When you have a headache or a pulled muscle, your first concern is relieving your pain. While common painkillers such as acetaminophen or codeine may stop your aches and pains, they can also cause severe side effects. Find out what they are and how you can avoid them.

Acetaminophen (Tylenol®, Tempra®)

Type of painkiller: Analgesic

Purpose: Acetaminophen is primarily used to relieve pain, such as headaches, toothache, or muscle or joint pain in conditions such as arthritis, spondylitis, or lupus erythematosus. It can also treat fever.

Side Effects: Acetaminophen is generally considered safe, even for treating pain and fever during pregnancy. However, the most common side effect associated with this painkiller is liver damage. It can also interact with some other medications, such as blood-thinning drugs.

Precautions to take: Try not to drink while you're taking acetaminophen; it can heighten your risk of liver damage. If you have any other liver problem, speak to your doctor before taking acetaminophen. Don't take acetaminophen with medications or drugs that thin your blood, such as warfarin, garlic, or hawthorn.

Get advice from your doctor about taking this painkiller when you're pregnant. Also, you shouldn't take acetaminophen for a long period or at high doses if you're nursing.

Ibuprofen (Advil®, Motrin®, Aleve®)

Type of painkiller: Non-steroidal anti-inflammatory (NSAIDs)

Purpose: NSAIDs, such as ibuprofen and naproxen (Aleve®), provide relief by blocking prostaglandins play a role in pain, inflammation, and fever in the body. This painkiller is frequently used to treat common pain conditions including joint pain and inflammation (for instance, in rheumatoid arthritis), muscle strains or pulls, menstrual cramps, headaches, neck pain and toothache.

Side Effects: According to the Mayo Clinic, this painkiller can cause a wide range of side effects, including skin rashes, nausea, ringing in the ears, diarrhea, and constipation. Ibuprofen can also cause stomach or intestinal bleeding, especially if you've had an ulcer, drink alcohol, excessively or take steroids or blood thinners.

For people with cardiovascular disease it can increase the risk of having a stroke. Other possible side effects include itching, sores, weakness, fluid retention and elevated blood pressure.

Precautions to take: If you have any medical known medical condition, ask your doctor for advice before taking ibuprofen or any other non-steroidal anti-inflammatory. These painkillers may make your condition worse, or interact with other medications such as lithium, high blood pressure medications and blood-thinning drugs.

You also should not take ibuprofen and other NSAIDs if you are pregnant or breastfeeding.


Type of painkiller: Opioid (opiate) analgesic, or narcotic pain medication

Purpose: Codeine treats mild or moderate pain by attaching to opioid receptors in the brain, spinal cord and gastrointestinal tract, and inhibiting pain perception. This painkiller can also treat a non-productive cough.

Side Effects: The most common concern with taking codeine or any narcotic painkiller is dependence. Other side effects include drowsiness, dizziness, nausea, vomiting, constipation, stomach pain, breathing problems, skin reactions, vision problems, and seizures. 

Precautions to take: Never take codeine, or drugs containing codeine such as Tylenol 2, without the advice of a doctor. You should fully disclose any health conditions--including pregnancy or breastfeeding - to your doctor beforehand. Never exceed the recommended dose because of the risk of dependence.

The National Institutes of Health also recommends not taking codeine if you drink alcohol or consume products containing alcohol. You also should never drive or operate heavy machinery when taking this painkiller.

If you suspect you've become dependent to codeine or a narcotic painkiller, consult your doctor; it's best to stop using the drug under medically supervised care.