THE UNIVERSITY OF
WESTERN
AUSTRALIA
DENT 3005:Introduction to
Pharmacology
**Renal and genitourinary**
**drugs**
Dr Thuy Linh Truong
**thuy.truong@uwa.edu.au**
# **DENT 3005: Introduction to Pharmacology**
## **Renal and genitourinary drugs**
**Dr Thuy Linh Truong**
**thuy.truong@uwa.edu.au**
<img > Abstract Indigenous artwork </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.
THE UNIVERSITY OF
**WESTERN**
**AUSTRALIA**
Artist: Dr Richard Barry Walley OAM
# **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) Understand the mechanism of diuretics
2) Broadly understand the function of the kidney
and chronic kidney disease
3) Broadly understand BPH, drugs used and
dental implication of these drugs
4) Recognise oral and dental side effects of
diuretic drugs
5) Recognise dental implications of renal
disease
6) Understand drugs interactions with dental
medications
7) Applied knowledge to clinical scenarios
![]()
Illustration of kidneys with a person holding a magnifying glass and another holding a syringe and pill, representing medical study or treatment of the kidneys.
# **Learning Outcomes**
## **Learning objectives**
1) Understand the mechanism of diuretics
2) Broadly understand the function of the kidney and chronic kidney disease
3) Broadly understand BPH, drugs used and dental implication of these drugs
4) Recognise oral and dental side effects of diuretic drugs
5) Recognise dental implications of renal disease
6) Understand drugs interactions with dental medications
7) Applied knowledge to clinical scenarios
Functions of
the kidney
* Filtration of Blood
* Regulation of Blood Pressure
* Electrolyte Balance
* Acid-Base Balance
* Erythropoiesis
Regulation
* Detoxification
<img src="Anatomy diagram of the kidney showing the cortex, medulla with collecting tubules, renal artery, renal vein, renal pelvis, ureter, calyx, and renal capsule. A magnified section illustrates the nephron, including the renal corpuscle (Bowman's capsule and Glomerulus), proximal convoluted tubule, capillaries, Loop of Henle (descending and ascending limb)."> </img>
# **Functions of the kidney**
- Filtration of Blood
- Regulation of Blood Pressure
- Electrolyte Balance
- Acid-Base Balance
- Erythropoiesis Regulation
- Detoxification
Glomerulus
Proximal
convoluted
tubule
Acids Bases
Lumen
120
<br>
ml min⁻¹
**HCO₃**
(reabsorption)
<br>
**Na⁺** (60%)
<br>
**Cl⁻** (45%)
<br>
**H₂O** **①**
<br>
**②**
<br>
**K⁺**
<br>
**Ca²⁺**
<br>
**Mg²⁺**
<br>
**Cl⁻**
<br>
**Na⁺** (25%)
Cortex
Medulla
**H₂O**
<br>
**H₂O**
<br>
**Thin**
<br>
**descending**
<br>
**loop**
<br>
<br>
**Loop of**
<br>
**Henle**
<br>
**Thin**
<br>
**ascending**
<br>
**loop**
<br>
**H₂O**
<br>
**Na⁺**
<br>
<br>
<br>
**Distal**
<br>
**convoluted**
<br>
**tubule**
<br>
<br>
**Na⁺** (10%) **Cl⁻ PTH sensitive (ADH)**
<br>
**Ca²⁺ ④**
<br>
**K⁺H⁺ ⑥**
<br>
**Na⁺** (5%) **⑤**
<br>
**③ Thick**
<br>
**ascending**
<br>
**loop**
<br>
**(ADH)**
<br>
**H₂O**
<br>
**Collecting**
<br>
**Ducts**
<br>
<br>
**① Carbonic anhydrase inhibitors**
<br>
**② Osmotic diuretics**
<br>
**③ Loop diuretics**
<br>
**④ Thiazides**
<br>
**⑤ K⁺ sparing**
<br>
**⑥ Aldosterone antagonists**
# **Nephron Sites of Action**
## **Glomerulus**
- 120 ml min⁻¹
## **Proximal convoluted tubule**
- Acids Bases
- Lumen
- **HCO₃** (reabsorption)
- **Na⁺** (60%)
- **Cl⁻** (45%)
- **H₂O**
- **① Carbonic anhydrase inhibitors**
- **② Osmotic diuretics**
## **Loop of Henle**
### **Thin descending loop**
- **H₂O**
### **Thin ascending loop**
- **H₂O**
### **Thick ascending loop**
- **K⁺**
- **Ca²⁺**
- **Mg²⁺**
- **Cl⁻**
- **Na⁺** (25%)
- **③ Loop diuretics**
## **Distal convoluted tubule**
- **Na⁺** (10%) **Cl⁻**
- **Ca²⁺**
- **④ Thiazides**
## **Collecting Ducts**
- Cortex
