Drug Interaction:
Interacting drugs- summary
Rifampicin +
Quinidine
metabolism of Quinidine increased & decreased therapeutic effect
Disopyram
Disopyramide serum levels decreased
Mexilitine
increased clearance lower steady-state plasma level
Propafenone
decreased plasma level & less therapeutic effect
Estrogens
barbiturates, rifampicin and other agents that induce hepatic microsomal enzymes with concomittant estrogen produce lower estrogen levels than expected
Norethindrone
rifampicin reduce the plasma levles of norethindrone via hepatic microsomal enzyme induction, possibly decreasing its pharmacologic effects
Contaceptives Oral
May decrease the hepatic metabolism of the OCs, resulting in decreased effectiveness of the OCs; menstrual irregularities
(spotting, breakthrough bleeding) may occur. An alternate form of birth control advisable
Corticosteroids
corticosteroid clearance increased resulting in decreased therapeutic activity
Sulfonylureas
the hypoglycemic effect of the sulfonylureas decreased due to various mechanisms (eg. increased hepatic metabolism, decreased insulin release,
increased renal excretion)
Tocainide
tocainides elimination half life, bioavailability decreased,
oral clearnace increased
Verapramil
loss of clinical effectiveness of oral verapramil occur; IV verapramil
circumvant the interaction
Betablockers
bioavailability and plasma levels of certain beta blockers
decreased by these agents, possibly resulting in decreased
pharmacologic effect
Carvediol
rifampin reduced plasma concentrations of carvediol
Enalapril
pharmacologic effects of enalapril decreased
Barbiturates
rifampicin induces hepatic microsomal enyymes and decrease
the effectiveness of barbiturates
Valproic acid
in one study, rifampicin, increased the oral clearance of valproate
Chloramphenicol
concomitant administration reduce serum chloramphenicol levels,
presumably through hepatic enzyme system
Ketoconazole
decreased serum levels of either drugs occur avoid concurrent use
Fluconazole
a single oral fluconazole dose after chronic rifampin resulted in decrease in AUC and a shorter half-life of fluconazole
Itraconazole
reduced plasma itraconazole levels occur
Ritonavir
coadmin decreased the ritonavir AUC by 35% and Cmax by 25%
Indinavir
because rifampin is a potent inducer of P450 which could markedly
diminish plasma conc of indinavir, coadmin is not recommended
Zidovudine
AUC of zidovudine decreased
Saquinavir
coadmin of rifampin decreased the steady-state AUC and Cmax of
saquinavir Steady-state AUC of siquinavir was deceased
when saquinavir was coadministered with rifabutin
Atovaquone
concurrent use with rifampicin results in a significant decrease in average
steady-state plasma concentrations.
Dapsone
rifampin lowers dapsone levels seven to tenfold, by accelrating plasma
clearance.
Tacrolimus
these agents decrease tacrolimus blood levels
Indication:
U.S FDA APPROVED DRUGS FROM 01-01-08 TO 31-12-08
Drug name Indication Date of Approval
254 Rifampicin 11-12-08
+ INH
+ Piperine( 200mg+300mg+10mg) capsules
For the treatment of adult patients with pulmonary tuberculosis
255. Rifampicin 11-12-08
+Piperine (200mg+10mg) capsules
For the treatment of adult patients with pulmonary tuberculosis
New Drugs Approved by (DCI) Drug Controller GENERAL - India For Marketing
(Ref- IDMA Publication)
Name of Drug Indication Date of Approval
1.Rifampicin 11-12-2008
+ INH
+ Piperine
(200mg +300mg+ 10mg) capsules
For the treatment of Adult patients with pulomonary Tuberculosis
2.Rifampicin 11-12-2008
+ Piperine
(200mg+ 10mg) capsules
For the treatment of Pulmonary Tuberculosis
FIXED DOSE COMBINATIONS APPROVED BY DCG(I)
FROM JANUARY 1961 TILL NOVEMBER 2014
Name of Drug Indication Date of Approval
Rifampicin 300mg/450mg/600mg + June 1983
INH 200mg/300mg/300mg
Tuberculosis
Adverse Reaction:
Shock like syndrome with intermittant use only. GI disturbances, pseudomembranous colitis (rare),abnormalities of liver function, Fatalities in those with liver disorders, Influenza-like symptoms, skin reactions, Eosinophillia,transient leucopenia, Thrombocytopenia, Shock, drowsiness, Headache,ataxia, Visual disturbances, Menstrual irregularities (women).
