Acetaminophen

1. Indications
   1. Pain
   2. Fever
      1. Temperature >102 degrees Fahrenheit
      2. Fever at bedtime
2. Efficacy: Acetaminophen with codeine
   1. See Narcotic Analgesics for efficacy studies
   2. Codeine adds side effects but no benefit to Tylenol
   3. Tylenol and NSAIDs are as effective as Tylenol #3
3. Efficacy: Rheumatologic conditions
   1. Scheduled dosing much more effective than prn
   2. Tylenol 1000 mg qid is as effective as Tylenol #3
4. Dosing: Children
   1. Dose: Acetaminophen
      1. Well hydrated child: 15 mg/kg every 4 to 6 hours
      2. Dehydration risk: 10 mg/kg every 4 to 6 hours
      3. Dosing by age
         1. Age >2 months (5 kg): 80 mg per dose
         2. Age >4 months (6.5 kg): 100 mg per dose
         3. Age >6 months (8 kg): 120 mg per dose
         4. Age >12 months (10 kg): 160 mg per dose
         5. Age >2 years (13 kg): 200 mg per dose
         6. Age >3 years (15 kg): 240 mg per dose
         7. Age >5 years (19 kg): 280 mg per dose
      4. Maximum: 90 mg/kg/day (to 4 grams per day)
   2. Dose: Acetaminophen with codeine Elixir
      1. Components
         1. Acetaminophen (120 mg/5ml Elixir)
         2. Codeine (12 mg/5ml Elixir)
      2. Dosing
         1. Age 3 to 6 years: 5 ml/dose every 4 hours prn
         2. Age 7 to 12 years: 10 ml/dose every 4 hours prn
5. Dosing: Adults
   1. Regular Dose: 650 mg PO every 4 to 6 hours prn
   2. Higher Dose (Osteoarthritis)
      1. Regular Strength Tablet (325 mg)
         1. Take 975 mg (3 tablets) PO every 6 hours
      2. Extra-Strength Tablet (500 mg)
         1. Take 1000 mg (2 tablets) PO every 6 hours
   3. Maximum: 4 grams per day
      1. Do not exceed 12 regular strength tablets (325 mg)
      2. Do not exceed 8 extra-strength tablets (500 mg)
6. Pharmacokinetics
   1. Similar potency and time-effect curve to Aspirin
   2. Duration: 4 hours
7. Preparations
   1. Chewable: 80 mg
   2. Elixir: 160 per 5 ml
   3. Dropper: 80 mg per 0.8 ml
   4. Suppository: 120 mg, 325 mg, 650 mg
   5. Tablet
      1. Regular strength: 325 mg
      2. Extra-Strength: 500 mg
8. Adverse Effects: Hepatotoxicity
   1. See Acetaminophen Toxicity
9. Precautions
   1. Dehydration predisposes to overdosage
   2. Never exceed maximum daily dosage (hepatotoxicity)
10. References
    1. (2000) Med Lett Drugs Ther 42(1085):73-8
    2. (1996) Med Lett Drugs Ther 38:5
    3. Katzung (1989) Basic and Clinical Pharmacology