Fosinopril / hydrochlorothiazide Side Effects

Not all side effects for fosinopril / hydrochlorothiazide may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

For the Consumer

Applies to fosinopril / hydrochlorothiazide: oral tablet

In addition to its needed effects, some unwanted effects may be caused by fosinopril / hydrochlorothiazide. In the event that any of these side effects do occur, they may require medical attention.

You should check with your doctor immediately if any of these side effects occur when taking fosinopril / hydrochlorothiazide:

Less common
  • Blurred vision
  • chest pain or discomfort
  • chills
  • cold sweats
  • confusion
  • decreased urination
  • dizziness, faintness, or lightheadedness when getting up from a lying or sitting position suddenly
  • dry mouth
  • fainting
  • fast, slow, or irregular heartbeat
  • muscle cramps or pain
  • numbness, tingling, pain, or weakness in hands or feet
  • rapid breathing
  • seizures
  • sunken eyes
  • sweating
  • thirst
  • trembling
  • unusual tiredness or weakness
  • weakness and heaviness of legs
  • wrinkled skin

Some of the side effects that can occur with fosinopril / hydrochlorothiazide may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

More common
  • Cough
Less common
  • Body aches or pain
  • diarrhea
  • difficult breathing
  • ear congestion
  • fever
  • headache
  • loss of voice
  • muscle or bone pain
  • nasal congestion
  • nausea and vomiting
  • runny nose
  • sneezing
  • sore throat
  • weakness

For Healthcare Professionals

Applies to fosinopril / hydrochlorothiazide: oral tablet


Fosinopril-hydrochlorothiazide (HCTZ) was evaluated for safety in over 660 patients with hypertension (approximately 137 of these patients were treated for more than 1 year; most patients were treated for 2 months). Adverse drug events (ADEs) led to discontinuation of therapy in 3.5% of treated patients, compared to 4.3% of placebo patients. The most common reasons for discontinuation of therapy were headache (0.3%), cough (0.3%), and fatigue (0.2%). The observed ADEs were generally mild, transient, and similar to those observed after use of fosinopril or HCTZ alone.


Hyperuricemia may be an important consideration in patients with a history of gout. Hypophosphatemia and low serum magnesium concentrations may occur, but are usually clinically insignificant except in malnourished patients.

HCTZ monotherapy has been associated with increased total serum cholesterol by 11%, LDL lipoprotein cholesterol by 12%, and VLDL lipoprotein cholesterol levels by 50%. Its use has also been association with decreased insulin secretion. As a single agent, therefore, it has been used cautiously in diabetic patients and in those with hypercholesterolemia. True glucose intolerance may develop in approximately 3% of patients. It is typically reversible within 6 months after discontinuation of therapy.

Metabolic side effects associated with the use of HCTZ (hypokalemia and hypercholesterolemia) are uncommon with the addition of fosinopril. In fact, total cholesterol may decrease in some patients with pretreatment hypercholesterolemia. (Fosinopril appears to have a favorable effect on the lipid profile. Data show that total serum cholesterol and lipoprotein A levels are significantly decreased during fosinopril therapy relative to placebo.)

Conversely, the hyperkalemia associated with the use of fosinopril monotherapy (2% of patients) is uncommon due to the opposing effects of HCTZ. Risk factors for the development of hyperkalemia include preexisting renal disease, diabetes mellitus, and the concomitant use of potassium-sparing diuretics.

HCTZ monotherapy is associated with hypomagnesemia, hypercalcemia, and elevated serum uric acid levels.


Hypersensitivity reactions have been associated with the use of either fosinopril or HCTZ in less than 1% of patients. However, these reactions (usually rash or pruritus without urticaria [fosinopril] or nausea, vomiting, diarrhea, and rash [HCTZ]) have occasionally been severe. Hypersensitivity reactions to angiotensin converting enzyme (ACE) inhibitors may be life threatening. Angioedema of the face, extremities, lips, tongue, glottis and/or pharynx have been reported rarely in patients receiving ACE inhibitors. In addition, intestinal angioedema has been reported in patients treated with ACE inhibitors. It is recommended that any patient with dyspnea, dysphagia, or significant facial angioedema stop therapy immediately and avoid ACE inhibitor therapy in general.

Hypersensitivity (usually nausea, vomiting, diarrhea, and rash) has been reported in less than 1% of patients receiving hydrochlorothiazide. Rare cases of acute pulmonary edema, interstitial cystitis, and interstitial nephritis, and anaphylaxis have been reported.

There have been approximately 34 known cases of thiazide-induced pulmonary edema, encompassing 52 episodes of pulmonary edema, as of 1991 (per a 1996 review). In some cases, doses as small as 12.5 mg were associated with the development of pulmonary edema. The average time to onset of this adverse reaction is 44 minutes, women carry a relative risk of 9:1, and the average age is 56 years. The mortality rate is 6%. Some experts consider this side effect grossly underreported.

Patients with intestinal angioedema generally present with abdominal pain (with or without nausea or vomiting) and in some cases there was no prior history of facial angioedema, and C-1 esterase levels were normal. These symptoms resolve after stopping the ACE inhibit

Nervous system

Nervous system side effects have included headache (7%), dizziness (3.2%), and tinnitus (less than 2%). Nervous system side effects associated with the use of fosinopril monotherapy have included lightheadedness, fatigue, dizziness, and headache in up to 3% of patients. Rare cases of cerebrovascular insufficiency have been associated with HCTZ-induced plasma volume contraction.


