Flexyx

Flexyx drugs: Valcyt

Valcyt - General Information:

Valcyt hydrochloride (Valcyte, manufactured by Roche) is an antiviral medication used to treat cytomegalovirus infections. As the L-valyl ester of ganciclovir, it is actually a prodrug for ganciclovir. After oral administration, it is rapidly converted to ganciclovir by intestinal and hepatic esterases.

Pharmacology:

Valcyt is an antiviral medication used to treat cytomegalovirus infections. As the L-valyl ester of ganciclovir, it is actually a prodrug for ganciclovir. After oral administration, it is rapidly converted to ganciclovir by intestinal and hepatic esterases.

Valcyt for patients

VALCYTE^® (VAL-site)

(valganciclovir HCl tablets) (Val-gan-SI-klo-veer HCl)

Rx only

Read the Patient Information that comes with Valcyte before you start using it and each time you get a refill. There may be new information. This information does not take the place of talking with your healthcare provider.

What is the most important information I should know about Valcyte?

· Valcyte can affect your blood cells and bone marrow causing serious and life-threatening problems. Valcyte can lower the amount of your white blood cells, red blood cells, and platelets. Your doctor may do regular blood tests to check your blood cells while you are taking Valcyte. Based on these tests, your doctor may change your dose or tell you to stop taking Valcyte.

· Valcyte may cause cancer. Valcyte causes cancer in animals. It is not known if Valcyte causes cancer in people.

· Valcyte may cause birth defects. Valcyte causes birth defects in animals. It is not known if Valcyte causes birth defects in people. Valcyte should not be used during pregnancy. Tell your doctor right away if you get pregnant while taking Valcyte. If you can get pregnant, you should use effective birth control during treatment with Valcyte. Men should use a condom during treatment with Valcyte, and for 90 days after treatment, if their partner can get pregnant. Talk to your doctor if you have questions about birth control. Valcyte may lower the amount of sperm in a man's body and cause fertility problems.

· Valcyte changes into the medicine ganciclovir once it is in your body. Ganciclovir is also the active ingredient in Cytovene^®-IV and ganciclovir capsules. Do not take ganciclovir capsules or Cytovene-IV if you are taking Valcyte tablets. The dose of medicine in Valcyte tablets and ganciclovir capsules is different. One tablet of Valcyte has more medicine than one capsule of ganciclovir . This means that one Valcyte tablet cannot be substituted for one ganciclovir capsule. You could overdose and become very sick if Valcyte is taken with ganciclovir capsules or Cytovene-IV. Talk to your doctor or pharmacist if you have questions about your medicine.

What is Valcyte?

Valcyte is an "antiviral" medicine used:

· to treat cytomegalovirus (CMV) retinitis in people who have acquired immunodeficiency syndrome (AIDS). When CMV virus infects the eyes, it is called CMV retinitis.

· to prevent cytomegalovirus (CMV) disease in people who have received a heart, kidney, or kidney-pancreas transplant and who have a chance for getting CMV disease.

Valcyte may:

· slow the growth of CMV virus in your body. CMV is an infection caused by a herpesvirus called cytomegalovirus. If CMV retinitis isn't treated, it can cause blindness. Valcyte may protect your eyesight from damage due to CMV disease. CMV can also infect other parts of the body.

· prevent CMV disease for up to 6 months after heart, kidney, or kidney-pancreas transplant. Valcyte may prevent CMV virus from spreading into healthy cells.

Valcyte does not cure CMV retinitis. You may still get retinitis or worsening of retinitis during or after treatment with Valcyte. Therefore, it is important to stay under a doctor's care and have your eyes checked regularly.

Valcyte has not been studied in children or in adults older than age 65.

Who should not take Valcyte?

Do not take Valcyte if you:

· are receiving hemodialysis. The use of ganciclovir capsules rather than Valcyte tablets is recommended. Valcyte does not come in the right dose for people on hemodialysis.

· are allergic to any of its ingredients or if you have ever had a serious reaction to ganciclovir capsules or Cytovene-IV. See the end of this leaflet for a list of the ingredients in Valcyte.

In addition, Valcyte is not for use in prevention of CMV disease in patients who have received a liver transplant. More research is needed before Valcyte can be recommended for use in the prevention of CMV disease in other organ transplant patients such as liver or lung transplant patients.

