Rifabutin (Rfb)

Therapeutic action

– Antibacterial (rifamycin) with bactericidal activity

Presentation

– 150 mg capsule

Dosage

− Child and adult: 5 to 10 mg/kg once daily
− Maximum dose: 300 mg daily
− Patient with severe renal impairment: reduce the dose by half
Dose adjustment may be required when combined with some antiretrovirals.

Weight
(kg)

Daily dose
(mg)

150 mg
capsule

5

25-50

6

30-60

7

35-70

8

40-80

9

45-90

10

50-100

11

55-110

12

60-120

13

65-130

14

70-140

15

75-150

1 caps

16

80-160

1 caps

17

85-170

1 caps

18

90-180

1 caps

19

95-190

1 caps

20

100-200

1 caps

21

105-210

1 caps

22

110-220

1 caps

23

115-230

1 caps

24

120-240

1 caps

25

125-250

1 caps

26

130-260

1 caps

27

135-270

1 caps

28

140-280

1 caps

29

145-290

1 caps


30-35

300

2 caps

36-45

300

2 caps

46-55

300

2 caps

56-70

300

2 caps

> 70

300

2 caps

Contra-indications, adverse effects, precautions

– Do not administer to patients with history of allergy or severe blood disorders (thrombocytopenia, purpura) during a previous treatment with rifamycins.
– Administer with caution to patients with severe hepatic or renal impairment, or with blood disorders.
– May cause: orange-red discolouration of skin and body fluid, gastrointestinal disturbances, hypersensitivity reactions, blood disorders (leukopenia, anaemia, thrombocytopenia), reversible uveitis, hepatic disorders.
– For the management of adverse effects, see Appendix 10.
– Monitor combination with fluconazole (increased risk of ocular toxicity).
– Rifabutin reduces the effect of many drugs (antimicrobials, some hormones, antidiabetics, corticoids, phenytoin, etc.):
• In women under contraception, use injectable medroxyprogesterone or a nonhormonal contraception or, as a last resort, an oral contraceptive used contains 50 μg ethinylestradiol per tablet.
• Do not combine with bedaquiline.
• For other drugs, adjust dosage if necessary.
Pregnancy and breast-feeding: avoid except is vital (safety is not established). If used in late pregnancy, administer phytomenadione (vitamin K) to the mother and the newborn to reduce the risk of bleeding disorders.

Monitoring

– Symptomatic monitoring, liver function in elderly and patients with hepatic disease

Patient instructions

– Take with or without food.
– Rifabutin causes a harmless orange-red discoloration of the skin, urine, saliva and other body fluids.

Remarks

– Rifabutin is use in place of rifampicin in patients taking nevirapine, indinavir, nelfinavir, lopinavir/ritonavir, atazanavir/ritonavir.
Storage: below 25°C