- Medulla
- **PTH sensitive (ADH)**
- **K⁺H⁺**
- **Na⁺** (5%)
- **(ADH)**
- **H₂O**
- **⑤ K⁺ sparing**
- **⑥ Aldosterone antagonists**
## Diuretics
**Classes of diuretics – Mechanism and sites of action**
<table>
<thead>
<tr>
<th>Medication</th>
<th>Mechanism of Action</th>
<th>Site of Action</th>
</tr>
</thead>
<tbody>
<tr>
<td>**Loop diuretics** (e.g. frusemide, bumetanide)</td>
<td>Inhibit Na⁺/K⁺/2Cl⁻ symport (NKCC2)</td>
<td>Thick ascending loop of Henle</td>
</tr>
<tr>
<td>**Thiazide diuretics** (e.g. hydrochlorothiazide, indapamide)</td>
<td>Inhibit Na⁺/Cl⁻ symport</td>
<td>Distal convoluted tubule</td>
</tr>
<tr>
<td>**Potassium-sparing diuretics** (aldosterone antagonists, e.g. spironolactone)</td>
<td>Aldosterone antagonists</td>
<td>Collecting duct</td>
</tr>
<tr>
<td>**Pteridine derivatives** (e.g. amiloride)</td>
<td>Inhibit Na⁺ entry through epithelial sodium channels (ENaC)</td>
<td>Collecting duct</td>
</tr>
<tr>
<td>**Carbonic anhydrase inhibitors** (e.g. acetazolamide)</td>
<td>Inhibit carbonic anhydrase</td>
<td>Proximal convoluted tubule</td>
</tr>
<tr>
<td>**Osmotic diuretics** (e.g. mannitol)</td>
<td>Increase in tubular fluid osmolality</td>
<td>Proximal convoluted tubule</td>
</tr>
</tbody>
</table>
# **Diuretics**
## **Classes of diuretics – Mechanism and sites of action**
| Medication | Mechanism of Action | Site of Action |
| :--- | :--- | :--- |
| **Loop diuretics** (e.g. frusemide, bumetanide) | Inhibit Na⁺/K⁺/2Cl⁻ symport (NKCC2) | Thick ascending loop of Henle |
| **Thiazide diuretics** (e.g. hydrochlorothiazide, indapamide) | Inhibit Na⁺/Cl⁻ symport | Distal convoluted tubule |
| **Potassium-sparing diuretics** (aldosterone antagonists, e.g. spironolactone) | Aldosterone antagonists | Collecting duct |
| **Pteridine derivatives** (e.g. amiloride) | Inhibit Na⁺ entry through epithelial sodium channels (ENaC) | Collecting duct |
| **Carbonic anhydrase inhibitors** (e.g. acetazolamide) | Inhibit carbonic anhydrase | Proximal convoluted tubule |
| **Osmotic diuretics** (e.g. mannitol) | Increase in tubular fluid osmolality | Proximal convoluted tubule |
**Thiazide & related anti-diuretics**
* **MOA:** inhibit reabsorption of Na & Cl
* **Dental implications**
* NSAIDs: may reduce renal function
| Generic name | Brand Name |
| :--- | :--- |
| Hydrochlorothiazide | Dithiazide |
| Chlorthalidone | Hygroton |
| Indapamide | Natrilix |
**Potassium sparring diuretics**
* **MOA:** inhibit reabsorption of Na in the distal tubule
* **Dental implications**
* NSAIDs: may increase risk for hyperkalemia & reduce renal function
* Dry mouth
| Generic name | Brand Name |
| :--- | :--- |
| Amiloride | Kaluril |
| Triamterene | Only available w/ hydrochlorothiazide |
# **Diuretic Classes and Dental Implications**
## **Thiazide & related anti-diuretics**
- **MOA:** inhibit reabsorption of Na & Cl
- **Dental implications**
- NSAIDs: may reduce renal function
| Generic name | Brand Name |
| :--- | :--- |
| Hydrochlorothiazide | Dithiazide |
| Chlorthalidone | Hygroton |
| Indapamide | Natrilix |
## **Potassium sparring diuretics**
- **MOA:** inhibit reabsorption of Na in the distal tubule
- **Dental implications**
- NSAIDs: may increase risk for hyperkalemia & reduce renal function
- Dry mouth
| Generic name | Brand Name |
| :--- | :--- |
| Amiloride | Kaluril |
| Triamterene | Only available w/ hydrochlorothiazide |
**Aldosterone antagonists**
* MOA: antagonize Aldosterone → inhibit Na absorption in distal tubule
* Dental implications
* Orthostatic hypotension & drug interaction w/ NSAIDS
| Generic name | Brand Name |
| :--- | :--- |
| Eplerenone | Inspra |
| Spironolactone | Aldactone, Spiractin |
**Loop diuretics**
* MOA: inhibit reabsorption of Na & Cl in ascending limb of loop of Henle
