INFLIXIMAB IS USED WITH METHOTREXATE IN RHEUMATOID ARTHRITIS; IN THE UK IT IS USUALLY LIMITED TO PATIENTS WHO HAVE HAD AN INADEQUATE RESPONSE TO STANDARD DISEASE-MODIFYING ANTIRHEUMATIC DRUGS (DMARDS) ALTHOUGH, IN SEVERE PROGRESSIVE CASES, IT MAY BE USED IN PATIENTS NOT PREVIOUSLY TREATED WITH METHOTREXATE OR OTHER DMARDS; IN THE USA IT MAY BE USED FOR TREATING EARLY RHEUMATOID ARTHRITIS, TO REDUCE THE SIGNS AND SYMPTOMS AND DELAY STRUCTURAL DAMAGE. INFLIXIMAB IS GIVEN IN A DOSE OF 3 MG/KG, REPEATED AT 2 AND 6 WEEKS, THEN EVERY 8 WEEKS THEREAFTER, IN COMBINATION WITH METHOTREXATE. IN THE USA, THE DOSE MAY BE INCREASED UP TO 10 MG/KG OR REPEATED AS OFTEN AS EVERY 4 WEEKS IN THOSE WITH AN INCOMPLETE RESPONSE. IN THE UK NICE RECOMMENDS, BASED ON GUIDELINES FROM THE BRITISH SOCIETY FOR RHEUMATOLOGY, THAT INFLIXIMAB BE WITHDRAWN IF THERE IS NO RESPONSE WITHIN 3 MONTHS OF STARTING TREATMENT.
PATIENTS WITH MODERATE TO SEVERE, ACTIVE CROHN'S DISEASE UNRESPONSIVE TO CONVENTIONAL TREATMENT MAY BE GIVEN A SINGLE INFLIXIMAB DOSE OF 5 MG/KG. THIS MAY BE FOLLOWED BY A MAINTENANCE REGIMEN OF ADDITIONAL INFUSIONS OF 5 MG/KG AT 2 AND 6 WEEKS AFTER THE INITIAL INFUSION AND THEN EVERY 8 WEEKS, OR THE DRUG MAY BE READMINISTERED WHEN SIGNS AND SYMPTOMS OF THE DISEASE RECUR (BUT SEE BELOW). UK LICENSED DRUG INFORMATION DOES NOT RECOMMEND FURTHER DOSES IN PATIENTS WHO ARE UNRESPONSIVE FOLLOWING THE FIRST DOSE; IN THE USA, A PATIENT IS NOT CONSIDERED TO BE UNRESPONSIVE UNTIL 3 DOSES HAVE BEEN GIVEN. A SIMILAR REGIMEN IS USED IN PATIENTS WITH FISTULISING CROHN'S DISEASE ALTHOUGH THERAPY SHOULD NOT BE CONSIDERED INEFFECTIVE UNTIL AFTER THE THIRD DOSE OF INFLIXIMAB. ALTHOUGH NOT LICENSED FOR CHILDREN IN THE UK, THE BNFC RECOMMENDS THE SAME DOSAGE REGIMEN AS ADULTS IN THOSE AGED 2 TO 18 YEARS WITH SEVERE, ACTIVE OR FISTULISING CROHN'S DISEASE. US LICENSED DRUG INFORMATION SUGGESTS THAT DOSES OF UP TO 10 MG/KG MAY BE USED IN ADULTS WITH CROHN'S DISEASE WHO RELAPSE AFTER AN INITIAL RESPONSE. INFLIXIMAB IS ALSO USED IN THE TREATMENT OF MODERATE TO SEVERE, ACTIVE ULCERATIVE COLITIS IN PATIENTS UNRESPONSIVE TO CONVENTIONAL THERAPY; THE RECOMMENDED DOSE IS 5 MG/KG GIVEN AS A REGIMEN SIMILAR TO THAT USED FOR CROHN'S DISEASE (SEE ABOVE).
IN THE TREATMENT OF ANKYLOSING SPONDYLITIS, THE UK MANUFACTURER RECOMMENDS THAT INFLIXIMAB SHOULD ONLY BE USED IN PATIENTS WITH SEVERE DISEASE WHO HAVE HAD AN INADEQUATE RESPONSE TO CONVENTIONAL TREATMENT; HOWEVER, IN THE USA IT MAY BE USED IN EARLY TREATMENT, TO REDUCE THE SIGNS AND SYMPTOMS. THE INITIAL DOSE IS 5 MG/KG, REPEATED AT 2 AND 6 WEEKS AND THEN EVERY 6 TO 8 WEEKS; IF THERE IS NO RESPONSE AFTER 2 DOSES NO FURTHER TREATMENT SHOULD BE GIVEN.
INFLIXIMAB IS ALSO USED WITH METHOTREXATE IN THE TREATMENT OF ACTIVE AND PROGRESSIVE PSORIATIC ARTHRITIS; IN THE UK, ITS USE IS LIMITED TO PATIENTS WHO HAVE HAD AN INADEQUATE RESPONSE TO STANDARD DMARD BUT, AS BEFORE, US LICENSED DRUG INFORMATION ALLOWS EARLIER USE. IT IS GIVEN IN A SINGLE DOSE OF 5 MG/KG, REPEATED AT 2 AND 6 WEEKS AND THEN EVERY 8 WEEKS THEREAFTER. IN THE USA, IT MAY BE GIVEN WITH OR WITHOUT METHOTREXATE.
IN SOME COUNTRIES, INCLUDING THE UK, INFLIXIMAB IS USED IN THE TREATMENT OF MODERATE TO SEVERE PLAQUE PSORIASIS. ITS USE IS USUALLY LIMITED TO PATIENTS IN WHOM OTHER TREATMENTS ARE NOT SUITABLE. INFLIXIMAB IS GIVEN IN A DOSE OF 5 MG/KG, REPEATED AT 2 AND 6 WEEKS, THEN EVERY 8 WEEKS THEREAFTER. TREATMENT SHOULD BE STOPPED AFTER 14 WEEKS IN PATIENTS WHO SHOW NO RESPONSE.
IF THE SIGNS AND SYMPTOMS OF RHEUMATOID ARTHRITIS OR CROHN'S DISEASE RECUR INFLIXIMAB MAY BE READMINISTERED IF WITHIN 16 WEEKS OF THE LAST INFUSION. READMINISTRATION AFTER A DRUG-FREE INTERVAL OF MORE THAN 16 WEEKS MAY BE ASSOCIATED WITH AN INCREASED RISK OF DELAYED HYPERSENSITIVITY AND CONSEQUENTLY IS NOT RECOMMENDED.