FOSINOPRIL (fos-in'o-pril)
Monopril Classifications: angiotensin-converting enzyme (ace) inhibitor; antihypertensive agent; Therapeutic: antihypertensive; ace inhibitor Prototype: Enalapril Pregnancy Category: C first trimester; D second and third trimesters
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Availability
10 mg, 20 mg, 40 mg tablets
Action
Lowers BP by interrupting conversion sequences initiated by renin that lead to formation of angiotensin II, a potent vasoconstrictor.
Inhibition of ACE also leads to decreased circulating aldosterone, a secretory response to angiotensin II stimulation.
Therapeutic Effect
Lowers blood pressure and reduces peripheral arterial resistance (afterload) and improves cardiac output as well as activity
tolerance.
Uses
Mild to moderate hypertension, CHF.
Contraindications
Hypersensitivity to fosinopril or any other ACE inhibitor; history of angioedema; renal artery stenosis; pregnancy [category
C (first trimester), category D (second or third trimester)], lactation.
Cautious Use
Impaired kidney function, hepatic disease; hyperkalemia, or surgery and anesthesia; aortic stenosis or cardiomyopathy; elderly.
Safety in children is not established.
Route & Dosage
Hypertension, CHF Adult: PO 540 mg once/d (max: 80 mg/d)
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Administration
Oral
- Discontinue diuretics 23 d before initiation of therapy if possible. If diuretics cannot be discontinued, start initial
dose ≤10 mg.
- Store at 15°30° C (59°86° F) and protect from moisture.
Adverse Effects (≥1%)
CV: Hypotension.
CNS: Headache,
fatigue, dizziness.
Endocrine: Hyperkalemia.
GI: Nausea, vomiting,
diarrhea.
Urogenital: Proteinuria.
Respiratory: Cough.
Skin: Rash.
Interactions
Drug: nsaids may decrease antihypertensive effects of fosinopril.
potassium supplements,
potassium-sparing diuretics increase risk of hyperkalemia.
ACE inhibitors may increase
lithium levels and
toxicity.
Pharmacokinetics
Absorption: Readily absorbed from GI tract; converted to its active form, fosinoprilat, in the liver.
Peak: 3 h.
Duration: 24 h.
Distribution: Approximately 90% protein bound; crosses placenta.
Metabolism: Hydrolyzed by intestinal and
hepatic esterases to its active form, fosinoprilat.
Elimination: 44% in urine, 46% in feces.
Half-Life: 34 h (fosinoprilat).
Nursing Implications
Assessment & Drug Effects
- Monitor BP at the time of peak effectiveness, 26 h after dosing and at the end of the dosing interval just before next
dose.
- Report diminished antihypertensive effect toward the end of the dosing interval. An inadequate trough response may be an indication
for dividing the daily dose.
- Monitor for first-dose hypotension, especially in salt- or volume-depleted patients.
- Lab tests: Obtain BUN and serum creatinine periodically. Increases may necessitate dose reduction or discontinuation of the
drug. Monitor serum potassium.
- Observe for S&S of hyperkalemia (see Appendix F).
Patient & Family Education
- Discontinue fosinopril and report to physician any of the following: S&S of angioedema (e.g., swelling of face or extremities,
difficulty breathing or swallowing); syncope; chronic, nonproductive cough.
- Maintain adequate fluid intake and avoid potassium supplements or salt substitutes unless specifically prescribed by the physician.
- Report vomiting or diarrhea to physician immediately.