Current P SYCHIATRY
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Primary care update Current p SYCHIATRY Hypertension Pitfalls to prescribing for patients with high blood pressure Edward Onusko, MD Assistant professor of family medicine University of Cincinnati College of Medicine Cincinnati, OH Chronic psychiatric disorders go hand-in-hand with risk factors for elevated blood pressure. Here are diagnostic and treatment strategies to help you detect comorbid hypertension and keep blood pressure in control. oughly 50 million adult Americans have hyperten- Causes of hypertension in mental illness R sion.1 Chances are some of them are—or soon will The Joint National Committee on Prevention, Detection, be—under your care. Evaluation, and Treatment of High Blood Pressure defines Hypertension is common among patients with psychi- elevated blood pressure as ≥ 140 mm Hg systolic and/or 90 atric disorders, particularly in those with chronic mental con- mm Hg diastolic. The diagnosis of hypertension should be ditions.2 Medication-associated weight gain and other reac- based on the average of two or more blood pressure readings tions to psychotropics, drug-drug interactions, lack of exer- at each of two or more visits after initial screening. cise, adverse dietary habits, and pre-existing medical condi- All patients with elevated blood pressure have an under- tions all predispose psychiatric patients to hypertension. lying physiologic abnormality that is causing their hyperten- Yet hypertension often goes undetected in psychiatric sion. The disorder falls within the following two categories: patients. Hypertension many times is asymptomatic—about • essential hypertension, emanating from an unknown 50% of all people with the disorder don’t even know they have cause it.3 Some symptoms of uncontrolled hypertension—fatigue, • secondary hypertension, resulting from an underlying, headache, palpitations, and dizziness—are also associated discoverable, often treatable cause. with many psychiatric disorders. As a result, psychiatrists may Researchers have speculated that certain psychiatric dis- attempt to manage the symptoms but miss the hypertension. orders might cause, or be risk factors for, hypertension. Psychiatrists need to be alert for hypertension, either as a Anxiety or panic disorders have been associated with acute possible contributing factor to a mental disorder or as a (and perhaps chronic) blood pressure elevations.2 Some potential side effect of a psychiatric disorder or treatment. research suggests that patients with alexithymia are at risk for The following diagnostic and treatment strategies will help developing hypertension.4 you detect and manage this common condition. Other studies suggest that hypertensive patients with VOL. 1, NO. 9/SEPTEMBER 2002 53 H ypertension certain psychological disorders (e.g., depression) or social selective serotonin reuptake inhibitors. Use of carbamazepine factors (e.g., substance abuse) are less likely than nonaffected with calcium-channel blockers can elevate carbamazapine patients to self-report the presence of hypertension and less levels and diminish the effectiveness of the calcium-channel likely to receive medical attention for it.5 blocker. Psychiatric drugs also may affect blood pressure by one of two mechanisms: Symptoms, complications of high blood pressure • Pharmacodynamic—direct effects at the site of action Symptoms that may be associated with high blood pressure (e.g., receptors) via physiologic mechanisms (Table 1). include headaches, dizziness, lightheadedness, fatigue, palpi- For example, amphetamines act directly on the sympa- tations, and chest discomfort. Patients may also experience thetic nervous system to elevate blood pressure. symptoms secondary to end-organ damage (e.g., shortness of breath from congestive heart Table 1 failure). POSSIBLE PHARMACODYNAMIC EFFECTS Most people, however, experi- OF PSYCHIATRIC MEDICATIONS ON BLOOD PRESSURE ence no symptoms when their blood pressure is elevated. This Psychiatric medication Effect on blood pressure is one reason most people with Amphetamines hypertension do not adequately Benzodiazepines Withdrawal may cause control their blood pressure. Tricyclic antidepressants or (postural hypotension or Aside from the long-term supine hypertension) end-organ damage caused by persistently elevated blood pres- Methylphenidate sure, hypertension also has been Monoamine oxidase inhibitors may precipitate an acute found to cause psychiatric disor- hypertensive crisis, especially with ders, though not directly. For foods with high tyramine content example, post-MI depression is (e.g., red wines, aged cheeses) well-recognized. Hypertension Lithium via direct effect on renal may also cause multi-infarct concentrating ability dementia with resultant