Aspirin was developed by Adolph Bayer in 1899 and is one of the oldest anti-inflammatory agents. Aspirin comes from the family of salicylates derived from salicylic acid and is also called as acetylsalicylic acid. Aspirin is widely used for its analgesic, anti-inflammatory, anti-pyretic and antiplatelet effects. Due to its instability in aqueous forms, it is available in dry forms like powder, capsule, suppository and tablet forms.
Aspirin is one of the most common drugs in use today. Although serious side effects of aspirin are infrequent, they may occur occasionally with higher and long-term use. The side effects of aspirin are caused by respiratory center stimulation, inhibition of carbohydrate, and amino acid metabolism, stimulation of lipid metabolism and uncoupling of oxidative phosphorylation.
List of Common Aspirin Side Effects
Minor Side effects
- Tinnitus (Ringing in ears)
- General Weakness
- Skin Rashes
Major Side effects
- Intestinal Bleeding
- Severe abdominal Pain
- Bloody stools
- Blood in vomiting
Side Effects of Aspirin in Detail
The detailed description of aspirin side effects are given hereunder:
Central nervous system
Aspirin may cause drowsiness, confusion, dizziness, seizures, hallucinations, headache, flushing, intracranial hemorrhage, and coma. Tinnitus and subjective hearing loss may occur.
Cardiovascular effects include salicylate induced variant angina, ventricular ectopy, conduction abnormalities and hypotension.
Salicylates may cause stimulation of the respiratory center leading to hyperpnoea, respiratory alkalosis, asthma and wheezing
The common side effects are heartburn, diarrhea, nausea, vomiting. These can be reduced by taking aspirin with a full glass of water or with food.
Occult GI bleeding is another side effect that usually occurs. This is the result of gastric ulceration due to direct irritant action of aspirin on the gastric mucosa and increased secretion of pepsin and acid
Aspirin may cause hepatotoxicity in patients with juvenile arthritis, active SLE, Rheumatic fever or preexisting hepatic impairment due to direct toxicity to the liver.
Acetylation of the bone marrow macromolecules by aspirin has been suggested as a possible mechanism causing blood disorders like thrombocytopenia (decreased numbers of platelets), agranulocytosis (severe reduction in granulocytes), leukopenia (decreased white cell count), neutropenia (decreased numbers of neutrophils). At the biochemical level, aspirin alters the red blood cell membrane functions, the cell shape and ion permeability leading to hemolytic anemia. Aspirin promotes bleeding by inhibiting the platelet aggregation, thus increasing PT, APTT and bleeding time.
Salicylate induced hypoglycemia is thought to be due to increased insulin sensitivity due to salicylates. Respiratory alkalosis, metabolic acidosis, water, and electrolyte loss leads to hyponatremia and hypokalemia.
Prostaglandins play a role in opposing potent renal vasoconstrictors, therefore when the action of these prostaglandins is inhibited, vasoconstriction occurs and renal blood flow is diminished, resulting in acute renal failure in susceptible patients. The other renal effects may be interstitial nephritis , nephrotic syndrome , increased BUN and creatinine levels. Aspirin also decreases uric acid excretion and hence may potentiate gout.
The integumentary side effects include rash, urticaria, skin blisters, and bruising.
Reye’s syndrome in children is a rare but serious side effect of aspirin in which a child’s blood sugar level typically drops while the levels of ammonia in his/her blood rise. There is brain edema and liver failure. The signs and symptoms of Reye’s syndrome include persistent vomiting, loss of consciousness, confusion and seizures that requires emergency treatment.