nph insulin (isophane insulin suspension)

Contraindicated in:

Hypoglycemia;
Allergy or hypersensitivity to a particular type of insulin, preservatives, or other additives.

Use Cautiously in:

Stress or infection (may temporarily ↑ insulin requirements);
Renal impairment (may ↓ insulin requirements);
Hepatic impairment (may ↓ insulin requirements);
OB: Pregnancy may temporarily ↑ insulin requirements;
Lactation: Use while breastfeeding only if potential maternal benefit justifies potential risk to infant.

Adv. Reactions/Side Effects ⬆ ⬇

Endo: HYPOGLYCEMIA

F and E: hypokalemia

Local: cutaneous amyloidosis, erythema, lipodystrophy, pruritus, swelling

Misc: HYPERSENSITIVITY REACTIONS (INCLUDING ANAPHYLAXIS)

Interactions ⬆ ⬇

Drug-drug:

Beta blockers and clonidine may mask some of the signs and symptoms of hypoglycemia.
Corticosteroids, thyroid supplements, estrogens, isoniazid, niacin, phenothiazines, and rifampin may ↑ insulin requirements.
Alcohol, ACE inhibitors, MAO inhibitors, octreotide, oral hypoglycemic agents, and salicylates may ↓ insulin requirements.
Pioglitazone may ↑ risk of fluid retention and worsening HF.

Drug-Natural Products:

Glucosamine may worsen blood glucose control.
Fenugreek, chromium, and coenzyme Q-10 may produce additive hypoglycemic effects.

Availability ⬆ ⬇

Solution for injection (vials and prefilled pens): 100 units/mL

Route/Dosage ⬆ ⬇

SC (Adults and Children ): 0.5–1 unit total insulin/kg/day. Adolescents during rapid growth: 0.8–1.2 units total insulin/kg/day.

US Brand Names ⬆ ⬇

HumuLIN N, HumuLIN N KwikPen, NovoLIN N, NovoLIN N FlexPen

Action ⬆ ⬇

Lowers blood glucose by:
- stimulating glucose uptake in skeletal muscle and fat,
- inhibiting hepatic glucose production.
Other actions of insulin:
- inhibition of lipolysis and proteolysis,
- enhanced protein synthesis.

Therapeutic effects:

Control of hyperglycemia in diabetic patients.

Classifications ⬆ ⬇

Therapeutic Classification: antidiabetics, hormones

Pharmacologic Classification: pancreatics

Pharmacokinetics ⬆ ⬇

Absorption: Rapidly absorbed from SUBQ administration sites. Presence of protamine delays peak effect and prolongs action.

Distribution: Identical to endogenous insulin.

Metabolism/Excretion: Metabolized by liver, spleen, kidney, and muscle.

Half-Life: Unknown.

Time/Action Profile ⬆ ⬇

(hypoglycemic effect)

ROUTE	ONSET	PEAK	DURATION
NPH SUBQ	2–4 hr	4–10 hr	10–16 hr
70% NPH/30% regular insulin mixture	30 min	2–12 hr	24 hr

Patient/Family Teaching ⬆

Explain purpose and side effects of medication. Advise patient to read Patient Information before starting therapy.
Advise patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult health care professional before taking other medications.
Instruct patient on proper technique for administration. Include type of insulin, equipment (syringe, cartridge pens, alcohol swabs), storage, and place to discard syringes. Discuss the importance of not changing brands of insulin or syringes, selection and rotation of injection sites, and compliance with therapeutic regimen. Caution patient that insulin pens should not be shared with others, even if clean needles are used.
Demonstrate technique for mixing insulins by drawing up regular insulin or insulin lispro first and rolling intermediate-acting insulin vial between palms to mix rather than shaking (may cause inaccurate dose).
Explain to patient that this medication controls hyperglycemia but does not cure diabetes. Therapy is long term.
Instruct patient in proper testing of serum glucose and ketones. These tests should be closely monitored during periods of stress or illness and health care professional notified of significant changes.
Emphasize the importance of compliance with nutritional guidelines and regular exercise as directed by health care professional.
Advise patient to notify health care professional of medication regimen prior to treatment or surgery.
Advise patient to notify health care professional if nausea, vomiting, or fever develops; if unable to eat regular diet; or if blood glucose levels are not controlled.
Instruct patient on signs and symptoms of hypoglycemia, hyperglycemia, and hypersensitivity reactions and what to do if they occur.
Patients with diabetes mellitus should carry a source of sugar (candy, glucose gel) and identification describing their disease and treatment regimen at all times.
Rep: Advise women of reproductive potential to notify health care professional if pregnancy is planned or suspected or if breastfeeding.

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Indications ⬇

Contraind./Precautions ⬆ ⬇