McKenna's Pharmacology for Nursing, 2e

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P A R T 8  Drugs acting on the cardiovascular system

directly onto any active bleeding site. These are not yet available in Australia and New Zealand. Thrombin, which is derived from bovine sources, is a solution that is applied topically and mixed in with the blood. Thrombin recombinant is also a solution and is applied directly to the bleeding site surface in conjunc­ tion with absorbable gelatin sponge; the amount needed varies with the area of tissue to be treated. Aminocaproic acid is contraindicated in the presence of allergy to the drug to prevent hypersensitivity reac- tions and with acute DIC because of the risk of tissue necrosis. Caution should be used in cardiac disease because of the risk of arrhythmias and in renal and hepatic dysfunction, which could alter the excretion of this drug and the normal clotting processes. Although the safety for use of this drug during pregnancy has not been established, it should be used only if the benefits to the mother clearly outweigh the potential risks to the neonate because of the potential for adverse effects on the fetus. It is recommended that nursing mothers use a different method for feeding the baby if this drug is used because of the potential for adverse effects on the baby. Topical haemostatic agents Use thrombin with caution for those people with an allergy to bovine products. Because thrombin comes from animal sources, it may precipitate an allergic response; the person needs to be carefully monitored for such a reaction . Many of the potential allergic reac­ tions associated with bovine thrombin will be decreased as a result of approval for thrombin recombinant to be made using recombinant DNA technology. Safety for use of thrombin recombinant in children has not been established. The most common adverse effect associated with systemic haemostatic agents is excessive clotting. In 2007, there were many reports of increased cardiovas­ cular events, including fatalities in people who received aprotinin. Some of the events occurred months after the drug was used. The drug was removed from the market in 2008. CNS effects of aminocaproic acid can include hallucinations, drowsiness, dizziness, headache and psy­ chotic states, all of which could be related to changes in cerebral blood flow associated with changes in clot dissolution. GI effects, including nausea, cramps and diarrhoea, may be related to excessive clotting in the GI tract, causing reflex GI stimulation. Weakness, fatigue, malaise and muscle pain can occur as small clots build Contraindications and cautions Systemic haemostatic agents Adverse effects Systemic haemostatic agents

up in muscles. Intrarenal obstruction and renal dysfunc­ tion have also been reported. Topical haemostatic agents Use of absorbable gelatin and microfibrillar collagen can pose a risk of infection because bacteria can become trapped in the vascular area when the sponge is applied. Immediate removal of the sponge and cleaning of the area can help to decrease this risk. Clinically important drug–drug interactions Systemic haemostatic agents Aminocaproic acid is associated with the develop­ ment of hypercoagulation states if it is combined with oral contraceptives or oestrogens. The risk of bleeding increases if it is given with heparin. Topical haemostatic agents There are no reported drug–drug interactions with the topically applied haemostatic agents.

Care considerations for people receiving systemic haemostatic

Care considerations for a person receiving topical haemostatic agents are similar to those with the use

of any topical drug (see Appendix C). Assessment: History and examination

■ ■ Assess for the following conditions, which could be cautions or contraindications to the use of systemic haemostatic agents : any known allergies to any component of the drug to prevent hypersensitivity reactions ; acute DIC because of the risk of tissue necrosis ; renal and hepatic dysfunction, which could alter the excretion of these drugs and the normal clotting processes ; and breastfeeding because of the potential for adverse effects on the neonate. ■ ■ Assess baseline status before beginning therapy to determine any potential adverse effects. Assess the following: body temperature; skin colour, lesions and temperature; affect, orientation and reflexes; pulse, blood pressure and perfusion; respirations and adventitious sounds; bowel sounds and normal output; urinalysis and clotting studies; and renal and hepatic function tests. Implementation with rationale ■ ■ Monitor clinical response and clotting factor levels regularly to arrange to adjust dose as needed. ■ ■ Monitor the person for any sign of thrombosis to arrange to use comfort and support measures