Are there over the counter medicines that I should avoid if I am taking high blood pressure medicine?

Experts believe that small elevations in blood pressure increase the risk of adverse cardiovascular events.1-4 Therefore, medications that cause even mild increases in blood pressure can negatively affect cardiovascular outcomes. 

At least one common over-the-counter cold medicine, pseudoephedrine, may increase blood pressure.5,6 

Chua et al. observed a significant increase in mean systolic blood pressure (SPB) (P < 0.03) in 20 hypertensive subjects in response to a single 60 mg dose of pseudoephedrine compared to placebo.6 SBP increased 2.1 ± 6.0 mm Hg in the placebo group compared to 5.0 ± 6.8 mm Hg in the pseudoephedrine group.6 However, other studies have found that pseudoephedrine does not increase blood pressure among those with controlled or moderate hypertension.7-9 Specifically, in a randomized, placebo controlled, double-blind, cross over study, Coates et al. studied the effect of pseudoephedrine on 25 patients with controlled hypertension (≤140/90 mm Hg).8 Participants were men and women, ages 31 to 68 years of age, on drug regimens that include calcium channel blockers, diuretics, or ACE inhibitors.8 Sixty milligrams of pseudoephedrine was administered four times a day for one week during the four week study.8 Throughout the study, and at the one-week post-study follow-up, there were no statistically significant differences in mean systolic and diastolic blood pressure among the groups.8 These findings suggest that 60 mg (or less) of pseudoephedrine may be used in patients with controlled hypertension without causing blood pressure to increase. 

Meta analyses have shown that NSAIDs increase blood pressure, decrease the efficacy of some antihypertensives, and increase the rate of vascular events10-13 For example, Johnson et al. found NSAIDs to be associated with a mean supine BP elevation of 5 mm Hg (CI: 1.2, 8.7 mm Hg).10 The effect was most significant in hypertensive people taking antihypertensive medications and least pronounced in normotensive volunteers not taking antihypertensive medication.10 While NSAIDs lowered the efficacy of all antihypertensives studied (beta blockers, vasodilators and diuretics) only the combination of NSAIDs and beta blockers resulted in a statistically significant blood pressure increase of 6.2 mm Hg (CI: 1.0, 11.4 mm Hg).10 A meta-analysis by Pope et al. also examined the effects of short-term NSAID use on mean arterial pressure (MAP) among hypertensives. Indomethacin and naproxen were associated with the greatest increase in MAP (unadjusted +4.77 mm Hg, adjusted for salt-intake +3.59 mm Hg and unadjusted +6.1 mm Hg, adjusted for salt-intake +3.74 mm Hg, respectively).11 Ibuprofen, aspirin and sulindac did not have a measurable effect on mean arterial pressure.11 

A meta-analysis by Bhala et al. investigated the impact of NSAIDs on major vascular events, major coronary events, stroke, mortality, heart failure, and upper gastrointestinal complications compared to placebo.12 Coxibs and diclofenac increased the rate of major vascular events (rate ratio [RR] 1.37, 95% CI 1.14-1.66; p=0.0009; and RR 1.41, 95% CI 1.12-1.78; p=0.0036, respectively). Ibuprofen significantly increased the rate of major coronary events (RR 2.22, 95% CI 1.10-4.48; p=0.0253), but not major vascular events (RR 1.44, 0.89-2.33), whereas naproxen did not significantly increase the rate of major vascular events (0.93, 0.69-1.27). Similarly, a meta-analysis by Trelle et al., analyzed cardiovascular safety of NSAIDs.13 Compared to placebo rofecoxib (RR 2.12, CI: 95% 1.26-3.56) and lumiracoxib (RR 2.0, 0.71-6.21) were associated with a higher risk of myocardial infarction.13 Ibuprofen was associated with the highest risk of stroke (RR 3.36, 1.0-11.6), followed by diclofenac (RR 2.86, CI: 1.09-8.36).13 Diclofenac was also associated with the highest risk of death (RR 3.98, 1.48-12.7).13 

As a result of such analyses, the Food and Drug Administration (FDA) now requires manufacturers to include information about cardiovascular risks in the package inserts for both prescription and over-the-counter NSAIDs.14 

