| ASPIRIN (ACETYLSALICYLIC ACID)
Alka-Seltzer, A.S.A., Aspergum, Astrin , Bayer, Bayer Children's, Cosprin, Easprin, Ecotrin, Empirin, Entrophen , Halfprin, Measurin, Novasen , St. Joseph Children's, Supasa , Triaphen-10 , ZORprin
Classifications: analgesic, salicylate; antipyretic; antiplatelet; Therapeutic: nonnarcotic analgesic, antipyretic; antiplatelet
Pregnancy Category: D
81 mg chewable tablets; 325 mg, 500 mg tablets; 81 mg, 165 mg, 325 mg, 500 mg, 650 mg, 975 mg enteric-coated tablets; 650 mg, 800 mg sustained release tablets; 120 mg, 200 mg, 300 mg, 600 mg suppositories
Major action is primarily due to inhibiting the formation of prostaglandins involved in the production of inflammation,
pain, and fever. Antiinflammatory action: Inhibits prostaglandin synthesis. As an antiinflammatory agent, aspirin appears to be involved in enhancing antigen removal
and in reducing the spread of inflammatory substances. Analgesic action: Principally peripheral with limited action in the CNS in the hypothalamus; results in relief of mild to moderate pain.
Antipyretic action: Suppress the synthesis of prostaglandin in or near the hypothalamus. Aspirin also lowers body temperature in fever by indirectly
causing centrally mediated peripheral vasodilation and sweating. Antiplatelet action: Aspirin (but not other salicylates) powerfully inhibits platelet aggregation. High serum salicylate concentrations can
impair hepatic synthesis of blood coagulation factors VII, IX, and X.
Reduces inflammation, pain, and fever. Also inhibits platelet aggregation, reducing ability of blood to clot.
To relieve pain of low to moderate intensity. Also for various inflammatory conditions, such as acute rheumatic fever, systemic
lupus, rheumatoid arthritis, osteoarthritis, bursitis, and calcific tendonitis, and to reduce fever in selected febrile
conditions. Used to reduce recurrence of TIA due to fibrin platelet emboli and risk of stroke in men; to prevent recurrence
of MI; as prophylaxis against MI in men with unstable angina.
As prophylactic against thromboembolism; to prevent cataract and progression of diabetic retinopathy; and to control symptoms
related to gluten sensitivity.
History of hypersensitivity to salicylates including methyl salicylate (oil of wintergreen); sensitivity to other NSAIDs; patients with "aspirin triad" (aspirin sensitivity, nasal polyps, asthma); chronic rhinitis; acute bronchospasm;
agranulocytosis; head trauma; increased intracranial pressure; intracranial bleeding; chronic urticaria; history of GI ulceration,
bleeding, or other problems; hypoprothrombinemia, vitamin K deficiency, hemophilia, or other bleeding disorders; CHF; pregnancy
(category D), especially in third trimester; lactation; or in prematures, neonates, or children under 2 y, except under
advice and supervision of physician; children or teenagers with chickenpox or influenza-like illnesses because of possible
association with Reye's syndrome.
Otic diseases; gout; children with fever accompanied by dehydration; hyperthyroidism; immunosuppressed individuals; asthma;
GI disease; history of gout; cardiac disease; renal or hepatic impairment; G6PD deficiency; vitamin K deficiency; anemia;
preoperatively; Hodgkin's disease.
Route & Dosage
|Mild to Moderate Pain, Fever
Adult: PO/PR 350650 mg q4h (max: 4 g/d)
Child: PO/PR 1015 mg/kg in 46 h (max: 3.6 g/d)
Adult: PO 3.65.4 g/d in 46 divided doses
Child: PO 80100 mg/kg/d in 46 divided doses; max 130 mg/kg/d
Adult: PO 81325 mg qd
Adult: PO 650 mg b.i.d.
Adult: PO 80325 mg/d
- Give with a full glass of water (240 mL), milk, food, or antacid to minimize gastric irritation.
- Enteric-coated tablets dissolve too quickly if administered with milk and should not be crushed or chewed.
- Store at 15°30° C (59°86° F) in airtight container and dry environment unless otherwise directed
by manufacturer. Store suppositories in a cool place or refrigerate but do not freeze.
Adverse Effects (≥1%)Body as a Whole:
Hypersensitivity (urticaria, bronchospasm, anaphylactic shock (laryngeal edema). CNS:
Dizziness, confusion, drowsiness. Special Senses:
Tinnitus, hearing loss. GI: Nausea,
, anorexia, heartburn, stomach pains,
ulceration, occult bleeding, GI bleeding. Hematologic: Thrombocytopenia
, hemolytic anemia,
prolonged bleeding time. Skin:
Petechiae, easy bruising, rash. Urogenital:
Prolonged pregnancy and labor with increased bleeding.
Diagnostic Test Interference
Bleeding time is prolonged 38 d (life of exposed platelets) following a single 325-mg (5 grains) dose of aspirin.
