Therapeutic Classification
Nonopioid analgesic, antipyretic
Pharmacologic Classification
Para-aminophenol derivative
Mechanism of Action
Inhibits COX
- May inhibit chemical mediators of pain
- Direct action on the heat-regulating center of the hypothalamus
Indications
- Mild to moderate pain
- Osteoarthritis of the hip or knee
- Dysmenorrhea
- Dental procedures
- Headache and myalgia
- Fevers
Contraindications
- Allergy to acetaminophen
Precautions
- Anemia
- G6PD deficiency
- Hepatic disease
- Rheumatoid or osteoarthritis
- Malnutrition
- Bone marrow depression
- Immunosuppression
- Renal impairment
pregnancy category?
Pregnancy Category B
Interactions with alcohol?
Increased hepatotoxicity.
Drug interactions with barbituates, carbamazepine, diphenylhyantoin, isoniazid, rifampin, and sulfinpyrazone?
Additive effect.
Drug interaction with Iamotrigine (an anti-seizure med)?
Will decrease levels of Iamotrigine if drugs are administered concurrently.
Drug interaction with warfarin?
Can increase hyperthrombinemic effects of warfarin.
Drug interaction with zidovudine (an HIV med)?
Can increase risk of bone marrow suppression.
Drug interaction with echinacea?
Hepatoxicity reported with echinacea/
Adverse Effects
At recommended doses, acetaminophen is well tolerated.
Serious Adverse Effects
- acute hepatic failure
- acute acetaminophen poisoning, with symptoms such as anorexia, nausea, diaphoresis, or abdominal pain
- Chronic use → Neutropenia, pancytopenia, leucopenia, thrombocytopenia purpura, hepatoxicity in alcoholics, renal damage
Nursing Considerations
- Assess recent drug history
- Assess effectiveness of the medication
- Perform baseline and periodic liver function tests (AST & ALT) & monitor for signs of hepatotoxicity
- Assess alcohol use
Patient & Family Teaching
- Do not increase the dose or take the drug more frequently
- Seek immediate medical attention for a fever lasting more than 3 days
- Do not drink alcohol
- Report any signs of potential liver toxicity
- Keep drug in a secure location away from small children
