"The U.S. Food and Drug Administration yesterday approved Obizur [Antihemophilic Factor (Recombinant), Porcine Sequence] for the treatment of bleeding episodes in adults with acquired hemophilia A (acquired Factor VIII [FVII] deficiency).
The most serious adverse reactions in patients receiving Rh0(D) immune globulin have been observed in the treatment of ITP. These reactions include intravascular hemolysis, clinically compromising anemia, acute renal insufficiency, and, very rarely, DIC and death (see Warnings and Precautions ).
The most common adverse reactions observed in the use of Rhophylac® (immune globulin intravenous (human) solution) for suppression of Rh isoimmunization are nausea, dizziness, headache, injection-site pain, and malaise.
The most common adverse reactions observed in the treatment of ITP are chills, pyrexia/increased body temperature, and headache. Mild extravascular hemolysis (manifested by an increase in bilirubin and a decrease in hemoglobin) was also observed.
Clinical Studies Experience
Because clinical studies are conducted under different protocols and widely varying conditions, adverse reaction rates observed cannot be directly compared to rates in other clinical trials and may not reflect the rates observed in practice.
Suppression of Rh Isoimmunization
In two clinical studies, 447 Rh0(D)-negative pregnant women received either an intravenous or intramuscular injection of Rhophylac® (immune globulin intravenous (human) solution) 1500 IU (300 mcg) at Week 28 of gestation. A second 1500 IU (300 mcg) dose was administered to 267 (9 in Study 1 and 258 in Study 2) of these women within 72 hours of the birth of an Rh0(D)-positive baby. In addition, 30 women in Study 2 received at least one extra antepartum 1500 IU (300 mcg) dose due to obstetric complications (see Clinical Studies).
The most common adverse reactions were nausea (0.7%), dizziness (0.5%), headache (0.5%), injection-site pain (0.5%), and malaise (0.5%). A laboratory finding of a transient positive anti-C antibody test was observed in 0.9% of subjects. All adverse reactions were mild to moderate in intensity.
In a clinical study, 98 Rh0(D)-positive adult subjects with chronic ITP received an intravenous dose of Rhophylac® 250 IU (50 mcg) per kg body weight (see Clinical Studies ). Premedication to alleviate infusion-related side effects was not used except in a single subject who received acetaminophen and diphenhydramine.
Adverse reactions were mild to moderate in intensity with the exception of one case of severe headache. Eighty-four (85.7%) subjects experienced 392 treatment-emergent adverse events (TEAEs). Sixty-nine (70.4%) subjects had 186 drug-related TEAEs (defined as TEAEs with a probable, possible, definite, or unknown relationship to the study drug). Within 24 hours of dosing, 73 (74.5%) subjects experienced 183 TEAEs, and 66 (67%) subjects experienced 156 drug-related TEAEs.
Mild extravascular hemolysis, manifested as an increase in bilirubin, a decrease in hemoglobin, or a decrease in haptoglobin, was observed, as expected when an anti-D product is given to an Rh-positive individual. An increase in blood bilirubin was seen in 21% of subjects. The median decrease in hemoglobin was greatest (0.8 g/dL) at Day 6 and Day 8 following administration of Rhophylac® (immune globulin intravenous (human) solution) .
Table 2 shows the most common TEAEs observed in the clinical study.
Table 2: Most Common Treatment-Emergent Adverse Events (TEAEs) in Subjects With ITP
|TEAE|| Number of Subjects (%)With a TEAE
| Number of Subjects (%) Witha Drug-Related
|Chills||34 (34.7%)||34 (34.7%)|
|Pyrexia/ Increased body temperature||32 (32.6%)||30 (30.6%)|
|Increased blood bilirubin||21 (21.4%)||21 (21.4%)|
|Headache||14 (14.3%)||11 (11.2%)|
|* Defined as TEAEs with a possible, probable, definite, or unknown relationship to the study drug.|
Serious adverse events (SAEs) were reported in 10 (10.2%) subjects. SAEs considered to be drug-related were intravascular hemolytic reaction (hypotension, nausea, chills and headache, and a decrease in haptoglobin and hemoglobin) in two subjects; headache, dizziness, nausea, pallor, shivering, and weakness requiring hospitalization in one subject; and an increase in blood pressure and severe headache in one subject. All four subjects recovered completely.
Because postmarketing reporting of adverse reactions is voluntary and from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to product exposure. Evaluation and interpretation of these postmarketing reactions is confounded by underlying diagnosis, concomitant medications, pre-existing conditions, and inherent limitations of passive surveillance.
Suppression of Rh Isoimmunization
The following adverse reactions have been identified during postapproval use of Rhophylac® (immune globulin intravenous (human) solution) for suppression of Rh isoimmunization: hypersensitivity reactions, including rare cases of anaphylactic shock or anaphylactoid reactions, headache, dizziness, vertigo, hypotension, tachycardia, dyspnea, nausea, vomiting, rash, erythema, pruritus, chills, pyrexia, malaise, and, rarely, diarrhea and back pain. Transient injection-site irritation and pain have been observed following intramuscular administration.
Transient hemoglobinuria has been reported in a patient being treated with Rhophylac® (immune globulin intravenous (human) solution) for ITP.
Read the Rhophylac (immune globulin intravenous (human) solution) Side Effects Center for a complete guide to possible side effects
Live Virus Vaccines
Immunoglobulin administration may transiently impair the efficacy of live attenuated virus vaccines such as measles, mumps, rubella, and varicella. The immunizing physician should be informed of recent therapy with Rhophylac® so that appropriate measures can be taken (see Patient Counseling Information ).
Read the Rhophylac Drug Interactions Center for a complete guide to possible interactions
Last reviewed on RxList: 5/18/2007
Additional Rhophylac Information
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