* Dental implications
* Orthostatic hypotension & drug interaction w/ NSAIDS
| Generic name | Brand Name |
| :--- | :--- |
| Bumetanide | Burinex |
| Ethacrynic acid | Edecrin |
| Frusemide | Lasix, Urex |
## **Aldosterone antagonists**
- **MOA:** antagonize Aldosterone → inhibit Na absorption in distal tubule
- **Dental implications**
- Orthostatic hypotension & drug interaction w/ NSAIDS
| Generic name | Brand Name |
| :--- | :--- |
| Eplerenone | Inspra |
| Spironolactone | Aldactone, Spiractin |
## **Loop diuretics**
- **MOA:** inhibit reabsorption of Na & Cl in ascending limb of loop of Henle
- **Dental implications**
- Orthostatic hypotension & drug interaction w/ NSAIDS
| Generic name | Brand Name |
| :--- | :--- |
| Bumetanide | Burinex |
| Ethacrynic acid | Edecrin |
| Frusemide | Lasix, Urex |
**Potassium sparing effect**
* **Retention of K while promoting the excretion of sodium and water**
* *Prevent potassium loss*
* **AIP – Aldosterone-induced protein**
* **ROMK - Renal outer medullary potassium channel**
* **NR3C2 - Nuclear hormone receptor**
* **Both Amiloride and Spironolactone lead to mild natriuresis with a K+ sparing effect**
* **Adverse effect = Hyperkalemia**
*Diagram illustrating the mechanism of potassium-sparing diuretics in the principal cell of the nephron.*
# **Potassium sparing effect**
- **Retention of K while promoting the excretion of sodium and water**
- *Prevent potassium loss*
- **AIP – Aldosterone-induced protein**
- **ROMK - Renal outer medullary potassium channel**
- **NR3C2 - Nuclear hormone receptor**
- **Both Amiloride and Spironolactone lead to mild natriuresis with a K+ sparing effect**
- **Adverse effect = Hyperkalemia**
*Diagram illustrating the mechanism of potassium-sparing diuretics in the principal cell of the nephron.*
# **Diuretics**
# **Dental**
# **implications**
* K+ imbalance
* Hypo and Hyperkaliemia → More prominent in thiazide and loop diuretics
* **Cardiac precautions e.g. Local anesthetic w/** **adrenaline**
* Ensure safe delivery of LA
* Triple whammy: consider other drugs w/ adverse renal effects (NSAIDs)
* **Dry mouth (Xerostomia)**
* Dental caries
* Difficult swallowing (Dysphagia)
* Taste alteration (Dysgeusia)
# **Diuretics: Dental implications**
- **K+ imbalance**
- Hypo and Hyperkaliemia → More prominent in thiazide and loop diuretics
- **Cardiac precautions e.g. Local anesthetic w/ adrenaline**
- Ensure safe delivery of LA
- **Triple whammy:** consider other drugs w/ adverse renal effects (NSAIDs)
- **Dry mouth (Xerostomia)**
- Dental caries
- Difficult swallowing (Dysphagia)
- Taste alteration (Dysgeusia)
**Chronic kidney disease**
* **Chronic Kidney Disease (CKD)** is a progressive condition
* **Risk factors:** diabetes, Hypertension, History of kidney disease
* **Drug therapy**
* Anti-hypertensives
* Diuretics
* Phosphate binders
* Vitamin D
* Erythropoietin injection and iron
# **Chronic kidney disease**
- **Chronic Kidney Disease (CKD)** is a progressive condition
- **Risk factors:** diabetes, Hypertension, History of kidney disease
- **Drug therapy**
- Anti-hypertensives
- Diuretics
- Phosphate binders
- Vitamin D
- Erythropoietin injection and iron
Chronic kidney disease
**Table 1 - Relationship between glomerular filtration rate and stage of chronic kidney disease\***
<table><thead><tr><th>Kidney function stage</th><th>eGFR (mL/min/1.73 m²)</th></tr></thead><tbody><tr><td>1</td><td>≥90</td></tr><tr><td>2</td><td>60–89</td></tr><tr><td>3a</td><td>45–59</td></tr><tr><td>3b</td><td>30–44</td></tr><tr><td>4</td><td>15–29</td></tr><tr><td>5</td><td><15 or on dialysis</td></tr></tbody></table>
https://www.nps.org.au/australian-prescriber/articles/how-to-adjust-drug-doses-in-chronic-kidney-disease
