Pacerone Side Effects
Generic Name: amiodarone
Note: This page contains side effects data for the generic drug amiodarone. It is possible that some of the dosage forms included below may not apply to the brand name Pacerone.
It is possible that some side effects of Pacerone may not have been reported. These can be reported to the FDA here. Always consult a healthcare professional for medical advice.
For the Consumer
Applies to amiodarone: oral tablet
Other dosage forms:
As well as its needed effects, amiodarone (the active ingredient contained in Pacerone) may cause unwanted side effects that require medical attention.
If any of the following side effects occur while taking amiodarone, check with your doctor immediately:More common
- dizziness, lightheadedness, or fainting
- fever (slight)
- numbness or tingling in the fingers or toes
- painful breathing
- sensitivity of the skin to sunlight
- shortness of breath
- trembling or shaking of the hands
- trouble with walking
- unusual and uncontrolled movements of the body
- weakness of the arms or legs
- Blue-gray coloring of the skin on the face, neck, and arms
- blurred vision or blue-green halos seen around objects
- dry eyes
- dry, puffy skin
- fast or irregular heartbeat
- pain and swelling in the scrotum
- sensitivity of the eyes to light
- sensitivity to heat
- slow heartbeat
- swelling of the feet or lower legs
- trouble with sleeping
- unusual tiredness
- weight gain or loss
- Skin rash
- yellow eyes or skin
- Abdominal or stomach pain
- back, leg, or stomach pains
- bleeding gums
- blistering, peeling, or loosening of the skin
- blood in the urine
- bloody, black, or tarry stools
- blue lips, fingernails, or skin
- blurred or double vision
- chest pain
- clay-colored stools
- confusion as to time, place, or person
- coughing or spitting up blood
- cracks in the skin
- dark urine
- decreased urine output
- difficult or labored breathing
- difficult urination
- dry cough
- eye pain
- fast heartbeat
- general body swelling
- high fever
- holding false beliefs that cannot be change by fact
- inability to have or keep an erection
- irregular, fast or slow, or shallow breathing
- joint or muscle pain
- large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
- loss in sexual ability, desire, drive, or performance
- loss of heat from the body
- lower back or side pain
- mood or mental change
- muscle cramps or spasms
- muscle pain or stiffness
- muscle twitching
- no breathing
- noisy breathing
- pain in the abdomen, groin, or scrotum
- pain or burning with urination
- pains in the stomach, side, or abdomen, possibly radiating to the back
- pale skin
- pinpoint red spots on the skin
- rapid weight gain
- red skin lesions, often with a purple center
- red, irritated eyes
- red, swollen skin
- scaly skin
- seeing, hearing, or feeling things that are not there
- severe headache
- sore throat
- sores, ulcers, or white spots on the lips or in mouth
- swelling of the face, ankles, or hands
- swelling of the scrotum
- swollen or painful glands
- tightness in the chest
- troubled breathing
- unpleasant breath odor
- unusual bleeding or bruising
- unusual excitement, nervousness, or restlessness
- unusual tiredness or weakness
- vomiting of blood
Some amiodarone side effects may not need any medical attention. As your body gets used to the medicine these side effects may disappear. Your health care professional may be able to help you prevent or reduce these side effects, but do check with them if any of the following side effects continue, or if you are concerned about them:More common
- loss of appetite
- nausea and vomiting
- Bitter or metallic taste
- decrease in sexual interest
- decreased sexual ability in males
- flushing of the face
For Healthcare Professionals
Applies to amiodarone: compounding powder, intravenous solution, oral tablet
Amiodarone-induced ocular side effects are time- and dose-dependent. The most commonly affected ocular structure is the cornea with punctuate opacities occurring in 69% to 100% of patients. Lenticular changes may include anterior, subcapsular, small, yellow-white punctuate opacities.
The incidence of optic neuropathy, the most severe ocular side effect of amiodarone (the active ingredient contained in Pacerone) ranges from 0.36% to 2%. Amiodarone-related optic neuropathy has been characterized as having an insidious onset, slow progression, bilateral vision loss, and protracted disc edema. In one report which was based on 50 cases, the median duration of treatment until onset of vision loss was 4 months. In one case, vision loss occurred after 24 months of treatment. It should be noted that because of similar clinical features, amiodarone-induced optic neuropathy can be confused with idiopathic nonarteritic anterior ischemic optic neuropathy.
