Effect of pain and nonsteroidal analgesics on blood pressure.

Acute pain increases blood pressure by increasing sympathetic activity, but the role of chronic pain on blood pressure is less well understood. Hypertension and co-existing musculoskeletal problems are two of the common conditions for which antihypertensives and analgesics are prescribed together. Among analgesics, nonsteroidal anti-inflammatory drugs (NSAIDs) are most frequently prescribed. NSAIDs decrease the synthesis of prostaglandins (PG) by inhibiting cyclo-oxygenase, an enzyme essential for transformation of arachidonic acid into PGs. The PGs are important in control of blood pressure by virtue of their effects on the kidney and blood vessels. Among the NSAIDs, indomethacin, naproxen and piroxicam have the greatest, and sulindac the least, pressor effect. The NSAIDs antagonize the antihypertensive effect of diuretics, beta-blockers and ACE inhibitors more than that of calcium-channel blockers. The elderly and those with salt-sensitive hypertension experience greater rise in blood pressure with NSAIDs. Physicians should avoid NSAIDs and instead use alternative analgesics such as acetaminophen and physical therapy for control of pain. If necessary, the dose of the antihypertensive medications may have to be increased for better control of blood pressure. It is commonly believed that acute pain increases blood pressure. The effect of chronic pain is less well understood. Certain analgesics may affect blood pressure and may interfere with the effects of antihypertensive therapy. Since both pain and hypertension are common, it is important that their relationship be well understood by the primary care physicians.