The use of oral therapy has increased over the past decade as newer targeted therapies and formulations of cytotoxic chemotherapy have become available. Oral therapy carries the same risks in terms of potential for error and toxicities as therapy administered by other routes.
Oral chemotherapy and targeted therapy must only be prescribed by clinicians with appropriate skills and qualifications in the management and treatment of cancer. GPs should not prescribe oral therapy unless directed by the patient’s oncologist or haematologist.
Table 10 outlines additional information that should be considered when prescribing oral therapy.
Oral chemotherapy and targeted therapy should be written to the same standards as parenteral therapy.
Dose changes to oral chemotherapy regimens which are communicated directly to patients and/or caregivers must also be documented on a prescription, medication order and/or the patient’s medical record (Neuss et al, 2017; Belderson and Billett, 2017).
Oral chemotherapy and targeted therapy should only be prescribed by clinicians with appropriate skills and qualifications in the management and treatment of cancer. GPs should not prescribe oral therapy unless directed by the patient’s oncologist or haematologist.
Careful evaluation for potential interactions between the oral cancer medication and other prescribed medicines, complementary medicines and food should be carried out prior to prescribing oral therapy (Carrington, 2013; Carrington, 2015; Thakerar et al, 2014).
Table 10: Prescribing oral chemotherapy and targeted therapy
|Oral chemotherapy and targeted therapy should be prescribed on the basis of an approved protocol|
| Oral therapy should be written on a designated chart where possible
A PBS script alone should not be used to prescribe oral chemotherapy as it has insufficient space to provide the information required to ensure safe dispensing. An order written on an appropriate chart should accompany a PBS script.
| The quantity prescribed should be the quantity of tablets/capsules the patient requires for that cycle of treatment
The use of PBS quantities as whole patient packs may pose a risk to patients if they contain more tablets than are needed for the cycle.
| Repeat prescriptions preferably should not be issued for oral chemotherapy due to the risk of misdosing
Chemotherapy doses may change according to blood results, side effects and therapeutic response. If this option is utilised within the PBS regulation then the patient should be directed to destroy any repeats or return them to the doctor or pharmacy if treatment is changed or stopped to avoid any inadvertent dispensing.
| Steps must be taken to round doses according to the strengths available when calculating dose requirements according to BSA
The strengths of oral formulations are often limited and chemotherapy and targeted therapy tables/capsules cannot generally be broken. Where rounding is inappropriate it may be necessary to alter dosing scheduling (e.g. where a patient requires a daily dose of 175 mg of cyclophosphamide the dose could be given as a 150 mg one day and 200 mg the next to make up the total dose).
| Do not advise a patient to crush or dissolve tablets at home
Advice should be sought from a pharmacist when a patient has difficulty swallowing. Crushing of tablets carries both exposure risks and changes to medication bioavailability. Pharmacists will have information on what formulations can be dissolved or made into a mixture.
- Carrington C. Safe use of oral cytotoxic medicines. Australian Prescriber 2013;36(1):9-12.
- Carrington C. Oral targeted therapy for cancer. Aust Prescr 2015 Oct;38(5):171-6 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/26648656.
- NHS National Patient Safety Agency UK. Rapid Response Report (NPSA/2008/RRR001). Risks of incorrect dosing of oral anti-cancer medicines. [homepage on the internet]; 2008 Jan 22 [cited 2016 Sep]. Available from: http://www.nrls.npsa.nhs.uk/resources/?entryid45=59880.
- Carrington C, Stone L, Koczwara B, Searle C, Siderov J, Stevenson B, et al. The Clinical Oncological Society of Australia (COSA) guidelines for the safe prescribing, dispensing and administration of cancer chemotherapy. Asia Pac J Clin Oncol 2010 Sep;6(3):220-37 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/20887505.
- Taylor JA, Winter L, Geyer LJ, Hawkins DS. Oral outpatient chemotherapy medication errors in children with acute lymphoblastic leukemia. Cancer 2006 Sep 15;107(6):1400-6 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/16909415.
- Society of Hospital Pharmacists of Australia. Committee of Specialty Practice in Cancer Services. Standards of Practice for the Provision of Pharmaceutical Care of Patients Receiving Oral Chemotherapy for the Treatment of Cancer. J Pharm Pract Res 2007;37,147-150.
- Neuss MN, Gilmore TR, Belderson KM, Billett AL, Conti-Kalchik T, Harvet BE, et al. 2016 Updated American Society of Clinical Oncology/Oncology Nursing Society Chemotherapy Administration Safety Standards, Including Standards for Pediatric Oncology. Oncol Nurs Forum 2017 Jan 6;44(1):31-43 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/28067033.
- Belderson KM, Billett AL. Chemotherapy safety standards: A pediatric perspective. Pediatr Blood Cancer 2017 Jun;64(6) Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/28306217.
- Thakerar A, Sanders J, Moloney M, Alexander M, Kirsa S. Pharmacist advice on the safety of complementary and alternative medicines during conventional anticancer treatment. Journal of Pharmacy Practice and Research 2014;44(4):231-7.