McKenna's Pharmacology, 2e

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P A R T 1  Introduction to nursing pharmacology

the lack of a cure. All literature associated with these drugs indicates that long-term effects and other infor- mation about the drug may not yet be known. In addition to the drug lag issue, there also are concerns about the high cost of drug approval. In 2011, Morgan et al. published a systematic review on the costs of drug development. These authors found that the estimated cost of taking a chemical from discovery to marketing as a drug could be as high as $US 1.8 billion. Because of this kind of financial investment, pharmaceu- tical companies are unwilling to risk approval of a drug that might cause serious problems and prompt lawsuits. Phase IV studies After a drug is approved for marketing, it enters a phase of continual evaluation, or phase IV study . Prescribers are obligated to report to the TGA any untoward or unexpected adverse effects associated with drugs they are using, and the TGA continually evaluates this infor- mation. Some drugs cause unexpected effects that are not seen until wide distribution occurs. Sometimes, those effects are therapeutic. For example, individuals taking the antiparkinsonism drug amantadine ( Symmetrel ) were found to have fewer cases of influenza than other people, leading to the discovery that amantadine is an effective antiviral agent. In other instances, the unexpected effects are danger- ous. In 1997, the diet drug dexfenfluramine ( Ponderax ) was removed from the market only months after its release because people taking it developed serious heart problems. In 2004, the drug company Merck withdrew its cyclooxygenase-2 (Cox-2) specific non-steroidal anti-inflammatory drug rofecoxib ( Vioxx ) from the market when post-marketing studies seemed to show a significant increase in cardiovascular mortality in indi- viduals who were taking the drug. These problems were not seen in any of the premarketing studies of the drug. The effects were only seen with a much wider use of the drug after it had been marketed. ■■ The TGA carefully regulates the testing and approval of all drugs in Australia. ■■ To be approved for marketing, a drug must pass through animal testing, testing on healthy humans, selective testing on people with the disease being treated and then broad testing on people with the disease being treated. LEGAL REGULATION OF DRUGS The Therapeutic Goods Administration (TGA), a division of the Commonwealth Department of Health KEY POINTS KEY POINTS

and Ageing, is responsible for administering the provi- sions of the Therapeutic Goods Act 1989 in Australia that regulates the manufacture, availability and supply of drugs. Each state and territory also has Acts and Regulations that deal with control and administration of drugs. In most cases, the strictest law is the one that prevails. Nurses and midwives should become familiar with the rules and regulations in the area in which they practise. They have a professional responsibility to be informed of the legislation underpinning administration and supply of drugs. MEDSAFE is New Zealand’s Medicines and Medical Devices Safety Authority. MEDSAFE is a business unit of the Ministry of Health (Acts and Regu­ lations; Medicine Management) and is the authority responsible for the regulation of therapeutic products in New Zealand. This includes medicines, related products, herbal medicines, medical devices, controlled drugs used as medicines, etc. through the Medicines Act 1981 and Regulations 1984, and parts of the Misuse of Drugs Act 1975 and Regulations 1977. The overall objective of these Acts is to ensure the quality, safety and efficacy of therapeutic goods, including medicines and medical devices, available to the Australian and New Zealand public. The Australian and New Zealand Governments are currently working to harmonise the regulatory arrange- ments for therapeutic products between both countries. Both governments signed a Treaty in Wellington in December 2003 to establish a single, bi-national agency to regulate therapeutic products, including medical devices and prescription medicines, and over-the- counter, complementary and alternative medicines. Transition to the new agency, Australia New Zealand Therapeutic Products Agency (ANZTPA) is underway. This agency will eventually replace the Australian TGA and the New Zealand MEDSAFE, will be accounta- ble to both Australian and New Zealand Governments and will have a fully functional office in both countries. Under the joint Australia–New Zealand therapeutic products agency (the joint agency), products represented as being for therapeutic use are to be regulated as thera- peutic products. This includes complementary medicines such as herbal, vitamin and mineral supplements, other nutritional supplements, traditional medicines and aromatherapy oils. Table 1.4 provides a summary of Aus- tralian and New Zealand legislation around medications. Safety during pregnancy As part of the standards for testing and safety, the TGA requires that each new drug be assigned to a pregnancy category (Box 1.1). The categories indicate a drug’s potential or actual teratogenic effects, thus offering guidelines for use of that particular drug in pregnancy. Research into the development of the human fetus,