ACETAMINOPHEN
Patient Counselling
What are you using this medication for?: to relieve mild-to-moderate pain due joint pain in the hip, knee or hand, also known as osteoarthritis (note: acetaminophen has other uses and dosing requirements – see acetaminophen under applicable EBSCR topic for these doses).
Names: Acetaminophen (generic), Tylenol®, Apo-acetaminophen (brand name examples)
Dosing (*IV dosing not included in this counseling summary)
Adults: Acetaminophen 1000 mg every 6 hours or 650 mg every 4 hours, as needed
Maximum: dose of acetaminophen from ALL sources (prescription and OTC) must never exceed 4 grams in 24 hours.
Geriatric: refer to adult dosing.
Dosing in Renal impairment:
Adults CrCL < 10 mL/min: administer every 8 hours.
Intermittent hemodialysis or peritoneal dialysis: administer every 8 hours
CRRT: no dose adjustments required.
Adults CrCL 10-50 mL/min: administer every 6 hours.
Dosing in Hepatic Impairment:
Oral: use acetaminophen with caution in patients with known hepatic impairment. Hepatotoxicity has been reported in cases of daily acetaminophen use below 4 g daily. LIMITED, LOW-DOSE therapy is usually well-tolerated in hepatic disease/cirrhosis. It is recommended to avoid chronic acetaminophen use in hepatic impairment.
Administration: take with a full glass of water, with or without food. If you experience an upset stomach on this medication, take it with food (example, with toast, a glass of milk, or a meal).
Pre-cautions/warnings: When taking acetaminophen, it is very important to avoid drinking alcohol, as this combination can cause serious liver damage or even death.
If you are taking any other products containing acetaminophen, always keep track of how much you are using in the day in total. Never use more than 4 grams of acetaminophen from any product in one day.
Tell your doctor and pharmacist if you have any liver damage (e.g. cirrhosis, alcoholic liver disease) and how much alcohol you consume on a regular basis. Continued use of high dose acetaminophen can cause further liver damage. Low-dose acetaminophen taken occasionally is usually safe if you have liver disease – always talk to your doctor and pharmacist before taking acetaminophen products.
Side Effects: Some possible side effects you might experience when taking acetaminophen include:
· Itching (also called pruritus) or skin rash
· Nausea
· Vomiting
· Stomach upset
· Headache
Contact your doctor immediately and stop acetaminophen if the following side effects occur:
· Serious allergic reaction (facial/tongue swelling, difficulty breathing, chest tightness)
· Blood in your stool or dark, tarry stool
· Dark or bloody urine
· Yellowing of the skin or eyes
· Bleeding that will not stop on its own
· Very easy bruising
Drug Interactions: If you are taking warfarin, tell your doctor or pharmacist. Acetaminophen can increase the effects of warfarin. Be aware of signs of bleeding (e.g. cuts that will not stop bleeding on their own, blood in the stool, dark tarry stool, blood in the vomit or vomit that looks like coffee grounds, bruising very easily). Ensure your INR is checked regularly by your doctor.
Avoid drinking alcohol with acetaminophen. Drinking more than 3 drinks per day can increase the risk of serious liver damage.
Pregnancy: acetaminophen is safe in all trimesters. Always use the lowest dose possible for the shortest amount of time. Talk to your doctor or pharmacist before starting acetaminophen.
If You Missed A Dose: take the missed dose as soon as you remember. If it is close to the time of your next dose, skip the missed dose and just go back to your normal dosing time. Never take 2 doses at the same time, or extra doses. Sometimes acetaminophen is used on an “as needed” basis – never take more than recommended by your doctor or pharmacist.
Storage: keep out of reach of children and pets. If you have expired or unused medications, ask your pharmacist how to throw these out.
Always store the product in the original container, with the lid closed tightly. Store in a cool, dry place, such as the kitchen cupboard or your nightstand. Keep the container out of the bathroom.
