Following on from part two exploring common medications dentists may come across, Hannah Hook and Frances Evelegh look into high blood pressure treatment.
High blood pressure presents a global burden, affecting one in four people in the United Kingdom. It causes 10.7 million deaths worldwide in 2017.
Taking this into consideration, more often than not you will have multiple patients taking medication to treat their high blood pressure.
A good knowledge and understanding of the various medications to treat this condition will improve your treatment planning and management.
Part three of ‘A dental student’s guide to…common medications’ will focus on drugs that are specific to treating high blood pressure; the following groups of medications are all commonly prescribed when lifestyle changes aren’t sufficient.
Below will cover five commonly encountered classes of drugs for the treatment of high blood pressure, which patients may take when attending the dentist (Atkin and Rogers, 2014; Audi et al, 2018) along with:
- Examples of common type(s) of the drug
- What the drug does
- How the drug works
- When the drug is prescribed
- Any warnings associated with that drug which may impact on dental treatment.
Angiotensin converting enzyme (ACE) inhibitors
Types: Ramipril, Lisinopril.
What: reduces blood pressure.
How: ACE inhibitors block angiotensin-II formation and inhibit bradykinin metabolism. This results in the vasodilation of arteries and veins, leading to a reduction in arterial pressure.
They also promote renal excretion of sodium and water by blocking the effects of angiotensin-II in the kidney. And by blocking angiotensin-II’s stimulation of aldosterone secretion, thereby reducing blood volume, and consequently venous and arterial pressure (Khan and Imig, 2018).
When: ACE inhibitors are considered the first line treatment for patients with hypertension. But are also known to be effective in the treatment of heart and kidney failure. They are often used in conjunction with a diuretic.
Warnings: increase incidence of angioedema (facial swelling).
Angiotensin-II receptor blockers (ARBs)
Types: Candesartan, Losartan.
What: reduces blood pressure.
How: selective inhibition of angiotensin-II by competitive antagonism of the angiotensin-II receptor.
ARBs displace angiotensin-II from the angiotensin-I receptor and produce their blood pressure lowering effects by antagonising angiotensin-II induced vasoconstriction and aldosterone release (Barreras and Gurk-Turner, 2003).
When: ARBs are used in a similar manner to ACE inhibitors for the treatment of hypertension. They do not cause an increase in bradykinin like ACE inhibitors, thereby reducing side effects such as the dry cough and angioedema often associated with ACE inhibitor treatments.
Warnings: along with ACE inhibitors they are contraindicated in pregnancy, due to increased risk of foetal renal damage.
Calcium channel blockers
Types: Amlodipine, Nifedipine.
What: reduces blood pressure.
How: calcium channel blockers inhibit the inward movement of calcium. This slows cardiac contractility and conduction, subsequently lowering blood pressure (Taddei and Bruno, 2018).
When: prescribed to patients to treat high blood pressure, angina and abnormal heart rhythms.
Warnings: can cause gingival hyperplasia (Livada and Shiloah, 2014).
Beta blockers
Types: Bisoprolol, Atenolol, Propranolol.
What: reduces blood pressure.
How: competitively inhibit receptor sites for adrenaline and noradrenaline. This results in a reduced effect of physical exertion or excitement on heart rate.
When: often prescribed to treat angina, heart failure, atrial fibrillation or high blood pressure.
Warnings: beta blockers increase the toxicity of adrenaline containing local anaesthetics. Avoid giving large doses of local anaesthetics to these patients or use an adrenaline-free solution.
Diuretics
Types: Thiazides (Bendroflumethiazide), Loop Diuretics (Furosemide).
What: reduces blood pressure.
How: removes excess fluids, improving hypertension and decreasing risk of heart failure by decreasing work rate of the heart.
When: to treat patients with high blood pressure, heart failure and oedema.
Warnings: may decrease saliva production so make sure to check for dry mouth.
References
Atkin P and Rogers H (2014) The 20 most frequently prescribed drugs – that your patients may be taking. Br Soc Dent Hyg Ther 53
Audi S, Burrage DR, Lonsdale DO, Pontefract S, Coleman J, Hitchings A and Baker E (2018) The ‘top 100’ drugs and classes in England: an updated ‘starter formulary’ for trainee prescribers. Br J Clin Pharmacol 84: 2562-71
Barreras A and Gurk-Turner C (2003) Angiotensin Ii Receptor Blockers. Baylor Univ Med Cent Proc 16: 123-6
Taddei S and Bruno RM (2018) Calcium channel blockers. Encyclopedia of Endocrine Diseases. Elsevier
Livada R and Shiloah J (2014) Calcium channel blocker-induced gingival enlargement. Journal of Human Hypertension 28: 10-4
