Interaction between oxprenolol and indomethacin on blood pressure in essential hypertensive patients

Abstract

A double-blind, cross-over study in 16 patients with essential hypertension was carried out, to evaluate any possible interference by indomethacin, a known prostaglandin-synthetase inhibitor, with the antihypertensive effect of oxprenolol, a non-selective beta-adrenoceptor blocking agent. Both indomethacin and oxprenolol, as well as the two drugs combined, inhibited plasma renin activity; no change was found in urinary sodium excretion or body weight. Oxprenolol alone caused a highly significant decrease in the systolic ( - 10.4 mmHg, p less than 0.001), diastolic ( - 7.4 mmHg, p less than 0.001) and mean ( - 7.7 mmHg, p less than 0.01) blood pressures, whereas indomethacin did not influence blood pressure. When the two drugs were given in combination, blood pressure decreased (systolic: - 5.9 mmHg; diastolic: - 4.0 mmHg; mean: - 4.6 mmHg), but the changes induced in blood pressure were reduced by about 50% when compared with those in the oxprenolol alone period. The data show that indomethacin seems to interfere with the antihypertensive effect of oxprenolol, by an action which may be due to the inhibition of prostaglandin synthesis.

The influence of indomethacin and sulindac on some pharmacological actions of atenolol in hypertensive patients.

“…In both protocols, indomethacin significantly reduced (circa 40-50%) the antihypertensive action of atenolol, while sulindac did not affect it. The first finding confirms that indomethacin can increase blood pressure in patients treated with atenolol (Salvetti et al, 1982b) as well as with other /8-adrenoceptor blockers (Durao & Rico, 1977;Lopez-Ovejero et al, 1978;Salvetti et al, 1982a;Salvetti & Pedrinelli, 1982). The lack of effect of sulindac extends to atenolol treated patients a finding which has been previously observed in captopril treated individuals (Salvetti et al, 1982c).…”

Flurbiprofen interaction with single doses of atenolol and propranolol.

“…For example, the antihypertensive efficacy of propranolol (Durao et al, 1977;Watkins et al, 1980), oxprenolol (Salvetti et al, 1982a) and atenolol (Salvetti et al, 1982b) appear to be attenuated by indomethacin. In contrast, other NSAID such as sulindac (Salvetti et al, 1983), naproxen and aspirin (Chalmers et al, 1983) appear not to be implicated in such effects.…”

Amlodipine and haemodynamic effects of cyclo‐oxygenase inhibition.

“…Brief courses of treatment with NSAIDs can increase blood pressure and reduce the efficacy of many antihypertensives administered chronically [7], particularly ,-adrenoceptor blockers and diuretics [15,16]. Evidence of effects on the efficacy of ACE inhibitors [17] is more limited.…”