Aspirin: Uses, Indications, Dosages, Precautions, contraindications, Side Effects & Interactions

Asprin

(as9pir-in)
Classification 
Pharmacotherapeutic: Nonsteroidal salicylate
Clinical: Anti-inflammatory, antiplatelet, antipyretic, nonopioid analgesic

APC-ASA Coated Aspirin , A.S.A., Ascriptin Enteric, Aspergum, Aspirin , Aspir-Low, Aspir-trin, Bayer, Easprin, Ecotrin, Ecotrin Maximum Strength, 8-Hour Bayer Time Release, Empirin, Genprin, Maximum Bayer, Norwich Extra-Strength, Novasen (CAN), Sal-Adult (CAN), Sal-Infant (CAN), St. Joseph Children’s, Supasa (CAN), Therapy Bayer, ZORprin

Pregnancy category D (3rd trimester)

General Information

In use for more than a century, aspirin relieves pain, reduces fever and relieves symptoms of arthritis. In low doses, it helps prevent blood clots, especially in atherosclerosis or angina due to coronary heart disease, and reduces the risk of heart attacks and strokes. It is present in many medications for colds, flu, headaches, menstrual cramps, and joint or muscle pain.

Aspirin can irritate the stomach and even cause peptic ulcers or bleeding. Another drawback of aspirin is that it can trigger asthma attacks. In children, aspirin can cause Reye's syndrome, a rare but serious disorder of the brain and liver. For this reason, aspirin should not be given to children under the age of 16, except on the advice of a doctor

Action

Blocks painful impulses in the CNS, lower inflammation by inhibiting the synthesis of prostaglandins, the antipyretic action results from the vasodilation of the peripheral vessels, reduces platelet aggregation

Therapeutic Effect

Decreased pain, inflammation, fever, absence of MI, transient ischemic attacks and thrombosis

Availability (Rx)

Caplets: 325 mg, 500 mg

Suppositories: 300 mg, 600 mg

Tablets: 81 mg, 325 mg, 500 mg, 650 mg

Capsule, Extended-Release: 162.5 mg

Uses

Mild to moderate pain or fever including rheumatoid arthritis, osteoarthritis, thromboembolic disorders, transient ischemic attacks, rheumatic fever, post-myocardial infarction, prophylaxis of myocardial infarction, ischemic stroke, angina, acute myocardial infarction

Cataract prevention (long-term use), vernal keratoconjunctivitis,PCI, pre-eclampsia, prevention of pregnancy loss in women with bleeding disorders, colorectal cancer prophylaxis, Kawasaki disease, thrombosis prophylaxis, pericarditis

Precautions

Sudden discontinuation, acetaminophen/NSAID hypersensitivity, acid/base imbalance, alcoholism, ascites, asthma, bone marrow suppression, geriatric patients, dehydration, G6PD deficiency, gout, heart failure, anemia, kidney /liver disease, pre/postoperative, gastritis, pregnancy C 1st trimester

Make sure to tell your doctor if:

• You have long-term liver or kidney problems

• You have asthma

• You have allergic to aspirin or any NSAID

• You have a blood clotting disorder

• You have a history of peptic ulcer

• You have glucose-6-phosphate dehydrogenase (G6PD) deficiency

• You are taking other medicines

Indications and Dosages

 ‣ To relieve Analgesia, fever

• Adult: PO/RECTAL 325-650 mg q4hr prn, for 4 g/day

• Child 2-11 yr: PO 10-15 mg/kg/dose q4hr, for 4 g/day

‣ Anti-inflammatory

PO

• Adults, Elderly: At the beginning, 2.4-3.6 g/ day in divided doses, then 3.6-5.4 g/day

‣ Kawasaki disease

PO

• Children: 80-100 mg/kg/day in divided doses during acute phase, then decrease to 3-5 mg/kg/day for maintenance.  Discontinue after 6 wks if no cardiac abnormalities, otherwise carry on

‣ To treat juvenile rheumatoid arthritis

• Children: At first 60-90 mg / kg / day in divided doses, then 80-100 mg / kg / day. Adjust the target salicylate concentration to 15-30 mg / dL

 ‣ To reduce the risk of recurrent transient ischemic attacks or stroke 

PO

• Adults, Elderly: 50-325 mg/day (grade 1A)

‣  To treat acute ischemic stroke

PO

• Adults, Elderly: 160-325 mg/day, initiated in persons who are not candidates for thrombolytics within 48 h and are not receiving systemic anticoagulation 

