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Cyclophosphamide

Last updated on 13/07/2021.

Overview   |   Dosage   |    Side Effects   |   Precautions   |   Tips   |   Where To Buy  

GENERIC NAME: Cyclophosphamide

CHINESE NAME: 環磷酰胺

BRAND NAME(S) IN HONG KONG: Endoxan 癌得星

DRUG CLASS: Antineoplastics

SUB CLASS: Alkylating agents

USED FOR: Cytotoxic chemotherapy, targeted cancer therapy, nephrotic syndrome

AVAILABLE DOSAGE FORMS:
– 200 mg, 1 g (injections)
– 50 mg (tablets)

What is Cyclophosphamide for?

Cyclophosphamide belongs to a class of medications called alkylating agents. It stops cells from replicating and dividing by interfering with their nucleic acid function. It also suppresses an overactive immune system. It kills cells and inhibits the growth of malignant tumours, and is therefore used to treat various types of cancers. It may also be taken orally to treat nephrotic syndrome in children.

How to use it?

Cyclophosphamide is available as oral tablets or injections. Tablets should be taken in the morning on an empty stomach, but may be taken with some food to minimise stomach irritation. Swallow the whole tablet with plenty of water. Do not divide, chew or crush the tablets. In some cases, Cyclophosphamide is injected into a vein as directed by your doctor. The dosage of Cyclophosphamide is calculated by your doctor based on your body weight or total body surface area. Your doctor will advise you on the dosage and frequency depending on your condition.

Malignant tumours
Adult
Oral: For low-dose regimen, 2-6 mg/kg every week, given in divided doses. Alternatively, 100-300 mg daily in divided doses, or 50-250 mg per m2 body surface area daily or 80-300 mg/m2 daily in divided doses.
Injections: For low-dose regimen, 2-6 mg/kg given as a single dose every week. For moderate-dose regimen, 10-15 mg/kg given as a single dose every week. For high-dose regimen, 20-40 mg/kg given as a single dose every 10-20 days. Alternatively, 80-300 mg/m2  daily as a single dose, or 300-600 mg/m2 weekly as a single dose, or 600-1500 mg/m2 as a single dose or short infusion at 10- to 20-day intervals

Nephrotic syndrome
Child
Oral: 2 mg/kg daily for 8-12 week. Maximum cumulative dose is 168 mg/kg. Maximum duration of treatment is 90 days.

What are the side effects of Cyclophosphamide?

Common side effects of Cyclophosphamide include dizziness, blurred vision, nausea, vomiting, diarrhoea, loss of appetite, stomach pain, hair loss, rashes, skin or nail discoloration, prolonged wound healing, absence of menstrual periods, low sperm count and infertility.

Who should not take Cyclophosphamide?

– People allergic to Cyclophosphamide or any component of the formulation
– Patients with bone marrow aplasia (disappearance of bone marrow cells)
– Patients with urinary outflow obstruction or urinary tract infection
– Pregnant women

Pharmacist Tips:

– This medication can cause blurred vision or dizziness. Avoid driving or operating machinery until you know how you respond to Cyclophosphamide.
– Wear gloves when handling this medicine to minimise any skin contact. Wash your hands immediately if you make contact with broken tablets.
– You will need regular blood tests during Cyclophosphamide treatment. Your doctor may order other tests too.
– Discuss with your doctor before taking any vaccinations as Cyclophosphamide can interfere with vaccines.

Common dosing schedule:
Take Cyclophosphamide in the morning on an empty stomach. Try to take it at the same time each day.

This schedule is for reference only, adjustments may be made according to individual needs.

Some common medications Cyclophosphamide may interact with:
– Antifungals, e.g. Ketoconazole, Fluconazole, Itraconazole
– Antiretroviral drugs, e.g. Ritonavir
– Antibiotics, e.g. Clarithromycin, Metronidazole, Amphotericin B
– Immunosuppressants, e.g. Azathioprine, Cyclosporine
– Drugs to treat heart diseases, e.g. Amiodarone
– Other cancer drugs, e.g. Busulfan
– Warfarin

Cyclophosphamide may interact with many other medications. Please notify your doctor or pharmacist if you are taking the above medication, dosage adjustments might be needed.

Where to buy Cyclophosphamide in Hong Kong?

In Hong Kong, Cyclophosphamide is a prescription only medicine, and requires a prescription from a doctor to be purchased in a pharmacy. It can also be obtained from doctors. To find a pharmacy near you, refer to the list of pharmacies (“Authorized Sellers of Poisons”) from the Hong Kong Department of Health.

For more information about drug names and ingredients, you can visit Hong Kong’s Drug Office at https://www.drugoffice.gov.hk

Need more information?

For detailed information about the use of Cyclophosphamide in children, pregnancy and breastfeeding, and for questions about drug interactions, please check with your pharmacist or doctor.

Disclaimer: our goal is to provide you with the most relevant drug information and common dosage for Hong Kong. This information does not constitute medical advice. For specific treatment recommendations and advice, always discuss with your doctor or pharmacist, and follow the instructions included with your specific medicine.