ogical half-life of rifampicin in serum averages about 3 hours after a 600 mg dose and increases to 5.1 hours after a 900 mg dose. With repeated administration, the half-life decreases and reaches average values of approximately 2-3 hours. At a dose of up to 600 mg/day, it does not differ in patients with renal failure and consequently, no dosage adjustment is required.
Rifampicin is rapidly eliminated in the bile and an enterophepatic circulation ensues. During this process, rifampicin undergoes progressive deacetylation, so that nearly all the drug in the bile is in this form in about 6 hours. This metabolite retains essentially complete antibacterial activity. Intestinal reabsorption is reduced by deacetylation and elimination is facilitated. Up to 30 % of a dose is excreted in the urine, with about half of this being unchanged drug.
Rifampicin is widely distributed throughout the body. It is present in effective concentrations in many organs and body fluids, including cerebrospinal fluid. Rifampicin is about 80 % protein bound. Most of the unbound fraction is not ionized and therefore is diffused freely in tissues.
5.3 Preclinical safety data
Not applicable
6. Pharmaceutical particulars
6.1 List of excipients
Corn starch Ph Eur
Magnesium stearate Ph Eur
6.2 Incompatibilities
None stated
6.3 Shelf life
3 years
6.4 Special precautions for storage
Store below 25°C.
Protect from light and moisture.
6.5 Nature and contents of container
Amber glass bottles of 100 capsules.
Blister packs of 100 capsules in cardboard cartons. Blister material is aluminium foil / PVDC (Aluminium 0.025 mm; PVDC 20 gsm) and transparent PVC / PVDC foil (PVC 0.25 mm; PVDC 60 gsm).
6.6 Special precautions for disposal and other handling
No special requirements.
7. Marketing authorisation holder
Aventis Pharma Limited
Trading as Marion Merrell or Aventis Pharma
One Onslow Street
Guildford
Surrey
GU1 4YS
UK
Or trading as
Sanofi-aventis or Sanofi
One Onslow Street
Guildford
Surrey
GU1 4YS
UK
8. Marketing authorisation number(s)
PL 04425/5916R
9. Date of first authorisation/renewal of the authorisation
09/04/2005
10. Date of revision of the text
13 January 2017