Before taking Valcyte, tell your doctor:

· if you are pregnant or plan to become pregnant. Valcyte may cause birth defects.

· if you are breast-feeding. It is not known if Valcyte passes into your milk and if it may harm your baby. You should not breast-feed if you are HIV-positive because of the chance of passing the HIV virus to your baby through your milk.

· if you have kidney problems. Your doctor may give you a lower dose of Valcyte, or check you more often if you are taking Valcyte.

· if you have blood cell problems if you are having radiation treatment

· about all the medicines you take, including prescription and nonprescription medicines, vitamins and herbal supplements. Do not take ganciclovir capsules or Cytovene-IV if you are taking Valcyte tablets. Valcyte and other medicines may affect each other. These interactions may cause serious problems. The following medicines may need dose changes if you are also taking Valcyte:

· Videx^® (didanosine, ddI)

· Retrovir^® (zidovudine, ZDV, AZT)

· Probenecid

Tell your doctor if you take medicines such as chemotherapy medicines that can lower your bone marrow function.

How should I take Valcyte?

· Take Valcyte exactly as your doctor prescribes it. Your dose of Valcyte will depend on your medical condition. If you have kidney problems or are over age 65, your doctor may give you a lower dose of Valcyte.

· the usual dose for adults to get active CMV retinitis under control (induction therapy) is two 450 mg tablets twice a day for 21 days.

· the usual dose for adults to help keep CMV retinitis under control (maintenance therapy) is two 450 mg tablets once a day.

· the usual dose to prevent CMV in adults who have had a heart, kidney, or kidney-pancreas transplant is two 450 mg tablets once a day starting within 10 days of transplant and continuing until 100 days after the transplant.

· Take Valcyte with food.

· Do not break or crush Valcyte tablets.

· If you miss a dose of Valcyte, take the missed dose as soon as you remember. Then, take the next dose at the usual scheduled time. However, if it is almost time for your next dose, do not take the missed dose.

· Do not let your Valcyte run out. The amount of virus in your blood may increase if your medicine is stopped, even for a short time.

· If you take too much Valcyte, call your local poison control center or emergency room right away. You may need treatment in a hospital.

· Do not substitute Valcyte tablets for ganciclovir capsules. Talk to your doctor, nurse or pharmacist if you have questions about your medicine.

What should I avoid while taking Valcyte?

· Do not get pregnant. Valcyte causes birth defects in animals. It is not known if Valcyte causes birth defects in people. Valcyte should not be used during pregnancy. Tell your doctor right away if you get pregnant while taking Valcyte. If you can get pregnant, you should use effective birth control during treatment with Valcyte. Men should use a condom during treatment with Valcyte, and for 90 days after treatment, if their partner can get pregnant. Talk to your doctor if you have questions about birth control. Valcyte may lower the amount of sperm in a man's body and cause fertility problems.

· Do not breast-feed. Valcyte may harm your baby. You should not breast-feed if you are HIV-positive because of the chance of passing the HIV virus to your baby through your milk.

· Do not drive a car or operate other dangerous machinery until you know how Valcyte affects you. Valcyte can cause seizures, sleepiness, dizziness, unsteady movements, and confusion.

· Do not break or crush Valcyte tablets. Avoid contact with broken Valcyte tablets on your skin, mucous membranes or eyes. If contact occurs, wash your skin well with soap and water or rinse your eyes well with plain water.

What are the possible side effects of Valcyte?

See " What is the most important information I should know about Valcyte? " for details on the most serious side effects. Valcyte can also cause the following serious side effects:

· kidney problems. Valcyte may affect your kidney function. Your doctor may do regular blood tests called serum creatinine levels to check your kidney function while you are taking Valcyte.

· brain and nerve problems. Valcyte may cause seizures, sleepiness, dizziness, unsteady movements, and confusion.

Common side effects of Valcyte include diarrhea, nausea, vomiting, stomach pain, fever, headache, shaky movements (tremors), graft rejection, swelling of the legs, constipation, back pain, trouble sleeping, and high blood pressure.

Common changes in blood tests for people taking Valcyte include low white blood cells (neutropenia or leukopenia), low red blood cells (anemia), increased blood creatinine levels, increased calcium in the blood, and abnormal liver function.

