Chest pain during treatment in a patient with angina

Correct answer: D. Stop treatment, sit her upright, give oxygen, and have her take HER OWN sublingual nitroglycerin

• A. EMS is activated if the pain does NOT resolve after three doses of nitroglycerin at five-minute intervals, or if it differs from her usual pattern, or if there is radiation, diaphoresis, dyspnoea or collapse — because that is a myocardial infarction until proven otherwise. Aspirin belongs to that scenario, not to a typical anginal episode that has not yet been treated.
• B. Continuing treatment while a cardiac patient has chest pain is indefensible. The stress prolongs the ischaemia.
• C. Supine positioning with legs elevated is for SYNCOPE, where the aim is to restore cerebral perfusion. In cardiac chest pain it increases venous return and preload, worsening the oxygen demand mismatch — the opposite of what is wanted.
• D. CORRECT. For a patient with KNOWN stable angina experiencing HER USUAL pain: stop the procedure, position her comfortably UPRIGHT or semi-upright, give oxygen, and administer nitroglycerin — HER OWN, because it is prescribed to her, she knows the dose, and its potency is assured, whereas an emergency kit vial may be expired. Sublingual nitroglycerin acts within one to three minutes. Monitor vital signs and reassure.

Note: Ask every anginal patient to BRING their nitroglycerin and place it on the bracket table before starting. Two cautions: nitroglycerin is contraindicated within 24 hours of sildenafil or 48 hours of tadalafil, since the combination causes profound hypotension; and hypotension is the limiting side effect in any case, so check the blood pressure between doses.

Correct answer: C. It releases nitric oxide, which stimulates guanylyl cyclase and raises cGMP, producing venodilation

• A. Calcium channel blockade describes amlodipine and diltiazem, again preventive agents.
• B. Beta-1 blockade describes metoprolol and atenolol, used for angina PREVENTION rather than for acute relief.
• C. CORRECT. Nitroglycerin is metabolised to NITRIC OXIDE, which activates soluble GUANYLYL CYCLASE in vascular smooth muscle. The resulting rise in cGMP dephosphorylates myosin light chains and relaxes the muscle. The dominant effect at therapeutic doses is on the VENOUS side: venodilation reduces preload and therefore ventricular wall tension and myocardial oxygen DEMAND. Coronary dilation contributes, but demand reduction is the main mechanism.
• D. Cyclo-oxygenase inhibition describes her ASPIRIN, which prevents thrombotic events but does nothing for an acute anginal episode.

Note: Tolerance develops rapidly with continuous nitrate exposure, which is why long-acting nitrate regimens build in a nitrate-free interval each day. Headache from cerebral vasodilation is the commonest side effect and is expected rather than alarming.

Correct answer: D. Losartan

• A. Statins are associated with myalgia, transaminase elevation and, rarely, rhabdomyolysis. Taste disturbance is not characteristic.
• B. Sublingual nitroglycerin is used intermittently for minutes at a time. It causes headache and flushing, not a persistent taste change.
• C. Low-dose aspirin causes gastrointestinal irritation and bleeding tendency, not dysgeusia. High-dose salicylates can cause tinnitus.
• D. CORRECT. LOSARTAN, like other angiotensin receptor blockers and the ACE inhibitors, is a recognised cause of DYSGEUSIA — a persistent metallic or altered taste. The ACE inhibitors are the more notorious for it, alongside their dry cough, but the sartans share the effect. It is dose-related and reversible on withdrawal, and it is worth raising with the prescribing physician, because taste disturbance is a common reason patients quietly stop taking antihypertensives.

Note: The dental drug-induced taste list worth knowing: ACE inhibitors and ARBs, metronidazole, clarithromycin, metformin, captopril, lithium, terbinafine, chlorhexidine and many chemotherapeutic agents. Distinguish drug-induced dysgeusia from the other causes — zinc or B12 deficiency, xerostomia, chorda tympani injury, burning mouth syndrome, and upper respiratory infection.