 ‣ To reduce the severity of acute MI

• Adults: Initial 160 to 162.5 mg (½ of a 325-mg tablet or two 80- or 81-mg tablets) as soon as MI is suspected

• Maintenance: 160 to 162.5 mg daily prolonged 30 days

 ‣ To reduce risk of MI in patients with prior MI or unstable angina

•  Adults: 325 mg daily

‣ To treat Coronary artery bypass graft

PO

• Adults, Elderly: 75-325 mg/day starting 6 h before procedure

‣ To treat Percutaneous transluminal coronary angioplasty

PO

• Adults, Elderly: 80-325 mg/day starting 2 h following procedure

‣ To treat Stent implantation

PO

• Adults, Elderly: 325 mg 2 h before implantation procedure, 160-325 mg daily thereafter 

‣ To treat Carotid endarterectomy

• Adults, Elderly: 81-325 mg/day pre-operatively and daily thereafter

Pharmacokinetics

It is rapidly and completely absorbed from the gastrointestinal tract, the absorption of the enteric lining is delayed, the rectal and incomplete absorption is delayed. Protein binding: high. Widely distributed. Quickly hydrolyzed to salicylate. Half-life: 15-20 min (aspirin), 2-3 h (low dose salicylate), more than 20 h (high dose salicylate)

Implementation

PO route

• Do not break, crush or chew the enteric product

• Administer crushed or whole to the patient, The chewy tab should be chewed

• Administer with food or milk to decrease gastric symptoms; separated by 2 h of enteric product, absorption can be slowed down

• Give antacids 1-2 hours after enteric products

• Administer with 8 oz of water and have patient sit upright for 30 minutes after dose, discard lashes if they smell like vinegar, avoid if allergic to tartrazine

• Give ½ hr before planned exercise

Rectal route

• Refrigerate suppositories, do not freeze

• If the suppository is too soft, leave it to cool for 30 minutes in the refrigerator or run cold water over the aluminum foil

• Moisten the suppository with cold water before inserting it well into the rectum

Contraindications

Pregnancy D (3rd trimester), breastfeeding, children ,12 yr, children/teenagers with chickenpox or flu-like symptoms, Allergy to tartrazine dye, asthma, bleeding problems (such as hemophilia), GI bleeding or ulceration, peptic ulcer, hepatic impairment, history of hypersensitivity to aspirin or NSAIDs, urticaria, vit K deficiency, acute bronchospasm, agranulocytosis, increased intracranial pressure, intracranial bleeding, nasal polyps

Interactions

Individual drugs

Alcohol, cefamandal, clopidogrel, eptifibatide, heparin, plicamycin, ticlopidine, tirofiban: increased risk of bleeding

Ammonium chloride, nizatidine: increase in the level of salicylate

Insulin, methotrexate, phenytoin, valproic acid, warfarin: increase in the effects of each specific product

Nitroglycerin: increased hypotension

Probenecid: reduces the effects of probenecid

Spironolactone, sulfinpyrazone: reduced effects

Drug classifications

• Anticoagulants Aspirin may add to the anticoagulant effect of such drugs, increasing the risk of abnormal bleeding. Drugs for gout Aspirin may decrease the effect of these drugs
• NSAIDs may increase the likelihood of stomach inflammation with aspirin
• Methotrexate Aspirin may rise the toxicity of this drug 

• Sulphonylurea antidiabetic drugs Aspirin may rise the effect of these drugs

• Corticosteroids and some SSRI antidepressants These may rise the risk of gastrointestinal bleeding with aspirin

Drug/laboratory tests

Increased: coagulation studies, liver function studies, serum uric acid, amylase, CO2, urinary protein (urinalysis)

Decreased: serum potassium, cholesterol, T3, T4

Interference: VMA, 5-HIAA, xylose tolerance test, pregnancy test, TSH test

May alter serum ALT, AST, alkaline phosphatase, uric acid; prolongs prothrombin time (PT) platelet function assay. The therapeutic aspirin level for antiarthritic effect is 20-30 mg/dL, if it is above >30 mg/dL is toxic  

Drugs/food

Increase: risk of bleeding—fish oil (omega-3 fatty acids)

• Foods that acidify urine may rise aspirin level

Herbal

Increase: risk of bleeding—feverfew, garlic, ginger, ginkgo, ginseng (Panax), horse chestnut

