Vantas (histrelin acetate)

Vantas can cause an increase in testosterone during the first week after it is inserted. Your symptoms may get worse during the first few weeks of treatment. You may get new symptoms. Call your doctor right away if you:

• get new or worse bone pain
• get weakness or lose feeling in your legs
• have blood in your urine
• have trouble urinating or cannot urinate

Vantas can cause a loss in bone mineral density. Low bone mineral density can lead to thinning of the bones (oesteoporosis).

The most common side effects of Vantas are:

• hot flashes
• tiredness
• skin reactions at the implant insertion site
• testicles become smaller
• urination problems
• breasts become larger
• erectile dysfunction (impotence)
• constipation

You may have some pain at the insertion site during and after Vantas is inserted and removed. You may get some bruising and redness at the site. These usually go away without treatment within 2 weeks. Call your doctor if you have unusual bleeding, redness or pain at the insertion site.

These are not all the side effects of Vantas. For more information, ask your doctor or pharmacist.

Recommended Dose

• The recommended dose of Vantas is one implant for 12 months.
• Each implant contains 50 mg histrelin acetate to deliver 41 mg histrelin.
• The implant is inserted subcutaneously in the inner aspect of the upper arm and provides continuous release of histrelin (50 mcg/day) for 12 months of hormonal therapy.
• Vantas should be removed after 12 months of therapy (the implant has been designed to allow for a few additional weeks of histrelin release, in order to allow flexibility of medical appointments).
• At the time an implant is removed, another implant may be inserted to continue therapy.

Overview

• No pharmacokinetic-based drug-drug interaction studies were conducted with Vantas.

Drug-Laboratory Test Interactions

• Therapy with histrelin results in suppression of the pituitary-gonadal system.
• Results of diagnostic tests of pituitary gonadotropic and gonadal functions conducted during and after histrelin therapy may be affected.

• Vantas is contraindicated in females who are or may become pregnant.
• Vantas can cause fetal harm when administered to a pregnant woman. The possibility exists that spontaneous abortion may occur.
• Vantas is not indicated for use in women.
• It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions in nursing infants from Vantas, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.