Before taking acetaminophen
Before taking acetaminophen, make sure your doctor, dentist or pharmacist knows:
If you are allergic to acetaminophen, or any other medications
If you have other medical problems, specially:
- Alcoholism (active);
- Hepatic disease;
- Viral hepatitis; or
- Renal function impairment, severe
If you are taking other medications such as: Barbiturates, Anticoagulants, nonsteroidal anti-inflammatory drugs (NSAIDs), Aspirin or other salicylates, other products containing acetaminophen.
Proper use of acetaminophen
- Do not take more of this medication than the amount recommended. Use acetaminophen exactly as prescribed by your doctor.
- Possible interference with some laboratory tests; preferably discussing use of this medication with physician in charge 3 to 4 days ahead of time; if this is not possible, informing physician in charge if acetaminophen taken within the past 3 or 4 days.
- Diabetics: Possible false results with blood glucose tests; checking with physician, nurse or pharmacist if changes in test results noted.
Warnings
- Risk of overdose if other medications containing acetaminophen are used.
- Risk of hepatotoxicity may be increased if acetaminophen used with alcohol.
- It is recommended that children up to 12 years of age receive no more than five doses in each twenty-four-hour period, unless otherwise directed by a physician.
Precaution while using acetaminophen
Checking with physician because additional treatment may be needed:
- If taking for pain, and pain persists for longer than 10 days for adults or 5 days for children, condition becomes worse, new symptoms occur, or the painful area is red or swollen.
- If taking for fever, and fever persists for longer than 3 days, condition becomes worse, or new symptoms occur.
- If taking for sore throat, and sore throat is severe, persists for longer than 2 days, or occurs together with or is followed by fever, headache, rash, nausea, or vomiting.
Dosage and administration
Usual adult and adolescent dose
Analgesic and antipyretic:
- 325 to 500 mg every three hours
- 325 to 650 mg every four hours
- 650 mg to 1 gram every six hours as needed, or
- 1300 mg every 8 hours, while symptoms persist
Usual adult prescribing limits
Usual pediatric dose
Analgesic and antipyretic:
- Oral, 1.5 grams per square meter of body surface a day in divided doses; or for
- Infants up to 3 months of age: Oral, 40 mg every four hours as needed
- Infants 4 to 12 months of age: Oral, 80 mg every four hours as needed
- Children 1 to 2 years of age: Oral, 120 mg every four hours as needed
- Children 2 to 4 years of age: Oral, 160 mg every 4 hours as needed, while symptoms persist
- Children 4 to 6 years of age: Oral, 240 mg every 4 hours as needed, while symptoms persist
- Children 6 to 9 years of age: Oral, 320 mg every 4 hours as needed, while symptoms persist
- Children 9 to 11 years of age: Oral, 320 to 400 mg every 4 hours as needed, while symptoms persist
- Children 11 to 12 years of age: Oral, 320 to 480 mg every 4 hours as needed, while symptoms persist
Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them.
Those indicating need for medical attention
Incidence rare
- Agranulocytosis (fever with or without chills; sores, ulcers, or white spots on lips or in mouth; sore throat);
- Anemia (unusual tiredness or weakness);
- Dermatitis allergic (skin rash, hives, or itching);
- Hepatitis (yellow eyes or skin);
- Renal colic (pain, severe and/or sharp, in lower back and/or side) - with prolonged use of high doses in patients with severe renal function impairment;
- Renal failure (sudden decrease in amount of urine);
- Sterile pyuria (cloudy urine);
- Thrombocytopenia (rarely, unusual bleeding or bruising; black, tarry stools; blood in urine or stools; pinpoint red spots on skin)
Overdose
- In case of overdose, contact a poison control center.
- Symptoms of acetaminophen overdosage may occur 2 to 4 days after ingestion of the overdose, but treatment must be begun as soon as possible to prevent liver damage or fatality; treatment started 24 hours or more after the overdose may be ineffective in preventing complications of overdose.
Storage
- Store below 30 and in a tight container. Protect from freezing.
- Keep this medicine out of the reach of children.