Ambisome Side Effects, and Drug Interactions - Amphotericin B

Ambisome Side Effects, and Drug Interactions - Amphotericin B

SIDE EFFECTS

The following adverse events are based on the experience of 592 adult patients (295 treated with Am B isome and 297 treated with amphotericin B deoxycholate) and 95 pediatric patients (48 treated with Am B isome and 47 treated with amphotericin B deoxycholate) in Study 94-0-002, a randomized, double-blind, multi-center study in febrile, neutropenic patients. Am B isome and amphotericin B were infused over two hours.

The incidence of common adverse events (incidence of 10% or greater) occurring with Am B isome compared to amphotericin B deoxycholate, regardless of relationship to study drug, is shown in the following table:

Am B isome was well tolerated. Am B isome had a lower incidence of chills, hypertension, hypotension, tachycardia, hypoxia, hypokalemia, and various events related to decreased kidney function as compared to amphotericin B deoxycholate.

In pediatric patients (16 years of age or less) in this double-blind study, Am B isome compared to amphotericin B deoxycholate had a lower incidence of hypokalemia (37% versus 55%), chills (29% versus 68%), vomiting (27% versus 55%), and hypertension (10% versus 21%). Similar trends, although with a somewhat lower incidence, were observed in open-label, randomized Study 104-14 involving 205 febrile neutropenic pediatric patients (141 treated with Am B isome and 64 treated with amphotericin B deoxycholate). Pediatric patients appear to have more tolerance than older individuals for the nephrotoxic effects of amphotericin B deoxycholate.

The incidence of adverse events occurring in more than 10% of subjects in one or more arms regardless of relationship to study drug are summarized in the following table:

Infusion Related Reactions

In Study 94-0-002, the large, double-blind study of pediatric and adult febrile neutropenic patients, no premedication to prevent infusion related reaction was administered prior to the first dose of study drug (Day 1). Am B isome-treated patients had a lower incidence of infusion related fever (17% versus 44%), chills/rigors (18% versus 54%), and vomiting (6% versus 8%) on Day 1 as compared to amphotericin B deoxycholate-treated patients.

The incidence of infusion related reactions on Day 1 in pediatric and adult patients is summarized in the following table:

Cardiorespiratory events, except for vasodilatation (flushing), during all study drug infusions were more frequent in amphotericin B-treated patients as summarized in the following table:

The percentage of patients who received drugs either for the treatment or prevention of infusion related reactions (e.g., acetaminophen, diphenhydramine, meperidine and hydrocortisone) was lower in Am B isome-treated patients compared with amphotericin B deoxycholate-treated patients.

In the empirical therapy study 97-0-034, on Day 1, where no premedication was administered, the overall incidence of infusion related events of chills/rigors was signifcantly lower for patients administered Am B isome compared with amphotericin B lipid complex. Fever, chills/rigors and hypoxia were significantly lower for each Am B isome group compared with the amphotericin B lipid complex group. The infusion related event hypoxia was reported for 11.5% of amphotericin B lipid complex-treated patients compared with 0% of patients administered 3 mg/kg per day Am B isome and 1.2% of patients treated with 5 mg/kg per day Am B isome.

Day 1 body temperature increased above the temperature taken within 1 hour prior to infusion (preinfusion temperature) or above the lowest infusion value (no preinfusion temperature recorded).

Patients were not administered premedications to prevent infusion related reactions prior to the Day 1 study drug infusion.

There have been a few reports of flushing, back pain with or without chest tightness, and chest pain associated with Am B isome administration; on occasion this has been severe. Where these symptoms were noted, the reaction developed within a few minutes after the start of infusion and disappeared rapidly when the infusion was stopped. The symptoms do not occur with every dose and usually do not recur on subsequent administrations when the infusion rate is slowed.

Toxicity and Discontinuation of Dosing

In Study 94-0-002, a significantly lower incidence of grade 3 or 4 toxicity was observed in the Am B isome group compared with the amphotericin B group. In addition, nearly three times as many patients administered amphotericin B required a reduction in dose due to toxicity or discontinuation of study drug due to an infusion related reaction compared with those administered Am B isome.

In empirical therapy study 97-0-034, a greater proportion of patients in the amphotericin B lipid complex group discontinued the study drug due to an adverse event than in the Am B isome groups.

Less Common Adverse Events

The following adverse events also have been reported in 2% to 10% of Am B isome-treated patients receiving chemotherapy or bone marrow transplantation in five comparative, clinical trials:

Body as a Whole abdomen enlarged, allergic reaction, cellulitis, cell mediated immunological reaction, face edema, graft versus host disease, malaise, neck pain, and procedural complication.

Cardiovascular System arrhythmia, atrial fibrillation, bradycardia, cardiac arrest, cardiomegaly, hemorrhage, postural hypotension, valvular heart disease, vascular disorder, and vasodilatation (flushing).