Talk to your doctor about side effects that bother you or that won't go away. These are not all the side effects of Valcyte. For more information, ask your doctor or pharmacist.

How do I store Valcyte?

· Store Valcyte at room temperature, 59° to 86° F (15° to 30° C.)

· Keep Valcyte and all medicines out of the reach of children.

General information about Valcyte

Medicines are sometimes prescribed for conditions that are not mentioned in patient information leaflets. Do not use Valcyte for a condition for which it was not prescribed. Do not give Valcyte to other people, even if they have the same symptoms you have. It may harm them.

This leaflet summarizes the most important information about Valcyte. If you would like more information, talk with your doctor. You can ask your doctor or pharmacist for information about Valcyte that is written for health professionals. Information about Valcyte is also available at 1-800-526-6367 (toll-free).

What are the ingredients in Valcyte?

Active Ingredient: Valganciclovir HCl

Inactive Ingredients: microcrystalline cellulose, povidone K-30, crospovidone, and stearic acid. The film-coating applied to the tablets contains Opadry Pink^®.

Valcyt Interactions

Drug Interaction Studies Conducted With Valcyte

No in vivo drug-drug interaction studies were conducted with valganciclovir. However, because valganciclovir is rapidly and extensively converted to ganciclovir, interactions associated with ganciclovir will be expected for Valcyte tablets.

Drug Interaction Studies Conducted With Ganciclovir

Binding of ganciclovir to plasma proteins is only about 1% to 2%, and drug interactions involving binding site displacement are not anticipated.

Drug-drug interaction studies were conducted in patients with normal renal function. Patients with impaired renal function may have increased concentrations of ganciclovir and the coadministered drug following concomitant administration of Valcyte tablets and drugs excreted by the same pathway as ganciclovir. Therefore, these patients should be closely monitored for toxicity of ganciclovir and the coadministered drug.

Table 6 Results of Drug Interaction Studies With Ganciclovir: Effects of Coadministered Drug on Ganciclovir Plasma AUC and Cmax Values
Coadministered Drug	Ganciclovir Dosage	n	Ganciclovir Pharmacokinetic (PK) Parameter	Clinical Comment
Zidovudine 100 mg every 4 hours	1000 mg every 8 hours	12	AUC � 17 ± 25% (range: -52% to 23%)	Zidovudine and Valcyte each have the potential to cause neutropenia and anemia. Some patients may not tolerate concomitant therapy at full dosage.
Didanosine 200 mg every 12 hours administered 2 hours before ganciclovir	1000 mg every 8 hours	12	AUC � 21 ± 17% (range: -44% to 5%)	Effect not likely to be clinically significant.
Didanosine 200 mg every 12 hours simultaneously	1000 mg every 8 hours	12	No effect on ganciclovir PK parameters observed	No effect expected.
administered with ganciclovir	IV ganciclovir 5 mg/kg twice daily	11	No effect on ganciclovir PK parameters observed	No effect expected.
	IV ganciclovir 5 mg/kg once daily	11	No effect on ganciclovir PK parameters observed	No effect expected.
Probenecid 500 mg every 6 hours	1000 mg every 8 hours	10	AUC ↑ 53 ± 91% (range: -14% to 299%) Ganciclovir renal clearance � 22 ± 20% (range: -54% to -4%)	Patients taking probenecid and Valcyte should be monitored for evidence of ganciclovir toxicity.
Zalcitabine 0.75 mg every 8 hours administered 2 hours before ganciclovir	1000 mg every 8 hours	10	AUC ↑ 13%	Effect not likely to be clinically significant.
Trimethoprim 200 mg once daily	1000 mg every 8 hours	12	Ganciclovir renal clearance � 16.3% Half-life ↑ 15%	Effect not likely to be clinically significant.
Mycophenolate Mofetil 1.5 g single dose	IV ganciclovir 5 mg/kg single dose	12	No effect on ganciclovir PK parameters observed (patients with normal renal function)	Patients with renal impairment should be monitored carefully as levels of metabolites of both drugs may increase.

