THE UNIVERSITY OF WESTERN AUSTRALIA DENT 3005:Introduction to Pharmacology **CAM** Dr Thuy Linh Truong thuy.truong@uwa.edu.au # **DENT 3005: Introduction to Pharmacology - CAM** **Dr Thuy Linh Truong** thuy.truong@uwa.edu.au <img /> # Acknowledgement of country The University of Western Australia acknowledges that its campus is situated on Noongar land, and that Noongar people remain the spiritual and cultural custodians of their land, and continue to practise their values, languages, beliefs and knowledge. Artist: Dr Richard Barry Walley OAM **Learning Outcomes** **Learning objectives** 1. Explain the role of complementary medicines in healthcare and dentistry 2. Identify uses, adverse effects, and interactions of key agents (St John's Wort, Valerian, Calcium, Evening Primrose, Ginkgo biloba) 3. Recognize clinically significant interactions 4. Apply this knowledge to safe patient management in dental practice <img alt="Icons representing various forms of complementary medicine, including aromatherapy, acupuncture, apitherapy (honeycomb), herbal medicine, relaxation techniques, meditation, reflexology, and massage." /> <table> <thead> <tr> <th>Term</th> <th>Definition</th> </tr> </thead> <tbody> <tr> <td>Traditional Chinese medicine</td> <td>- Has been established for over 2000 years</td> </tr> <tr> <td></td> <td>- Disease is result of disturbance in natural environment of the body</td> </tr> <tr> <td></td> <td>- Purpose is to restore the balance of Yin and Yang</td> </tr> <tr> <td>Ayurveda</td> <td>- Practiced primarily in the Indian subcontinent for 5,000 years</td> </tr> <tr> <td>Aromatherapy</td> <td>- Involves the use of essential oils to promote health and well-being</td> </tr> <tr> <td>Homeopathic medicine</td> <td>- A belief that “like cures like”</td> </tr> <tr> <td></td> <td>- Involves dilutions of active compounds</td> </tr> <tr> <td>Naturopathic medicine</td> <td>- Practitioners work with natural healing forces within the body</td> </tr> <tr> <td></td> <td>- Goal of helping the body heal from disease and attain better health</td> </tr> <tr> <td>Qi gong</td> <td>- A component of traditional Chinese medicine</td> </tr> <tr> <td>Reiki</td> <td>- A Japanese word representing universal life energy</td> </tr> <tr> <td>Osteopathic medicine</td> <td>- Conventional medicine</td> </tr> <tr> <td></td> <td>- Emphasizes diseases arising in the musculoskeletal system</td> </tr> <tr> <td></td> <td>- Underlying belief that all of the body’s systems work together, and</td> </tr> <tr> <td></td> <td>disturbances in one system may affect function elsewhere in the body</td> </tr> </tbody> </table> # Complementary medicines * Herbal products have pharmacological effects – benefits, side effects, allergies, drug interactions * Professional guidance essential for safe use and correct dosing * Regulation in Australia – Therapeutic Goods Administration (TGA) & Office of Complementary Medicines ensure safety, quality, efficacy * Regulation in NZ – Ministerial Advisory Committee on Complementary & Alternative Health advises government * Challenges * Misconception: “Natural” = safe (e.g. strychnine is natural but toxic) * Variable active ingredient levels due to climate & growth conditions * Risk of contamination (e.g. heavy metals) **St John's Wort** * Active compound: *Hypericin* – standardised in commercial preparations * Primary use: antidepressant for mild–moderate depression * Not effective in severe depression * **Pharmacology** * MOA: Inhibits reuptake of serotonin, noradrenaline, dopamine, GABA, glutamate * Avoid with other antidepressants – risk of serotonin excess * Weak MAOI activity (mainly in vitro) * **Serious interactions** * Serotonergic drugs: SSRIs, venlafaxine, buspirone, tramadol, triptans, pethidine, dexamphetamine, illicit stimulants * Drugs metabolised by CYP3A4, CYP2C9, CYP2C19 * May enhance CNS depressant effects of sedatives & alcohol * Can alter blood levels of some medicines | Medication | Interaction Severity | Potential Effect | | :--- | :--- | :--- | | **ST JOHN'S WORT (DENTAL DRUG INTERACTIONS)** | | | | Azithromycin | Major | Possible photosensitivity reactions | | Benzodiazepines | Major | Reduced effectiveness | | Clarithromycin | Major | Reduced anti-infective effectiveness | | Clindamycin | Major | Reduced anti-infective effectiveness | | Codeine | Major | Increased sleep time and analgesia | | Dexamethasone | Major | Reduced effectiveness | | Diphenhydramine | Major | Possible photosensitivity reactions | | Doxycycline | Major | Reduced anti-infective effectiveness<br>Possible photosensitivity reactions | | Erythromycin | Major | Reduced anti-infective effectiveness | | Hydrocodone | Major | Increased sleep time and analgesia | | Ibuprofen | Major | Possible photosensitivity reactions | | Oxycodone | Major | Increased sleep time and analgesia | | Prednisone | Major | Reduced effectiveness | | Tetracycline | Major | Reduced anti-infective effectiveness | | Zolpidem | Major | Reduced effectiveness | St John's – clinical considerations * Risk when combined with other serotonergic agents * Symptoms * Mental: agitation, confusion * Motor: tremor, hyperreflexia, poor coordination * Temperature: fever, sweating, shivering * GI: diarrhoea * Management: discontinue contributing drugs, seek urgent medical review Nature's Own MOOD BALANCE ST JOHN'S WORT, 50 TABLETS: Hypericum perforatum ext. 450mg, from 2.7g [of] dry herb top flowering (St John's Wort). CALMS NERVES. Supports healthy mood balance. BLACKMORES ST JOHN'S WORT, 90 TABLETS, **MOOD BALANCE**: Hypericum perforatum (St John's Wort) extract dry conc. 300 mg equiv. to dry top flowering 1.8 g (1800 mg) std. to contain hypericin 990 micrograms. Traditionally used in Western herbal medicine to support healthy mood balance & relieve symptoms of mild anxiety. **Valerian (Valeriana officinalis)** * Strong odour due to **valeric acid** – attractive to cats, used as bait for feral cat control * *Officinalis* = cultivated historically in monasteries for medicine & flavouring (e.g., root beer) * **Pharmacology** * Roots used for sedative effect in insomnia * Some evidence: ↓ time to fall asleep, ↑ sleep quality, minimal “hangover” effect * Evidence mixed in recent studies * Generally safe for short-term use * Active compounds: **valepotriates** * May ↑ serotonergic activity (serotonin-like structure) * Possible action via GABA receptor complex (benzodiazepine-like) * **Interactions & ADR** * Prolongs barbiturate effects – avoid with thiopentone & barbiturates (e.g., epilepsy treatment) * Adverse effects: headache, restlessness, occasional palpitations (rare) **VALERIAN (DENTAL DRUGS INTERACTIONS)** <table> <thead> <tr> <th>Concomitant Drug</th> <th>Interaction Severity</th> <th>Potential Effect</th> </tr> </thead> <tbody> <tr> <td>Benzodiazepines</td> <td>Major</td> <td>Excess sedation</td> </tr> <tr> <td>Codeine</td> <td>Major</td> <td>Excess sedation</td> </tr> <tr> <td>Diphenhydramine</td> <td>Major</td> <td>Excess sedation</td> </tr> <tr> <td>Hydrocodone</td> <td>Major</td> <td>Excess sedation</td> </tr> <tr> <td>Oxycodone</td> <td>Major</td> <td>Excess sedation</td> </tr> <tr> <td>Zaleplon</td> <td>Major</td> <td>Excess sedation</td> </tr> <tr> <td>Zolpidem</td> <td>Major</td> <td>Excess sedation</td> </tr> </tbody> </table> Valerian – clinical considerations * Take at night to avoid daytime sedation * Avoid caffeine, nicotine, high-sugar/fat foods in the evening (reduce sleep disturbance) * Avoid in hepatic dysfunction – risk of increased hepatotoxicity with high doses * Avoid in pregnancy – insufficient safety data; potential altered absorption during gestation <img > Nature's Own Valerian Forte 2000mg product label with visual of Valerian plant roots and flowers. </img> # Other | SUBSTANCE + DRUG | INTERACTION SEVERITY | POTENTIAL EFFECT | | :--- | :--- | :--- | | **Calcium + Doxycycline** | **Moderate** | **Reduced anti-infective effectiveness** | | **Calcium + Tetracycline** | **Moderate** | **Reduced anti-infective effectiveness** | | **Evening Primrose + Aspirin** | **Moderate** | **Enhanced bleeding** | | **Evening Primrose + Ibuprofen** | **Moderate** | **Enhanced bleeding** | | **Ginkgo biloba + Aspirin** | **Major** | **Enhanced bleeding** | | **Ginkgo biloba + Ibuprofen** | **Major** | **Enhanced bleeding** | <img alt="Image displaying bottles of Ostelin Calcium & Vitamin D3, Healthy Care Evening Primrose Oil 1000mg, and Life Extension Ginkgo Biloba Certified Extract 120 mg."/> # **Other Interactions** | SUBSTANCE + DRUG | INTERACTION SEVERITY | POTENTIAL EFFECT | | :--- | :--- | :--- | | **Calcium + Doxycycline** | **Moderate** | **Reduced anti-infective effectiveness** | | **Calcium + Tetracycline** | **Moderate** | **Reduced anti-infective effectiveness** | | **Evening Primrose + Aspirin** | **Moderate** | **Enhanced bleeding** | | **Evening Primrose + Ibuprofen** | **Moderate** | **Enhanced bleeding** | | **Ginkgo biloba + Aspirin** | **Major** | **Enhanced bleeding** | | **Ginkgo biloba + Ibuprofen** | **Major** | **Enhanced bleeding** | THE UNIVERSITY OF **WESTERN** **AUSTRALIA** DENT 3005:Introduction to Pharmacology **Special populations** Dr Thuy Linh Truong thuy.truong@uwa.edu.au A slide background with various pills and capsules with the text DENT 3005: Introduction to Pharmacology and Special Populations. <img src="An abstract black and white painting often associated with Indigenous art, featuring flowing lines and circular patterns, positioned on the right half of the image."> </img> ## **THE UNIVERSITY OF** ## **WESTERN** ## **AUSTRALIA** # Acknowledgement # of country The University of Western Australia acknowledges that its campus is situated on Noongar land, and that Noongar people remain the spiritual and cultural custodians of their land, and continue to practise their values, languages, beliefs and knowledge. Artist: Dr Richard Barry Walley OAM **Learning Outcomes** **Learning objectives** 1. Explain how pregnancy, ageing, and childhood affect pharmacokinetics 2. Recognise key pharmacotherapy considerations in special populations 3. Identify risks of interactions and adverse effects 4. Apply safe prescribing and dosing principles 5. Integrate pharmacology into dental treatment planning Icons representing different special populations: a person in a wheelchair, an elderly person with a cane, a person pushing a stroller, a person changing a baby, and a pregnant person. **Special populations** * **Considerations for** * Dental care must be adapted for different patient groups with unique needs * Today's focus: pregnancy, elderly, and children * **Pregnant patients** * Balance maternal oral health with foetal safety * Timing of treatment is critical * Careful selection of medications and radiographs * **Elderly patients** * Complex medical histories and comorbidities * Polypharmacy → increased risk of drug interactions * Age-related changes in oral tissues and reduced healing capacity * **Children** * Require modified communication and behaviour management * Strong focus on prevention and early intervention * Growth and development influence treatment planning **Pregnancy: absorption & drug action** * Hormonal changes alter GI function * Slower peristalsis & gastric emptying $\rightarrow$ drug absorption affected * Erratic gastric acid secretion $\rightarrow$ impacts acidic drug absorption * Effects vary between individuals $\rightarrow$ unpredictable outcomes * Important to be aware of possible pharmacokinetic changes **Pregnancy: distribution** * Plasma volume expands in pregnancy * May dilute drug concentration at receptor sites * Little direct evidence of major altered drug effects * Possible lower drug levels $\rightarrow$ reduced effect **Drug safety in pregnancy** - Timing of exposure $\rightarrow$ key to foetal effects - Limited safety data (excluded from trials, few large studies) - Risk–benefit balance must be assessed individually - Australian pregnancy drug categories: no longer used - Use evidence-based resources & drug info services for support A signpost indicating Drug safety, Drug efficacy, and Healthy pregnancy with a pregnant woman and DNA helix in the background. # **Australian pregnancy categories** - Not hierarchical - Category B (B1, B2, B3): animal data - B $\neq$ safer than C - Category D not always contraindicated (e.g. anticonvulsants) - System = general guide, not patient-specific advice - **Limitations** - Implies safety ranking - No info on stage of foetal development - Not always updated with new data - Moving away from category use **Australian pregnancy categories** <table><thead><tr><th>Category</th><th>Definition</th></tr></thead><tbody><tr><td>A</td><td>Drugs which have been taken by a large number of pregnant women and women of childbearing age without any proven increase in the frequency of malformations or other direct or indirect harmful effects on the foetus having been observed</td></tr><tr><td>B1</td><td>Drugs which have been taken by only a limited number of pregnant women and women of childbearing age, without an increase in the frequency of malformation or other direct or indirect harmful effects on the human foetus having been observed. Studies in animals have not shown evidence of an increased occurrence of foetal damage</td></tr><tr><td>B2</td><td>Drugs which have been taken by only a limited number of pregnant women and women of childbearing age, without an increase in the frequency of malformation or other direct or indirect harmful effects on the human foetus having been observed. Studies in animals are inadequate or may be lacking, but available data show no evidence of an increased occurrence of foetal damage</td></tr><tr><td>B3</td><td>Drugs which have been taken by only a limited number of pregnant women and women of childbearing age, without an increase in the frequency of malformation or other direct or indirect harmful effects on the human foetus having been observed. Studies in animals have shown evidence of an increased occurrence of foetal damage, the significance of which is considered uncertain in humans</td></tr><tr><td>C</td><td>Drugs which, owing to their pharmacological effects, have caused or may be suspected of causing, harmful effects on the human foetus or neonate without causing malformations. These effects may be reversible. Accompanying texts should be consulted for further details</td></tr><tr><td>D</td><td>Drugs which have caused, are suspected to have caused or may be expected to cause, an increased incidence of human foetal malformations or irreversible damage. These drugs may also have adverse pharmacological effects. Accompanying texts should be consulted for further details</td></tr><tr><td>X</td><td>Drugs which have such a high risk of causing permanent damage to the foetus that they should not be used in pregnancy or when there is a possibility of pregnancy</td></tr></tbody></table> Please don't try to remember this, no longer recommended as part of standard practice ## Age and pharmacokinetics * Drug handling changes across lifespan * Children: developing organs $\rightarrow$ variable responses * Elderly: age-related decline in organ function * Both groups $\rightarrow$ higher risk of adverse effects Illustration of an elderly woman holding the hand of a young boy. (Paeds & Elderly) **Absorption** * Slower peristalsis & gastric emptying at both extremes * Infants: low bile & erratic gastric acid $\rightarrow$ altered absorption * Example: penicillin absorbed better in infants * Elderly: reduced perfusion & muscle mass $\rightarrow$ slower absorption * Infants: thinner skin $\rightarrow \uparrow$ topical absorption risks <img Drug Absorption Diagram> </img> (Paeds & Elderly) ## Distribution - Lower plasma proteins → ↑ free drug levels in infants & elderly - Neonates: risk of toxicity from high protein-bound drugs - Kernicterus risk → bilirubin displacement - Body composition changes with age - Infants: more body water, less fat - Elderly: less water, more fat Figure illustrating Pharmacokinetics (The principles of ADME), including Absorption (How will it get in?), Metabolism (How is it broken down?) via the Liver, Distribution (Where will it go?) with Transporters, and Excretion (How does it leave?). ## **Distribution** - Lower plasma proteins → ↑ free drug levels in infants & elderly - **Neonates:** risk of toxicity from high protein-bound drugs - Kernicterus risk → bilirubin displacement - Body composition changes with age - **Infants:** more body water, less fat - **Elderly:** less water, more fat **(Paeds & Elderly)** ## Metabolism * Infants: immature liver enzymes $\rightarrow$ slower clearance * Some drugs can induce enzyme activity (e.g. anti-seizure meds) * Children 1–9 yrs: $\uparrow$ metabolism $\rightarrow$ higher clearance * Elderly: reduced microsomal enzyme activity $\rightarrow$ slower metabolism Cartoon drawing of a liver and a pill with faces. ## **Metabolism** - **Infants:** immature liver enzymes $\rightarrow$ slower clearance - Some drugs can induce enzyme activity (e.g. anti-seizure meds) - **Children 1–9 yrs:** $\uparrow$ metabolism $\rightarrow$ higher clearance - **Elderly:** reduced microsomal enzyme activity $\rightarrow$ slower metabolism (Paeds & Elderly) # Excretion * Neonates: immature kidneys &arr; slower drug clearance * Dosing intervals need adjusting * Elderly: declining renal function with age * Risk of drug accumulation & toxicity ## **Excretion** - **Neonates:** immature kidneys &arr; slower drug clearance - Dosing intervals need adjusting - **Elderly:** declining renal function with age - Risk of drug accumulation & toxicity (Paeds & Elderly) ## Paediatric: dosage considerations * Children $\neq$ small adults * Dose not simply scaled by weight * Organ maturity matters * Best practice: dose by body surface area * Some drugs require specialised paediatric dosing guidelines An illustration of a woman administering medicine to a child with a spoon. # **Clinical Considerations for Special Populations** ## **Paediatric: dosage considerations** - Children $\neq$ small adults - Dose not simply scaled by weight - Organ maturity matters - Best practice: dose by body surface area - Some drugs require specialised paediatric dosing guidelines (Paeds & Elderly) **Geriatric: clinical considerations** * Multiple comorbidities & polypharmacy * Risk of drug interactions & adverse effects * Falls & fractures linked to some drugs * Non-adherence common * Cognitive decline * Social isolation * Financial/transport issues An illustration of an elderly man looking confused while holding two bottles of medication. ## **Geriatric: clinical considerations** - Multiple comorbidities & polypharmacy - Risk of drug interactions & adverse effects - Falls & fractures linked to some drugs - Non-adherence common - Cognitive decline - Social isolation - Financial/transport issues **Special populations: key takeaways** * Pregnancy: absorption & distribution altered, but variable * Paediatrics: immature systems $\rightarrow$ careful dosing, $\uparrow$ risk of toxicity * Elderly: declining organ function & polypharmacy $\rightarrow$ higher risk * Safe care = understanding pharmacokinetics across lifespan <img alt="Illustration of noodles in a takeout box with chopsticks." /> # **Special populations: key takeaways** - **Pregnancy:** absorption & distribution altered, but variable - **Paediatrics:** immature systems $\rightarrow$ careful dosing, $\uparrow$ risk of toxicity - **Elderly:** declining organ function & polypharmacy $\rightarrow$ higher risk - Safe care = understanding pharmacokinetics across lifespan **References** - Ritter JM, Flower RJ, Henderson G, Loke YK, MacEwan D, Robinson E, editors. *Rang & Dale’s pharmacology*. 