Just some interesting facts on RIBA
Physically ribavirin is similar to the sugar D-ribose from which it is derived. It is freely soluble in water, and is re-crystallized as fine silvery needles from boiling methanol
Ribavirin is absorbed from the GI tract probably by nucleoside transporters. Absorption is about 45%, and this is modestly increased (to about 75%) by a fatty meal. Once in the plasma, ribavirin is transported through the cell membrane also by nucleoside transporters.
Ribavirin is widely distributed in all tissues, including the CSF and brain. The pharmacokinetics of ribavirin is dominated by trapping of the phosphated form inside cells, particularly red blood cells (RBCs) which lack the enzyme to remove the phosphate once it has been added by kinases, and therefore attain high concentrations of the drug. Most of the kinase activity which converts the drug to active nucleotide form, is provided by adenine kinase. This enzyme is more active in virally infected cells.
The volume of distribution of ribavirin is large (2000 L/kg) and the length of time the drug is trapped varies greatly from tissue to tissue. The mean half-life for multiple doses in the body is about 12 days, but very long-term kinetics are dominated by the kinetics of RBCs (half-life 40 days). RBCs store ribavirin for the lifetime of the cells, releasing it into the body's systems when old cells are degraded in the spleen.
About a third of absorbed ribavirin is excreted into the urine unchanged, and the rest is excreted into urine as the de-ribosylated base 1,2,4-triazole 3-carboxamide, and the oxidation product of this, 1,2,4- triazole 3-carboxylic acid.
My rx states:
If you miss a dose Copegus and remember the same day, take the missed dose as soon as you remember. If the whole day has passed, ask your health care provider what to do. Do not take two doses at the same time.
Hope that helps.
Don't worry. The short answer is Riba has such a long half life that it really don't matter. Pick up with the next scheduled dose.
i had a medical card issued to me that said if my missed dose was less than 2 hours before my next one...it was ok to take the mising dose..so if your dose was at 6 am....and your next one is at 6 pm....skip the dose if its after 4pm