Ocular side effects have been reported the most frequently and have included corneal microdeposits (up to 98%) which only rarely caused visual halos or blurred vision, corneal opacities, lenticular changes, loss of eyelashes or eyebrows, papilledema, photosensitivity, scotoma, macular degeneration, and optic neuropathy or optic neuritis.
Cardiovascular side effects have included hypotension (10% to 30%), bradycardia (1% to 10%), worsening heart failure (1% to 5%), asystole/cardiac arrest/electromechanical dissociation (3.5%), cardiogenic shock (3%), congestive heart failure (2.2%), ventricular tachycardia (1.8%), second- and third-degree AV nodal block (less than 2%), AV heart block (1%), and Torsades de pointes (0.7%). Rarely, cases of ventricular fibrillation have been reported. Hypotension, vasculitis, and sinus arrest have been reported in postmarketing experience. One- year sudden death has been reported. A case of endocarditis and pleuropericardial effusion has been reported.
Limited data have shown that the incidence of one-year sudden death was markedly and significantly increased in patients with advanced heart failure and a history of torsades de pointes taking amiodarone compared with such patients who were not taking amiodarone.
The results of a meta-analysis indicate that use of amiodarone for the prevention of postoperative atrial fibrillation increases the risk of developing bradycardia and hypotension. However, other meta- analyses have shown that the use of amiodarone in the same setting reduced the rate of postoperative atrial fibrillation and stroke.
Amiodarone-induced pulmonary toxicity (AIPT) occurs with an incidence of 1% to 17%, typically manifests as acute pneumonitis and chronic fibrosis, and can be life threatening. In general, AIPT develops in 0.1% to 0.5% of patients that take up to 200 mg daily and 5% to 15% of patients that take 500 mg or more daily. AIPT has proven fatal in approximately 5% to 10% of cases when patients were on dosages of more than 400 mg daily; however, in patients who develop acute respiratory failure due to AIPT and require ventilation, mortality is 50% to 100%. AIPT may occur early in therapy or after several years of treatment. Patients with preexisting pulmonary disease are at an increased risk of developing AIPT. The proposed mechanism of lung damage is the accumulation of phospholipids in the lungs. AIPT is reversible if diagnosed early. The more common form of AIPT is associated with doses of 400 mg daily or more, it has an insidious onset, typically manifests after 2 or more months of therapy and is characterized by a progressive nonproductive cough, dyspnea, weight loss, and possibly fever.
Respiratory side effects including chronic pulmonary fibrosis have been reported in 1% to 7% of patients. Bronchial asthma has also been reported. Rarely, acute respiratory failure and pneumonitis have been reported. Pulmonary infiltrates, alveolar hemorrhage, bronchospasm, wheezing, fever, dyspnea, cough, hemoptysis, hypoxia, pleuritis, possibly fatal respiratory distress, respiratory failure, respiratory arrest, acute respiratory distress syndrome, and bronchiolitis obliterans organizing pneumonia have been reported in postmarketing experience. There have been additional postmarketing reports of eosinophilic pneumonia, pleural effusion, and acute respiratory distress syndrome in the postoperative setting.
Endocrine side effects have included thyroid abnormalities (30%), hyper- and hypothyroidism (5% to 10%), and thyrotoxicosis. Rare cases of thyroiditis have been reported. Syndrome of inappropriate antidiuretic hormone secretion (SIADH), thyroid nodules, and thyroid cancer have been reported in postmarketing experience.
A 67-year-old male with SIADH developed hyponatremia. Although common comorbid conditions associated with SIADH were excluded as possible causes, his drug regimen and medical history were extensive. However, he had been taking spironolactone, amiodarone, and simvastatin for less than 3 months. The patient's serum sodium level began to rise within 3 days of discontinuation of amiodarone and returned to normal within 1 month.
Amiodarone-induced hypothyroidism occurs more frequently in iodine- sufficient regions than in iodine-deficient regions. It also occurs more frequently in female and elderly patients than in male or younger patients. Clinical manifestations of amiodarone- induced hypothyroidism may include fatigue, lethargy, bradycardia, dyspnea, cold intolerance, dry skin, weight gain, constipation, and reduced appetite.
