Fosinopril
Mechanism :
Fosinopril is a phosphonic acid-containing ester prodrug that belongs to the angiotensin-converting enzyme (ACE) inhibitor class of medications. It is rapidly hydrolysed to fosinoprilat, its principle active metabolite. Fosinoprilat inhibits ACE, the enzyme responsible for the conversion of angiotensin I (ATI) to angiotensin II (ATII). ATII regulates blood pressure and is a key component of the renin-angiotensin-aldosterone system (RAAS).
Indication :
- Mild to moderate hypertension
Contraindications :
Hypersensitivity, ACE inhibitor angioedema, Hereditary angioedema, Idiopathic angioedema.
Dosing :
Hypertension:
Under 50 kg:
0.1-0.6 mg/kg orally once daily.
Over 50 kg:
5-10 mg orally once a day initially, Max: 40 mg/day.
Adverse Effect :
Common Reactions: Fatigue, hypotension, dizziness, cough, musculoskeletal pain, hyperkalemia, nausea/vomiting, elevated BUN, creatinine, photosensitivity, hyperuricemia.
Serious Reactions: Anaphylactoid reactions, neutropenia agranulocytosis, pancreatitis, Stevens-Johnson syndrome.
Interaction :
Potassium: Combining fosinopril with potassium supplements, potassium containing salt substitutes, or potassium-conserving diuretics such as amiloride, spironolactone and triamterene, can lead to dangerously high blood levels of potassium (hyperkalemia) since fosinopril tends to reduce the excretion of potassium.
Aluminium or Magnesium: Fosinopril should not be taken at the same time as aluminium or magnesium-based antacids, such as simethicone or Maalox since these antacids bind fosinopril and decrease the amount of fosinopril that is absorbed from the intestine.
Antacids: Patients should take antacids and fosinopril at least two hours apart.
Renal Dose :
Dose in Renal Impairment GFR (mL/min)
| 20-50 | Dose as in normal renal function |
| 10-20 | Dose as in normal renal function. Start with low dose |
| <10 | Dose as in normal renal function. Start with low dose |
Dose in Patients undergoing Renal Replacement Therapies
| CAPD | Not dialysed. Dose as in GFR<10 mL/min |
| HD | Not dialysed. Dose as in GFR<10 mL/min |
| HDF/High flux | Unlikely to be dialysed. Dose as in GFR<10 mL/min |
| CAV/VVHD | Unlikely to be dialysed. Dose as in GFR=10–20 mL/min |
Hepatic Dose :
Fosinopril clearance is approximately one-half in patients with hepatic impairment. Treatment should be initiated at a lower dose.