The effect of nonsteroidal anti-inflammatory drugs on blood pressure in patients treated with different antihypertensive drugs.

Hypertension and arthritis are both common diseases in the older age group and require pharmacologic treatment. Nonsteroidal anti-inflammatory drugs (NSAIDs) alter renal function if given in high enough doses, reducing renal blood flow and the glomerular filtration rate and causing sodium retention. In salt sensitive subjects, this retention of sodium will cause blood pressure to rise. Salt sensitivity is more common in elderly patients, in diabetics, and in people with renal failure. When most antihypertensive drugs are used, people become salt sensitive, as shown by the additive effect of salt restriction or diuretics on blood pressure response. The responses to dihydropyridine and possibly other calcium channel blocking drugs are not affected to any major extent by sodium intake or by diuretics. Studies are described which indicate that indomethacin elevates blood pressure in elderly people treated with enalapril, but not in people whose blood pressure is controlled with amlodipine or felodipine. It is unclear whether the various NSAIDs have different effects on blood pressure. It is proposed that if the same analgesic effect is achieved with the same amount of cyclooxygenase inhibition, the response will be similar. Aspirin, used in a prophylactic dose, does not inhibit to this extent and does not elevate blood pressure. If elderly people require NSAIDs, it would appear that dihydropyridine calcium channel blocking drugs are more effective at lowering and maintaining blood pressure control and should be one of the drugs used. If patients are on other antihypertensive agents, it is important to monitor blood pressure when a NSAID is added to therapy.