Regular acetaminophen use and blood pressure in people with hypertension: The PATH-BP trial
Double-blind, placebo-controlled, crossover study (n=110) found regular paracetamol was associated with an increase in mean daytime systolic and diastolic BP (placebo-corrected increase of 4.7 mm Hg [95% CI 2.9–6.6] and 1.6 mm Hg [0.5–2.7], respectively).
Source:
Circulation
SPS commentary:
A related editorial notes the PATH-BP study overcomes several limitations of previous studies and provides strong additional evidence in support of a clinically important BP-elevating effect of paracetamol in patients with pre-existing hypertension. Yet, there remain some unanswered questions, including whether these BP effects translate to increased cardiovascular risk, and also the generalisability of the results (most studies have been short-term; it is not known if these effects continue with chronic treatment).
It goes on to note the exact mechanism through which paracetamol may increase BP is unknown, but previous research suggests it may inhibit COX-2 isoenzymes, similar to NSAIDs. If this mechanism is responsible for the effect of paracetamol on BP, then it seems reasonable to assume that it may blunt antihypertensive efficacy of some antihypertensive classes. The authors conclude the results of this study “should at least give us pause in routinely recommending paracetamol as a ‘safe’ alternative to chronic NSAID use, especially in patients with, or at risk of developing, hypertension”.