Do nonsteroidal anti-inflammatory drugs interfere with blood pressure control in hypertensive patients?

Current options for the treatment of resistant hypertension

Patients with resistant hypertension are those who have uncontrolled blood pressure despite use of three or more antihypertensive medications, or those who require four or more medications to achieve control. When evaluating resistant hypertension it is important to rule out pseudoresistant hypertension that may result from factors including poor blood pressure measurement technique and the white coat effect. Potential contributing factors should be identified and reversed if possible, including obesity, excess alcohol intake and use of interfering medications such as NSAIDS, sympathomimetics and oral contraceptives. Modification of lifestyle factors such as weight loss, sodium restriction and physical activity is paramount for treatment success. Secondary causes of hypertension are common in this patient group and, therefore, appropriate screening tests should be carried out as necessary. Pharmacologic therapy is centered on combination therapy of medications from different mechanisms of action, especially diuretics, which are essential in maximizing antihypertensive effects. The role of mineralocorticoid antagonists is expanding, especially in patients with obstructive sleep apnea and obesity where aldosterone excess may be implicated. Finally, when appropriate, specialist referral may facilitate blood pressure reduction and the ability to meet target blood pressure goals.

Prospects for changing the burden of nonsteroidal anti-inflammatory drug toxicity

Traditional nonsteroidal anti-inflammatory drugs (NSAIDs) increase the risk of clinically important upper gastrointestinal ulcers and bleeds about fourfold. Other risk factors for these events include advanced age, higher NSAID dose, prior ulcer or bleed, use of anticoagulants, use of corticosteroids, and poor general health. Among NSAID users with more than one risk factor, the incidence of serious ulcer complications may be as high as 4% to 8% per year. NSAIDs may also increase blood pressure and have adverse effects on renal function. NSAID-associated toxicity may be decreased by (1) trying less toxic alternative drugs; (2) using NSAIDs less frequently or at a lower dose; (3) use of cotherapy, such as misoprostol or proton pump inhibitors, to prevent complications; (4) or use of the more selective cyclooxygenase-2 inhibitors. More research is needed to determine which of these strategies or combination of strategies is optimal in terms of patient safety and cost.

Antagonism between the metabolic responses induced by epinephrine and piroxicam on isolated rat hepatocytes

Nonsteroidal anti-inflammatory drugs (NSAIDs) are one of the most employed therapeutic agents. They have a wide spectrum of biological effects, some of which are independent of cyclooxygenase inhibition, such as the alterations on the components of signal transduction systems. In particular, previous data from our laboratory suggested an antagonism between epinephrine and piroxicam, one of the most prescribed NSAIDs. Thus, this study deals with the epinephrine-piroxicam antagonism recorded for metabolic responses in isolated rat hepatocytes. The obtained results show that epinephrine stimulates lactate and ethanol consumption, stimulates glucose release from lactate only, and has no effect on cellular triacylglycerides content. Otherwise, in a dose-dependent basis, piroxicam stimulates lactate and ethanol consumption accompanied by an increase in triacylglycerides content, without changes in glucose release by hepatocytes. Piroxicam blocks the epinephrine-induced stimulation of glucose release from lactate, and epinephrine blocks the piroxicam-mediated increase in triacylglycerides content from lactate or ethanol. In contrast, the effects of epinephrine and piroxicam, promoting the consumption of lactate and ethanol, are not antagonized or added after the simultaneous administration of both compounds. This last result is probably related to the ability of both compounds to stimulate oxygen consumption. On isolated rat liver mitochondria, micromolar doses of piroxicam partially uncouple oxidative phosphorylation, and paradoxically stimulates an ATP-dependent mitochondrial function as citrullinogenesis. These results show for first time, on isolated rat hepatocytes, an antagonism between the metabolic responses of epinephrine and piroxicam, at the concentration found in plasma after its therapeutical administration.

Epidemiology of nonsteroidal anti-inflammatory drug-associated gastrointestinal injury

