Contraindications are classified into two broad types. An absolute contraindication means the intervention must not be administered under any circumstances , the risk of serious adverse outcome is considered unacceptable regardless of the clinical context. A relative contraindication signals that the intervention may still be considered, but only after careful individual assessment, because the risk is elevated compared with the general population. The distinction carries direct prescribing and dispensing consequences under Australian law.
In the Australian regulatory framework, contraindication information is a mandatory component of a product's approved Product Information (PI) document, as required by the Therapeutic Goods Administration (TGA) under the Therapeutic Goods Act 1989 (Cth). Sponsors must provide evidence supporting each stated contraindication at the time of registration on the Australian Register of Therapeutic Goods (ARTG). For Schedule 4 (prescription only) and Schedule 8 (controlled drug) substances listed in the Poisons Standard, prescribers are legally and professionally obliged to screen for contraindications before supply.
Contraindications relevant to plant-based medicines, cannabinoids, and peptides are an active area of pharmacological research. For example, published literature has examined potential contraindications relating to cytochrome P450 enzyme interactions with certain phytochemicals, and the TGA's guidance on medicinal cannabis products specifically addresses contraindication disclosure within approved PI documents. Research findings in this space carry the standard limitations of emerging evidence: many studies are small, short in duration, or conducted in populations that may not represent all clinical groups.
The term derives from the Latin contra (against) and indicare (to indicate or point out). It entered clinical usage in English medical literature from at least the seventeenth century and remains a standard term across pharmacopoeia, regulatory documentation, and clinical guidelines worldwide.
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