 

Table 7 Results of Drug Interaction Studies With Ganciclovir: Effects of Ganciclovir on Plasma AUC and CmaxValues of Coadministered Drug
Coadministered Drug	Ganciclovir Dosage	N	Coadministered Drug Pharmacokinetic (PK) Parameter	Clinical Comment
Zidovudine 100 mg every 4 hours dosage.	1000 mg every 8 hours	12	AUC0-4 ↑ 19 ± 27% (range: -11% to 74%)	Zidovudine and Valcyte each have the potential to cause neutropenia and anemia. Some patients may not tolerate concomitant therapy at full
Didanosine 200 mg every 12 hours when administered 2 hours prior to or concurrent with ganciclovir	1000 mg every 8 hours	12	AUC0-12 ↑ 111 ± 114% (range: 10% to 493%)	Patients should be closely monitored for didanosine toxicity.
Didanosine 200 mg every 12 hours	IV ganciclovir 5 mg/kg twice daily	11	AUC0-12 ↑70 ± 40% (range: 3% to 121%) Cmax ↑ 49 ± 48% (range: -28% to 125%)	Patients should be closely monitored for didanosine toxicity.
Didanosine 200 mg every 12 hours	IV ganciclovir 5 mg/kg once daily	11	AUC0-12 ↑ 50 ± 26% (range: 22% to 110%) Cmax ↑ 36 ± 36% (range: -27% to 94%)	Patients should be closely monitored for didanosine toxicity.
Zalcitabine 0.75 mg every 8 hours administered 2 hours before ganciclovir	1000 mg every 8 hours	10	No clinically relevant PK parameter changes	No effect expected.
Trimethoprim 200 mg once daily	1000 mg every 8 hours	12	Increase (12%) in Cmin	Effect not likely to be clinically significant.
Mycophenolate Mofetil (MMF) 1.5 g single dose	IV ganciclovir 5 mg/kg single dose	12	No PK interaction observed (patients with normal renal function)	Patients with renal impairment should be monitored carefully as levels of metabolites of both drugs may increase.

Valcyt Contraindications

Valcyte tablets are contraindicated in patients with hypersensitivity to valganciclovir or ganciclovir.

Additional information about Valcyt

Valcyt Indication: For the treatment of cytomegalovirus infections.
Mechanism Of Action: Valcyt is a prodrug of ganciclovir that exists as a mixture of two diastereomers. After administration, these diastereomers are rapidly converted to ganciclovir by hepatic and intestinal esterases. In cytomegalovirus (CMV)-infected cells, ganciclovir is initially phosphorylated to the monophosphate form by viral protein kinase, then it is further phosphorylated via cellular kinases to produce the triphosphate form. This triphosphate form is slowly metabolized intracellularly. The phosphorylation is dependent upon the viral kinase, and occurs preferentially in virus-infected cells. The virustatic activity of ganciclovir is due to the inhibition of viral DNA synthesis by ganciclovir triphosphate.
Drug Interactions: Not Available
Food Interactions: Not Available
Generic Name: Valganciclovir
Synonyms: Cymeval; L-valine, ester with ganciclovir
Where to order Valganciclovir (and Valcyt analogs) online:
Drug Category: Antiviral Agents
Drug Type: Small Molecule; Approved; Investigational
Other Brand Names containing Valganciclovir: Cymeval; Valcyt; Valcyte;
Absorption: Valganciclovir is well absorbed from the gastrointestinal tract and the absolute bioavailability from valganciclovir tablets (following administration with food) is approximately 60%.
Toxicity (Overdose): It is expected that an overdose of valganciclovir could also possibly result in increased renal toxicity.
Protein Binding: Plasma protein binding of ganciclovir is 1% to 2% over concentrations of 0.5 and 51 mg/mL.
Biotransformation: Rapidly hydrolyzed in the intestinal wall and liver to ganciclovir. No other metabolites have been detected.
Half Life: Approximately 4.08 hours. Increased in patients with renal function impairment.
Dosage Forms of Valcyt: Tablet Oral
Chemical IUPAC Name: [2-[(2-amino-6-oxo-3H-purin-9-yl)methoxy]-3-hydroxypropyl] (2S)-2-amino-3-methylbutanoate
Chemical Formula: C14H22N6O5
Valganciclovir on Wikipedia: http://en.wikipedia.org/wiki/Valganciclovir
Organisms Affected: Human Herpes Virus