Adverse drug interactions in dental practice: interactions associated with analgesics, Part III in a series

By Haas DA

Date: 03/1999
Journal: J Am Dent Assoc

Purpose:   overview of drug interactions with analgesics and identifies those that are clinically relevant.

Most highlighted Results: 

NSAIDs and antihypertensives.

•There is sufficient evidence to support an interaction between NSAIDs and three major classes of antihypertensives:

1.Angiotensin-converting enzyme inhibitors, or ACEIs, such as captopril 2.Diuretics such as furosemide

3.ß-blockers such as propranolol

NSAIDs may attenuate ACEI action directly by inhibiting renal prostaglandin synthesis and indirectly by interfering with ACEI-induced prostaglandin production. Also with ß-blockers, NSAID-induced blockade of prostaglandin synthesis.  NSAIDs interfere with diuretics by reducing their efficacy in secreting sodium and affecting plasma renin activity.

•The calcium-channel blockers such as nifedipine do not interact with NSAIDs.

To what degree do NSAIDs inhibit antihypertensive action?

NSAIDs raise mean blood pressure by 5 mm of mercury. the amount of blood pressure increase induced by NSAIDs is clinically relevant when NSAIDs are used chronically and may be of little importance in the short term. Short-term prescribing is most common in dentistry, and this fact may allow dentists to continue using NSAIDs when indicated to manage acute pain.

 What period of NSAID administration is required to affect antihypertensives?

An assessment of the agents used in dentistry shows that the minimum time for an effect has been 8 days for ibuprofen . Therefore, NSAID may be prescribed provided the duration is 4 days or less.

  • NSAIDs for a short duration to patients taking antihypertensives. Possible exceptions are those who are most susceptible to this interaction: patients who are elderly, have severe congestive heart failure or have low concentrations of renin. In these cases, use of acetaminophen is most appropriate.

NSAIDs and anticoagulants:

when an NSAID is combined with an anticoagulant such as warfarin, there is a potential for excessive bleeding. NSAIDs, and particularly aspirin, should not be taken by patients who are receiving anti- coagulant therapy. Avoidance is most important in elderly patients, as they are most susceptible to this adverse event.

NSAIDs and other NSAIDs or acetaminophen.

Associated with nephrotoxicity when used improperly, particularly when taken chronically or in combination with other NSAIDs or acetaminophen.

Aspirin and sulfonylureas (oral hypoglycemics).

An increase in hypoglycemic effect occurs.

Table 1, 2 showed adverse drug interactions in dentistry involving analgesics used for a period of less than five days.


Acetaminophen (Tylenol), commonly used to manage mild-to-moderate pain, has the advantage of providing analgesia without the side effects associated with NSAIDs or opioids. 

Acetaminophen is safe when taken in recommended dosages for a short duration, consistent with the management of acute pain in dentistry.

A number of drug interactions are reported, but the only one clinically relevant to dentistry is the result of acetaminophen’s combination with alcohol.