Kenneth Iwuji MDa, Hezekiah Sobamowo MDb, James Tarbox MDc, Rose Egbe MDd
Correspondence to Kenneth Iwuji MD. Email: Kenneth.Iwuji@ttuhsc.edu
SWRCCC 2016;4(16): 67-70
doi: 10.12746/swrccc2016.0416.224
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Keywords: angioedema, angiotensin-converting enzyme inhibitor, nephrotic syndrome
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Angiotensin converting enzyme (ACE) inhibitor induced angioedema can occur with single or repeated drug exposure. In most cases, angioedema is a diagnosis of exclusion when there is no other explanation for the patient’s facial, airway, and extremity swelling. Facial edema involving the upper lips should raise suspicion for angioedema in an atraumatic patient.
This is a case of a 40-year-old Caucasian woman with a past medical history of grade II diastolic heart failure, hypertension, hyperlipidemia, type 2 diabetes mellitus, hypoalbuminemia, and nephrotic range proteinuria. She presented to the hospital with a 6-month history of bilateral lower extremity swelling, periorbital edema, swelling of the upper lip, and vague generalized abdominal pain. Two months ago she had a similar presentation and was treated in the hospital with diuretics for 3 days and discharged home with moderate resolution of her symptoms. During this hospitalization, she denied any shortness of breath, orthopnea, headache, changes in mental status, vision changes, fever, cough, or chest pain. She admitted to having nausea with no vomiting, vague generalized abdominal discomfort with an approximate 10 pound weight gain, and inability to open her eyes due to periorbital edema.
Relevant physical examination revealed clear lung sounds, normal S1 and S2 heart sounds with no murmurs, no jugular venous distention, and no acute distress. Some positive findings in this patient were periorbital edema, significant swelling of the upper lips, 2+ bilateral lower extremity pitting edema, and mild generalized abdominal tenderness to palpation.
Current medications included bumetanide, codeine/ acetaminophen as needed for pain, gabapentin, gemfibrozil, metoprolol, simvastatin, and lisinopril which was increased from 5mg to 30mg/day during her last hospitalization.
Laboratory findings included a normal complete blood count result, serum sodium 143mmol/L, serum creatinine of 0.9 mg/dL, blood urea nitrogen of 16 mg/dL, total serum protein 5.2 g/dL, albumin 2.3 g/ dL, hemoglobin A1C 5.2%, urine microalbumin 440, urine protein 1,040 mg/dL, urine random protein/creatinine ratio 17.4, and 24 hour urine protein 12,728 mg. Abdominal ultrasound, chest X-ray, and abdominal CT scan showed no acute pathology. Left renal ultrasound guided biopsy showed diabetic nephropathy with nodular glomerulosclerosis.
With intensive diuretic therapy, fluid restriction, and strict intake and output, patient’s lower extremities edema resolved, but there was no improvement in the facial, periorbital and upper lips edema. Other causes of the facial swelling were considered. She had a normal chest X-ray, normal ejection fraction on recent echocardiogram, normal serum sodium with improving serum albumin and urinary protein. Review of her medications indicated that the patient had been on lisinopril 5 mg per day for renoprotection from diabetic nephropathy which was recently increased to 30 mg during the last hospitalization. Two days after this increase, she started noticing the leg swelling, periorbital edema and upper lips swelling. Angiotensinconverting enzyme inhibitor induced angioedema was suspected and the lisinopril was discontinued.
Twenty four hours after discontinuation of the lisinopril, her facial swelling, periorbital edema and upper lips swelling completely cleared. Complements C3, C4, C1 esterase inhibitor assay (functional and quantitative) and C1q level were tested for hereditary and acquired angioedema. All these results came back normal. Patient was discharged home the next day, and lisinopril was added to her allergy list.
Epidemiology
Angiotensin-converting enzyme inhibitors are
the leading cause of drug-induced angioedema in the
United States because they are widely prescribed
for several common medical problems. Angiotensin-converting enzyme inhibitors cause angioedema in
0.1 to 0.7 percent of recipients.1-3 This percentage
may seem low for a drug adverse effect; considering
that 40 million patients in the United States are taking
some form of ACE-inhibitor, it makes this adverse effect
not uncommon.1
Pathophysiology
Angiotensinogen, a prometabolite that is
produced by the liver, is converted to angiotensin I
by renin in the kidneys. Angiotensin converting enzyme
metabolizes angiotensin I to angiotensin II in
the lungs. Angiotensin II helps regulate blood pressure
by acting as a vasoconstrictor. It binds to angiotensin
II receptors in the vasculatures and causes
vasoconstriction resulting in an increase in the blood
pressure. Angiotensin II also inactivates bradykinin,
a nine amino acid peptide that increases capillary
permeability and causes vasodilation. Angiotensinconverting
enzyme inhibitors prevent the conversion
of angiotensin I to II and cause the accumulation of
bradykinin. Impaired bradykinin metabolism leads to
release of other metabolites, such as nitric oxide and
prostaglandin resulting in vasodilation, an increase in
vascular permeability, and a decrease in blood pressure.4 For reasons not well understood, some patients
are prone to developing impaired bradykinin metabolism
from ACE-inhibitors that results in angioedema.
In these patients, bradykinin levels are high while on
ACE-inhibitors and return to normal after withdrawal.11
Clinical Presentation
Angioedema is a nonpitting edema that generally
affects the nondependent areas of the body, such
as the lips, tongue, face, upper airway and intestinal
wall, and causes symptoms, such as diffuse abdominal
pain, nausea, vomiting, and diarrhea. With ACEinhibitor
induced angioedema, there is no itching or
urticaria, and if present, other etiologies need to be
investigated. Potential risk factors for ACE-inhibitor
induced angioedema include a previous history of
angioedema, age older than 65 years, female sex,
smoking, African American race, and underlying C1
esterase inhibitor dysfunction.5-6
Angioedema related to ACE-inhibitors can occur at the beginning of therapy, during dose increases as in the case of our patient, or at any time during the course of treatment.6,9 The severity of angioedema ranges from mild facial and lip swelling to airway obstruction requiring endotracheal intubation. Some fatalities with ACE-inhibitor induced angioedema have been reported.4 Whenever a patient has unexplainable symptoms, careful medication review is warranted.
Diagnosis
Angioedema is a clinical diagnosis made by
careful review of the patient history, detailed physical
examination, and medication review. Angiotensinconverting
enzyme inhibitor induced angioedema
still remain a diagnosis of exclusion with most cases
resolved after a few days of being off the medication,
yet some studies note persistence months later.11
Functional and quantitative levels of C1 esterase inhibitor,
C3, and C1q could then be ordered to confirm
the diagnosis.
Treatment
Treatment mostly involves supportive care
by stopping the causative agent and monitoring the
patient very closely for signs of airway compromise
and possible cardiovascular collapse. Antihistamines,
corticosteroids, and epinephrine are commonly used
during acute episodes; however, these medications
are often not effective for ACE-inhibitor induced angioedema.12 A recent study by Bas et al. showed that
icatibant, a bradykinin B2 receptor antagonist, led to
a significantly faster resolution of angioedema compared
to antihistamine and glucocorticoids. C1 esterase
inhibitors, ecallantide (a kallikrein inhibitor), and
fresh frozen plasma have also been used effectively
in the treatment of ACE-inhibitor induced angioedema.12
Angiotensin converting enzyme inhibitor induced angioedema can occur anytime during the course of treatment with ACE-inhibitors. Prompt recognition and treatment will help minimize the severity and potential life threatening situations that can result.
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