Side effects

• CNS: Stimulation, drowsiness, dizziness, confusion, seizures, CNS depression, diaphoresis, headache, hyperventilation, and lassitude, flushing, hallucinations, coma

• CV: Rapid pulse, pulmonary edema

• EENT: Tinnitus, hearing loss

• ENDO: Hypoglycemia, hyponatremia, hypokalemia

• GI: Nausea, stomach pain, vomiting, GI bleeding, diarrhea, heartburn, anorexia, hepatitis, GI ulcer

• HEMA: Decreased blood iron level, thrombocytopenia, agranulocytosis, leukopenia, neutropenia, hemolytic anemia, increased PT, aPTT, prolonged bleeding time, shortened life span of RBCs

• INTEG: Rash, urticaria, bruising/ Ecchymosis

• RESP: Wheezing, hyperpnea, bronchospasm

• SYST: Reye’s syndrome (children), anaphylaxis, laryngeal edema

Nursing considerations

Baseline assessment

Do not give to children or adolescents who have or have recently had viral infections (increases risk of Reye's syndrome). Do not use if you notice a vinegar-like odor (indicates chemical decomposition). Evaluate history of gastrointestinal bleeding, peptic ulcer, OTC use of products that may contain aspirin. Assess the type, location, duration of pain, and inflammation. Inspect the appearance of the affected joints for immobility, deformity, or skin condition. Therapeutic serum level for antiarthritic effect: 20 to 30 mg / dL (The toxicity results if the level is more than 30 mg / dL)

Intervention/evaluation

• Monitor urinary pH (sudden acidification, pH 6.5 to 5.5, can cause toxicity). Assess skin for evidence of ecchymosis. If given as an antipyretic, check the temperature directly before and 1 hour after drug administration

• Assess the therapeutic response: pain relief, stiffness, swelling, increased joint mobility, reduced joint pain, improved grip strength

• Lower doses of aspirin are recommended for older patients because they are more susceptible to aspirin toxicity. Discontinue medications and contact your doctor if breaths are 12 / min or less (20 / min or less in children)

Equipment must be available for anaphylaxis

• Monitor liver function tests: AST, ALT, bilirubin, creatinine, in case that the patient is on long-term therapy

• Monitor renal function tests: BUN, urine creatinine if the patient is on long-term therapy

• Monitor blood tests: CBC, Hct, Hgb, PT if the patient is on long-term therapy

• Check I&O ratio, decreasing output may indicate kidney failure (long-term therapy)

• Monitor salicylate level: therapeutic level 150-300 mcg/ml with regard to chronic inflammation

• Check edema in feet, ankles, legs

• Identify past product history, there are many product interactions

• Assess for allergic reactions: Urticaria, rash, if these occur, may have discontinue product, in patients with asthma, nasal polyps, allergies, severe allergic reactions may occur

• Assess for ototoxicity: tinnitus, ringing, roaring in ears, audiometric testing needed before, after long-term treatment

• Therapeutic anti-inflammatory effect noted in 1–3 wks

• Behavioral changes, which that persistent vomiting may be early signs of Reye’s syndrome, contact doctor

Evaluation

Positive therapeutic result

• Decreased pain

• Decreased inflammation

• Decreased fever

• Absence of MI

• Absence of transient ischemic attacks, thrombosis

Patient/family teaching

• Do not crush timed-release or controlled-release aspirin tablets unless instructed to do so
• Instruct patient to take aspirin with food or after meals, may cause GI

upset if taken on an empty stomach

• To avoid alcohol ingestion, gastrointestinal bleeding may occur
• This drug should not be given to children or adolescents with symptoms similar to those of the flu or chickenpox because Reye's syndrome can develop
• Instruct the patient to report any symptoms of vision changes, ototoxicity, allergic reactions, renal / hepatic toxicity, bleeding for long-term therapy
• Advise adult patient taking low-dose aspirin not to also take ibuprofen, as it may minimize the cardioprotective and stroke-preventing effects of aspirin
• Tell patient to consult doctor before taking aspirin with any prescription drug

for blood disorder, diabetes, gout, or arthritis

• Advise patient with allergies, nasal polyps, asthma, that allergic reactions may result

• Instruct patient not to exceed recommended dosage; acute poisoning may occur

• Advise patient to read the label of other over-the-counter (OTC) products, many contain aspirin

• Advise patient to read labels on other OTC products, may contain salicylates

• Tell the patient not to use aspirin if it has a strong vinegar smell