202
P A R T 2
Chemotherapeutic agents
TABLE 14.2
DRUGS IN FOCUS Antimetabolites (continued)
Drug name
Dosage/route
Usual indications
methotrexate
(Methoblastin)
Dose varies with route and disease being
treated; 15–30 mg/day PO or IM is common
Treatment of leukaemias, psoriasis,
rheumatoid arthritis and
choriocarcinomas
Special considerations:
hypersensitivity
reactions can be severe; liver toxicity
and GI complications are common;
monitor for bone marrow suppression
and increased susceptibility to infections;
dose pack available for the oral treatment
of psoriasis and rheumatoid arthritis
pemetrexed (Alimta)
500 mg/m
2
IV over 10 minutes on day one with
75 mg/m
2
cisplatin IV over 2 hours; repeat
cycle every 21 days
Treatment of malignant mesothelioma in
people whose disease is unresectable
or who are not candidates for surgery;
locally advanced or metastatic non–small
cell lung cancer as a single agent after
other chemotherapy
Special considerations:
pretreat
with corticosteroids, folic acid and
vitamin B12; monitor for bone marrow
suppression and GI effects
raltitrexed (Tomudex)
Dosage: 3 mg/m
2
IV over 15 minutes; repeated
q 3 weeks
Palliative treatment for advanced colorectal
cancer
Special considerations:
GI and
haematologic toxicity; full blood count
prior to each treatment
thioguanine (Lanvis)
2 mg/kg per day PO for 4 weeks; then dose
may be increased if tolerated well
Remission induction and maintenance
of acute leukaemias alone or as part of
combination therapy
Special considerations:
bone marrow
suppression, GI toxicity, miscarriage and
birth defects have been reported; monitor
bone marrow status to determine dose
and redosing; ensure that the person is
well hydrated during therapy to minimise
hyperuricaemia—person may respond to
allopurinol and urine alkalinisation
Phases of
cell cycle
G
1
G
0
G
2
S
M
Mitotic inhibitors
prevent mitosis
Antimetabolites
inhibit DNA
synthesis
FIGURE 14.5
Sites of action of cell cycle–specific
antineoplastic agents.
