Painkillers are drugs used to treat acute and chronic pain. Many disorders can be addressed by taking these medicines and some of them include arthritis, earache, backache, menstrual cramps, the flu, the common cold, sinusitis, sore throat and post-operative pain, as well as the after-effects of excessive muscle strain.


The most commonly used painkillers are:


  • The paracetamol: effective against pain, both acute and chronic, mild to moderate in intensity. It is useful in case of fever, headaches and other common aches. Moreover, it can be taken for long periods to control pain associated with arthritis and other chronic pain syndromes. The mechanism of its analgesic and antipyretic effects is not yet fully understood, but it is believed that there is an inhibition of cyclooxygenase enzymes, which activates pathways leading to pain reduction. However, paracetamol does not seem to be able to reduce inflammation.


  • The anti-inflammatory: effective against pain, both acute and chronic, mild to moderate in intensity. Commonly known as NSAIDs (nonsteroidal anti-inflammatory drugs), they are useful in cases of fever and swelling (such as those associated with arthritis). They include aspirin, ibuprofen, naproxen, celecoxib, etoricoxib, nimesulide and several other active ingredients. The feature that unites them is the ability to inhibit one or more steps of the arachidonic acid metabolism, the molecule from which the prostaglandins are derived, important inflammatory mediators also involved in the control of body temperature. Their operation is based precisely on the reduction of the synthesis of these molecules.


  • The opioid analgesics (also called narcotics): useful in cases of severe to moderate pain that cannot be relieved with other painkillers. They belong to the class of drugs such as morphine, methadone and codeine, all molecules that act by binding to receptors in the brain and thereby blocking the sensation of pain.


Flupiritina, a molecule with a central analgesic action also belongs to the family of painkillers but it is not included in the opioid class.


Moreover, other drugs are used to enhance the action of painkillers or to control their side effects. This may also lead to prescribing:


  • Anxiolytics
  • Anticonvulsants useful in the treatment of neuropathic pain
  • Antidepressants, for example amitriptyline, that at low doses can prevent some types of headache
  • Antiepileptic
  • Antinauseants
  • Corticosteroids
  • Tranquilizers

Finally, cannabis, with its active ingredient THC (delta-9-tetrahydrocannabinol), is used to treat pain. Its use, however, is limited to special cases (for example, serious diseases such as multiple sclerosis and amyotrophic lateral sclerosis).


How should painkillers be taken?


A low dose of acetaminophen and NSAIDs can be taken without medical prescription. However, more and higher doses can only be prescribed by a doctor, including the use of opioids. In any case it is always good to consult a doctor before taking a painkiller, whose assumption is not without side effects even at low doses.


There are many dosage forms of paracetamol and NSAIDs available on the market. There are powders to prepare for suspension of oral use, granules to be dissolved directly under the tongue, drops, ampoules, tablets, sprays, mouthwashes and even suppositories. Opioids may instead be taken orally, rectally, intramuscular, intravenous, subcutaneous, spinal or transdermal.


Contraindications and warnings associated with the use of painkillers


Even when they are used to control a simple headache, painkillers should be used sparingly, because unwanted adverse effects may also include chronic pain.

The side effects of paracetamol are rare. The excessive intake and the simultaneous consumption of alcohol, however, can damage the liver.

On the other hand, the Fans may irritate the stomach, in severe cases they may trigger stomach bleeding or kidney damage. Their intake may also worsen high blood pressure problems and interfere with antihypertensive medications. Opioids may instead trigger nausea, vomiting, constipation and drowsiness. Taking narcotics is also associated with the risk of developing an addiction and should not be continued for more than 3-4 months.


Finally, in some people the flupirtine can cause dizziness, fatigue, nausea, constipation, diarrhea, increased liver transaminases, skin reactions, increased sweating and visual disturbances.


Therefore it is important to:

  • Not exceed the doses indicated by the doctor or given in the leaflet
  • Ask your doctor whether the painkiller you are about to take can interfere with other medications taken daily
  • Not take on more different painkillers simultaneously.
  • Acetaminophen should not be taken in cases of severe kidney disease or liver disease and if you consume more than 3 alcoholic beverages a day.
  • NSAIDs should not be used in case of allergy to aspirin, gastrointestinal bleeding, peptic ulcer, kidney or liver problems, heart disease, use of anticoagulants, coagulation disorders, and if you consume more than 3 alcoholic beverages a day.
  • Children and teenagers who may have the flu or chickenpox should not take aspirin because of the risk of Reye's syndrome.