Amiodarone-induced thyrotoxicosis (AIT) occurs more frequently in iodine-deficient regions and it primarily occurs in men (male to female ratio 3:1). AIT may develop in patients with or without preexisting thyroid dysfunction and at anytime during therapy including following discontinuation of treatment. In patients with AIT, laboratory results will reveal marked increases in the serum levels of thyroxine (T4) and possibly triiodothyronine (T3). When AIT occurs in patients with preexisting thyroid dysfunction (e.g., goiter, Grave's disease) it is referred to as AIT type I. When AIT occurs in patients without preexisting thyroid dysfunction it is referred to as AIT type II. AIT type II may be related to destructive inflammatory thyroiditis, caused by the cytotoxic effects of amiodarone and its metabolites on thyroid cells, which results in glandular damage and subsequent leakage of preformed thyroid hormones. Clinical manifestations of AIT may include palpitations, supraventricular tachycardia, weight loss, sweating, muscle weakness, tremor, insomnia, and mood swings. In type I AIT, serum levels of interleukin-6 are normal or slightly elevated, 24-hour uptake of radioactive iodine by the thyroid gland is normal to high, and there is an increase in vascularity. In type II AIT, serum levels of interleukin-6 are markedly increased, 24-hour uptake of radioactive iodine by the thyroid gland is low to none, and vascularity is normal. It should be noted that a patient may also have a mixture of type I and II AIT where the different features of the two types may coexist.
Gastrointestinal side effects including anorexia have been reported in 2% to 20% of patients. Nausea, vomiting, constipation, and altered taste have been reported.
Hypersensitivity side effects including photosensitivity have been reported in 70% of patients. Toxic epidermal necrolysis and exfoliative dermatitis have been reported rarely. Anaphylactic/anaphylactoid reaction (including shock), angioedema, Stevens-Johnson syndrome, and erythema multiforme have been reported in postmarketing experience. A case of drug-induced lupus erythematosus has been reported. Postmarketing reports have included drug rash with eosinophilia and systemic symptoms.
A hypersensitivity (possible cross reactivity) reaction (i.e., lip swelling and tingling) to oral amiodarone (the active ingredient contained in Pacerone) has been described in a patient with a previous history of hypersensitivity to an iodinated radiocontrast agent.
Immunologic side effects have been reported rarely. These have included polyserositis and cutaneous leukocytoclastic vasculitis.
In one case report, a patient developed hepatic cirrhosis associated with microvesicular steatosis after 22.5 months of low-dose (200 mg daily) oral amiodarone (the active ingredient contained in Pacerone) therapy.
According to the results of a retrospective study (n=720), the prevalence of significant liver dysfunction in patients taking oral amiodarone with or without elevated baseline alanine aminotransferase (ALT) is similar. The authors suggest that amiodarone may be safety administered to patients with elevated baseline ALT, but recommend close monitoring of liver function.
Hepatic side effects including symptomatic elevations in liver function tests have been reported in 50% of patients. Rarely, fatal cases of cirrhosis have been reported. A single case of hepatitis with pancreatitis has been reported. Jaundice has been reported. Hepatitis, cholestatic hepatitis, pancreatitis, and cirrhosis have been reported in postmarketing experience.
Dermatologic side effects have included photosensitivity (24% to 57%) and blue/gray skin discoloration (1% to 7%). Rarely, cases of toxic epidermal necrolysis, exfoliative dermatitis, reversible alopecia, bullous dermatosis, linear IgA disease, cutaneous vasculitis, and pustular psoriasis have been reported. Exfoliative dermatitis, toxic epidermal necrolysis, skin cancer, and pruritus have been reported in postmarketing experience. Additional postmarketing reports have included urticaria and eczema.
A retrospective study of 44 patients found by univariate analysis that patients who experienced dermatologic side effects were younger than patients who did not (mean age 48 years vs. 60 years, respectively). Patients younger than 60 years were more likely to develop photosensitivity or blue-gray skin discoloration than those 60 years or older.
In one study of 102 patients treated for a mean duration of nine months, 45 (44%) developed some sort of neurotoxic reaction that required discontinuation of therapy. The most frequent findings were tremor in 44, peripheral neuropathy in 10, and ataxia in 7 patients.