A 67-year-old woman with hypothyroidism, hypercalcemia, depression, and hypertension developed facial erythema, headaches, tremors, confusion and personality changes associated with a new positive ANA and anti-nRNP, and a skin biopsy consistent with lupus erythematosus while taking HCTZ, levothyroxine, and amitriptyline. The eruption resolved upon discontinuation of HCTZ, but she later developed a higher ANA titer associated with symptomatic diffuse interstitial pulmonary infiltrates. She was successfully treated with corticosteroids.

Dermatologic reactions to HCTZ have included case reports of erythema annular centrifugum, acute eczematous dermatitis, and morbilliform and leukocytoclastic vasculitis. Thiazides may induce phototoxic dermatitis. In addition, a rare, distinct entity with clinical and laboratory features indistinguishable from those of subacute cutaneous lupus erythematosus has been associated with the use of HCTZ.


Renal side effects including new or worsened renal insufficiency has been associated with the use of either fosinopril or HCTZ. The mechanism is probably either fosinopril-induced hypotension and/or HCTZ-induced intravascular volume depletion. Fosinopril-HCTZ-induced renal insufficiency is more likely in patients with a history of congestive heart failure, preexisting renal insufficiency, renal artery stenosis, or sodium or intravascular volume depletion. These patients are relatively more dependent on the renin-angiotensin-aldosterone axis to maintain systemic blood pressure compared with patients without CHF. Rare cases of interstitial nephritis have been associated with the use of HCTZ.


Cardiovascular side effects including orthostatic hypotension has been observed in approximately 2% of patients. The risk of hypotension is increased in the presence of heart failure. The use of some ACE inhibitors has been associated with "first-dose" hypotension, and the use of HCTZ has been associated with the development of orthostatic hypotension with or without syncope, particularly in the elderly. Significant fosinopril-HCTZ-induced hypotension can result in oliguria, azotemia, and (rarely) acute renal failure and death, particularly in patients with preexisting heart failure, regardless of the presence of preexisting renal insufficiency.

Cardiac arrhythmias, including ventricular ectopy and complete AV heart block, have been associated with HCTZ-induced hypokalemia and hyponatremia . However, these side effects are far less likely in the presence of fosinopril.

Should significant hypotension associated with fosinopril-HCTZ occur, experts recommend placing affected patients in the supine position and administration of intravenous physiologic saline.


Gastrointestinal side effects have included nausea, vomiting, diarrhea, dyspepsia, heartburn, general abdominal pain, dysgeusia, gastritis, esophalgia, and dry mouth have been associated with the use of the combination drug in less than 2% of patients. Rare cases of pancreatitis and acute cholecystitis have been associated with the use of HCTZ monotherapy.

The use of thiazide diuretics has been associated with increased serum cholesterol and triglycerides, which has rarely resulted in an increased risk of cholesterol gallstone formation. Reports of bowel strictures associated with thiazide ingestion have been reported in the 1960's although these patients were on a combination HCTZ-potassium product.


A retrospective study has revealed a significantly higher incidence of discontinuation of ACE inhibitor therapy due to cough among black patients compared to non-black patients (9.6% vs. 2.4%).

Several agents have been studied for treating cough with ACE inhibitors. No long term trials exist to allow a definitive treatment option. Cromolyn has the most data showing some benefit. Other agents studied include baclofen, theophylline, sulindac, and benzonatate.

Upper respiratory tract infections, including sinus congestion, pharyngitis, or rhinitis have been associated with the use of fosinopril-HCTZ. A causal relationship has not been established, and, in some trials, the incidence was similar among placebo patients.

Respiratory side effects associated with the use of fosinopril have been mainly limited to an idiosyncratic cough in approximately 2% to 5% of patients. A rare syndrome of cough, bronchospasm, and eosinophilia has been rarely associated with the use of fosinopril. There have been approximately 30 case reports of acute noncardiogenic pulmonary edema (thought to be due to idiosyncrasy or hypersensitivity) associated with the use of HCTZ.


Immunologic side effects associated with the use of HCTZ have been rare, and have included case reports of allergic vasculitis and hemolytic anemia. There have been numerous case reports of patients developing a rash histologically identical to subacute cutaneous lupus following HCTZ administration.


Hepatic side effects associated with the use of fosinopril or other ACE inhibitors have included a rare syndrome that begins with cholestatic jaundice and progresses to fulminant hepatic necrosis and (sometimes) death. Experts recommend discontinuation of therapy with this drug if jaundice or markedly elevated hepatic serum enzymes develop.


Hematologic side effects associated with the use of either fosinopril or other ACE inhibitors have included agranulocytosis and neutropenia. Use of HCTZ has rarely been associated with the development of immune-complex hemolytic anemia, aplastic anemia, and thrombocytopenia.


Genitourinary complaints of impotence have been associated with the use of fosinopril in 1% of male patients.


Musculoskeletal side effects have only rarely been associated with the use of thiazide-type diuretics or this combination product, and have included myalgias and chills.


A prospective study of 34 patients who received oral thiazide-type diuretics for 14 years without interruption revealed an increased average fasting blood glucose level after treatment. Withdrawal of thiazide therapy for 7 months in 10 of the patients resulted in average reductions of 10% in the fasting blood glucose and 25% in the 2-hour glucose tolerance test values. A control group was not reported.

Endocrinologic problems associated with the use of thiazide-type diuretics have included glucose intolerance and a potentially deleterious effect on the lipid profile. This may be important in some patients with or who are at risk for diabetes or coronary artery disease. A single case of recurrent parathyroid adenoma has also been reported, although the association is probably coincidental.

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