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Nitrek Side Effects

Generic name: nitroglycerin

Medically reviewed by Last updated on Aug 5, 2023.

Note: This document contains side effect information about nitroglycerin. Some dosage forms listed on this page may not apply to the brand name Nitrek.

Applies to nitroglycerin: capsule extended release, packet, spray, tablet. Other dosage forms:

Serious side effects of Nitrek

Along with its needed effects, nitroglycerin (the active ingredient contained in Nitrek) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking nitroglycerin:

Less common

  • Bloating or swelling of the face, arms, hands, lower legs, or feet
  • burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
  • difficult or labored breathing
  • feeling faint, dizzy, or lightheadedness
  • feeling of warmth or heat
  • flushing or redness of the skin, especially on the face and neck
  • headache
  • rapid weight gain
  • sweating
  • tightness in the chest
  • tingling of the hands or feet
  • unusual weight gain or loss


  • Bluish-colored lips, fingernails, or palms
  • dark urine
  • fever
  • pale skin
  • rapid heart rate
  • sore throat
  • unusual bleeding or bruising
  • unusual tiredness or weakness

Incidence not known

  • Arm, back, or jaw pain
  • blurred vision
  • chest pain or discomfort
  • chest tightness or heaviness
  • confusion
  • cough
  • cracks in the skin
  • difficulty with swallowing
  • dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
  • fainting
  • fast, irregular, pounding, or racing heartbeat or pulse
  • feeling of constant movement of self or surroundings
  • feeling of warmth
  • hives, itching, or rash
  • increased sweating
  • loss of heat from the body
  • nausea or vomiting
  • puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  • red, swollen skin
  • redness of the face, neck, arms, and occasionally, upper chest
  • scaly skin
  • sensation of spinning
  • weakness

Get emergency help immediately if any of the following symptoms of overdose occur while taking nitroglycerin:

Symptoms of overdose

  • Bluish-colored lips, fingernails, or palms
  • blurred or loss of vision
  • bulging soft spot on the head of an infant
  • change in consciousness
  • change in the ability to see colors, especially blue or yellow
  • cold, clammy skin
  • dark urine
  • difficulty breathing
  • disturbed color perception
  • dizziness or lightheadedness
  • double vision
  • fever
  • flushed skin
  • halos around lights
  • headache, severe and throbbing
  • increased sweating
  • loss of appetite
  • loss of consciousness
  • night blindness
  • overbright appearance of lights
  • pale skin
  • paralysis
  • slow or irregular heartbeat
  • sore throat
  • tunnel vision
  • unusual bleeding or bruising
  • unusual tiredness or weakness

Other side effects of Nitrek

Some side effects of nitroglycerin may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less common

  • Abdominal or stomach pain
  • body aches or pain
  • congestion
  • hoarseness
  • lack or loss of strength
  • runny nose
  • sneezing
  • stuffy nose
  • tender, swollen glands in the neck
  • voice changes

For Healthcare Professionals

Applies to nitroglycerin: buccal tablet extended release, intravenous solution, oral capsule extended release, rectal ointment, sublingual powder, sublingual spray, sublingual tablet, transdermal film extended release, transdermal ointment.


The most common side effect is headache.[Ref]

Nervous system

Very common (10% or more): Headache (up to 64%)

Common (1% to 10%): Dizziness, lightheadedness, syncope, vertigo, drowsiness

Rare (0.1% to 0.01%): Severe and prolonged headache

Very rare (less than 0.01%): Cerebral ischemia

Frequency not reported: Faintness, somnolence[Ref]


Common (1% to 10%): Hypotension, angina increased, paradoxical bradycardia, tachycardia, orthostatic hypotension, blood pressure decreased, facial flushing

Uncommon (0.1 to 1%): Circulatory collapse

Rare (less than 0.1%): Bradycardia, cyanosis, flushing, heart rate increase

Frequency not reported: Crescendo angina, rebound hypertension, palpitations, hypertension, decreased arterial oxygen tension, severe arterial hypotension with bradycardia, transient flushing[Ref]


Common (1% to 10%): Nausea, vomiting

Rare (0.01% to 0.1%): Dry mouth

Very rare (less than 0.01%): Heartburn, halitosis

Frequency not reported: Abdominal pain, retching, lip and tongue swelling[Ref]


Uncommon (0.1% to 1%): Dermatitis contact, erythema, pruritus, burning, irritation, eczema, urticaria

Rare (0.01 to 0.1%): Allergic skin reactions, rash

Very rare (less than 0.01%): Exfoliative dermatitis, drug rash

Frequency not reported: Cutaneous flushing, diaphoresis, angioedema

Postmarketing reports: Rash generalized[Ref]


Common (1% to 10%): Asthenia, weakness

Frequency not reported: Retrosternal discomfort[Ref]


Rare (less than 0.1%): Hypersensitivity reactions, anaphylaxis

Frequency not reported: Allergic reaction, anaphylactoid reaction[Ref]


Common (1% to 10%): Restlessness

Frequency not reported: Apprehension[Ref]


Very rare (less than 0.01%): Impairment of respiration

Frequency not reported: Hypoxemia, dyspnea[Ref]


Very rare (less than 0.01%): Methemoglobinemia[Ref]


Rare (less than 0.1%): Blurred vision

Frequency not reported: Increased ocular pressure[Ref]


Frequency not reported: Muscle twitching[Ref]

Frequently asked questions


1. Product Information. Tridil (nitroglycerin). DuPont Pharmaceuticals. 2002.

2. Product Information. Nitrostat (nitroglycerin). Parke-Davis. 2002.

3. Product Information. Nitrolingual (nitroglycerin). First Horizon Pharmaceutical Corporation. 2004.

4. Cerner Multum, Inc. UK Summary of Product Characteristics.

5. Cerner Multum, Inc. Australian Product Information.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.