TELMISARTAN

TELMISARTAN (tel-mi-sar'tan) Micardis Classifications: angiotensin ii receptor antagonist, antihypertensive; Therapeutic: antihypertensive, angiotensin ii receptor antagonist Prototype: Losartan potassium Pregnancy Category: C first trimester; D second and third trimester

Availability

40 mg, 80 mg tablets

Action

Angiotensin II receptor (type AT₁) antagonist. Selectively blocks the binding of angiotensin II to the AT₁ receptors in many tissues (e.g., vascular smooth muscles, adrenal glands). Blocks the vasoconstricting and aldosterone-secreting effects of angiotensin II, thus resulting in an antihypertensive effect.

Therapeutic Effect

Effectiveness is indicated by a reduction in BP.

Uses

Treatment of hypertension.

Contraindications

Hypersensitivity to telmisartan or other angiotensin receptor antagonists (e.g., losartan, eprosartan, etc.); pregnancy (category C first trimester; category D second and third trimester), lactation.

Cautious Use

Coronary artery disease (CAD); hypertropic cardiomyopathy; CHF; oliguria; hypotension; renal artery stenosis; older adult patients; biliary obstruction; liver dysfunction; renal impairment. Safety and efficacy in children <18 y are not established.

Route & Dosage

Hypertension Adult: PO 40 mg q.d., may increase to 80 mg/d

Administration

Oral

• Do not remove tablets from blister pack until immediately before administration.
• Correct volume depletion prior to initial dose.
• Store at 15°–30° C (59°–86° F).

Adverse Effects (≥1%)

Body as a Whole: Back pain, flu-like syndrome, myalgia, headache, fatigue. CNS: Dizziness. CV: Hypotension, hypertension, chest pain, peripheral edema. GI: Diarrhea, dyspepsia, abdominal pain, nausea. Respiratory: Sinusitis, pharyngitis.

Interactions

Drug: Telmisartan may increase digoxin levels.

Pharmacokinetics

Absorption: Absorption is dose dependent, 42% of 40 mg dose is absorbed. Peak: 0.5–1 h. Distribution: >99% protein bound. Metabolism: Minimally metabolized. Elimination: Primarily in feces as unchanged drug. Half-Life: 24 h.

Nursing Implications

Assessment & Drug Effects

• Monitor BP carefully after initial dose; and periodically thereafter. Monitor more frequently with preexisting biliary obstructive disorders or hepatic insufficiency.
• Monitor dialysis patients closely for orthostatic hypotension.
• Lab tests: Periodic Hgb, creatinine clearance, liver enzymes.
• Monitor concomitant digoxin levels throughout therapy.

Patient & Family Education

• Report pregnancy to physician immediately.
• Allow between 2–4 wk for maximum therapeutic response.

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Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug