Titrating antihypertensive meds
How soon after starting a patient on an antihypertensive medication should its effects be reviewed and the dosage adjusted?
—Bhavana Japi, MD, New Hyde Park, N.Y.
The timing of dosage adjustment depends on three factors: the class of medication, the severity of the hypertension, and the ability of the patient to follow home BP and titrate his own medication. If the hypertension is mild, it is customary to reassess after two to four weeks. If the hypertension is severe or symptomatic or if it is problematic because of comorbid problems, earlier titration is often needed. This may be considered after a few days, although it is preferable to wait a week or two, when the BP level is not an urgent issue.
For thiazide diuretics, one should wait at least a week in order to assess both BP response and effects on electrolytes before increasing dosage. Spironolactone is different: The full effect can take four to six weeks. It is wrong to assume that higher dosage is needed after only a week or two. The impact of calcium channel blockers on BP can be assessed within a few days (four to five days for the longer-acting amlodipine to reach steady state level). The full effect of ACE inhibitors and angiotensin receptor blockers (ARBs) takes three weeks, but most of the effect is apparent within a couple of days. The effect of beta blockers on BP depends on the pharmacokinetics of the beta blocker selected. Dosage can be titrated based on observed slowing of heart rate, usually apparent within a day or two. Alpha blockers can be adjusted after a day or two.
Dosage can be titrated more quickly in patients who monitor their BP at home. It is entirely appropriate to provide guidelines for dosage adjustment to patients who self-monitor their BP, particularly for calcium channel blockers, ACE inhibitors, and ARBs.
—Samuel J. Mann, MD (120-12)