Nervous system side effects have been reported the most frequently. These have included tremor (9% to 59%), ataxia (2% to 37%), and peripheral neuropathy (1% to 10%). Dyskinesia, disorientation, confusion, paresthesias, headache, sleep disturbances, impaired memory, ataxia, diplopia, proximal muscle weakness, acute narcotizing myopathy, acute intracranial hypertension, and pseudotumor cerebri have been reported. Pseudotumor cerebri, confusional state, disorientation, and parkinsonian symptoms such as akinesia and bradykinesia (sometimes reversible upon discontinuation of therapy) have been reported in postmarketing experience. Also, there have been spontaneous reports of demyelinating polyneuropathy.
Hematologic side effects have been reported rarely. Cases of bone marrow suppression resulting in normocytic, normochromic anemia or thrombocytopenia have been reported. Granuloma formation and neutropenia have been reported. Agranulocytosis, hemolytic anemia, aplastic anemia, pancytopenia, neutropenia, thrombocytopenia, and granuloma have been reported in postmarketing experience.
A 45-year-old male with Wolff-Parkinson-White syndrome developed diffuse petechiae and ecchymoses associated with thrombocytopenia two weeks after beginning amiodarone. The patient's lymphocytes showed a high stimulation index using amiodarone, but not with other antiarrhythmic agents, such as quinidine. The platelet count returned to normal after amiodarone was stopped and prednisone was given. Rechallenge two months later resulted in recurrent thrombocytopenia.
A 63-year-old male with atrial fibrillation developed bone marrow granulomas after 17 months of treatment with amiodarone. The patient's course was suggestive of amiodarone-induced granulomas, although a definitive cause was not determined.
A 71-year-old male with a history of chronic lymphatic leukemia underwent amiodarone therapy after developing atrial fibrillation. Four weeks after amiodarone therapy was initiated, the patient developed neutropenia which later resolved seven days after discontinuation.
In a series of 30 consecutive patients started on amiodarone (the active ingredient contained in Pacerone) and followed for 12 months, 28 (93%) developed a mean increase in the serum creatinine of 11%. Two patients were excluded from analysis. One had previous exposure to amiodarone, which was consider a confounding variable, and one had severe congestive heart failure, which was considered the probable cause of decreased renal function in that case. No patient had renal insufficiency that warranted discontinuation of therapy. Amiodarone may alter creatinine renal tubular secretion or creatinine release by muscle. It is not known whether amiodarone affects the vascular tone of the afferent or efferent arterioles of the renal glomeruli.
Renal side effects including renal insufficiency, acute renal failure, and renal impairment have been reported in postmarketing experience.
A 66-year-old male with refractory ventricular tachycardia developed psychotic delusions 17 days after beginning amiodarone (the active ingredient contained in Pacerone) therapy. The delirium persisted after the addition of benzodiazepines and when all drugs except amiodarone were discontinued. Delusions resolved one week after amiodarone was stopped. The patient subsequently did well after substitution with flecainide.
Psychiatric side effects including altered mental status, hallucinations, and delirium have been reported in postmarketing experience.
A significant correlation between the development of epididymitis and prolonged therapy with high dose amiodarone (the active ingredient contained in Pacerone) has been noted in the urological literature. In one series of 56 men who were treated with amiodarone, an atypical epididymitis syndrome developed in 6, of whom 5 had bilateral scrotal swelling. The mean daily dose was 700 mg and the mean duration of amiodarone therapy at the time of presentation ranged from 7 to 15 months.
Genitourinary side effects have been reported rarely. These have included noninfectious epididymitis, testicular dysfunction, and male impotence. Epididymitis and impotence have been reported in postmarketing experience.
Metabolic side effects have included increased total serum cholesterol and triglycerides, decreased glucose tolerance, and increased or decreased thyroid hormone secretion.
Local side effects have included thrombophlebitis.
Oncologic side effects have included basal cell carcinoma.
Musculoskeletal side effects including myopathy, muscle weakness, and rhabdomyolysis have been reported in postmarketing experience.
Generally, checking amiodarone (the active ingredient contained in Pacerone) blood levels has limited clinical usefulness since there is wide interpatient variability in the blood amiodarone level and toxicity profile. Side effects occurred more frequently with prolonged administration (greater than 6 months) and appeared to be related to the total cumulative dose. Although as many as 80% of patients have had some side effects, discontinuation of therapy because of serious or disturbing toxicity has occurred in only 10% to 15% of patients.
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