Analgesics - 10 Things You Should Know

Analgesic Safety Decreases Unwanted Side Effects

Acetaminophen is the active ingredient in Tylenol.
Acetaminophen is the active ingredient in Tylenol. Scott Olson/Getty Images

Analgesics are commonly called painkiller medications. It's important to know about safety warnings associated with analgesics so that undesirable side effects can be minimized. Some of the painkillers you think are the safest, because they are non-narcotic, actually have significant risk for deadly overdoses. Here are 10 important things you should know about using analgesics.

1 - Analgesics are a class of drugs used to relieve pain. They are also referred to as painkillers.

For pain relief to occur by taking an analgesic medication, it must either block the pain signals going to the brain or it must interrupt the interpretation of the signals by the brain.

2 - There are two categories of analgesics: non-narcotics and narcotics.

Acetaminophen is the most widely used non-narcotic analgesic. It is sold over-the-counter as Tylenol or acetaminophen. It also can be an ingredient in narcotic analgesics.

3 - Acetaminophen is most effective for mild to moderate pain. It is extremely important to follow the prescribing instructions.

The safety range for acetaminophen between a therapeutic dose and a toxic dose is narrow, so extra caution must be taken in order to prevent an accidental overdose. The daily maximum dose of acetaminophen is 4000 mg. Taking more than the maximum allowable dose or taking it for long duration can increase the risk of liver damage. Alcohol consumption when using acetaminophen also increases the risk of liver damage or may have fatal consequences. The oral dose of acetaminophen for a child is based on age, with the allowable range from 40-650 mg every 4 hours.

4 - Patients must be aware of the cumulative effect of acetaminophen since it is found in so many products, including cold, sinus, cough, and allergy medications.

The cumulative daily total for acetaminophen should not exceed 4000 mg, even if the acetaminophen is coming from various sources. This is a significant warning and cannot be emphasized enough.

It is very easy to exceed the safety margin and get into the toxic overdose zone.

5 - There are two categories of narcotic analgesics - opiates and opioids.

Opiates are the alkaloids found in opium. Opioids are derivatives of opiates.

6 - Opioids bind to opioid receptors in the central nervous system and gastrointestinal tract.

There are four categories of opioids: endogenous opioids (produced in the body), opium alkaloids, semi-synthetic opioids, fully synthetic opioids. Endorphins are an example of an endogenous opioids. Morphine is an opium alkaloid. Semi-synthetic examples include, oxycodone, hydrocodone, hydromorphone. Fully synthetic includes propoxyphene, tramadol, pentazocine, Demerol.

7 - Opioids are strong analgesics, typically reserved for severe, chronic pain.

For patients with severe, intractable pain, there is not an upper limit for dose of opioids but the dose MUST be increased gradually to avert serious side effects like respiratory distress.

8 - There are common side effects associated with opioids.

Nausea, vomiting, drowsiness, constipation, dry mouth, urinary retention, and orthostatic hypotension are among the common side effects.

9 - There are less common side effects associated with opioids.

Confusion, hallucinations, itching, hives, slow or rapid heart rate, flushing, raised intracranial pressure, and muscle rigidity are among the less common side effects.

10 - Severe side effects and adverse reactions are possible with opioids.

Respiratory depression and fatal overdose are possible with opioid use. It is critical that exact directions be followed when using these drugs.


FDA’s Safe Use Initiative: Reducing harm risk from acetaminophen September 2010 Pharmacy Today

Use Caution With Pain Reliever. FDA Consumer Magazine. Jan-Feb 2003.

Narcotic Analgesics and Acetaminophen. 5/2001.

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