depression, paranoia, or other Venlafaxine dose-related, <1% incidence psychotic features. Antipsychotics The psychological burden (both typical and atypical) of having chronic and usually incurable (though controllable) • Pharmacokinetic—indirect effects on blood pressure via hypertension may worsen depression or anxiety disorders. drug/drug interactions that alter the absorption, distrib- Patients with a chronic psychiatric illness generally have a ution, metabolism, or clearance of antihypertensive higher incidence of chronic medical problems. medications. Thiazide diuretics, angiotensin-converting Likewise, patients with chronic medical disorders have a enzyme (ACE) inhibitors, and salt intake restrictions higher incidence of psychiatric complaints.6 can raise lithium levels. The calcium-channel blockers verapamil and diltiazem can unpredictably increase or Patient evaluation decrease lithium levels, but the combination generally is When evaluating the patient with elevated blood pressure, it safe. Verapamil also raises tricyclic antidepressant levels. is important to: Monoamine oxidase inhibitors (MAOIs) used in tandem • detect and confirm hypertension with the antihypertensive reserpine can cause hypomania. • detect target-organ disease (e.g., renal damage or Beta-blocker levels are increased when used in concert with congestive heart failure) continued on page 57 54 Current VOL. 1, NO. 9 / SEPTEMBER 2002 p SYCHIATRY Current p SYCHIATRY continued from page 54 Table 2 ANTIHYPERTENSIVE MEDICATIONS AND SIDE EFFECTS Antihypertensive class Agent(s) Possible associated psychiatric symptoms Beta-adrenergic blocking agents Propranolol, atenolol, Fatigue, depression, psychosis, delirium, anxiety, metoprolol, others sexual dysfunction, nightmares, hallucinations* Angiotensin-converting enzyme Captopril, enalapril, Mania, anxiety, hallucinations (ACE) inhibitors lisinopril, ramipril, others Angiotensin II receptor blockers Losartan, valsartan, Probably same as ACE inhibitors (ARBs or AIIAs) others Diuretics Hydrochlorothiazide, Sexual dysfunction, depression furosemide Calcium-channel blockers Nifedipine, verapamil, Dizziness, headache, flushing, tachycardia, diltiazem depression Alpha-adrenergic blockers Prazosin, terazosin, Syncope, dizziness and vertigo, palpitations, doxazosin drowsiness, weakness, confusion Central alpha-adrenergic agonists Clonidine, methyldopa Drowsiness, sedation, fatigue, depression, impotence, delirium, psychosis, nightmares, amnesia Direct vasodilators Hydralazine, minoxidil Tachycardia, headache, dizziness Peripheral adrenergic Reserpine, guanadrel Drowsiness, depression, nightmares, neuron antagonists tardive dyskinesia *May occur with ophthalmic preparations • identify other cardiovascular risk factors (e.g., diabetes All other factors being equal, the sixth report of the Joint mellitus, hyperlipidemia, obesity) National Committee on Prevention, Detection, Evaluation • identify secondary causes of hypertension, such as and Treatment of High Blood Pressure (JNC-VI) recom- endocrine abnormalities (e.g., hyperaldosteronism, mends initial treatment with a diuretic or beta-blocker. thyroid disorders), kidney disease, obstructive sleep These classes of drugs have been shown to significantly apnea, and response to medications. reduce overall hypertension-related mortality. A thorough history and physical examination should be Most patients with hypertension—particu- performed to assess these four areas. Routine laboratory test- larly the elderly, patients with diabetes melli- ing for the hypertensive patient should include a urinalysis, a tus, and those with renal disease—will complete blood count, an assessment of blood chemistries need two or more agents to control (potassium, sodium, creatinine, fasting glucose, fasting lipid their blood pressure. Avoid prescrib- profile), and a 12-lead electrocardiogram. ing agents that may worsen an existing condition (e.g., beta-block- Treating hypertension ers may worsen bronchospasm in Many medications are used to treat hypertension. Most class- patients with asthma). Use agents that may help improve es of antihypertensive agents have been shown to be about comorbid conditions (e.g., beta-blockers have been shown to equally effective in lowering blood pressure. reduce mortality in patients with previous MI). VOL. 1, NO. 9/SEPTEMBER 2002 57 H ypertension Box As more is learned about genetic and other causes of THE FUTURE OF HYPERTENSION TREATMENT hypertension, more-effective treatments for hypertension could become available (Box). he Joint National Committee on Detection, Evaluation, Tand Treatment of High Blood Pressure (JNC), which Treating high-risk groups has issued six previous reports on hypertension control, Special considerations apply to two patient groups with a is expected to issue