10th ed. Edinburgh: Elsevier; 2023 - Becker DE, Reed KL. *Pharmacology and Therapeutics for Dentistry*. 7th ed. St. Louis: Elsevier; 2017 - Bullock S, Manias E. *Fundamentals of pharmacology*. 8th ed. Frenchs Forest, NSW: Pearson Australia; 2017 - Stringer JL. *Basic concepts in pharmacology*. 6th ed. New York (US): McGraw Hill Medical; 2022 Feb 18 - American Dental Association. The ADA practical guide to patients with medical conditions. 2nd ed. Hoboken (NJ): Wiley; 2016. Available from: https://onlinelibrary.wiley.com/doi/epdf/10.1002/9781119121039 - Little JW. Complementary and alternative medicine: Impact on dentistry. J Am Dent Assoc. 2004 Aug;135(8):1134-44 doi:10.14219/jada.archive.2004.0367 - Pharmaceutical Society of Australia. Australian Pharmaceutical Formulary and Handbook: A Guide to Best Practice. 25th ed. Canberra: Pharmaceutical Society of Australia; 2021 - Kennedy D, Batagol R. Drug safety in pregnancy. Aust Prescr. 2025;48(1):5–9. DOI:10.18773/austprescr.2025.008 - Therapeutic Goods Administration. *Australian categorisation system for prescribing medicines in pregnancy*. TGA; updated 28 March 2025. Available from: https://www.tga.gov.au/products/medicines/find-information-about-medicine/prescribing-medicines-pregnancy-database/australian-categorisation-system-prescribing-medicines-pregnancy *** *** *** Illustration of a woman blowing her nose with a box of medication and scattered pills around her. Illustration of three pill bottles with scattered pills. Illustration of a woman blowing her nose with a box of medication and scattered pills around her. # **References** - Ritter JM, Flower RJ, Henderson G, Loke YK, MacEwan D, Robinson E, editors. *Rang & Dale’s pharmacology*. 10th ed. Edinburgh: Elsevier; 2023 - Becker DE, Reed KL. *Pharmacology and Therapeutics for Dentistry*. 7th ed. St. Louis: Elsevier; 2017 - Bullock S, Manias E. *Fundamentals of pharmacology*. 8th ed. Frenchs Forest, NSW: Pearson Australia; 2017 - Stringer JL. *Basic concepts in pharmacology*. 6th ed. New York (US): McGraw Hill Medical; 2022 Feb 18 - American Dental Association. The ADA practical guide to patients with medical conditions. 2nd ed. Hoboken (NJ): Wiley; 2016. Available from: https://onlinelibrary.wiley.com/doi/epdf/10.1002/9781119121039 - Little JW. Complementary and alternative medicine: Impact on dentistry. J Am Dent Assoc. 2004 Aug;135(8):1134-44 doi:10.14219/jada.archive.2004.0367 - Pharmaceutical Society of Australia. Australian Pharmaceutical Formulary and Handbook: A Guide to Best Practice. 25th ed. Canberra: Pharmaceutical Society of Australia; 2021 - Kennedy D, Batagol R. Drug safety in pregnancy. Aust Prescr. 2025;48(1):5–9. DOI:10.18773/austprescr.2025.008 - Therapeutic Goods Administration. *Australian categorisation system for prescribing medicines in pregnancy*. TGA; updated 28 March 2025. Available from: https://www.tga.gov.au/products/medicines/find-information-about-medicine/prescribing-medicines-pregnancy-database/australian-categorisation-system-prescribing-medicines-pregnancy [[L19 CAM & Special populations2025.pdf#page=1|L19 CAM & Special populations2025, p.1]] [[L19 CAM & Special populations2025.pdf#page=2|L19 CAM & Special populations2025, p.2]] [[L19 CAM & Special populations2025.pdf#page=12|L19 CAM & Special populations2025, p.12]] [[L19 CAM & Special populations2025.pdf#page=24|L19 CAM & Special populations2025, p.24]] [[L19 CAM & Special populations2025.pdf#page=25|L19 CAM & Special populations2025, p.25]] [[L19 CAM & Special populations2025.pdf#page=26|L19 CAM & Special populations2025, p.26]] [[L19 CAM & Special populations2025.pdf#page=27|L19 CAM & Special populations2025, p.27]] [[L19 CAM & Special populations2025.pdf#page=28|L19 CAM & Special populations2025, p.28]] [[L19 CAM & Special populations2025.pdf#page=29|L19 CAM & Special populations2025, p.29]] [[L19 CAM & Special populations2025.pdf#page=30|L19 CAM & Special populations2025, p.30]]