Pharmacology Notes

NSAIDs are indicated for mild to moderate pain and are particularly effective for bone pain, which makes them very useful for many dental conditions. Evidence exists to indicate that an NSAID should be the drug of first choice for acute dental pain. There are many different NSAIDs available. They have similar efficacy; hence, the choice of which drug to use is largely based on safety, availability, cost, and the route of administration required. The most commonly used NSAIDs for dental, oral and facial pain are ibuprofen and aspirin. Severe pain usually requires the additional use of another analgesic, such as paracetamol.

The dose of NSAID used affects its performance, particularly its anti-inflammatory action. Lower doses can provide pain relief, but higher doses are required for effective anti-inflammatory action (eg a single dose of 200 mg ibuprofen may relieve pain temporarily, but at least 400 mg is required to reduce the inflammatory response; it is even more effective with 600 mg or 800 mg). The time interval of the drug doses is important to maintain blood levels at a level that reduces the inflammatory response. These drugs should be used as a ‘course of treatment’ with regular doses at the correct time intervals rather than just when the patient feels pain or discomfort. It is important to educate the patient about how to use these drugs properly.

Ibuprofen produces greater analgesia than paracetamol+codeine combinations, and produces a dose-related analgesia over the range of 200 mg to 800 mg (ie increasing the dose from 400 mg to 600 mg will provide better pain relief, as will increasing it from 600 mg to 800 mg). However, adverse effects are also dose-related, and therefore the analgesic needs of the patient must be balanced with the risk of producing adverse effects. If ibuprofen is required following dental treatment, a dose range of 200 to 600 mg every 4 to 6 hours up to a daily maximum of 2400 mg can be used for a short time (up to 24 hours). A higher dose (600 to 800 mg) can be used as a loading dose for severe pain. The dose range of ibuprofen for children is 5 to 10 mg/kg every 6 to 8 hours (to a maximum daily dose of 2400 mg).

Aspirin has a dose range in adults of 300 to 900 mg, every 4 to 6 hours up to a daily maximum of 3600 mg. Aspirin should be avoided in children because it has been implicated as a cause of Reye’s syndrome (a disorder of hepatic and central nervous system function).

All NSAIDs have potential adverse effects; these should be discussed with the patient. In patients who require NSAIDs, particularly where risk factors are present, strategies may be needed to reduce the risk of gastrointestinal toxicity.

NSAIDs are available both as over-the-counter medications and on prescription; they are packaged in different dosages for different markets. It is important that the prescriber prescribes the correct dosage and explains the potential problems to the patient. Some commercial formulations combine NSAIDs with other drugs; hence a careful history needs to be taken to determine a total daily dose of each component.