insulin NPH (Humulin N, Novolin N)

Dosing and uses of Humulin N, Novolin N (insulin NPH)

• Adult
• Pediatric

 

Adult dosage forms and strengths

injectable suspension

• 100units/mL (3mL)
• 100units/mL (10mL)

 

Type 1 Diabetes Mellitus

Suggested guidelines for beginning dose

• Usual daily maintenance range is 0.5-1 unit/kg/day SC in divided doses; nonobese may require 0.4-0.6 unit/kg/day; obese may require 0.8-1.2 units/kg/day

 

Type 2 Diabetes Mellitus

Suggested guidelines for beginning dose: 0.2 unit/kg/day

Morning

• Give two thirds of daily insulin SC
• Ratio of regular insulin to NPH insulin 1:2

Evening

• Give one third of daily insulin SC
• Ratio of regular insulin to NPH insulin 1:1

 

Dosing Considerations

Dosage of human insulin, which is always expressed in USP units, must be based on the results of blood and urine glucose tests and must be carefully individualized to optimal effect

Dose adjustments should be based on regular blood glucose testing

Adjust to achieve appropriate glucose controL

Blood sugar patterns (>3 days)

• Look for consistent pattern in blood sugars for >3 days
• For the same time each day: Compare blood glucose level
• For each time of day: Calculate blood glucose range
• Calculate median blood glucose
• Consider eating and activity patterns during day

Blood glucose adjustments

• Adjust only 1 insulin dose at a time
• Correct hypoglycemia first
• Correct highest blood sugars next
• If all blood sugars are high (within 2.75 mmol/L [50 mg/dL]): Correct morning fasting blood glucose first
• Change insulin doses in small increments: Type 1 diabetes (1-2 unit change); type 2 diabetes (2-3 unit change)

Sliding scales

• Many sliding scales exist to determine exact insulin dose based on frequent blood glucose monitoring
• Commonly written for q4hr blood glucose test
• Sliding scale coverage usually begins after blood glucose >11 mmol/L (200 mg/dL)
• If coverage is needed q4hr x 24 hr, then base insulin dose is adjusted first; sliding scale doses may be adjusted upwards as well

 

Administration

Administer within 15 minutes before a meal or immediately after a meaL

 

Pediatric dosage forms and strengths

injectable suspension

• 100units/mL (3mL)
• 100units/mL (10mL)

 

Type 1 Diabetes Mellitus

<12 years: Safety and efficacy not established

>12 years: Suggested dose is 0.5-1 unit/kg/day SC; use adult dosing; usual daily maintenance range in adolescents is ≤1.2 units/kg/day during growth spurts

Dosing considerations

• Dosage of human insulin, which is always expressed in USP units, must be based on the results of blood and urine glucose tests and must be carefully individualized to optimal effect

 

Humulin N, Novolin N (insulin NPH) adverse (side) effects

Frequency not defined

Hypoglycemia

Lipodystrophy

Lipohypertrophy

Local allergic reaction

Hypokalemia

Muscle weakness

Paresthesia

Tremor

Edema

Pain

Itching

Nausea

Hunger

Numbness of mouth

 

Warnings

Contraindications

Hypoglycemia

 

Cautions

Never share pen between patients even if needle is changed

Intermediate-acting insulin; do not use for circumstances that require rapid-acting insulin

Caution with decreased insulin requirements: Diarrhea, nausea/vomiting, malabsorption, hypothyroidism, renal impairment, hepatic impairment

Hypokalemia may occur

Not for IV or IM administration

Use with caution in renal and hepatic impairment (dosage requirements may be reduced)

Caution with increased insulin requirements: Fever, hyperthyroidism, trauma, infection, surgery

Thiazolidinediones are peroxisome proliferator-activated receptor (PPAR)-gamma agonists and can cause dose-related fluid retention, particularly when used in combination with insulin; fluid retention may lead to or exacerbate heart failure; monitor for signs and symptoms of heart failure, treat accordingly, and consider discontinuing thiazolidinediones

 

Pregnancy and lactation

Pregnancy category: B

Lactation: Safe to use while breastfeeding

 

Pregnancy categories

A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

NA: Information not available.

 

Pharmacology of Humulin N, Novolin N (insulin NPH)

Mechanism of action

Regulates glucose metabolism

Insulin and its analogues lower blood glucose by stimulating peripheral glucose uptake, especially by skeletal muscle and fat, and by inhibiting hepatic glucose production; insulin inhibits lipolysis and proteolysis and enhances protein synthesis; targets include skeletal muscle, liver, and adipose tissue

Insulin NPH and insulin regular is a combination insulin product with intermediate action that has more rapid onset than that of insulin NPH alone

 

Absorption

Bioavailability (IM, SC, IP): Well absorbed

Onset: 1-1.5 hr (a combination insulin product, insulin NPH and insulin regular, also has intermediate action, but it has a more rapid onset than does insulin NPH alone); 4-12 hr peak effect

Duration: 14-24 hr

Peak plasma time: 6-10 hr

 

Distribution

Protein bound: 5% (not bound to serum binding protein, but present as a monomer in plasma)

Vd: 0.15 L/kg

 

Elimination

Excretion: Urine