## **Chronic kidney disease Staging**
**Table 1 - Relationship between glomerular filtration rate and stage of chronic kidney disease\***
| Kidney function stage | eGFR (mL/min/1.73 m²) |
| :--- | :--- |
| 1 | ≥90 |
| 2 | 60–89 |
| 3a | 45–59 |
| 3b | 30–44 |
| 4 | 15–29 |
| 5 | <15 or on dialysis |
https://www.nps.org.au/australian-prescriber/articles/how-to-adjust-drug-doses-in-chronic-kidney-disease
**Renal disease**
**Dental**
**implications**
* **Compromised kidney function**
* Impaired drug metabolism, bleeding risks, susceptible to infections
* **Altered drug clearance**
* Prolonged effect/toxicity
* **Altered platelet function**
* Bleeding risks: monitor use of NSAIDs
* **Weakened immune response**
* Educate OH and preventative dental tx
* **Renal osteodystrophy**
* Weakened bones: jaw?
# **Renal disease: Dental implications**
- **Compromised kidney function**
- Impaired drug metabolism, bleeding risks, susceptible to infections
- **Altered drug clearance**
- Prolonged effect/toxicity
- **Altered platelet function**
- Bleeding risks: monitor use of NSAIDs
- **Weakened immune response**
- Educate OH and preventative dental tx
- **Renal osteodystrophy**
- Weakened bones: jaw?
**Renal disease**
**Dental**
**implications**
* If patients are taking high doses of corticosteroids for a long duration of time [i.e. *polymyalgia rheumatica*]
* Schedule the dental session in the morning
* Try to avoid nephrotoxic medications → If necessary → Dose / Frequency adjust
* **NSAID** - Can cause bleeding tendencies
* **Aspirin** - Increases platelet dysfunction
* LA, paracetamol, codeine
- If patients are taking high doses of corticosteroids for a long duration of time [i.e. *polymyalgia rheumatica*]
- Schedule the dental session in the morning
- Try to avoid nephrotoxic medications → If necessary → Dose / Frequency adjust
- **NSAID** - Can cause bleeding tendencies
- **Aspirin** - Increases platelet dysfunction
- LA, paracetamol, codeine
**Benign prostatic hyperplasia**
* Non-cancerous enlargement of the prostate gland
* The prostate surrounds the urethra, and as it enlarges $\rightarrow$ compress the urethra $\rightarrow$ urinary symptoms
* Driven by hormonal changes
* Increase in dihydrotestosterone (DHT) levels $\rightarrow$ LUTS
* Frequent urination (especially at night)
* Difficulty starting urination
* Weak urine stream
* Incomplete bladder emptying
* Urgency to urinate
* $\alpha$1-adrenoceptor antagonists
* Smooth muscle relaxation $\rightarrow$ urinate
# **Benign prostatic hyperplasia**
- Non-cancerous enlargement of the prostate gland
- The prostate surrounds the urethra, and as it enlarges → compress the urethra → urinary symptoms
- Driven by hormonal changes
- Increase in dihydrotestosterone (DHT) levels → LUTS
- Frequent urination (especially at night)
- Difficulty starting urination
- Weak urine stream
- Incomplete bladder emptying
- Urgency to urinate
- $\alpha$1-adrenoceptor antagonists
- Smooth muscle relaxation → urinate
Incontinence
* **Neurogenic Bladder:** this condition refers to bladder dysfunction that results from a neurological impairment. It can affect bladder control and the ability to store or void urine properly
* **Incontinence:** this is the inability to control urination, leading to involuntary leakage of urine
* **Oxybutynin:** muscarinic receptor antagonist, reduce involuntary contractions of bladder muscle
[Anticholinergic effect - Dry mouth]
![]()
Illustration depicting the bladder muscle receptors and the mechanisms of normal, urgency, and stress incontinence
# **Incontinence**
- **Neurogenic Bladder:** this condition refers to bladder dysfunction that results from a neurological impairment. It can affect bladder control and the ability to store or void urine properly
