Angiotensin II-Receptor Antagonists: An Overview

Raquel Dina and Mahtab Jafari

Disclosures

Am J Health Syst Pharm. 2000;57(13) 

In This Article

Eprosartan Mesylate

Eprosartan mesylate was the fourth selective nonpeptide AT-II type 1-receptor antagonist to gain approval for use in the treatment of hypertension in the United States. It was marketed by Unimed Pharmaceuticals in October 1999 under the name Teveten. After oral administration of a single dose of 300 mg of eprosartan, plasma concentration peaks in one to two hours in the fasted state.[59] Eprosartan is less bioavailable than other AT-II-receptor antagonists ( Table 1 ); this may be related to incomplete absorption. Eprosartan yields no active metabolites after oral administration. It is eliminated primarily in bile (90%) and to a lesser extent in urine (7%) as unchanged drug. There is negligible systemic accumulation of eprosartan with long-term use, so dosage adjustment is not warranted in patients with hepatic or renal disease.

When eprosartan is used as monotherapy in patients who are not volume depleted, a starting dosage of 600 mg once daily is recommended. If a further decrease in blood pressure is warranted, the dosage may be increased to 800 mg/day.[59,60] In most patients it may take two to three weeks of treatment to see a maximum response in blood pressure. When used in combination with other antihypertensive agents, such as thiazide diuretics and calcium-channel blockers, an additive effect is seen [61,62] ; however, a recommended starting dosage in this situation has not yet been established. Hypotension may occur in volume- or salt-depleted patients, so caution is needed in treating this patient population, and these conditions should be corrected before starting eprosartan therapy.

There appears to be a dose-response relationship between blood pressure decrease and dosage of eprosartan. [63] Neither the frequency of eprosartan administration nor an escalation in dosage is associated with an increase in adverse effects, as demonstrated by clinical studies that assessed dosages of up to 1200 mg/ day.[64] Eprosartan has a relatively safe tolerability profile, with headache (10%), upper-respiratory-tract infection (8%), and myalgia (4%) being the most commonly reported adverse events (rates similar to those for placebo). [62,65] There is an extremely low rate of hyperkalemia associated with eprosartan (<0.2%).

Eprosartan does not inhibit CYP450 isoenzymes and is not metabolized via this pathway. Thus, eprosartan would not be expected to inhibit the metabolism of drugs that require this enzyme system for elimination (such as warfarin), nor should it be prone to drug interactions mediated by this pathway.[61,67] When administered with warfarin, eprosartan had no apparent influence on the anticoagulatory effect of warfarin, as determined by the International Normalized Ratio.[68] In conclusion, no dosage adjustments are necessary when eprosartan is administered with warfarin, digoxin, or glyburide. [61,67,68,69]

Comments

3090D553-9492-4563-8681-AD288FA52ACE
Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.

processing....