rapid, deep breathing, polyuria; loss of ...