Contra-Indications:
Hypersens, lactation. Jaundice, biliary obstruction.
Special precautions:
Pregnancy. Concurrent admin of anticoagulants, steroids, oral contraceptives, oral hypoglycaemics. Impaired hepatic/renal function. Elderly, malnourished or very young patients.
Dosages/ Overdosage Etc:
Indications:
Tuberculosis
Dosage:
Administer once daily either 1 hour before or 2 hours after meals. Adults- 600 mg once daily. Children- 10 to 20 mg/kg/day, not to exceed 600 mg/day. Children below 5 years- Data not established.
Missed dose-
1. If you miss a dose of this medicine, take it as soon as possible.
2. However, if it is almost time for next dose, skip the missed dose and go back to your regular dosing schedule.
3. Do not double doses.
Other Information:
For Availability/supplies
Contact -
1.Indian Drug Manufacturers Association (IDMA)
Phone- 022- 24944624/ 24974308
Fax- 022- 24950723
Email- idma@vsnl.com
Website: www.idma-assn.org
2.Bulk Drug Manufacturers Association (India)(BDMA)
Phone - 040-23703910/ 23706718
Fax- 040-23704804
Email- info@bdmai.org
Website: www.info@bdmai.org
Hyperbilirubimemia- (1454)
In disorders associated with hemolysis, most commonly the hemolytic anemias, the rate of bilirubin production is
increased and may even exceed the amount that can be removed by a normal liver. This resulting jaundice is primarily
unconjugated hyperbilibinemia. There is often also a small but definite increase in the serum conjugated bilirubin
when the amount of bilirubin glucoronate formed exceeds the amount the liver can excrete.
Drugs causing adverse reactions- ( 386 )
1. Rifampicin
2. Novobiocin
Patient Information:
1.Take on an empty stomach,atleast 1 hour before or 2 hours after meals.
2. Take medication on a regular basis; avoid missing dose. Do not discontinue therapy except on advice of physician.
3. Medication may cause a reddish-orange discolouration of urine, stools, saliva, tears, sweat, and sputum. This is expected and not harmful. May also permanently discolour soft contact lens.
4. Notify physician, if flu-like symptoms(fever, chills, muscle and bone pain, headache),
excessive tiredeness or weakness, anorexia, nausea, vomiting, sore throat, unusual bruising or bleeding.
5. Allergies- tell your doctor if you have ever had any unusual or allergic reaction to rifampicin. Also tell your doctor if you are allergic to any other substances, such as foods,
presevatives or dyes.
6.Pregnancy - pregnant women with tuberculosis should be treated with TB medicines including rifampicin. Rarely rifampicin has caused bleeding in newborn babies and mothers when taken during the last weeks of pregnancy.
7.Breast feeding- rifampicin passes into the breast milk. However it has not been reported cause problems in nursing babies
8.Children- this medicine has been tested in children and in effective doses ,has not been shown to cause different side effects or problems in children than it does in adults.
9. Elderly- not expected to cause different side effects or problems in older people than in younger adults.
10. Missed dose -
If you miss a dose of this medicine, take it as soon as possible. however, if it is almost time for the next dose, skip the missed dose. Do not double doses.
11. Storage -
Keep out of reach of children. Store away from heat or direct sunlight. Do not store
the capsule in bathroom, near the kitchen sink, or in other damp places.
12. Outdated medicines -
Do not keep outdated medicine or medicine no longer needed. Be sure that any
discarded medicine is out of reach of children.
Pharmacology/ Pharmacokinetics:
Pharmacology:
Rifampin inhibits DNA- dependent RNA polymerase activity in susceptible cells. It interacts with bacterial RNA polymerase, but does not inhibit the mammalian enzyme.
Pharmacokinetics:
Rifampin 600mg administered orally is almost completely absorbed and acheives mean peak plasma levels within 1 to 4 hours. Food interferes with absorption. Rifampin is metabolised in the liver by deacetylation. The half-life is approximately 3 hours after a 600mg oral dose, and upto 5.1 hours after a 900mg oral dose.
Interaction with Food:
Food interfers with absorption
Pregnancy and lactation:
Pregnancy:
The effect of rifampin( alone or in combinations is not known on the human fetus. Carefully weigh possible tetragenic potential in women capable of bearing children, against the benefits of therapy.
Lactation:
Rifampin is excreted in breast milk with a milk plasma ratio of 0.2 to 0.6. Decide whether to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother.