Nonaspirin, nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most frequently used drugs in many countries. Use of the majority of NSAIDs increases with age, primarily for symptoms associated with osteoarthritis and other chronic musculoskeletal conditions. Population-based studies have shown that, on any given day, 10-20% of elderly people (> or = 65 years old) have a current or recent NSAID prescription. Over a 6-month period in Alberta, Canada, 27% of elderly people were prescribed NSAIDs. Furthermore, in Tennessee (USA), 40% of elderly people received at least one NSAID prescription annually, and 6% had NSAID prescriptions for > 75% of the year. NSAIDs cause a wide variety of side-effects. The most clinically important side-effects are upper gastrointestinal tract dyspepsia, peptic ulceration, hemorrhage, and perforation, leading to death in some patients. Gastrointestinal side-effects are common; the most common NSAID-associated side-effect is epigastric pain/indigestion. Gastrointestinal side-effects are also a frequent reason both for withdrawal of NSAIDs and for co-treatment with another drug. Indeed, in two population-based studies of people aged > or = 65 years, the use of agents to prevent peptic ulcers or relieve dyspepsia was nearly twice as common in regular NSAID users (20-26%) than in non-NSAID users (11%). In Alberta, Canada, it has been estimated that NSAID use accounts for 28% of all prescriptions for anti-ulcer drugs in people aged at least 65 years. Many studies have now shown that NSAIDs increase the risk of peptic ulcer complications by 3-5-fold, and in several different populations it has been estimated that 15-35% of all peptic ulcer complications are due to NSAIDs. In the United States alone, there are an estimated 41,000 hospitalizations and 3,300 deaths each year among the elderly that are associated with NSAIDs. Factors that increase the risk of serious peptic ulcer disease include older age, history of peptic ulcer disease, gastrointestinal hemorrhage, dyspepsia, and/or previous NSAID intolerance, as well as several measures of poor health.

Nonsteroidal anti-inflammatory drugs and hypertension. The risks in perspective

Prostaglandins play an important role in cardiovascular homeostasis. Among other things, they promote vasodilation and enhance sodium excretion. Since they act as local hormones, it is difficult to assess their activity in the intact organism. Nonsteroidal anti-inflammatory drugs (NSAIDs) block the synthesis of prostaglandins, and thus may interfere with circulatory control. Indeed, many reports show that blood pressure may rise during treatment with one of these drugs. However, meta-analyses of such reports indicate that the rise in mean arterial pressure is relatively small, being approximately 5 mm Hg. At the present time, it is not known whether this confers any risk in terms of cardiovascular complications. Moreover, the trials on which this information is based are of relatively short duration. Whether the increment in blood pressure following administration of NSAIDs is sustained over time has not been established. Also, there is insufficient information regarding whether there are any special subgroups in the population who are at risk of developing hypertension during exposure to NSAIDs. Some data suggest that elderly people and patients with pre-existing hypertension carry an increased risk, notably when they are receiving antihypertensive treatment. Available data suggest that not all NSAIDs are equal as far as their effect on blood pressure is concerned. Sulindac, and perhaps also aspirin, seem to be less troublesome in this respect than other NSAIDs. This also applies to their effects on the kidney. Unfortunately, the mechanisms whereby NSAIDs may raise blood pressure are not fully understood. Interference with both the control of vascular resistance and the regulation of extracellular volume homeostasis has been incriminated, but several other putative mechanisms such as moderation of adrenergic activity or resetting of the baroreceptor response may also be involved. For the practising physician, it is wise to balance the risk of an increase in blood pressure against the expected benefit of treatment with an NSAID. In patients with (treated) hypertension and in the elderly, the benefits may not always outweigh the admittedly small risk. Should the physician nevertheless decide to prescribe an NSAID, frequent measurement of blood pressure may be necessary during the first weeks of treatment.

The problems and pitfalls of NSAID therapy in the elderly (Part II)

The elderly are most susceptible to pharmacokinetic drug interactions between various NSAIDs and anticoagulants, sulphonylurea hypoglycaemic agents, certain anticonvulsants, methotrexate, digoxin, aminoglycosides and lithium. Pharmacodynamic interactions between some NSAIDs and antihypertensive drugs, anticoagulants, sulphonylurea agents and other NSAIDs are also potentially significant in the elderly. Despite the finding that mean therapeutic responses of large groups of patients have been generally equivalent for the wide range of NSAIDs studied thus far, it is also apparent that marked variability exists in the response of individual patients to different NSAIDs. Subsequent dosage increments may predispose 'nonresponders' and some less sensitive 'responders' to toxicity from NSAIDs. This interindividual variability in response to NSAIDs may be contributed to by the differing physicochemical properties of NSAIDs, physician prescribing habits and patient expectations, variations in NSAID pharmacokinetics, and the differing effects of NSAIDs other than their common ability to inhibit prostaglandin synthesis. The principles for drug prescribing in the elderly are no different from those that should be applied to the prescribing of medication in any patient. The clinician should strive to make a diagnosis and should avoid treating symptoms in isolation. Critical assessment of the indication for prescribing NSAID therapy must include consideration of the available effective and safe alternatives. If an NSAID is commenced the lowest effective dose should be the desired goal, but after an appropriate trial it is acceptable clinical practice to employ an alternative NSAID. There is no justification for combination NSAID therapy. The progress of each patient must be carefully monitored, particularly during the first few months of treatment, while periodic review of the ongoing need for the NSAID is essential.