References:
1. LexiComp Product Monograph. Acetaminophen. 2014. Accessed March 14, 2014 at http://online.lexi.com.proxy.lib.uwaterloo.ca/lco/action/doc/retrieve/docid/patch_f/6264
2. E-therapeutics. Osteoarthritis. Accessed March 14, 2014 at https://www.e-therapeutics.ca/tc.showChapter.action?documentId=c0059
e-CPS CPhA Drug Monograph. Tylenol (Acetaminophen). 2012. Accessed March 14, 2014 at https://www.e-therapeutics.ca/cps.showCphaMonograph.action#
Names: Acetaminophen (generic), Tylenol®, Apo-acetaminophen (brand name examples)
Dosing (*IV dosing not included in this counseling summary)
Adults: Acetaminophen 1000 mg every 6 hours or 650 mg every 4 hours, as needed
Maximum: dose of acetaminophen from ALL sources (prescription and OTC) must never exceed 4 grams in 24 hours.
Geriatric: refer to adult dosing.
Dosing in Renal impairment:
Adults CrCL < 10 mL/min: administer every 8 hours.
Intermittent hemodialysis or peritoneal dialysis: administer every 8 hours
CRRT: no dose adjustments required.
Adults CrCL 10-50 mL/min: administer every 6 hours.
Dosing in Hepatic Impairment:
Oral: use acetaminophen with caution in patients with known hepatic impairment. Hepatotoxicity has been reported in cases of daily acetaminophen use below 4 g daily. LIMITED, LOW-DOSE therapy is usually well-tolerated in hepatic disease/cirrhosis. It is recommended to avoid chronic acetaminophen use in hepatic impairment.
Administration: take with a full glass of water, with or without food. If you experience an upset stomach on this medication, take it with food (example, with toast, a glass of milk, or a meal).
Pre-cautions/warnings: When taking acetaminophen, it is very important to avoid drinking alcohol, as this combination can cause serious liver damage or even death.
If you are taking any other products containing acetaminophen, always keep track of how much you are using in the day in total. Never use more than 4 grams of acetaminophen from any product in one day.
Tell your doctor and pharmacist if you have any liver damage (e.g. cirrhosis, alcoholic liver disease) and how much alcohol you consume on a regular basis. Continued use of high dose acetaminophen can cause further liver damage. Low-dose acetaminophen taken occasionally is usually safe if you have liver disease – always talk to your doctor and pharmacist before taking acetaminophen products.
Side Effects: Some possible side effects you might experience when taking acetaminophen include:
· Itching (also called pruritus) or skin rash
· Nausea
· Vomiting
· Stomach upset
· Headache
Contact your doctor immediately and stop acetaminophen if the following side effects occur:
· Serious allergic reaction (facial/tongue swelling, difficulty breathing, chest tightness)
· Blood in your stool or dark, tarry stool
· Dark or bloody urine
· Yellowing of the skin or eyes
· Bleeding that will not stop on its own
· Very easy bruising
Drug Interactions: If you are taking warfarin, tell your doctor or pharmacist. Acetaminophen can increase the effects of warfarin. Be aware of signs of bleeding (e.g. cuts that will not stop bleeding on their own, blood in the stool, dark tarry stool, blood in the vomit or vomit that looks like coffee grounds, bruising very easily). Ensure your INR is checked regularly by your doctor.
Avoid drinking alcohol with acetaminophen. Drinking more than 3 drinks per day can increase the risk of serious liver damage.
Pregnancy: acetaminophen is safe in all trimesters. Always use the lowest dose possible for the shortest amount of time. Talk to your doctor or pharmacist before starting acetaminophen.
If You Missed A Dose: take the missed dose as soon as you remember. If it is close to the time of your next dose, skip the missed dose and just go back to your normal dosing time. Never take 2 doses at the same time, or extra doses. Sometimes acetaminophen is used on an “as needed” basis – never take more than recommended by your doctor or pharmacist.
Storage: keep out of reach of children and pets. If you have expired or unused medications, ask your pharmacist how to throw these out.
Always store the product in the original container, with the lid closed tightly. Store in a cool, dry place, such as the kitchen cupboard or your nightstand. Keep the container out of the bathroom.
References:
1. LexiComp Product Monograph. Acetaminophen. 2014. Accessed March 14, 2014 at http://online.lexi.com.proxy.lib.uwaterloo.ca/lco/action/doc/retrieve/docid/patch_f/6264
2. E-therapeutics. Osteoarthritis. Accessed March 14, 2014 at https://www.e-therapeutics.ca/tc.showChapter.action?documentId=c0059
e-CPS CPhA Drug Monograph. Tylenol (Acetaminophen). 2012. Accessed March 14, 2014 at https://www.e-therapeutics.ca/cps.showCphaMonograph.action#