Anascorp

Included as part of the PRECAUTIONS section.

Mechanism Of Action

Anascorp is composed of venom-specific F(ab')2 fragments of immunoglobulin G (IgG) that bind and neutralize venom toxins, facilitating redistribution away from target tissues and elimination from the body. 1

Pharmacokinetics

Eight clinically healthy volunteers (6 males and 2 females, age: 17 to 26 years) received a bolus intravenous dose o f 47.5 mg of Centruroides (Scorpion) Immune F(ab')2, (Equine) Injection. Blood samples were collected till 504 hours (21 days) and pharmacokinetic parameters were estimated by non-compartmental analysis which are summarized in Table 2.

Table 2: Pharmacokinetic parameters of scorpion antivenom

Clinical Studies

The efficacy of Anascoip was assessed in a prospective double-blinded randomized placebo-controlled study, four open-label studies and one retrospective study in various treatment settings in the United States and Mexico, where scorpion envenomation is common. A total of 1534 patients ranging from less than one month to 90 years old were treated. The majority of patients (78%, 1204/1534) were pediatric, ranging from less than one month to 18.7 years of age. Male (52.3%) and female patients (47.7%) were equally represented. Treatment success was determined by resolution of clinically important signs o f scorpion envenomation within four hours of starting infusion. The randomized placebo study enrolled 15 subjects, eight to the Anascorp treated group and seven to the placebo. The symptom resolution success rate was 100% for the Anascorp treated and 14.3% for the placebo group.

A retrospective hospital chart review provided historical data from envenomated patients (N=97) who did not receive antivenom but were treated with sedatives and supportive care for symptoms of envenomation. These data were used as a historical control for expected outcomes in the absence of antivenom treatment. The historical controls were pediatric patients admitted to two pediatric intensive care units between 1990 and 2003 for the treatment of scorpion envenomation with supportive care only. The proportion of patients that required intensive care support four hours after intensive care unit admission, and the overall duration of the intensive care support requirement were calculated.

Overall, 95-100% of patients were relieved of systemic signs associated with scorpion envenomation in less than four hours after initiating Anascorp treatment. In the historical control database, only 3.1 % of patients experienced relief of symptoms within 4 hours o f hospital admission.

In 1396/1534 patients the mean time from start of Anascorp infusion to resolution of clinical signs and symptoms of envenomation was 1.42 hours (0.2 to 20.5 hours). Pediatric patients generally experienced a slightly faster time to resolution (1.28 ± 0.8 hours) compared with that of adult patients (1.91 ±1.4 hours). The time to resolution of symptoms was not affected by use of sedatives (474 patients who received sedatives resolved in 1.49 ± 1.1 hours and 922 patients who did not receive sedatives resolved in 1.38 ± 0.9 hours).

REFERENCES

1. Krifi M.H, Savin S, Debray M, Bon C, Ayeb M.E, Choumet V. Pharmacokinetic studies of scorpion venom before and after antivenom immunotherapy. Toxicon, 2005;45:187-198.

No formal drug interaction studies to date.1

A nurse or other trained health professional will give you this medicine in a hospital. This medicine is given through a needle placed in one of your veins.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur:

• Chest pain
• confusion
• cough
• dizziness
• fast heartbeat
• feeling of discomfort
• fever or chills
• inflammation of the joints
• itching
• muscle aches
• rash
• shakiness and unsteady walk
• shortness of breath
• sneezing
• sore throat
• swelling of the eye
• swollen lymph glands
• tightness in the chest
• troubled breathing
• unsteadiness, trembling, or other problems with muscle control or coordination
• weakness
• wheezing

• Fast, irregular, pounding, or racing heartbeat or pulse

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

• Diarrhea
• difficulty with moving
• headache
• joint pain
• muscle cramping
• muscle pains or stiffness
• nausea
• runny nose
• swollen joints
• unusual drowsiness, dullness, tiredness, weakness, or feeling of sluggishness
• vomiting

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

• It is used to treat scorpion stings.

Use this medicine as ordered by your doctor. Read all information given to you. Follow all instructions closely.

• It is given as a shot into a vein over a period of time.

What do I do if I miss a dose?

• Call your doctor to find out what to do.

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
• Very bad muscle or joint pain.
• Feeling very tired or weak.
• Swollen gland.

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

• If your symptoms or health problems do not get better or if they become worse, call your doctor.
• Do not share your drugs with others and do not take anyone else's drugs.
• Keep a list of all your drugs (prescription, natural products, vitamins, OTC) with you. Give this list to your doctor.
• Talk with the doctor before starting any new drug, including prescription or OTC, natural products, or vitamins.
• Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
• Check with your pharmacist about how to throw out unused drugs.
• Some drugs may have another patient information leaflet. Check with your pharmacist. If you have any questions about this medicine, please talk with your doctor, nurse, pharmacist, or other health care provider.
• If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

This information should not be used to decide whether or not to take Anascorp or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this medicine. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to Anascorp. This information is not specific medical advice and does not replace information you receive from the healthcare provider. You must talk with the healthcare provider for complete information about the risks and benefits of using this medicine.

Review Date: October 4, 2017