Abatacept

Source: UK SPC (eMC) §4.2 for ORENCIA 125 mg solution for injection, pre-filled syringe (https://www.medicines.org.uk/emc/product/2877/smpc). VERBATIM (RA): 'ORENCIA SC should be administered weekly at a dose of 125 mg abatacept by subcutaneous injection regardless of weight.' Subcutaneous treatment may be initiated with or without an intravenous loading dose; if a single IV infusion is given to initiate treatment, the first 125 mg SC dose should be administered within a day of the IV infusion, followed by weekly 125 mg SC injections. THE INTRAVENOUS LOADING/MAINTENANCE POSOLOGY IS NOT IN THIS BUNDLE — the SPC cross-refers to §4.2 of ORENCIA 250 mg powder for concentrate for solution for infusion; source that separately if the IV regimen is needed. PSORIATIC ARTHRITIS: 125 mg weekly by subcutaneous injection without the need for an IV loading dose. SWITCHING FROM IV: patients switching from intravenous therapy should administer the first subcutaneous dose instead of the next scheduled intravenous dose. No dose adjustment is required when used in combination with other DMARDs, corticosteroids, salicylates, NSAIDs or analgesics. REVIEW: treatment should be initiated and supervised by specialist physicians experienced in the diagnosis and treatment of rheumatoid arthritis; if a response is not present within 6 months of treatment, continuation should be reconsidered. MISSED DOSE: if within three days of the planned date, take the missed dose immediately and remain on the original weekly schedule; if missed by more than three days, the timing of the next dose should be based on medical judgment. ELDERLY: no dose adjustment required. ADMINISTRATION: rotate injection sites; never inject into areas where the skin is tender, bruised, red or hard. PAEDIATRIC (weight-band fixed doses, NOT per-kg, so paedDose is null): for polyarticular juvenile idiopathic arthritis in patients 2 to 17 years of age the recommended WEEKLY subcutaneous dose is initiated without an IV loading dose and given by weight band — 10 kg to less than 25 kg: 50 mg; 25 kg to less than 50 kg: 87.5 mg; 50 kg or more: 125 mg. Safety and efficacy in children below 2 years of age have not been established and there is no relevant use under two years old. The intravenous powder for concentrate is available for paediatric pJIA patients 6 years of age and older (separate SPC). Verify any under-18 use against a children's formulary. §4.5 was not retrieved from the UK SPC in this bundle — interactions below come from the §4.4 text and the US ORENCIA label §7.