McKenna's Pharmacology for Nursing, 2e

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P A R T 8  Drugs acting on the cardiovascular system

AGENTS USED FOR IRON-DEFICIENCY ANAEMIA Although most people get all of the iron they need through diet, in some situations diet alone may not be adequate. The iron preparations that are available include ferrous fumarate ( Ferro-F-tab ), ferrous sulfate ( Fefol, Ferro-Gradumet ), iron polymaltose ( Ferrosig, Ferrum H ), iron sucrose ( Venofer ) and ferric pyrophos- phate ( Accomin, Incremin Iron [not available in New Zealand]). See also Table 49.2 Therapeutic actions and indications Iron preparations elevate the serum iron concentra- tion (see Figure 49.2). They are then either converted Z-track injections The Z-track method is used when injecting iron to reduce the risk of subcutaneous staining and irritation. It is a good idea to review the method of giving Z-track injections before giving one. The area to be injected is prepped for the injection. Place your gloved finger on the skin surface and pull the skin and the subcutaneous layers out of alignment with the muscle lying beneath. Try to move the skin about 1 cm. Insert the needle at a 90-degree angle at the point where you originally placed your finger. Inject the drug and then withdraw the needle. Remove your finger from the skin, which will allow the layers to slide back into their normal position. The track that the needle made when inserting into the muscle is now broken by the layers, and the drug is trapped in the muscle (see Figure 49.4). Safe medication administration

Cultural considerations

BOX 49.2

Haematological laboratory test variations There are racial variations in haematological laboratory test results: Haemoglobin/haematocrit —Levels in African Americans are generally 1 g lower than in other groups. Serum transferrin levels (children aged 1–3.5 years)—The mean value for African American children is 22 mg/100 mL higher than that for Caucasian children. (This may be because African Americans have lower haematocrit and haemoglobin; transferrin levels increase normally in the presence of anaemia.) Because of these variations, the diagnosis and treatment of anaemia in African Americans should be based on a different norm to that of other ethnic groups.

KEY POINTS

■■ Erythropoiesis-stimulating drugs are used to act like erythropoietin and stimulate the bone marrow to produce more RBCs. ■■ These drugs must be given IV or by subcutaneous injection. Individuals must have an adequate supply of the other components of RBCs, including iron, for these drugs to be effective. ■■ Erythropoiesis-stimulating drugs should be used with a target haemoglobin level of no more than 12 g/dL. Higher levels are associated with an increased risk of cardiovascular events and increased tumour growth in people with cancer.

TABLE 49.2

DRUGS IN FOCUS Agents used for iron-deficiency anaemia

Drug name

Dosage/route

Usual indications

ferric pyrophosphate (Accomin, Incremin Iron)

Adult 10 mL/day PO Paediatric >2 years: 5 mL/day PO Paediatric <2 years: 2.5 mL/day PO

Treatment of iron-deficiency anaemia and for people with Helicobacter pylori overgrowth Treatment of iron-deficiency anaemia

ferrous fumarate (Ferro-tab)

1 tab/day PO before food

325 mg/day PO Children 2–12 years: 50–100 mg/day PO Children 6 months–2 years: 6 mg/kg per day PO Infants: 10–25 mg/day PO 2 mL IM alternate days, using Z-track technique 100 mg one to three times per week given IV during dialysis sessions, slowly over 1 minute

Treatment of iron-deficiency anaemia

ferrous sulfate (Ferro-Gradumet)

iron polymaltose complex (Ferrosig, Ferrum H)

Treatment of iron-deficiency anaemia (parenteral) Treatment of iron deficiency in people undergoing chronic haemodialysis or non-dialysis people with renal failure who are also receiving supplemental erythropoietin therapy

iron sucrose (Venofer)