The effects of sulindac and diclofenac in essential hypertension controlled by treatment with a beta blocker and/or diuretic

A placebo-controlled, double blind crossover study of the non-steroidal anti-inflammatory drugs (NSAIDs) sulindac and diclofenac was conducted in 16 patients with essential hypertension that was controlled by treatment with a beta blocker, a diuretic or co-administration of both. In 4 cases, another antihypertensive agent (prazosin or verapamil) was also co-administered. In every patient, plasma creatinine concentration was less than 0.14 mmol/l (normal range 0.07-0.12 mmol/l). Sulindac and diclofenac were each given for 7 weeks. Diclofenac caused a decrease of borderline significance in plasma aldosterone concentration. Neither NSAID altered the mean values for systolic or diastolic blood pressure, body weight, plasma electrolyte concentrations, urate clearance, creatinine clearance or plasma renin activity. However, rises in plasma creatinine concentration and falls in creatinine clearance occurred during NSAID therapy in three individual subjects. No significant differences were observed in this study between the effects on renal function or blood pressure of sulindac and diclofenac, both of which appear not to interfere with the antihypertensive actions of beta blockers and diuretics.

Conducting a matched-pairs historical cohort study with a computer-based ambulatory medical record system

We describe techniques for using the Computer-Stored Ambulatory Record (COSTAR) at the Massachusetts General Hospital to conduct a historical cohort study of the effect of nonsteroidal anti-inflammatory drugs (NSAIDs) on blood pressure control. A query language was used to identify patients satisfying clinical and data-availability criteria, to match these patients with clinically similar patients not exposed to NSAIDs, and to collect data from the COSTAR records of both groups of patients to determine any differences in outcome. We analyzed over 30,000 patient records to select 90 pairs of patients used in the study. This approach to clinical research uses data collected for purpose of patient care and so does not require the separate recording of patient data for clinical research. Using computer-based medical record systems with a query language allows selection and matching of patients using detailed demographic and clinical criteria. The ability to conduct such studies is an advantage of computer-based medical record systems over the paper record system.

Effect of naproxen and sulindac on blood pressure response to atenolol

Twenty-eight patients with mild to moderate essential hypertension well controlled by atenolol entered a five-week, double-blind, placebo-controlled trial of the effects of sulindac and naproxen on blood pressure (BP) control. Atenolol alone was administered during weeks 1, 3, and 5. Naproxen or sulindac was administered with atenolol during week 2, with crossover during week 4. Data were analyzed for 27 of the patients (one dropped out after developing a skin rash). Naproxen significantly increased the systolic BP compared with placebo (mean 4.0 mm Hg; 95 percent confidence interval, 1.1-7.0; p less than 0.05). There were no significant differences in systolic BP during sulindac administration compared with placebo or naproxen. No significant effects on diastolic BP were observed. Weight was increased by naproxen and sulindac compared with placebo (mean 0.6-0.8 kg, p less than 0.05), although not to a clinically significant extent. One-week therapy with naproxen has a greater potential than sulindac to increase systolic BP in well-controlled hypertensive patients receiving atenolol; however, the increase is minor and unlikely to be of clinical significance.

Side-effects of non-steroidal anti-inflammatory drugs

Despite a continuing lack of good quality epidemiological studies, our knowledge of the side-effects of NSAIDs has advanced in recent years. The most important reactions are those which are related predictably to the pharmacology of the drugs and these need to be considered whenever a NSAID is prescribed, particularly for patients who can be identified as belonging to high-risk groups. The important reactions are: 1. Gastrointestinal damage, which is now known to extend to some degree from the oesophagus to the rectum, although the acid contact areas of the stomach and duodenum are the most important. Although the studies have produced heterogeneous results, NSAIDs probably double or triple the risk of an individual developing serious gastrointestinal haemorrhage or perforation. The risk increases with age and previous history of ulceration, and, in communities with particularly high use of NSAIDs, the drugs may account for up to 30% of all cases of ulcer complications. 2. Renal syndromes, of which functional renal impairment is the most important. This may precipitate cardiac failure, and hyperkalaemia is an additional hazard. Antagonism of the action of diuretics may contribute to the fluid retention, and antagonism of antihypertensive therapy is probably quite common and may result in additional unnecessary therapy. Patients at risk of functional renal impairment from NSAIDs can be identified readily and in these subjects the drugs have to be used with great care and with appropriate monitoring. 3. Respiratory effects, in particular acute bronchospasm in subjects with a history of aspirin sensitivity. NSAIDs should be used with caution in asthmatics, and patients purchasing NSAIDs without prescriptions need to be warned of these effects. Other uncommon serious reactions include hepatocellular damage, acute interstitial nephritis, agranulocytosis and aplastic anaemia, Stevens-Johnson syndrome and toxic epidermal necrolysis. These are unpredictable reactions which generally need not be considered before prescribing. However, in patients who present with any of these conditions, NSAIDs, because of their wide use, should always be considered as a possible cause.