01What the pharmacology section is for
In product information material, the pharmacology section explains why the drug works. Drawing on clinical pharmacology studies and non-clinical studies, it sets out the pharmacological actions and the mechanism of action that support the approved indication. Order matters here. The pharmacological claim does not come first; the observed study results come first, and the text then explains how those results support the approved indication. Reverse that order and you are left with a persuasive story of "it seems to work" with no data underneath it.
As the foreword establishes, a Product Information Summary complements the (electronic) package insert and must never contradict it. The pharmacology section answers to the same spirit. Write the pharmacology that grounded the approval, within the range that was actually observed, without exaggeration and without inviting misreading. That is the destination.
Pharmacology is not "advertising the indication"; it is "the scientific explanation of the indication." The readers are healthcare professionals, and what they need is the pharmacological reasoning by which one can judge that this drug works for this disease.
02Clinical and non-clinical — two sources, two sets of rules
The evidence for pharmacology falls into two broad streams: results obtained in humans from clinical pharmacology studies, and results obtained in animals or in vitro from non-clinical studies. Because their evidentiary weight differs, the rules for presenting them differ too.
When clinical pharmacology goes in the clinical results section
Clinical pharmacology results may, where appropriate, be placed in sections such as clinical results. But a condition attaches: the wording must not become an emphasis on safety. You may not borrow the pharmacology discussion to plant, ahead of time, an impression such as "few adverse reactions." Safety belongs in the safety section, shown fairly and including unfavourable information, and pharmacology must not become a back door for safety appeals.
Non-clinical must be flagged as "not about humans"
When non-clinical results are presented, always state the animal species used, as "(animal species)," or for an in vitro system, as "(in vitro)." The reason is simple: an action observed in animals or in vitro does not, on its own, guarantee efficacy or safety in humans. Different species have different metabolism and different receptors. The notation is honesty toward the reader and a brake on over-interpretation. Using non-clinical data to emphasise or guarantee human efficacy or safety is not permitted.
| Category | Required notation | Line not to cross |
|---|---|---|
| Clinical pharmacology | Population (healthy/patients, sex, adult/child) | Do not divert into a safety emphasis |
| Non-clinical (animal) | "(animal species)" | Does not guarantee human efficacy/safety |
| Non-clinical (test tube) | "(in vitro)" | Same as above |
| Overseas data | "(overseas data)" | Do not conflate with the domestic approval basis |
03Population and overseas data — whose results, obtained where
"It worked" means different things in a healthy volunteer and in a patient. So when stating clinical pharmacology, specify the population: healthy persons or patients, sex, adult or paediatric. The reader uses that classification to judge whether it applies to the patient in front of them. Omit the classification and you make the scope look broader than it is.
Results obtained abroad carry the note "(overseas data)." Differences in ethnicity and medical setting can change how a result should be read, and above all the data must not be mistaken for the very basis of domestic approval. Showing the origin does not demote the data; it hands the reader the material needed to weight it correctly.
04The discipline of comparison — facts only, on equal terms
Nothing in pharmacology invites misreading more easily than comparison. Comparison is powerfully persuasive, and mishandled it becomes an implied claim of superiority. Several clear fences stand here.
Comparison with a control: facts only
If results comparing the drug with a control are shown, state only the facts. Add no commentary. Do not use the title or the design of figures and tables to emphasise the comparison. Staging the axes, colours or headings so the reader concludes "this one is better" is not presentation of fact; it is steering.
Comparison with other drugs requires the same approved indication
Comparison with other drugs, including competitors' products, holds only when both carry the same approved indication. Lining up drugs with different indications is not a comparison; only an apparent ranking remains. The same applies to non-clinical comparison: both must stay within the range of pharmacological actions that support the approved indication. Further, results from another company obtained in a comparative study are not to be carried into one's own material.
Stay inside the approved dosage and administration
If you present results obtained under conditions deviating from the approved dosage and administration, you must also state the approved dosage and administration. Dosages used in comparison must stay within the approved range, with both sides placed fairly. Running only one side at a favourable dose is not an equal comparison.
The same data leaves a different impression depending on how it is shown. That a difference exists and that the difference is clinically meaningful are separate questions. The maker has a duty to self-check that a figure emphasising a statistical difference has not quietly been substituted for proof of clinical significance.
05Combination drugs and antibacterials — specific rules
Combination drugs: the pharmacology of each component, without misleading
The pharmacology of a combination drug is written from the pharmacological action of each individual component. On that basis, the requirement is not to mislead about the combined indication. In particular, any claim of synergistic action is allowed only when objective data exist. Avoid "add them together and of course it gets stronger" reasoning and any unsupported claim of synergy.
Antibacterials: do not stray outside the approved range of species
For antibacterials, whether standard strains or clinical isolates, if species outside the approval are included, say so. Keep the species and diseases described within the approved range. Lining up activity against unapproved organisms as if it were ordinary risks suggesting off-label use.
06Handling reference information, and disclosing conflicts of interest
A pharmacological action whose relationship to the indication is unclear is positioned as "reference information" and not emphasised. Push it to the front as if it were grounds for efficacy and you make something unconfirmed look confirmed. In comparative studies, even as reference information, competitors' results are not carried over.
And when citing studies or literature in which one's own company was involved, state the conflict of interest (COI) together with the bibliographic details. Who funded and who took part in the research is prerequisite information the reader needs to gauge the weight of the result. Not hiding it is what sustains trust in the data.
Drawing the line for reference information and disclosing COI are both ways of honestly separating "what is known" from "what is not yet known." The spirit of the foreword — avoid not only falsehood but also misunderstanding — runs through here as well.
The pharmacology section is the place to ground the approved indication in pharmacology, not the place to sell it. Write clinical and non-clinical results separately and with their origins, flag population, overseas data and in vitro, and place comparisons only between the same approved indications, with facts alone on equal terms.
Combination drugs proceed from the pharmacology of their components; antibacterials keep to the approved range of species; actions of unclear relevance stay as reference information; and one's own COI is disclosed. These rules are not scattered prohibitions but flow from one spirit: hand over observed facts at their true weight, without inviting misunderstanding. That is the scientific accountability of explaining a drug.