Large doses of salicylates equivalent to 5 g or more of aspirin per day may cause prolonged prothrombin time by decreasing prothrombin production; interference with pregnancy tests (using mouse or rabbit); decreases in serum cholesterol, potassium, PBI, T3 and T4 concentrations, and an increase in T3 resin uptake. Serum uric acid may increase when plasma salicylate levels are below 10 and decrease when above 15 mg/dL using colorimetric methods. Urine 5-HIAA: Aspirin may interfere with tests using fluorescent methods. Urine ketones: Salicylates interfere with Gerhardt test (reaction with ferric chloride produces a reddish color that persists after boiling).
Urine glucose: Moderate to large doses of salicylates equivalent to an aspirin dosage ≥2.4
g/d may produce false-negative results with glucose oxidase methods (e.g., Clinistix, TesTape) and false-positive results with copper reduction methods (Benedict's solution, Clinitest). Urinary PSP excretion may be reduced by salicylates. Salicylates may cause urine VMA to be falsely elevated (by most tests), or reduced (by Pisano method). Salicylates may interfere with or cause false decreases
in plasma theophylline levels using Schack and Waxler method. High plasma salicylate levels may cause abnormalities in liver function tests.
InteractionsDrug: Aminosalicylic acid
increases risk of salicylate toxicity
. Ammonium chloride
and other acidifying agents
elimination and increase risk of salicylate toxicity
increase risk of bleeding. oral hypoglycemic agents
increase hypoglycemic activity with aspirin doses >2 g/d. carbonic anhydrase inhibitors
enhance salicylate toxicity
add to ulcerogenic effects. Methotrexate toxicity
is increased. Low doses of salicylates
may antagonize uricosuric effects of probenecid
and sulfinpyrazone. Herbal: Feverfew, garlic, ginger, ginkgo
may increase bleeding potential.
80100% absorbed (depending on formulation), primarily in stomach and upper small intestine. Peak levels:
15 min to 2 h. Distribution:
Widely distributed in most body tissues; crosses placenta. Metabolism:
Aspirin is hydrolyzed to salicylate in GI mucosa
, and erythrocytes
; salicylate is metabolized in liver. Elimination:
50% of dose is eliminated in the urine in 24 h (low doses) or 1530 h (high doses). Excreted into breast
Aspirin 1520 min; salicylate 218 h (dose dependent).
Assessment & Drug Effects
- Monitor for loss of tolerance to aspirin. The reaction is nonimmunologic; symptoms usually occur 15 min to 3 h after ingestion:
profuse rhinorrhea, erythema, nausea, vomiting, intestinal cramps, diarrhea.
- Lab tests: Frequent PT and IRN with concurrent anticoagulant therapy; more frequent fasting blood glucose levels with diabetes.
- Monitor the diabetic child carefully for need to adjust insulin dose. Children on high doses of aspirin are particularly
prone to hypoglycemia (see Appendix F).
- Monitor for salicylate toxicity. In adults, a sensation of fullness in the ears, tinnitus, and decreased or muffled hearing
are the most frequent symptoms associated with chronic salicylate overdosage.
- Monitor children closely because salicylate toxicity is enhanced by the dehydration that frequently accompanies fever or
illness. Children tend to manifest salicylate toxicity by hyperventilation, agitation, mental confusion, or other behavioral
changes, drowsiness, lethargy, sweating, and constipation.
- Note: Potential for toxicity is high in older adults and patients with asthma, nasal polyps, perennial vasomotor rhinitis, hay
fever, or chronic urticaria.
Patient & Family Education
- Do not give aspirin to children or teenagers with symptoms of varicella (chickenpox) or influenza-like illnesses because
of association of aspirin usage with Reye's syndrome.
- Use enteric-coated tablets, extended release tablets, buffered aspirin, or aspirin administered with an antacid to reduce
- Take aspirin 12 d before menses when prescribed for dysmenorrhea. When experiencing heavy menstrual blood loss, take
another analgesic, such as acetaminophen, instead of aspirin.
- Discontinue aspirin therapy about 1 wk before surgery to reduce risk of bleeding. Do not use aspirin-containing gum or gargles
or chew aspirin products for at least 1 wk following oral surgery.
- Note: Chronic use of high-dose aspirin during the last 3 mo of pregnancy can prolong pregnancy and labor, increase maternal bleeding
before and after-delivery, and cause weight increase and hemorrhage in the neonate.
- Discontinue aspirin use with onset of ringing or buzzing in the ears, impaired hearing, dizziness, GI discomfort or bleeding,
and report to physician.
- Do not use aspirin for self-medication of pain (adults) beyond 5 d without consulting a physician. Do not use aspirin longer
than 3 d for fever (adults and children), never for fever over 38.9° C (102° F) in older adults or 39.5° C
(103° F) in children and adults under 60 y or for recurrent fever without medical direction.
- Consult physician before using aspirin for any fever accompanied by rash, severe headache, stiff neck, marked irritability,
or confusion (all possible symptoms of meningitis).
- Avoid alcohol when taking large doses of aspirin.
- Observe and report signs of bleeding (e.g., petechiae, ecchymoses, bleeding gums, bloody or black stools, cloudy or bloody
- Maintain adequate fluid intake when taking repeated doses of aspirin.
- Avoid other medications containing aspirin unless directed by physician, because of danger of overdosing (there are more
than 500 OTC aspirin-containing compounds).