Digestive System anorexia, constipation, dry mouth/nose, dyspepsia, dysphagia, eructation, fecal incontinence, flatulence, hemorrhoids, gum/oral hemorrhage, hematemesis, hepatocellular damage, hepatomegaly, liver function test abnormal, ileus, mucositis, rectal disorder, stomatitis, ulcerative stomatitis, and veno-occlusive liver disease.

Hemic & Lymphatic System anemia, coagulation disorder, ecchymosis, fluid overload, petechia, prothrombin decreased, prothrombin increased, and thrombocytopenia.

Metabolic & Nutritional Disorders acidosis, amylase increased, hyperchloremia, hyperkalemia, hypermagnesemia, hyperphosphatemia, hyponatremia, hypophosphatemia, hypoproteinemia, lactate dehydrogenase increased, nonprotein nitrogen (NPN) increased, and respiratory alkalosis.

Musculoskeletal System arthralgia, bone pain, dystonia, myalgia, and rigors.

Nervous System agitation, coma, convulsion, cough, depression, dysesthesia, dizziness, hallucinations, nervousness, paresthesia, somnolence, thinking abnormality, and tremor.

Respiratory System asthma, atelectasis, hemoptysis, hiccup, hyperventilation, influenza-like symptoms, lung edema, pharyngitis, pneumonia, respiratory insufficiency, respiratory failure, and sinusitis.

Skin & Appendages alopecia, dry skin, herpes simplex, injection site inflammation, maculopapular rash, purpura, skin discoloration, skin disorder, skin ulcer, urticaria, and vesiculobullous rash.

Special Senses conjunctivitis, dry eyes, and eye hemorrhage.

Urogenital System abnormal renal function, acute kidney failure, acute renal failure, dysuria, kidney failure, toxic nephropathy, urinary incontinence, and vaginal hemorrhage.

The following infrequent adverse experience have been reported in post-marketing surveillance, in addition to those mentioned above: angioedema, erythema, urticaria, cyanosis/hypoventilation, pulmonary edema, agranulocytosis, hemorrhagic cystitis.

Clinical Laboratory Values

The effect of Am B isome on renal and hepatic function and on serum electrolytes was assessed from laboratory values measured repeatedly in Study 94-0-002. The frequency and magnitude of hepatic test abnormalities were similar in the Am B isome and amphotericin B groups. Nephrotoxicity was defined as creatinine values increasing 100% or more over pretreatment levels in pediatric patients, and creatinine values increasing 100% or more over pretreatment levels in adult patients provided the peak creatinine concentration was >1.2 mg/dL. Hypokalemia was defined as potassium levels ≤2.5 mmol/L any time during treatment.

Incidence of nephrotoxicity, mean peak serum creatinine concentration, mean change from baseline in serum creatinine, and, incidence of hypokalemia in the double-blind randomized study were lower in the Am B isome group as summarized in the following table:

In empirical therapy study 97-0-034, the incidence of nephrotoxicity as measured by increases of serum creatinine from baseline was significantly lower for patients administered Am B isome (individual dose groups and combined) compared with amphotericin B lipid complex.

No formal clinical studies of drug interactions have been conducted with Am B isome. However, the following drugs are known to interact with amphotericin B and may interact with Am B isome.

Antineoplastic agents:   Concurrent use of antineoplastic agents may enhance the potential for renal toxicity, bronchospasm, and hypotension. Antineoplastic agents should be given concomitantly with caution.

Corticosteroids and corticotropin (ACTH):   Concurrent use of corticosteroids and ACTH may potentiate hypokalemia which could predispose the patient to cardiac dysfunction. If used concomitantly, serum electrolytes and cardiac function should be closely monitored.

Digitalis glycosides:   Concurrent use may induce hypokalemia and may potentiate digitalis toxicity. When administered concomitantly, serum potassium levels should be closely monitored.

Flucytosine:   Concurrent use of flucytosine may increase the toxicity of flucytosine by possibly increasing its cellular uptake and/or impairing its renal excretion.

Azoles (e.g. ketoconazole, miconazole, clotrimazole, fluconazole, etc.):  In vitro and in vivo animal studies of the combination of amphotericin B and imidazoles suggest that imidazoles may induce fungal resistance to amphotericin B. Combination therapy should be administered with caution, especially in immunocompromised patients.

Leukocyte transfusions:   Acute pulmonary toxicity has been reported in patients simultaneously receiving intravenous amphotericin B and leukocyte transfusions.

Other nephrotoxic medications:   Concurrent use of amphotericin B and other nephrotoxic medications may enhance the potential for drug-induced renal toxicity. Intensive monitoring of renal function is recommended in patients requiring any combination of nephrotoxic medications.

Skeletal muscle relaxants:   Amphotericin B-induced hypokalemia may enhance the curariform effect of skeletal muscle relaxants (e.g. tubocurarine) due to hypokalemia. When administered concomitantly, serum potassium levels should be closely monitored.