A systematic review conducted by Tsai et al. examined drug interactions and contraindications of herbal and dietary supplements. St. John’s Wort had a specific interaction with Calcium Channel Blockers (CCB’s) by reducing the effectiveness of CCBs via the Cytochrome P450 3A4 pathway.15 The following herbal supplements were found to be contraindicated for use among patients with hypertension: American ginseng, Asian ginseng, bitter orange, ginkgo, goldenseal, mate, and Siberian ginseng.15  More specifically, patients taking spironolactone experience an increased risk for hyperkalemia when taking arginine supplements.15  Potassium supplements can also increase the risk of hyperkalemia in patients taking ACE inhibitors or diuretics.15  In another systematic review, Tachjian et al. found the herbal products fumitory, lily of the valley and night-blooming cereus increase the effects of beta-blockers and calcium channel blockers.16 Gossypol increases the effects of diuretics while Irish moss, kelp and licorice may increases the effects of all antihypertensives.16 

References

1. Collaboration BPLTT. Effects of different blood-pressure-lowering regimens on major cardiovascular events: results of prospectively-designed overviews of randomised trials. The Lancet. 2003;362(9395):1527-1535.
2. Trialists’Collaboration BPLT. Effects of different regimens to lower blood pressure on major cardiovascular events in older and younger people: meta-analysis of randomised trials. Bmj. 2008;336:1121-1123.
3. Lewington S, Clarke R, Qizilbash N, Peto R, Collins R. Age-specific relevance of usual blood pressure to vascular mortality: a meta-analysis of individual data for one million adults in 61 prospective studies. Lancet (London, England). Dec 14 2002;360(9349):1903-1913.
4. Collins R, Peto R, MacMahon S, et al. Blood pressure, stroke, and coronary heart disease. Part 2, Short-term reductions in blood pressure: overview of randomised drug trials in their epidemiological context. Lancet (London, England). Apr 07 1990;335(8693):827-838.
5. Reference PD. Prescribers Digital Reference. 2016.
6. Chua SS, Benrimoj SI, Gordon RD, Williams G. A controlled clinical trial on the cardiovascular effects of single doses of pseudoephedrine in hypertensive patients. British journal of clinical pharmacology. Sep 1989;28(3):369-372.
7. Bradley JG, Kallail KJ, Dorsch JN, Fox J. The effect of pseudoephedrine on blood pressure in patients with controlled, uncomplicated hypertension: a randomized, double-blind, placebo-controlled trial. The Journal of the American Board of Family Practice. 1991;4(4):201-206.
8. Coates ML, Rembold CM, Farr BM. Does pseudoephedrine increase blood pressure in patients with controlled hypertension? Journal of Family Practice. Vol 401995:22+.
9. Greening G. The effect of an antihistamine-pseudoephedrine drug on the blood pressure of moderate hypertensives. Current therapeutic research, clinical and experimental. 1969;11(5):252-255.
10. Johnson AG, Nguyen TV, Day RO. Do nonsteroidal anti-inflammatory drugs affect blood pressure? A meta-analysis. Annals of internal medicine. Aug 15 1994;121(4):289-300.
11. Pope JE, Anderson JJ, Felson DT. A meta-analysis of the effects of nonsteroidal anti-inflammatory drugs on blood pressure. Archives of internal medicine. Feb 22 1993;153(4):477-484.
12. Bhala N, Emberson J, Merhi A, et al. Vascular and upper gastrointestinal effects of non-steroidal anti-inflammatory drugs: meta-analyses of individual participant data from randomised trials. Lancet (London, England). Aug 31 2013;382(9894):769-779.
13. Trelle S, Reichenbach S, Wandel S, et al. Cardiovascular safety of non-steroidal anti-inflammatory drugs: network meta-analysis. Bmj. 2011;342:c7086.
14. Blankfield RP, Iftikhar IH. Food and drug administration regulation of drugs that raise blood pressure. Journal of cardiovascular pharmacology and therapeutics. Jan 2015;20(1):5-8.
15. Tsai HH, Lin HW, Simon Pickard A, Tsai HY, Mahady GB. Evaluation of documented drug interactions and contraindications associated with herbs and dietary supplements: a systematic literature review. International Journal of Clinical Practice. 2012;66(11):1056-1078.
16. Tachjian A, Maria V, Jahangir A. Use of herbal products and potential interactions in patients with cardiovascular diseases. Journal of the American College of Cardiology. 2010;55(6):515-525.