- **Incontinence:** this is the inability to control urination, leading to involuntary leakage of urine
- **Oxybutynin:** muscarinic receptor antagonist, reduce involuntary contractions of bladder muscle [Anticholinergic effect - Dry mouth]
**Anti-muscarinic medications**
* Competitive antagonists of acetylcholine at muscarinic receptors – reduction in parasympathetic activity
* Dental relevance = Dose-dependent effect $\rightarrow$ Salivary secretion is reduced
* Symptoms
* Unpleasant dryness
* Difficulty swallowing
* Examples
* Oxybutynin
* Atropine
* Scopolamine
* Ipratropium
* Benztropine
```mermaid
flowchart TD
A[Anticholinergic effects]
B[Urinary retention]
C[Dry throat, dry mouth, constipation]
D[Feeling hot, decreased sweating]
E[Tachycardia]
F[Blurred vision, dry eyes]
G[Sedation, dizziness, confusion, hallucinations]
A --> B
A --> C
A --> D
A --> E
A --> F
A --> G
```
# **Anti-muscarinic medications**
- Competitive antagonists of acetylcholine at muscarinic receptors – reduction in parasympathetic activity
- Dental relevance = Dose-dependent effect → Salivary secretion is reduced
- **Symptoms**
- Unpleasant dryness
- Difficulty swallowing
- **Examples**
- Oxybutynin
- Atropine
- Scopolamine
- Ipratropium
- Benztropine
```mermaid
flowchart TD
A[Anticholinergic effects]
B[Urinary retention]
C[Dry throat, dry mouth, constipation]
D[Feeling hot, decreased sweating]
E[Tachycardia]
F[Blurred vision, dry eyes]
G[Sedation, dizziness, confusion, hallucinations]
A --> B
A --> C
A --> D
A --> E
A --> F
A --> G
```
**Anti-muscarinic drugs**
**Dental implications**
* Dry mouth 😊
# **Anti-muscarinic drugs: Dental implications**
- Dry mouth 😊
**References**
* Ritter JM, Flower RJ, Henderson G, Loke YK, MacEwan D, Robinson E,
editors. *Rang & Dale’s pharmacology*. 10th ed. Edinburgh: Elsevier; 2023
* Australian Medicines Handbook Online [Internet]. Adelaide (AU):
Australian Medicines Handbook Pty Ltd;2000. Cardiovascular,
Genitourinary; [updated 2025; cited 2025]. Available from: UWA
Onesearch
* Pharmaceutical Society of Australia. Australian Pharmaceutical
Formulary and Handbook: A Guide to Best Practice. 25th ed. Canberra:
Pharmaceutical Society of Australia; 2021
* Ali K. Clinical dental pharmacology. 1st ed. Oxford: Wiley-Blackwell; 2023
* Bullock S, Manias E. *Fundamentals of pharmacology*. 8th ed. Frenchs
Forest, NSW: Pearson Australia; 2017
* MIMS Australia. *eMIMSelite: Consumer medicine information, specific
clinical monograph* [Internet]. Sydney: MIMS Australia; [updated 2025;
cited 2025 Apr 17]. Available from: UWA Onesearch
![]()
A series of three illustrations showing people feeling unwell and various medicine bottles and pills.
# **References**
- Ritter JM, Flower RJ, Henderson G, Loke YK, MacEwan D, Robinson E, editors. *Rang & Dale’s pharmacology*. 10th ed. Edinburgh: Elsevier; 2023
- Australian Medicines Handbook Online [Internet]. Adelaide (AU): Australian Medicines Handbook Pty Ltd;2000. Cardiovascular, Genitourinary; [updated 2025; cited 2025]. Available from: UWA Onesearch
- Pharmaceutical Society of Australia. Australian Pharmaceutical Formulary and Handbook: A Guide to Best Practice. 25th ed. Canberra: Pharmaceutical Society of Australia; 2021
- Ali K. Clinical dental pharmacology. 1st ed. Oxford: Wiley-Blackwell; 2023
- Bullock S, Manias E. *Fundamentals of pharmacology*. 8th ed. Frenchs Forest, NSW: Pearson Australia; 2017
- MIMS Australia. *eMIMSelite: Consumer medicine information, specific clinical monograph* [Internet]. Sydney: MIMS Australia; [updated 2025; cited 2025 Apr 17]. Available from: UWA Onesearch
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