Nitroglycerin / Glyceryl Trinitrate for Angina in Dental Practice

Generic name: Nitroglycerin / Glyceryl Trinitrate / GTN

German term: Nitroglycerin / Glyceryltrinitrat bei Angina pectoris

Category: Emergency drug; nitrate vasodilator; anti-anginal medicine

Dental role: Relief of angina-type chest pain during dental treatment while the dental team assesses for myocardial infarction and activates emergency services when needed

Emergency form: Glyceryl trinitrate spray, commonly 400 micrograms per metered dose, used sublingually according to local emergency protocol.

This article is for dental education only. Chest pain in the dental chair may be stable angina, myocardial infarction, anxiety, reflux, musculoskeletal pain, pulmonary embolism, or another emergency. Do not assume it is harmless. Stop dental treatment, assess the patient, use GTN only when appropriate, give aspirin when myocardial infarction is suspected and not contraindicated, and call emergency medical services for persistent, severe, unusual, or worsening chest pain.

Nitroglycerin, also called glyceryl trinitrate or GTN, is a fast-acting nitrate used to relieve angina-type chest discomfort. In dental practice, it is most relevant when a patient with known angina develops chest pain, tightness, heaviness, or pressure during treatment.

GTN may relieve stable angina within minutes, but failure to respond quickly, atypical symptoms, severe pain, shortness of breath, sweating, nausea, collapse, or radiation of pain should raise suspicion of myocardial infarction.

The key clinical principle is: treat chest pain seriously until proven otherwise. GTN is useful, but it must not delay emergency escalation.

• Best dental use: rapid relief of suspected angina in a conscious patient
• Drug class: nitrate vasodilator
• Emergency kit form: GTN spray 400 micrograms per metered dose
• Main danger: severe hypotension, especially with PDE-5 inhibitors or riociguat
• Clinical priority: distinguish known stable angina from possible myocardial infarction

GTN releases nitric oxide, which relaxes vascular smooth muscle. This causes venous and arterial vasodilation, reduces cardiac workload, and can improve the balance between myocardial oxygen supply and demand.

• Venodilation: reduces preload and myocardial oxygen demand.
• Coronary vasodilation: may improve blood flow in coronary circulation.
• Fast sublingual effect: spray or tablet under the tongue avoids first-pass metabolism and acts quickly.
• Short duration: useful for acute angina relief, not a definitive treatment for myocardial infarction.
• Important: vasodilation can cause headache, dizziness, faintness, or dangerous hypotension.

1. Stop dental treatment immediately.
2. Remove instruments and reassure the patient.
3. Place the patient at rest in a comfortable position, usually upright or semi-reclined unless faint.
4. Assess ABCDE, pulse, blood pressure if available, oxygen saturation, and symptoms.
5. For known angina, allow the patient to use their own GTN or administer clinic GTN according to local protocol if appropriate.
6. If pain is not relieved after a few minutes, repeat GTN according to protocol.
7. If pain persists, is severe, unusual, or associated with systemic symptoms, suspect myocardial infarction and call emergency services.
8. Give aspirin 300 mg to chew if myocardial infarction is suspected and there is no clear contraindication or allergy.
9. Give oxygen if the patient is breathless, hypoxic, seriously unwell, or according to local emergency protocol.
10. Prepare for CPR and AED use if the patient becomes unresponsive or collapses.

Many dental emergency protocols list glyceryl trinitrate spray as 400 micrograms per metered dose. A common emergency approach is 400–800 micrograms sublingually, typically 1–2 sprays, then reassess after a few minutes.

• Route: under the tongue / sublingual.
• Do not swallow immediately: the medicine is intended to absorb through oral mucosa.
• Repeat: repeat according to local protocol if symptoms persist.
• Escalate: persistent pain after GTN and rest should be treated as possible myocardial infarction.

• Patient has taken a PDE-5 inhibitor such as sildenafil, tadalafil, vardenafil, or avanafil within the unsafe interval.
• Patient is taking riociguat or another soluble guanylate cyclase stimulator.
• Patient is hypotensive, faint, collapsed, or has signs of shock.
• Patient has known allergy or serious previous reaction to nitrates.
• Chest pain is accompanied by collapse, unconsciousness, absent normal breathing, or cardiac arrest signs — start emergency response, CPR, and AED.
• Symptoms suggest anaphylaxis, severe asthma, aspiration, or another emergency where GTN is not the primary treatment.
• There is no safe way to assess the patient and monitor response.

GTN must not be combined with PDE-5 inhibitors because the combination can cause severe hypotension, syncope, or myocardial ischemia. Ask about sildenafil or vardenafil within 24 hours and tadalafil within 48 hours when relevant. Also avoid GTN with riociguat.

• Headache
• Flushing or warmth
• Dizziness or light-headedness
• Postural hypotension
• Faintness or syncope
• Palpitations or reflex tachycardia
• Nausea
• Burning or tingling sensation under the tongue
• Severe hypotension if combined with PDE-5 inhibitors or riociguat

• Tell the dental team if you have angina, previous myocardial infarction, stents, bypass surgery, heart failure, or recent chest pain.
• Bring your GTN spray or tablets to every dental appointment.
• Tell the dentist if you have used medicines for erectile dysfunction or pulmonary hypertension.
• Stop dental treatment immediately if chest tightness, heaviness, pressure, or pain starts.
• Do not drive yourself home after a serious chest pain episode.
• Seek urgent medical care if chest pain is new, severe, longer than usual, not relieved by GTN, or associated with breathlessness, sweating, nausea, faintness, or pain spreading to the arm, jaw, neck, back, or stomach.

GTN is for angina relief, not for diagnosing chest pain. If the pain is unusual, persistent, severe, or accompanied by systemic symptoms, manage as possible myocardial infarction and activate emergency services.

• Chest pain not relieved by rest and GTN
• Chest pressure, tightness, or heaviness spreading to the arm, jaw, neck, back, or stomach
• Shortness of breath, sweating, nausea, pallor, or clamminess
• New chest pain in a patient without known angina
• Severe or unusual chest pain compared with the patient’s normal angina
• Syncope, collapse, confusion, or cyanosis
• Very low blood pressure or signs of shock
• Unresponsive patient, absent normal breathing, or cardiac arrest signs
• Chest pain after PDE-5 inhibitor use where GTN must be avoided

• Aspirin for Suspected Myocardial Infarction
• Oxygen in Dental Emergencies
• Syncope in Dental Practice
• Anaphylaxis vs Asthma vs Chest Pain
• Medical History and Cardiovascular Risk
• Local Anesthetic with Epinephrine in Cardiac Patients
• Emergency Drug Kit in Dental Practice
• CPR and AED Readiness

Nitroglycerin, also called glyceryl trinitrate or GTN, is an emergency nitrate vasodilator used to relieve angina-type chest pain in the dental clinic. The usual dental emergency kit form is GTN spray 400 micrograms per metered dose. During chest pain, dental treatment must stop, the patient should rest in a comfortable position, ABCDE assessment should begin, and GTN may be given sublingually if appropriate. Persistent or unusual chest pain should be managed as possible myocardial infarction with emergency services, aspirin 300 mg to chew if not contraindicated, oxygen when indicated, continuous monitoring, and readiness for CPR/AED. GTN must be avoided in patients using PDE-5 inhibitors such as sildenafil, tadalafil, vardenafil, or avanafil, and in patients taking riociguat, because severe hypotension can occur. The safest dental approach is to identify cardiac risk before treatment and to escalate early when chest pain does not resolve quickly.