McKenna's Pharmacology, 2e

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C H A P T E R 3  Toxic effects of drugs

■■ Adverse drug effects can range from allergic reactions to tissue and cellular damage. The nurse or midwife, as the healthcare provider associated with drug administration, needs to assess each situation for potential adverse effects and intervene appropriately to minimise those effects. ■■ Adverse effects can be extensions of the primary action of a drug or secondary effects that are not necessarily desirable, but are unavoidable. ■■ Allergic reactions can occur when a person’s body makes antibodies to a drug or drug-protein complex. If the person is exposed to that drug at another time, an immune response may occur. Allergic reactions can be of various types. The exact response should be noted to avoid future confusion in care provision. ■■ Tissue damage can include skin problems, mucous membrane inflammation, blood dyscrasia, superinfections, liver or renal toxicity, poisoning, hypoglycaemia or hyperglycaemia, electrolyte disturbances, various central nervous system problems (ocular damage, auditory damage, atropine- like effects, Parkinson-like syndrome, neuroleptic malignant syndrome) and teratogenicity.

■■ BOX 3.1  Summary of adverse drug effects

• Alterations in glucose metabolism Hypoglycaemia Hyperglycaemia • Electrolyte imbalances

• Extension of primary action • Occurrence of secondary action • Allergic reactions Anaphylactic reactions Cytotoxic reactions Serum sickness reactions Delayed allergic reactions • Tissue and organ damage Dermatological reactions Stomatitis

Hypokalaemia Hyperkalaemia • Sensory effects Ocular toxicity

Auditory damage • Neurological effects General CNS effects Atropine-like (anticholinergic) effects Parkinson-like syndrome Neuroleptic malignant syndrome (NMS) • Teratogenicity • Iatrogenicity

Superinfections Blood dyscrasia

• Toxicity

Liver injury Renal injury Poisoning

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against the potential risks. All pregnant women should be advised not to self-medicate during the pregnancy. Emotional and physical support is needed to assist the woman in dealing with the possibility of fetal death or birth defects. Box 3.1 summarises all of the adverse effects that have been described throughout this chapter. Iatrogenicity The terms iatrogenesis and iatrogenic artifact refer to inadvertent adverse effects or complications caused by, or as a result of, medical treatment or advice. In addition to harmful consequences of actions by doctors, iatrogenesis can also refer to actions by other health­ care professionals, such as psychologists, therapists, pharmacists, nurses, dentists, midwives and others. Iatrogenesis is not restricted to conventional medicine, as iatrogenesis can also result from complementary and alternative medicine treatments. Causes of iatrogenesis include chance, medical error, negligence, social control, anxiety or annoyance related to medical procedures, and the adverse effects or interactions of medications.

ONLINE RESOURCES

An extensive range of additional resources to enhance teaching and learning and to facilitate understanding of this chapter may be found online at the text’s accompanying website, located on thePoint at http://thepoint.lww.com. These include Watch and Learn videos, Concepts in Action animations, journal articles, review questions, case studies, discussion topics and quizzes.

WEBLINKS

Healthcare providers and students may want to consult the following Internet source: www.who.int/patientsafety/events/05/Reporting_ Guidelines.pdf World Health Organization (2005) World Alliance for Patient Safety—WHO Draft Guidelines for Adverse Event Reporting and Learning Systems—from information to action. BIBLIOGRAPHY Dempsey, J., Hillege, S. & Hill, R. (2014). Fundamentals of Nursing and Midwifery: A Person-centred Approach to Care (2nd Australian and New Zealand edn). Sydney: Lippincott Williams & Wilkins.

CHAPTER SUMMARY

■■ No drug does only what is desired of it. All drugs have adverse effects associated with them.